OCS Study 

MMS 95-0028 

Texas-Louisiana Shelf Circulation 

and Transport Processes Study: 

Year 2, Annual Report 

U .S . Department of the Interior 

Minerals Management Service 

Gulf of Mexico OCS Region 
OCS Study 

MMS 95-0028 

Texas-Louisiana Shelf Circulation 

and Transport Processes Study: 

Year 2, Annual Report 

Editors 

Ann E . Jochens 

Worth D . Nowlin, Jr. 

Prepared under MMS Contract 

14-35-0001-30509 

by 

Texas A&M University 

College Station, Texas 77843-3146 

Published by 

U.S . Department of the Interior 

Minerals Management Service New Orleans 

Gulf of Mexico OCS Region May 1995 
111 

DISCLAIMER 

This report was prepared under contract between the Minerals Management Service 

(MMS) and the Texas A&M Research Foundation. This report has been technically 

reviewed by the MMS and approved for publication. Approval does not signify that the 

contents necessarily reflect the views and policies of the Service, nor does mention of 

trade names or commercial products constitute endorsement or recommendation for use. 

It is, however, exempt from review and compliance with MMS editorial standards . 

REPORT AVAILABILITY 

Extra copies of the report may be obtained from the Public Information Unit (Mail Stop 

5034) at the following address : 

U.S . Department of the Interior 

Minerals Management Service 

Gulf of Mexico OCS Regional Office 

1201 Elmwood Park Boulevard 

New Orleans, Louisiana 70123-2394 

Attention: Public Information Unit (MS 5034) 

Telephone Number: 1-800-200-4853 

CITATION 

Jochens, A.E. and W.D. Nowlin, Jr ., eds. 1995 . Texas-Louisiana Shelf Circulation and 

Transport Processes Study: Year 2 - Annual Report. OCS Study MMS 95-0028, 

U.S . Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS 

Region, New Orleans, LA. 172 pp. 
ABSTRACT 

V 

The Louisiana-Texas Shelf Physical Oceanography Program (LATEX) is supported by 

the Minerals Management Service of the U. S. Department of the Interior. The Texas 

A&M University System is conducting Study Unit A of LATEX, the Texas-Louisiana 

Shelf Circulation and Transport Processes Study (LATEX A) . The second field year of 

LATEX A was April 1993 through March 1994 . Data were collected from an array of 

current meter moorings, bottom wave recorders, meteorological buoys, drifting buoys, 

and hydrographic and acoustic Doppler current profiler (ADCP) surveys deployed on the 

Texas-Louisiana continental shelf in the Gulf of Mexico. Historical and concurrent data 

from other programs in this region also were collected. 

The current meter array consisted of 66 current meters measuring current speed and 

direction, temperature, and conductivity on 27 moorings ; five directional wave gauges 

measuring current speed and direction, temperature, and pressure ; and two inverted echo 

sounders measuring acoustic travel time and bottom temperature and pressure . Eight 

meteorological buoys were installed on the shelf to measure wind speed and direction, air 

and sea surface temperature, and barometric pressure . Four drifting buoys were deployed 

and provided information on their locations and sea surface temperature via satellite. 

Three hydrographic/ADCP surveys were conducted with over 200 hydrographic sampling 

stations per survey and continuous ADCP measurements along the cruise track. At each 

hydrographic sampling station continuous profiles were made of conductivity, 

temperature, dissolved oxygen, downwelling irradiance, particle scattering, fluorescence, 

and beam attenuation. Up to twelve water samples were taken at each station and 

analyzed for six nutrients: nitrate, nitrite, phosphate, silicate, urea, and ammonium. At 

100 or more stations, water samples were analyzed for dissolved oxygen, salinity, 

phytoplankton pigments, and surface and bottom particulate matter concentrations . 

Secchi disk depths were taken at each daylight station. Meteorological measurements 

were transmitted via the Global Telecommunications System four times a day. The 

instrumentation as well as calibration and sampling procedures are described in Jochens 

and Nowlin (1994b). 

The collected data were subjected to quality control/assurance procedures as described or 

referenced in Jochens and Nowlin (1994b) . They then were archived with the LATEX A 

Data Management Office and are regularly transmitted to the National Oceanographic 

Data Center (NODC) . It should be noted that all LATEX data are still considered 

preliminary. Only after the field program is completed and final synthesis is well along 

will final data sets be submitted to the NODC. LATEX A initiated or maintained data 

sharing agreements with more than 20 other programs or researchers during the second 

field year. 

Information regarding LATEX has been disseminated in various ways. To the 

GiJLF.MEX bulletin board on the electronic mail service ScienceNet of Omnet wee 

posted cruise plans and reports, meeting announcements, weekly drifter trajectories and 

meteorological summaries, and the LATEX calendar. The Defense Mapping Agency, 

U.S . Navy Submarine Command, and the United States Coast Guard are regularly 

advised regarding changes in LATEX A mooring positions and deployments . A meeting 

on the oceanography of the LATEX region was organized. It was well attended by 

representatives from LATEX A, B, and C, state and federal agencies, other concurrent 

research programs, and the LATEX Science Advisory Panel. The LATEX Fortnightly 

News was published bi-weekly throughout the second field year. This single sheet, twosided newsletter was mailed to approximately 2500 addressees, giving them news and 
V1 

announcements regarding the LATEX program. LATEX A scientists presented talks or 

papers in a variety of forms during the period covered by this report . 

Assembly is underway of collateral data that will be of assistance in the interpretation/synthesis of the LATEX data. These collateral data consist of information from 

pertinent historical reports of physical oceanographic work in the Gulf of Mexico and 

from other programs collecting physical oceanographic data during the LATEX field 

years . Concurrent and historical data have been compiled from 15 sources ; some of 

these, e.g ., NODC, constitute very large data sources. Historical information compiled 

also includes climatologies of temperature, salinity, surface waves, tides and tidal 

currents . Model results have been gathered from models on general circulation, storm 

surges, and tides. 

Many graphical products have been produced to aid in the quality control/assurance and 

in initial interpretation of the LATEX data sets. For time series collected (i .e., from 

meteorological buoys and moored current meters) a series of standard products for the 

second field year were produced and will be included in the microfiche appendix of the 

final report ; these include monthly time series plots, current roses, and statistics . 

Representative samples presented here and discussed include wind fields and eddy-shelf 

interactions . A representative plot is presented of a trajectory for one or four drifters 

deployed during the second field year by LATEX A. Also shown are representative plots 

of wave heights and spectral periods for a case recorded during the passage of Hurricane 

Andrew ; scales analyses from the first seven LATEX A hydrographic cruises ; vertical 

sections of measured hydrographic properties; and geopotential anomaly distributions . 
vii 

TABLE OF CONTENTS 

PAGE 

LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv 

ACRONYMS AND ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii 

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix 

1 EXECUTIVE SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

1 .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

1 .2 Field Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1 .2 .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1 .2 .2 Moored Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

1 .2 .3 Drifting Buoy Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

1 .2 .4 Hydrographic/ADCP Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

1 .3 Collateral Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

1 .4 Observations/Model Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

1 .5 Technical Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

1 .5 .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

1 .5 .2 Scales Analyses of Hydrographic Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

1 .5 .3 Seasonal and Interannual Variability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

1 .5 .4 Coastal Upwelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

1 .5 .5 Phenomena at the Outer Shelf Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

1 .5 .6 Cyclogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

2 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

2.1 Programmatic Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

2.2 Overview of Cruise Schedule and Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

2.3 Report Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

3 DATA ACQUISITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

3 .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

3 .2 Moored Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

3.2 .1 Mooring Maintenance Cruises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

3.2 .1 .1 Cruise M09CPW9307 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

3 .2 .1 .2 Cruise M l OCPW9310 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

3 .2 .1 .3 Cruise M11CPW9312 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

3 .2 .1 .4 Cruise M12CPW9315 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 
viii 

TABLE OF CONTENTS (continued) 

PAGE 

3 .2 .1 .5 Cruise M13CPW9402 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

3 .2 .1 .6 Cruise M14CSS9414. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

3.2.2 Instrumentation, Calibration, and Sampling Procedures . . . . . . . . . . . . 17 

3.2.3 Summary of Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

3 .2 .3 .1 Current Meter Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

3 .2 .3 .2 Wave Gauge Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

3 .2 .3 .3 Meteorological Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 

3 .2 .3 .4 IES Data . . . . . . . .------ . . . . . . . . . .--- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . . . . . . 32 

3 .3 Drifting Buoy Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 

3.3 .1 Deployment Times and Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 

3.3 .2 Instrumentation and Sampling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

3.3 .3 Summary of Data Collection .-- . .- .-- . .----- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

3 .4 Hydrographic Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

3.4.1 Synopsis of Hydrographic Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

3 .4 . 1 .1 Cruise HOSCPW9306 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

3 .4 .1 .2 Cruise H06CPW9311 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . .--- . . . . . . . . 39 

3 .4 .1 .3 Cruise H07CPW9314 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . 45 

3.4.2 Instrumentation, Calibration, and Sampling Procedures . . . . . . . . . . . . 51 

3.4.3 Summary of Data Collection . . . . . . . . . . . . . . . . . . . . . . . .---- . . . . . . . . . . . . .---- . . . . . . . . . . 52 

3 .5 Acoustic Doppler Current Profiler Measurements (ADCP) . . . . . . . . . . . . . . . . . . . 52 

3.5 .1 Synopsis of ADCP Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 

3 .5 .1 .1 Cruise H()SCPW9306 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . . . . . .--- 52 

3 .5 .1 .2 Cruise H06CPW9311 . . . . . . . . . . . . . . . .-- . .---- . . . . . . . . . . .---- . . .------ . . . 53 

3 .5 .1 .3 Cruise H07CPW9314 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . .---- . . . . 54 

3.5 .2 Instrumentation, Calibration, and Sampling Procedures . . . . . . . . . . . . 54 

3.5 .3 Summary of Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 

3 .6 Collateral Data . . .--- .----- . . . . . . . . . . . . . . . . . . . . .------- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 

3.6 .1 BibliograPhY----- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 

3.6 .2 Concurrent Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 

3.6 .3 Historical Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 

4 DATA QUALITY ASSURANCE AND CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 

4.1 Introduction . . . . . . .--- . . . . . . . . . . . .--- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .---- . . . . . 57 
1X 

TABLE OF CONTENTS (continued) 

PAGE 

4.2 Moored Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 

4.3 Drifting Buoy Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 

4.4 Hydrographic Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 

4.5 Acoustic Doppler Current Profiler Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 

5 DATA MANAGEMENT AND INFORMATION TRANSFER. . . . . . . . . . . . . . . . . . . . . . . . . . . 59 

5 .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 

5 .2 Data Archival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 

5.3 Data Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 

5.4 Information Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

5.4 .1 GULF.MEX Bulletin Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

5.4 .2 Public Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

5.4.3 LATEX Meetings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

5.4.4 The LATEX Fortnightly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

6 TECHNICAL DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

6.2 Scale Analyses for the LATEX Shelf Based on Hydrographic 

Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

6.3 Seasonal and Interannual Variability over the Texas-Louisiana 

Continental Shelf. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 

6.4 Coastal Upwelling and Related Currents in Spring and Summer off 

South Texas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 

6.5 Phenomena at the Outer Shelf Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 

6.6 Analysis of Wind Fields over Texas-Louisiana Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 

6 .7 Summary of Cyclogenesis Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 

6 .8 Summary of LATEX Wave Observations during Hurricane 

Andrew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

6.9 Acoustic Doppler Current Profiler Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 

6.10 Maximum Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 

6.11 Observations/Model Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 

6.12 LATEX Science Advisory Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

7 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 
LIST OF FIGURES 

FIGURE DESCRIPTION PAGE 

1 .2 .1 Moored array locations. . . . . . . .- .- .---- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .---- . . . 5 

1 .2 .2 Typical hydrography/ADCP cruise track and station locations. . . . . . . . . . . . . . . . . . . . . . 6 

3.2 .1 Mooring locations and maintenance intervals for the second field year. . . . . . . . . 13 

3.2 .2 Current meter data recovered for the second year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

3.2 .3 Timelines of data returns for five MiniSpecs at LATEX moorings 1, 16, 

17, 20, 23 during the second field year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

3.2 .4 Meteorological buoy data recovered during the second year. . . . . . . . . . . . . . . . . . . . . . . . . 31 

3.4.1 CTD stations and cruise track, LATEX HOS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 

3.4.2 CTD stations and cruise track, LATEX H06. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 

3.4.3 CTD stations and cruise track, LATEX H07. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 

6.2.1 (-) 3-m salinity observed at each station on cross-shelf transect 4 (94° W) 

during LATEX May 1992 hydrographic cruise HO I ; (---) 3-m salinity from 

mean May field interpolated to May 1992 station positions. . . . . . . . . . . . . . . . . . . . . . . . . . . 67 

6 .2 .2 Autocorrelation function for difference between May 1992 and mean May 

3-m salinities as function of cross-shelf separation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 

6 .2 .3 Structure function as for Figure 6 .2 .2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 

6 .3 .1 Average geopotential anomaly at sea surface relative to 70 db for nine May 

cruises. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . . . . . . . . . . . 72 

6.3 .2 Average geopotential anomaly at sea surface relative to 70 db for eight 

July-August cruises. . . .--- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 

6.3 .3 Geopotential anomaly at sea surface relative to 70 db for LATEX HOS 

cruise (26 April - 10 May 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 

6.3 .4 Differences or geopotential anomalies at sea surface relative to 70 db for 

LATEX HOS cruise (26 April - In May 1993). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

6.3 .5 Standard deviation of geopotential anomaly at sea surface relative to 70 db 

for nine May cruises. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .- .------ .-- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 

6.4 .1 Climatic monthly mean wind stress for 2° squares along the western 

boundary or the Gulf of Mexico between 20° and 30° N. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 

6.4 .2 Example of NOAA/NOS/OPC Oceanographic Features Analysis 

showing the cool hand along the western boundary of the Gulf. . . . . . . . . . . . . . . . . . . . . 81 

6.4 .3 Locations or measurement stations discussed in the text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 
X11 

LIST OF FIGURES (continued) 

FIGURE DESCRIPTION PAGE 

6.4 .4 Monthly or fortnightly means of (a) near-surface temperature for inner 

shelf and outer or off-shelf locations, and (b) near-surface salinity for 

inner shelf locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 

6.4 .5 Shallowest (1-3 m) CID temperatures measured in (a) early August 1993 

and (b) early August 1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 

6.4.6 Shallowest (1-3 m) CTD salinities measured in (a) early May 1993 

and (b) early August 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 

6.4.7 Topography of the 6e = 25.0 surface based on measurements made in 

(a) early May 1993 and (b) early August 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 

6.4.8 Vertical section of 6e along line 7 made in (a) early May 1993 and 

(b) early August 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 

6.4.9 Geopotential anomaly of 3 over 400 db based on measurements made 

in (a) early May 1993 and (b) early August 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 

6.5 .1 Geopotential anomaly of 3 db relative to 200 db for the LATEX HOS 

cruise, May 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 

6.5 .2 Vertical section of potential temperature along the 200-m isobath for the 

LATEX HOS cruise, May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 

6.5 .3 Potential temperature - salinity diagrams for stations 91, 136, 168, and 208, 

located in the western half of the LATEX Shelf along the 200-m isobath. . . . . 95 

6.5 .4 Monthly plot of current velocity, temperature, and salinity for mooring 4 

at 12 m for May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 

6.5 .5 Monthly plot of current velocity, temperature, and salinity for mooring 6 

at 13 m for May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 

6.5 .6 Monthly plot of current velocity, temperature, and salinity for mooring 7 

at 14 m for May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 

6.5 .7 Monthly plot of current velocity, temperature, and salinity for mooring 8 

at 15 m for May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 

6.5 .8 Trajectory of drifter 6938, May to October 1993, with U (east) and V (north) 

velocity components and speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

6.5 .9 Salinity at 3 m depth for LATEX HOS cruise, May 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 
X111 

LIST OF FIGURES (continued) 

FIGURE DESCRIPTION PAGE 

6.5 .10 Distribution of particle bean attenuation coefficient (m-1) at 2 m depth 

for the LATEX HOS cruise, May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 

6.5.11 Vertical section of particle beam attenuation coefficient (m-1) along 

transect 7 for the LATEX HOS cruise, May 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 

6 .6 .1 National Meteorological Center analyzed wind field at 0600 UTC on 

4 November 1992. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . . . . . . . . . .--- . . .--- . . . .--- . . . . . . . 107 

6.6 .2 The distribution or observing stations used in analysis of surface 

meteorological variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 

6.6 .3 Mean 10-m wind field for November 1992. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 

6.6 .4 10-m wind field at 0600 UTC on 4 November 1992. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 

6.6 .5 Wind field at 1700 UTC, 7 November 1992. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 

6.6.6 NMC analyzed wind field at 1700 UTC, 7 November 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . 112 

6.6 .7 ERS-1 wind field at 1700 UTC, 7 November 1992. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 

6.7 .1 Locations for the winter cyclogenesis case study, 12-14 December 1993. . . . . 117 

6.7 .2 Characteristics or atmospheric pressure over the LATEX region during 

the winter cyclogenesis case of 12-14 December 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 

6.7 .3 Characteristics of wind speeds over the LATEX region during the winter 

cyclogenesis case of 12-14 December 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 

6.7 .4 Characteristics of Hs over the LATEX region during the winter 

cyclogenesis case of 12-14 December 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 

6.7 .5 Measurements of HS and TP from NDBC buoys #42002, #42020, and 

#42035 during the cyclogenesis period 12-14 December 1993. . . . . . . . . . . . . . . . . . . . . . 123 

6.7 .6 A relationship between Cd and U 10 based on the wind-wave interaction 

method for the LATEX region and its comparison to the North Sea and 

East China Sea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . . . . . . . 124 

6.7 .7 A relationship between Cd and U 10 based on the wind-wave interaction 

method for the LATEX region- ----- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .--- . . . . .--- . . . . . . . . . . . .- .---- 125 

6.7 .8 A comparison of Cd formulations over the LATEX region and others 

published in the literature- -- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 

6.8 .1 Map of the northwestern Gulf showing 50-, lOn-, and 200-m isobaths, 

Hurricane Andrew storm track, and LATEX wave gauge and NDBC 

buoy locations. . . . . . . . . . . . . . . . . . . .-- . .-------- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 
X1V 

LIST OF FIGURES (continued) 

FIGURE DESCRIPTION PAGE 

6.8 .2 HS measured at LATEX moorings 1, 16, 20, and 23 during Hurricane 

Andrew. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 

6.8 .3 Spectral peak periods at LATEX moorings 1, 16, 20, and 23 during 

Hurricane Andrew. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 

6 .8 .4 Contour plot of energy density versus time with significant wave height 

(SWH) superimposed at mooring 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

6 .9 .1 Vector stick plots of currents at 10 m, measured by ADCP during cruise 

H06, 25 July - 7 August 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 

6.9 .2 Transects along the 50-m and 200-m isobaths along which ADCP data from 

cruise H06 were employed to evaluate empirical orthogonal profiles of 

current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 

6.9 .3 The first three EOFs derived from ADCP data along the 50-m transect of 

cruise H06. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 

6.9 .4 The first three EOFs derived from ADCP data along the 200-m transect of 

cruise H06. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

6.11 .1 Eastward (-) and northward (---) 40-hr low pass wind stress components 

from moorings 50 and 53 for the three-day March 1993 storm. . . . . . . . . . . . . . . . . . . . . . 145 

6.11 .2 Observed 40-hr low pass and simulated longshore currents for moorings 

1(-),18( ---), and 23 (- .-) for the three-day March 1993 storm. . . . . . . . . . . . . . . . . . . 146 

6.11 .3 Observed 40-hr low pass and simulated longshore currents for moorings 

23 (-) and 25 (---) for the three-day March 1993 storm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 
XV 

LIST OF TABLES 

TABLE DESCRIPTION PAGE 

1 .2 .1 Typical mooring configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

2.2 .1 Cruise identifiers and dates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

3.2 .1 Mooring configurations as of April 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

3.2 .2 Mooring maintenance by cruise for the second field year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

3.2 .3 New locations of moorings 1, 16, and 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

3.2 .4 LATEX current meter data, April 1993 - April 1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

3.2 .5 MiniSpec wave gauge deployment data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 

3.2 .6 SeaData 635-8 wave gauge deployment data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 

32 .7 Meteorological data recovered April 1993 - March 1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

3 .3 .1 LATEX A drifter deployment dates and disposition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 

3 .4 .1 Station times and positions for LATEX A cruise HOS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

3 .4 .2 Launch locations of LATEX A drifting buoys on cruise HOS. . . . . . . . . . . . . . . . . . . . . . . . 39 

3 .4 .3 Station times and positions for LATEX A cruise H06. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 

3 .4 .4 Station times and positions for LATEX A cruise H07. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 

3 .4 .5 Hydrographic equipment available on each hydrography cruise . . . . . . . . . . . . . . . . . . . . 52 

3 .4 .6 Summary of data collected and scientific participation in the LATEX A 

standard grid hydrography surveys in the second field year. . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 

3 .4 .7 Complementary programs on LATEX A hydrography surveys. . . . . . . . . . . . . . . . . . . . . . 53 

3 .5 .1 ADCP configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 

3 .6 .1 Collateral data assembled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 

4.1 .1 Personnel performing QA/QC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 

5.3 .1 LATEX A data shared with others . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 

5.4 .1 Agenda for LATEX III meeting of October 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 

5.4 .2 Volume 2 LATEX Fortnightly News, 12 April - 20 December 1993. . . . . . . . . . . . . . 63 

5.4 .3 Volume 3 LATEX Fortnightly News, 1 January - 28 March 1994. . . . . . . . . . . . . . . . . . 64 

6.2 .1 Spatial scales of anomaly field of selected transects and variables as 

described in the text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 

6.4 .1 Relative frequency of coastal cool bands that are cooler by 2°C or more 

than the adjacent open Gulf and extend 4° or more in latitude along the 

western boundary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 

6.4 .2 Six-week means of the alongshore component of currents at top curent 

meters (10-14 m) of moorings 1, 2, and 3 combined (cm-s-1) . . . . . . . . . . . . . . . . . . . . . . . . 90 
XVl 

LIST OF TABLES (continued) 

TABLE DESCRIPTION PAGE 

6.7 .1 Winter cyclogenesis over the northwestern Gulf of Mexico from November 

1993 through May 1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 

6.9 .1 Dates, time-intervals and number of ADCP profiles along the 50-m and 

200-m isobaths during the LATEX cruise H06. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 

6.10.1 Maximum speeds and corresponding directions observed in 40-hr lowpassed current record from each LATEX A mooring during the second 

field year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 

6.12.1 Members of the LATEX Science Advisory Panel from 1 April 1993 

through 31 March 1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 
XVll 

ACRONYMS AND ABBREVIATIONS 

ADCP acoustic Doppler current profiler 

ARGOS Service ARGOS 

AVHRR Advanced Very High Resolution Radiometer satellite 

C-MAN Coastal-Marine Automated Network 

CTD conductivity-temperature-depth 

DMA Defense Mapping Agency, Bethesda MD 

DMT digital magnetic tape 

DSI Defense Systems, Inc . 

EHI Evans-Hamilton, Inc . 

EOF empirical othogonal function 

GDAS Global Data Assimilation System 

GMT Generic Mapping Tool software 

GMT Greenwich Mean Time 

GPS Global Positioning System 

GTS Global Telecommunications System 

HPLC high performance liquid chromatography 

ICS ICSensors 

IFS inverted echo sounder 

LATEX Louisiana-Texas Shelf Physical Oceanography Program 

LATEX A Texas-Louisiana Shelf Circulation and Transport Processes Study of 

LATEX (also LATEX Shelf) 

LATEX B Mississippi River Plume Hydrography Study of LATEX (also LATEX 

Plume) 

LATEX C Gulf of Mexico Eddy Circulation Study of LATEX (also LATEX Eddy) 

LSU Louisiana State University 

MMA Maine Maritime Academy 

MMS Minerals Management Service, U.S. Department or the Interior 

M/V motor vessel 

NDBC National Data Buoy Center 

NMC National Meteorological Center 

NOAA National Oceanic and Atmospheric Administration 

NODC National Oceanographic Data Center 
X V 111 

ACRONYMS AND ABBREVIATIONS (continued) 

NWS National Weather Service 

PBAC particle beam attenuation coefficient 

PTAT2 G MAN station at Port Aransas TX 

QA/QC quality assurance/quality control 

RCM recording current meter 

RDI RD Instruments, Inc. 

R/V research vessel 

SAIC Science Applications International Corporation 

SAP LATEX Science Advisory Panel 

SAS statistical analysis system 

SEAS Shipboard Environmental data Acquisition System 

SNL surface nepheloid layer 

SOOP Ship of Opportunity Program 

SRST2 C- MAN station at Sabine, TX 

SSM solid state memory 

TAMU Texas A&M University 

TAMUG Texas A&M University at Galveston 

TIGER Texas Institutions Gulf Ecosystem Research initiative 

USCG United States Coast Guard 

USM University of Southern Mississippi 

USN U.S . Navy Submarine Group 10, Kings Bay GA 

LTTC Universal Coordinated Time 

XCP expendable current profiler 

XBT expendable bathythermograph probe 

XSV expendable sound velocity probe 
xix 

ACKNOWLEDGMENTS 

This report would not have been possible without the contributions of a large number of 

people from Texas A&M University (TAMU), Louisiana State University (LSU), EvansHamilton, Inc. (EHI), Maine Maritime Academy (MMA), and the University of Southern 

Mississippi (USM). Each LATEX A principal investigator contributed portions of the 

text dealing with the tasks for which he/she was responsible. The principal investigators, 

their affiliations, and their tasks are: 

Worth D. Nowlin, Jr. TAMU Program Management, Tasks A-2 and A-8 

Ann E. Jochens TAMU Program Management, Task A-8 

Norman L. Guinasso, Jr. TAMU Data Management, Task A-5, A-7, A-10, A-11 

Robert C. Hamilton EHI Tasks A-1 and A-12 

Denis A. Wiesenburg USM Task A-3 

Douglas C. Biggs TAMU Task A-4 

S .A. Hsu LSU Task A-6 

Robert O. Reid TAMU Task A-9 

The editors were assisted greatly by the efforts and contributions of the excellent LATEX 

A staff at TAMU. Special thanks to Matt Howard for his writing and graphics 

contributions . We thank Steven DiMarco, Linwood Lee III, and Carrie Neuhard for their 

contributions to the writing, graphics, and data corrections for this report. We thank 

Debz DeFreitas, Frank Kelly, and Jodi Hughes for their help in providing information and 

graphics for this report. We appreciate the efforts or Yongxiang Li, Wensu Wang, Carole 

Current, and Hsien-Wen Chen for their work nn figures and Paul Griffin for assisting as 

needed. 

We also thank John Cochrane, a member of the LATEX Science Advisory Panel, for 

contributing his thoughts on upwelling nn the shelf and for showing an active interest in 

the LATEX data set above and beyond that required of Panel members. 

To all who participated on the nine LATEX A cruises during the second field year we 

extend our great appreciation . Special thanks go to Ken Bottom, Mark Garner, Dennis 

Guffy, Rick O'Neill, Mark Spears, and Eddie Webb of the Technical Support Services 

Group, Department or Oceanography, TAMU; Bob Albers, Roy Davis, Mike Fredericks, 

Jim Jobling, Chris Nugent, and John Shannon or the Geochemical and Environmental 

Research Group (GERG), TAMU; Paula Bontempi, graduate student in the Department 

of Oceanography, TAMU; Lauren Sahl of MMA; Joel Chaky, Ken Fitzgerald, and Rod 

Fredericks of the Coastal Studies Institute at LSU; Brian W. Blanchard of LSU; and 

Chuck Abbott, Jeff Cox, Doug Evans, Troy Horton, Dan Howard, Keith Kurrus, and Eric 

Noah of EHI. Also, EHI's land crew: Barbara Allen and Jackie Abert. 

We extend our appreciation to Roger Fay of GERG for his work in coordinating logistical 

and onshore support for LATEX A current meter cruises. Nn data could be collected 

without outstanding work by the crew of the vessels : Thus, our thanks go to Captain 

Mike Field on the R/V Gyre and Captain Pat Sherrard on the R/V J. W. Powell, and to 

their crews. Captain Dean Letzring and Sandra Green of Marine Operations, Department 

of Oceanography, TAMU, offered assistance with many aspects of the LATEX cruises. 

Their unfailing cooperation has been invaluable and is appreciated greatly. 
XX 

Thanks also to Phyllis Bonifazi, Charlene Miller, Teresa O'Brien, and team Neptune at 

the Texas A&M Research Foundation for helping us purchase equipment quickly, pay 

our bills on time, and keep our budgets in line. 

Thanks to the LATEX Science Advisory Panel for stimulating discussions and ideas. 

Finally, and especially, we thank Maureen Reap for her editorial work on this report and 

for putting together the slide set. 

Ann E. Jochens 

Worth D. Nowlin, Jr. 

ERS-1 data were obtained from the NASA Physical Oceanography Distributed Active 

Archive Center at the Jet Propulsion Laboratory, California Institute of Technology, 

Pasadena, CA. 
1 EXECUTIVE SUMMARY 

1 .1 Introduction 

The Minerals Management Service (MMS) of the U.S. Department of the Interior 

supports the Louisiana-Texas Shelf Physical Oceanography Program (LATEX). LATEX 

is divided into three study units: Study Unit A, Texas-Louisiana Shelf Circulation and 

Transport Processes (LATEX A or LATEX Shelf) ; Study Unit B, Mississippi River 

Plume Hydrography (LATEX B or LATEX Plume); and Study Unit C, Gulf of Mexico 

Eddy Circulation (LATEX C or LATEX Eddy). LATEX A, the largest of the three 

studies, covers the middle and outer Texas-Louisiana continental shelf from the 

Mississippi River to the Rio Grande. This report focuses on the work of LATEX A 

during the second field year, April 1993 through March 1994. Per the contract, this 

report does not contain detailed analyses or interpretation of the data collected . 

Information on the first field year (April 1992 through March 1993) can be found in 

Jochens and Nowlin (1994a, 1994b) . 

The contract for LATEX A was awarded to the Texas A&M Research Foundation on 30 

September 1991 . The Texas A&M University System, a combination of Texas 

institutions of higher learning and Texas state agencies dedicated to training, research, 

and extension, conducts the LATEX A Program. In addition to support from the MMS, 

financial backing for LATEX A is provided by the Texas Institute of Oceanography, the 

Texas Engineering Experiment Station, and Texas A&M University (TAMU), all 

components of the System. The System is assisted in this program by subcontracts with 

Evans-Hamilton, Inc . (EHI), Louisiana State University (LSU), Maine Maritime 

Academy (MMA), and the University or Southern Mississippi (USM). 

The major objective of LATEX A is to identify key dynamical processes governing 

circulation, transport, and cross-shelf mixing on the Texas-Louisiana shelf. This 

objective will be met through the completion or a three-year field program over the 

Texas-Louisiana continental shelf, after which observations will be synthesized, 

interpreted, and reported to provide a better understanding of circulation and transport of 

properties over the shelf. 

Program management is overseen by the Program Management Office, under Dr. Worth 

D. Nowlin, Jr., Program Manager, and Dr. Ann E. Jochens, Deputy Program Manager. 

Data collection is accomplished through six tasks in LATEX A. These are: 

" Current and Meteorological Measurement Moorings (Task A-1, Mr. Robert C. 

Hamilton or EHI, Principal Investigator) : provides a shelf-wide network of current, 

temperature, salinity, and meteorological time series with which to identify, characterize, 

and parameterize circulation processes. The moored array in year two consisted of a 

boundary array along the shelf edge, cross-shelf arrays for study or along-shelf transports, 

and two deep-water inverted echo sounders to monitor the westward passage of rings into 

the Texas-Louisiana shelf region . The wild card array deployed during the first field year 

was removed to provide a source of spare instruments for the main array. 

" ARGOS-Tracked Drifting Buoys (Task A-2, Dr. Worth D. Nowlin, Jr ., of 

TAMU, Principal Investigator) : deploys sixteen drifters to study the continunity of 

alongshore flow . During the second field year, four drifters were deployed on the middle 

and outer shelf near 94°W. 
2 

" Standard Grid Hydrography (Task A-3, Dr. Denis A. Wiesenburg of TAMU 

(now with USM), Principal Investigator) : conducts hydrographic/acoustic Doppler 

current profiler (ADCP) survey work to characterize the seasonal patterns of circulation 

and water mass characteristics and to allow initial assessment of interannual variability. 

Three full shelf surveys were completed during the second field year. 

" Task A-4, Acoustic Doppler Current Surveys (Task A-4, Dr. Douglas C. Biggs 

of TAMU, Principal Investigator): conducts ADCP surveys on all hydrographic cruises 

to provide vertical profiles or currents. Three were conducted in the second field year. 

" Collateral Data Collection (Task A-5, Dr. Norman L. Guinasso, Jr., of TAMU, 

Principal Investigator): consists of the assembly of data from concurrent programs in the 

LATEX region and from historical sources to expand the data base available for study. 

" Winter Northers/Cyclogenesis (Task A-6, Dr. S.A. Hsu of LSU, Principal 

Investigator): consists or the deployment and maintenance of four meteorological buoys 

during the winter season and the study of cyclogenesis resulting from cold air outbreaks 

over the Texas-Louisiana shelf. 

Data quality control and processing are provided under Task A-7, Data Quality Control, 

by the LATEX A Data Management Office at the direction of Dr. Norman L. Guinasso, 

Jr., Data Manager. Additionally, the Data Office oversees Task A-10, Information 

Transfer, under which the GULF.MEX electronic bulletin board on Omnet is maintained, 

and Task A-11, Public Notification, Cooperation, and Data Dissemination, under which 

the LATEX Fortnightly newsletter is published and information is provided to federal 

agencies and the public . 

Once data have undergone quality control, the analysis phase of LATEX A begins . There 

are three tasks under this phase: First is the Analyses and Reports task (Task A-8, Dr. 

Worth D. Nowlin, Jr., and Dr. Ann E. Jochens or TAMU, Co-Principal Investigators) 

under which the scientific analyses and syntheses of the data are performed and annual 

reports to MMS are prepared and finalized. Second is the Field Measurements/Model 

Comparisons task (Task A-9, Professor Robert O. Reid of TAMU, Principal Investigator) 

which is to compare the LATEX observational data with model results ; the LATEX 

Science Advisory Panel is supported under this task . Third is the analysis portion of Task 

A-6. 

All government furnished equipment and capital equipment provided by MMS will be 

refurbished and returned to MMS under the Government Furnished Equipment/Capital 

Equipment task (Task A-12, Mr. Robert C. Hamilton, Principal Investigator). There was 

nn activity under this task during the second field year. 

1 .2 Field Activities 

1 .2 .1 Introduction 

Six mooring cruises and three hydrographic/ADCP survey cruises were conducted in the 

second field year. From April 1993 through March 1994, data were collected from an 

array of current meter moorings, meteorological buoys, drifting buoys, and 

hydrographic/ADCP surveys nn the Texas-Louisiana continental shelf in the Gulf of 

Mexico . After collection, the data sets were processed for quality assurance and quality 

control . 
1 .2 .2 Moored Measurement 

The current meter array consisted of 66 current meters measuring current speed and 

direction, temperature, and conductivity on 27 moorings ; five directional wave gauges 

measuring current speed and direction, temperature, and pressure near the sea floor; and 

two inverted echo sounders measuring acoustic travel time and bottom temperature and 

pressure . Eight meteorological buoys, including four Task A-6 buoys, were installed on 

the shelf to measure wind speed and direction, air and sea surface temperature, and 

barometric pressure. Table 1 .2 .1 lists the instrumentation typically deployed on each 

mooring and the maintenance schedule. Figure 1 .2 .1 shows the locations of the 

moorings. 

1 .2.3 Driftine Buov Measurements 

Four drifting buoys were deployed during the second-year hydrographic surveys, all on 

the May 1993 hydrographic cruise . They were deployed along 94° W over the outer shelf 

near the continental shelf break (~200-m isobath). The drifter deployed at the shelf break 

was drawn off the shelf into Loop Current Eddy Vazquez. All drifters provided 

information on their locations and sea surface temperature via satellite. The mean 

lifetime of the four drifters was 168 days with a range of 71 to 251 days . 

1 .2 .4 Hydragraphic/ADCP Measurements 

Three hydrographic/ADCP surveys were conducted with over 200 hydrographic sampling 

stations per survey and continuous ADCP measurements along the cruise track. Figure 

1 .2 .2 shows a typical cruise track and station locations. At each hydrographic sampling 

station, continuous profiles were made of conductivity, temperature, dissolved oxygen, 

downwelling irradiance, particle scattering, fluorescence, and percent transmission 

(which gives the paricle beam attenuation coefficient) . Up to 12 water samples were 

taken at each station and analyzed for six nutrients : nitrate, nitrite, phosphate, silicate, 

urea, and ammonium . At half or more of the stations, the water samples were analyzed 

for dissolved oxygen, salinity, phytoplankton pigments, and the surface and bottom 

particulate matter concentrations. Secchi disk depths were taken at each daylight station. 

Meteorological measurements were transmitted to the Global Telecommunications 

System four times daily. Several complementary research programs were conducted on 

each of the LATEX A hydrographic surveys. 

1 .3 Collateral Data 

Collateral data consists of information from historical or concurrent programs on the 

Texas-Louisiana shelf. These data are collected to augment the LATEX A data set and to 

aid in interpretations. Historical information was compiled during the first field year. 

Concurrent data were obtained from numerous other programs collecting oceanographic 

data in the LATEX region during the second field year, including data from LATEX B 

and C and weather buoy data from NOAA. 
4 

Table 1.2.1 . Typical mooring configurations . 

Mooring 

No. 

Water 

Depth 

(m) 

Latitude 

(°N) 

Longitude 

(°W) Comments 

Top 

Meter 

Depth 

Middle 

Meter 

Depth 

Bottom 

Meter 

Depth 

Maintenance 

Interval 

(Day) 

1 21 2701539' 97°14.81' Platform lOm 19m 120 

2 37 27017.09' 96058.81' Platform lOm 30m 120 

3 66 2701735' 96044.18' Platform lOm 30m 61m 120 

4 201 27007.76' 96021.63' MarkerBuoy 14m 100m 190m 120 

5 199 27027.82' 96004.12' MarkerBuoy 14m 100m 190m 120 

6 201 27042.59' 95039.76' MarkerBuoy 14m 100m 190m 120 

7 199 27050.12' 95004.19' MarkerBuoy 14m 100m 190m 120 

8 200 27049.47' 94°10.77' MarkerBuoy 14m 100m 190m 120 

9 200 27048.92' 93031.91' MarkerBuoy 14m 100m 190m 120 

10 200 27056.07' 92044 .70' MarkerBuoy 14m 100m 190m 120 

11 200 27050.64' 92000.45' MarkerBuoy 14m 100m 190m 120 

12 505 27055.76' 90°29 .64' MarkerBuoy 14m 100m 495m 180 

13 200 28003.48' 90029 .18' MarkerBuoy 14m 100m 190m 120 

14 47 28°23.74' 90°29 .65' Platform 14m 26m 42m 60 

15 27 28036.49' 90029 .53' Platform lOm 24m 60 

16 19 2805 1 .96' 90°29 .50' Platform lOm 17m 60 

17 7 29011.82' 91057 .89' MetBuoy ;Platform 3m 5m 60 

18 22 28057.74' 91059A1' Platform lOm 21m 60 

19 51 2R°27.92' )2°02.OG MetBuoy;Platform 3m 21m 44m 60 

20 15 29015.67' 94003 .82' MetBuoy ;Platform 3m 13m 60 

21/51 24 2R°50.28' 94°04.79' MetBuoy ;Platform lOm 21m 60 

22 55 2802139' 9305734' MetBuoy ;Platform 3m 20m 48m 60 

23 15 28042.77' 95032.13' Platform 9m 13m 60 

24 30 28032.21' 95023 .61' Platform llm 27m 60 

25 45 28°1933' 95°21 .57' Platform 13m 23m 38m 60 

42 1540 27007.00' 92000.00' IES;at sea floor 1540m 360 

43 3130 25032.52' 92000.00' IES;at sea floor 3130m 360 

44 Removed 

45 Removed 

46 Removed 

48 200 27058 .98' 91016.99' MarkerBuoy 14m 100m 190m 120 

49 505 27023 .13' 95053.96' MarkerBuoy 14m 100m 495m 180 

50 20 28°52.86' 95°02.20' MetBuoy ;Platform 60 

51/21 24 28050.28' 94004.79' MetBuoy ;Platform lOm 21m 60 

52 27 28048.18' 93001 .11' MetBuoy ;Platform 60 

53 15 28°48.04' 90°57.22' MetBuoy ;Platform 60 

MetBuoy = DSI Surface Meteorological Buoy; Marker Buoy = Lighted Surface Marker Buoy; 

IES = Inverted Echo Sounder; blank=No instrument Platform=Mooring loaded near permanent structure 
LOUISIANA 

30°N 

~ . N ew 

29'N 

0 5:~23 

28'N 

1 1 

27°N 

26'N 

1 1 

97'W 96'W 95'W 94'W 93'W 92'W 91'W 90'W 

Figure 1 .2.1 . Moored array locations. 

TEXAS 

H~ust n Orlea 

Galvest ~ 

o 

20 , . 

w .- - 

.. - 

, 

21/51 52 18 2~0 

O 

6 

53 

O1 

O 2a ~ y ~ 5 20p 

l/ 20 22 50 

2s 

~o as ~s 

7 8 9 ~~ ~12 

d s 1000 100p ~ "" 

1 2 .3 049 

42 

Maintenance 

2000 O 60 days 

" 120 days 

D 180 days 

" 360 days 

43 
30 

29 

28 

27 

26 

_ . . 

uston _C 

~L ' ;~7 

stori 

-1z . 

-,2s . ... . . . . . . 0 . a 

jno 

-129 :lm -IM p i~oe .1a1 

Y'4 .iax e~m ~,r 

t .11t " 10! 

" 1342 ~'it05 

.tb : " 11~ .1W 

.. .~*» .. .. .__ ... .su ... ._~ .. .. ..... .. ... 

-,iu 

'`'~°° ~':Yil -97 

" sz 

" ~57 

UISIAN 

. .. 

" 7D C 

.~l 

1000 

LATEX Cruise Track 

HO6CPW9311 

26 July - 8 August, 1993 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

o1~ 

Figure 1 .2 .2 . Typical hydrographic/ADCP cruise track and station locations. 
1 .4 Observations/Model Comparison 

To assist with the observation/model comparisons, the LATEX Science Advisory Panel 

(SAP) was formed . The members or the SAP and their affiliations are: John S. Allen, 

Chairman (Oregon State University), John D. Cochrane (Texas A&M University, retired), 

Gabriel T. Csanady (Old Dominion University), Richard W. Garvine (University of 

Delaware), Dong-Ping Wang (SUNY - Stony Brook), Clinton D. Winant (Scripps 

Institution of Oceanography), and William J. Wiseman, Jr. (Louisiana State University). 

Members George Z. Forristall (Shell Development Company) and A.D. Kirwan (Old 

Dominion University) rotated off the SAP during the second field year. One meeting of 

the SAP was held during the second annual report year. It was held in New Orleans on 

26-28 October 1993 . 

1 .5 Technical Discussion 

1 .5 .1 Introduction 

This second annual report focuses on the data collection and processing activities of 

LATEX A. As required by the contract, it contains representative graphical products but 

no detailed analyses or the data. The results of several preliminary analyses associated 

with interesting phenomena, however, are presented as the vehicles for providing 

examples or representative products that will be provided in the final report. Section 6 of 

this report provides the discussion and examples of representative products. Additional 

examples of products can be round in the first annual report (Jochens and Nowlin 1994b) . 

Below are given brief summaries or the preliminary results from several of the analyses 

presented in section 6. 

1 .5 .2 Scales Analyses of Hydro raphic Parameters 

Horizontal scales or temperature, salinity, and geopotential anomaly distributions were 

analyzed using hydrographic data. A spatial mean reference field for each parameter, 

obtained using a quadratic fit, was removed from the individual LATEX A data fields to 

to allow study of the spatial variability at smaller (anomaly) scales . Preliminary results 

indicate that over the eastern and central portions of the Texas-Louisiana shelf, the crossshelf anomaly scales for surface salinity, surface temperature, and geopotential anomaly 

are near 20 km. Temperature scales are somewhat shorter. In contrast, the cross-shelf 

anomaly scales from the western portion of the shelf (although represented by fewer 

realizations) range from 8 to 15 km, with averages of 8 to 14 km ; again temperature 

scales are slightly shorter. The average alongshelf anomaly scales over the east and 

central shelf are 30 to 38 km, with no real difference between scales at the shelf edge 

(200-m isobath) and those at mid-shelf (50-m isobath). The surface salinity scales are 

somewhat shorter than those for temperature and geopotential anomaly. 

1 .5 .3 Seasonal and Interannual Variability 

Historical hydrographic data are being combined with LATEX A hydrographic data to 

study the seasonal and interannual variability of the general circulation patterns over the 

Texas-Louisiana Shelf. Preliminary results indicate that the distributions of temperature, 

salinity, and geopotential anomaly generally conform to the seasonal patterns 

hypothesized by Cochrane and Kelly (1986) ; there are, however, significant deviations, 

e.g ., at times of anomalous river discharge. 
1 .5 .4 Coastal Upwellin 

An analysis of wind-driven coastal upwelling and related currents off south Texas was 

conducted using climatological monthly mean wind stresses, satellite infrared imagery, 

and salinity and temperature data from hydrography, current meters, and tide stations. 

Preliminary results indicate that data showing upcoast wind stress, cooler nearshore water 

temperatures, higher nearshore salinities, and upcoast currents are indicative of upwelling 

conditions . These conditions occur predominanly in July and August. Weaker upwelling 

may occur in transition periods in June and September. 

1 .5 .5 Phenomena at the Outer Shelf Boundary 

Data from hydrography, current meters, and drifters are combined, together with sea 

surface height anomalies from satellite altimeters (not shown), in a preliminary analysis 

of the effects of the anticyclonic Loop Current Eddy Vazquez (Eddy V) on the shelf 

circulation. The data set shows shelf water flowing across the shelf edge on the eastern 

flank of Eddy V and on the south flank of a cyclonic eddy located to the west of Eddy V. 

The data set also indicates that water from the northwest side or Eddy V was moving onto 

the shelf. 

1 .5 .6 Cvclo enesis 

Based nn the classification scheme of Hsu (1993), there were 13 winter cyclogenesis 

events between November 1993 and May 1994. Typically, there are 10 cyclogenesis 

events per year (Johnson et al . 1984) . Two or these were "meteorological bombs" with 

pressures at or below 1006 mb. These occurred nn 13 December 1994 and 27 March 

1994. The more severe winter cyclogenesis events over the LATEX region can produce 

wave steepness that exceeds the statistical extreme steepness value obtained by Buckley 

(1988) from a review of the archive of NDBC and Canadian oil rig stations . 
9 

2.1 Programmatic Chance 

2 INTRODUCTION 

No programmatic changes were made to the current measurement mooring program 

during the second field year. Because numerous current meters were lost due to fishing 

pressure and other problems, moorings 25 and 12 were removed during the second year 

so their instruments could be used as spares to keep the main array intact . 

The original hydrographic sampling plan called for four cruises per year, each covering 

half the Texas-Louisiana shelf. During the first field year, four cruises were conducted 

over the eastern half of the shelf. During the second field year, the plan was modified to 

provide three cruises per year, each covering the full shelf. Hydrographic/ADCP surveys 

covering the full shelf were conducted during April/May, July/August, and November 

1993, with the February 1994 cruise being eliminated . Details on the rationale for this 

change were provided in Jochens and Nowlin (1994b). 

2.2 Overview of Cruise Schedule and Nomenclature 

Six mooring cruises and three hydrographic/ADCP survey cruises were conducted in the 

LATEX A program during the second field year. All LATEX A cruises were conducted 

aboard the R/V J. W. Powell, the M/V Erica Tide, or the M/V Seis Surveyor. Table 2.2.1 

provides a listing of these cruises, their various designators, and their start and end dates. 

The MMS identifying code is the number assigned each LATEX cruise in the LATEX 

Calendar that is posted to GULF.MEX. This designator is deciphered as follows 

First character: M=mooring cruise ; H=hydrographic/ADCP survey 

Second & third characters: 

Fourth character: 

Fifth & Sixth characters: 

Seventh & eighth characters : 

Ninth & tenth characters : 

LATEX A mooring cruise number, 

LATEX A hydrographic/ADCP survey number 

C=cruise 

vessel identifier (PW = R/V J. W. Powell; 

SS = M/V Seis Surveyor) 

year or cruise 

vessel cruise number 

Note for cruise 10, the MMS ID for the R/V J. W. Powell was used, although the cruise 

was divided into two legs. The first leg was aboard the R/V Powell (M 10A) to conduct 

the regular mooring maintenance. The second leg was aboard the M/V Erica Tide 

(M06B) to conduct maintenance on the inverted echo sounders. 

The LATEX ID is the shorthand identifier used in this report . The cruise ID number is 

the standard cruise identifier in wide use in the oceanographic community. The first two 

characters give the year of the cruise, the third character gives the ship identifier (P = 

Powell; S = Seis Surveyor), and the last two characters give the number of the ship cruise 

for that year. 
10 

Table 2 .2 .1 . Cruise identifiers and dates. 

Current Mooring Maintenance Cruises 

ruise Descrintion MMS ID Start Date End Date LATEX ID Cruise ID 

9 120 Day Maintenance M09CPW9307 05/18/93 05/28/93 M09 93P07 

l0A 60 Day Maintenance M10CPW9310 07/13/93 07/19/93 M10A 93P10 

lOB IES Maintenance M10CPW9310 07/22193 07126/93 M10B Erica Tide 

11 120 Day Maintenance MI 1CPW9312 09/21/93 10/01/93 Mil 93P12 

12 120 Day Maintenance M12CPW9315 12!03/93 12/13/93 M12 93P15 

13 60 Day Maintenance M13CPW9402 02/09/94 02!16/94 M13 94P02 

14 120 Day Maintenance M14CSS9414 03/21/94 04/01/94 M14 94S13 

Hydrographic Surveys 

Survey Description MMS m Start Date End Date LATEX ID Cruise ID - 

5 Full Shelf HOSCPW9306 04/25/93 05/11/93 HOS 93P06 

6 Full Shelf H06CPW9311 07/25/93 08/07/93 H06 93P11 

7 Full Shelf H07CPW9314 11/06/93 11/22/93 H07 93P14 

2.3 Report Organization 

This is the second annual report of the LATEX A Study . It reports on the results of the 

second 12 months of field work in terms or data-gathering efforts, the measurement and 

analytical methodologies employed, quantity of data collected, the results of quality 

control exercises and determinations, the status of data archiving and data sharing with 

other contractors, standard computer-produced graphics, and comparisons between 

standard computer-produced graphics and any graphics provided from model simulations 

performed by a designated other contractor. There are no extensive analyses or syntheses 

of the information. Section 3 of the report details the data acquisition for the moored 

measurements, drifting buoy measurements, hydrographic and ADCP measurements, and 

collateral data assembly. Section 4 discusses data quality and analysis for the 

observations collected, including data processing efforts and data quality control methods 

and results. Section 5 summarizes the data archiving and information sharing through 

March 1994. Section 6 provides a technical discussion or the data, with samples of data 

products, from the moorings, drifters, hydrographic/ADCP surveys, and cyclogenesis 

study. It also provides a discussion of the model/data comparison study and the activities 

or the Science Advisory Panel . All times are reported in Universal Coordinated Time 

(UTC) unless stated otherwise. Although the data have been processed for quality control 

and quality assurance, they are still preliminary ; users should expect that subsequent 

corrections will he made to all data sets prior to the final submission to the NODC in 

1996. 
11 

3 DATA ACQUISITION 

3 .1 Introduction 

Section 3 provides an overview of the LATEX A data acquisition activities . It includes a 

discussion of data gathering efforts from the moored current meter array, meteorological 

buoys, drifting buoys, hydrographic/ADCP surveys, and collateral data assembly. Six 

mooring maintenance cruises and three hydrographic/ADCP cruises are summarized, 

giving data types, data collection methods, and locations and times of data collection . 

3 .2 Moored Measurements 

3 .2 .1 Mooring Maintenance Cruises 

During the second year of field operations, six mooring cruises were conducted. The 

dates for these cruises are summarized in Table 2.2 .1 . Maintenance work consisted of 

retrieval of instruments and moorings, as necessary, check-out and refurbishment of 

equipment, downloading of data, and redeployment of equipment. CTD casts were taken 

at each mooring visited to provide calibration information for temperature and 

conductivity sensors and for interpretation. 

Moorings in different water depths were maintained on different schedules as indicated in 

Table 3 .2 .1, which gives the mooring configurations at the beginning of the second field 

year. Modifications to these configurations are discussed under descriptions of each 

cruise . Figure 3.2 .1 shows the locations of the moorings. 

During the second year of operations, 66 current meters, eight meteorological buoys, five 

directional wave gauges, one wave meter, 17 acoustic releases, 12 transponders, and two 

inverted echo sounders (IES) were used. Of these instruments, 12 current meters, five 

surface marker buoys, one meteorological buoy, one directional wave gauge, 3 acoustic 

releases, 5 transponders, and one inverted echo sounder were lost permanently due to 

fishing activity, failure of the instrument to surface, damage beyond repair, or other 

difficulties such as loss due to flooding . 

The following is a summary of the major events of the six current meter cruises made 

during the second year of field operations. All cruises on the R/V J. W. Powell departed 

from and returned to Galveston, Texas. Table 3.2 .2 lists the stations visited each cruise . 

3.2 .1 .1 Cruise M09CPW9307 

The first 120-day mooring maintenance cruise (M09) of the second field year was 

conducted from the R/V J. W. Powell 18-28 May 1993 . Thirty moorings were recovered 

and maintained. The Endeco current meters were retrimmed and reballasted. Twenty-six 

moorings were re-deployed. Meteorological moorings 50, 51, 52, and 53, used for the 

winter norther/cyclogenesis study, were removed for the hurricane season . The MiniSpec 

directional wave gauges at moorings 16, 17, 20, and 23 were removed for postdeployment testing. A Sea Data 635-8 wave gauge was removed from mooring 1 and 

installed at mooring 16. Surface marker buoys were replaced at 5, 9, and 11 . The surface 

marker buoy at mooring 49 had washed ashore just prior to the cruise ; it was replaced and 

maintenance was performed on the mooring . The planned reinstallation of the surface 

marker buoy at mooring 12 was prevented due to lack of spare marker buoys, and the 
Table 3 .2 . l. Mooring configurations as of April 1993. 

Water 

Mooring Depth 

No. (m) 

Latitude 

(IN 

Longitude 

(°W) Comments Too Middle Bottom Release 

Maintenance 

Interval 

( Day) 

1 21 27°1539' 97°14.81' Platform 17410m , T,C NONE Mini-19m, T NONE' 120 

2 37 27°17.09' 96°58.81' Platform 17410m,T,C NONE 17430m,T,C NONE 120 

3 66 27° 1735' 96°44.18' Platform 17410m, T,C 17430m, T,C 174-61m, T,C 397 120 

4 201 27°07.76 96°21.63' Marker Buoy "L" 17414m, T,C Aand-100m, T,C Aand-190m, T,C 397 120 

5 199 27°27.8T 96°04.12' Marker Buoy "M" 17414m, T,C Aand-IOOm, T,C Aand-190m, T,C 397 120 

6 201 27°42.59' 95°39.76' Marker Buoy "N" 17414m, T,C Aand-IOOcn, T,C Aand-190m, T,C 397 120 

7 199 27°50.1 x 95°04.19' Madcer Buoy "O" 17414m, T,C Aand-100m, T,C Aand-190m. T,C 397 120 S 200 27°49.4T 94°10.77' Marker Buoy "P" 17414m, T,C Aand-100m, T,C Aand-190m, T,C 397 120 

9 200 27°48.92' 93°31.91' Marker Buoy "Q" 17414m, T,C Aand-100m, T,C Aand-190m, T,C 397 120 

10 200 27°56.OT 92°44.70' Marker Buoy "R" 17414m, T,C Aand-100m, T,C Aand-190m, T,C 397 120 

11 200 27°50.64' 92°00.45' Medcu Buoy "S" 17414m, T,C Aand-100m, T,C Aand-190m. T,C Srnthos 120 

12 505 27°55.76 90°29.64' Maker Buoy "T" 17414m, T,C Aand-100m, T,C RCM-495m. T,C Brnthoa 180 

13 ?AO 28°03.48' 90°29.18' Marker Buoy "U" 17414m, T,C Aand-100rn, T,C Aand-190m, T,C Benthos 120 

14 47 28°23.74' 90°29.65' Platform 17414m, T,C 1742&n, T,C 174-4?m, T,C NONE 60 

I S 27 28°36.49' 90°29.53' Platform 17410m, T,C NONE 1747Am, T,C NONE 60 

16 19 28°51 .96 90°29.50' Platform 17410m, T,C NONE Mini-17m, T NONE 60 

17 7 29°11 .8T 91 °57.89' Platform Bc Ma Buoy 'C"937 S4-3m, T,C NONE Mini-5m, T NONE 60 

18 22 28°57.74' 91 °59.01' Platform 17410m, T,C NONE 17421m, T,C NONE 60 

19 51 28°T7.92' 92°02.06' Platform & Met Buoy 'D"=930 S4-3m, T,C 17421m, T,C 174-04m, T,C 397 60 

20 15 29'15.6-P 94°03.82' Platform & Met Buoy "E"=931 S4-3m, T,C NONE Mini-13m, T NONE 60 

21/51 24 28°50.28' 94°04.79' Platform & Met Buoy "F=934 17410m, T,C NONE 17421m, T,C NONE 60 

22 55 28°21 .39' 93°57.34' Platform & Ma Buoy "G"--932 S4-3m, T,C 17420m, T,C 174-48m, T,C 397 60 

23 15 28°42.7T 95°32.13' Platform 1749m, T,C NONE Mini-13m, T NONE 60 

24 30 28°32.21' 95°23.61' Platform 17411m, T,C NONE 17427m, T,C NONE 60 

25 45 28°1933' 95°21.ST Platform 17413m, T,C 17423m, T,C 17438m, T,C NONEe 60 

42 1540 27°07.00' 92°00.00' At Sea Floor NONE NONE IES-1540m, T Internal 360 

43 3130 25°325T 92°00.00' At Sea Floor NONE NONE IES-3130m, T Internal 360 

44 56 Permanently Removed 

45 200 Permanently Removed 

46 91 Permanently Removed 

47 ?AO Permanently Removed 

48 200 27°58.98' 91 °16.99' Marker Buoy 7" 17414m, T,C Aand-IOOm, T Aand-190m, T Brnthos 120 

49 505 27°23.13' 95°53.96' Marker Buoy "W" 17414m, T,C Aand-100m, T,C Aand-495m, T,C Benthoa 180 

50 20 28°5286 95°02.20' Platform & Met Buoy "H"=936 NONE NONE NONE NONE 60 

S1/Ll 24 28°50.28' 94°04.79' Platform & Met Buooy "F-934 17410m, T,C NONE 17421m, T,C NONE 60 

52 27 28°48.18' 93°01 .11' Platform & Ma Buoy "I"-933 NONE NONE NONE NONE 60 

53 IS 28°48.04' 90°57.22' Platform & Ma Buoy "7"=935 NONE NONE NONE NONE 60 

Met Buoy = DSI Surface Meteorological Buoy pand = Aandcna Models RCM 7 or 8 IES = Inverted Echo Sounder 

S4 = IntexOccan S4 Electromagnetic Current Meter RCM = Aanderaa Models RCM 4 a 5 T = Tanperacute Sensor 

174 = Endeco Model 174SSM Current Mesa 397 = Dausarica Model 397 Acoustic Release C - Conductivity Sensor (not on all instruments) 

Benthos = Benthos Model 865-A Acrostic Release 

N 
30'N 

N ew 

17 

29'N 

16 

INO 

28'N 

[j49 

42 

27'N 

26'N 

97'W 96'W 95'W 94'W 93'W 92'W 91'W 90'W 

Figure 3 .2 .1 . Mooring locations and maintenance intervals for the second field year. 

LOUISIAN 

TEXAS 

Houst n Orleans 

Galvest ~ 

20 0° v - , . 

" ~`1 S 

50 

21/51 52 78 j0 ~ 

23 

? 

0 

53 

~ 2a ~ 9 

- 

t ~ 5 2p~ 

20 22 'S0 

y 2s 

10 48 73 

7 8 9 11 V Q 12 

d 5 1000 

i 2 ~ s 

a 

Maintenance 

2000 O 60 days 

" 120 days 

D 180 days 

" 360 days 

43 

w 
14 

Table 3.2 .2 . Mooring maintenance by cruise for the second field year. 

1 

,I J ~l J 

,I J J ~I 

4 

5 

6 

7 

8 

9 

10 

i i ,I ~1 J J J 

12 X ~ Remove 

13 

is J J ~l ,I ,~ ,I 

i s J "I ,~ ~l J J 

16 

17 

18 

19 J ~l J J J ~I 

20 J ~I J ~I .I J 

21 J ,l J ,I J ~I 

22 

23 

24 J J J ~l J "I 

25 Remove 

42 

43 Lost 

44 (Removed) 

45 (Removed) 

46 (Removed) 

47 (Removed) 

as J ,I ~l J 

49 

50 Remove Deploy 

51 Remove Deploy 

52 Remove Deploy 

53 Remove Deploy 

=Mooring maintenance conducted 

X = Mooring visited, but left in place w/o maintenance 
15 

upper instrument on the mooring could not be checked for fouling due to poor visibility 

in the water. The top Endeco SSM current meter at mooring 9 was missing and presumed 

lost ; it was replaced. Sediment traps were recovered or reinstalled at moorings 15, 16, 

18, and 19 for LATEX B. 

3.2 .1 .2 Cruise M10CPW9310 

The first 60-day maintenance cruise (M10) of the second field year occurred in two legs 

on 13-19 July 1993 and 22-26 July 1993 . The first leg was conducted aboard the RN 

J.W. Powell. Fourteen moorings were recovered, maintained, and redeployed. Unusually 

strong currents were encountered at the moorings on the eastern end of the study area. 

New mooring wires and hardware were installed on moorings 14 through 23 not 

previously replaced. The Sea-Data 635-8 wave gauge was removed from mooring 16. 

Mooring 11, which had been retrieved by a fishing vessel prior to the cruise, was 

reinstalled . The surface marker buoy at mooring 12 was reinstalled . Sediment traps were 

recovered or reinstalled at moorings 14, 15, 16, 18, and 19 for LATEX B . 

Due to scheduling constraints of the RN J.W. Powell, the second leg of M10 was 

conducted using the M/V Erica Tide to recover moorings 42 and 43, which were 

instrumented with the inverted echo sounders. The IES at mooring 42 was retrieved and 

redeployed. Although it appeared to have received the release signal, the IES at mooring 

43 did not surface, even after numerous attempts to trigger its release. It was not 

recovered. XCP profiles were taken at moorings 42 and 43 . An XSV and an XBT were 

launched at mooring 42 . Fifteen XBTs were launched at 11 .1-km (6-nm) intervals 

between the 50-m isobath and mooring 42. Three were launched at the first location 

without success due to a faulty launcher that caused intermittent breaks in the wire. The 

launcher was repaired. Twelve XBTs returned good profiles. Ten XBTs were launched 

successfully at 18 .5-km (10-nm) intervals between moorings 42 and 43. 

Moorings 20 and 17 were visited by LSU personnel aboard the 26-ft RN Changes In 

Latitude on August 19 and 20, 1993, respectively . The InterOcean S4 current meters and 

meteorological buoys were inspected for biofouling . The S4s were cleaned to remove the 

biofouling on the hulls and electrodes. The tower of the meteorological buoy at mooring 

17 had been ripped off the buoy and was resting on top of the anchor with all instruments 

intact . The tower was removed 

3 .2 .1 .3 Cruise M11CPW9312 

The second 120-day maintenance cruise (M11) was conducted aboard the R/V J. W. 

Powell from 21 September - 1 October 1993. Twenty-five moorings were recovered, 

maintained and redeployed. The five MiniSpec directional wave gauges were reinstalled 

at moorings 1, 16, 17, 20, and 23. Moorings 1, 16, and 20 were relocated to shallower 

water to enhance the collection of wave data. The new locations are shown in Table 

3.2 .3 . New mooring wires and hardware were installed at moorings 1, 2, 16, and 20. The 

tower and sensors for the meteorological buoy at mooring 17 were replaced. The 

meteorological buoy, without its tower, and the InterOcean S4 current meter from 

mooring 19 were found adrift near mooring 15 by a service vessel for a nearby platform . 

They were retrieved from the platform owner. The remainder of mooring 19 was not 

recovered. Mooring 19 was replaced . The bottom current meter at mooring 22 exploded 

during recovery, apparently having flooded . The top current meter at mooring 18 was 

flooded. The top current meter at mooring 14 was missing and presumed lost . Moorings 

11 and 48 were missing and presumed lost . Due to lack or spare instruments these two 
16 

moorings were not redeployed. Due to corrosion from oxygen starvation on the 

conductivity cells, many of the Endeco current meters could not be repaired in the field. 

This greatly reduced the number of spare current meters available for replacing lost or 

malfunctioning instruments . As a result, no current meters were deployed at the top of 

moorings 3, 5, 7, 10, 13, 14, 23, and 25 or at the bottom of mooring 3. Sediment traps 

were recovered or reinstalled at moorings 14, 15, 16, 17, and 18 for LATEX B . 

Table 3.2 .3 . New locations of moorings 1, 16, and 20. 

Mooring No 

1 

16 

20 

Latitude N 

27019.41' 

28°56.36' 

29°30.03' 

Longitude W 

97018.42' 

90°26.10' 

94°01 .34' 

Water Depth (m) 

13.3 

15.9 

12.4 

3 .2 .1 .4 Cruise M 12CPW9315 

To fill the current meter gaps left at the 200-m isobath nn the previous cruise, the twelfth 

cruise (M12) became the third 120-day maintenance cruise. It was conducted aboard the 

R/V J.W. Powell from 3-13 December 1993. Thirty moorings were visited. Twentyseven current meter moorings were recovered and maintained . Twenty-five were 

redeployed . Moorings 12 and 25 were removed from the water to provide spare 

equipment for the program. Moorings 11 and 48 were redeployed. The missing surface 

marker buoy at mooring 49 was replaced and the mooring was refurbished. Equipment 

remaining at the bottom at mooring 19 from the previous cruise, including two current 

meters, was recovered . Meteorological buoys at moorings 50, 51, 52, and 53 were 

redeployed. Service ARGOS transmitters were deactivated on all meteorological buoys 

except those at moorings 19 and 22. Sediment traps were recovered or reinstalled at 

moorings 15, 16, and 17 for LATEX B. 

3 .2 .1 .5 Cruise M13CPW9402 

The second 60-day mooring maintenance cruise (M 13) took place on the R/V J. W. Powell 

from 9-16 February 1994. Fourteen moorings were recovered, maintained, and 

redeployed. Poor weather made the maintenance work difficult and slow. Current meters 

were deployed at 11 of these moorings ; five of these mooring locations were also 

occupied by meteorological buoys. Three moorings were occupied by meteorological 

buoys alone. The masts of the meteorological buoys at moorings 19, 50, and 52 had been 

torn off. The damage to the meteorological buoys appears to have been caused by vessels 

tying off to the buoys. Due to lack of spares, no meteorological buoys were deployed at 

moorings 51 and 52. The bottom meter at mooring 21 was flooded. A Woods Hole 

Instrument System Ltd PAC 2000 was installed at mooring 16, adjacent to the MiniSpec, 

to conduct a calibration test for the MiniSpec . Sediment traps were recovered or 

reinstalled at moorings 15 and 16 for LATEX B. 

3 .2 .1 .6 guise M 14CSS9414 

The fourth 120-day mooring maintenance cruise (M14) was carried out aboard the M/V 

Seis Surveyor from 21 March - 1 April 1994. Twenty-eight moorings were recovered, 
17 

maintained, and redeployed. Current meters were deployed at 25 moorings ; five of these 

also were occupied by meteorological buoys . Three moorings are occupied by 

meteorological buoys alone. Mooring 23 was missing, including the MiniSpec, and 

presumed lost . It is possible that a jack-up rig working in the area inadvertently may 

have destroyed the mooring, but there is no actual indication of the cause of this loss. 

The mooring was redeployed without a MiniSpec, due to lack of spares . The 

meteorological buoys at moorings 51 and 52 were redeployed . The Woods Hole 

Instrument System Ltd PAC 2000 was removed from mooring 16. The surface marker 

buoys at moorings 8, 48, and 49 were missing and were replaced . To avoid potential loss 

of instrumentation from seismic work being done in the area, mooring 9 was relocated to 

27048 .82'N 93032.84'W. Sediment traps were recovered or reinstalled at moorings 14, 

15, 16, and 18 for LATEX B. 

3.2.2 Instrumentation. Calibration, and Sampling Procedures 

The calibration of all instruments and sampling procedures were performed, in general, as 

noted in sections 9.3 and 9.4 of Nowlin et al. (1991) and in section 2.2.2 of Jochens and 

Nowlin (1994b). Some variations from the procedures set out in these references 

occurred due to time constraints and the actual instruments used. Because of instrument 

loss, the current meters could not be returned to shore for major refurbishment and 

recalibration as frequently as originally planned. Therefore, the data from the CTD casts 

taken before and/or after instrument recovery and redeployment were used to assist with 

instrument calibrations . 

3.2 .3 Summary of Data Collection 

The second year or deployment was from April 1993 through March 1994. Data were 

recovered from the moored instrumentation during mooring maintenance cruises M09 

through M14. Moored instrumentation consisted or current meters collecting current 

speed and direction, temperature, and conductivity ; meteorological buoys collecting wind 

speed and direction, air and sea surface temperature, and barometric pressure ; MiniSpec 

directional wave gauges collecting current speed and direction, temperature, and pressure 

and inverted echo sounders collecting acoustic travel time, temperature, and pressure . 

3.2 .3 .1 Current Meter Data 

Table 3 .2 .2 shows moorings visited for maintenance on each cruise . Figure 3 .2 .2 

summarizes the recovery results for the second year. In Figure 3 .2 .2, T stands for the top 

instrument, M for the middle, and B for the bottom instrument on the numbered mooring; 

see Table 3 .2 .1 for instrument types . For each current meter on each mooring, Table 

3.2 .4 shows the data recovery and problems during the second field year. 

3.2 .3 .2 Wave Gau eg Data 

For much or the second field year, the MiniSpec instruments were removed from service 

for extensive testing of their ICS pressure sensors. This testing culminated in a pressure 

calibration at NOAA's Northwest Regional Calibration Center in Bellevue, WA, during 

the summer of 1993. This calibration is documented in Kelly et al . (1993) and was 

addressed in Jochens and Nowlin (1994b). The MiniSpecs were returned to the field in 

late September 1993 equipped with new ICS pressure transducers which removed the 

warm-up transient present during the first field year. The instruments were configured to 

report raw pressure counts and burst temperature so that the LATEX quadratic 
Current Meter Data from Second Field Year 

I T 7 

01T 11m 

~2T iSm 

I 03T 10m 

04 B 190 m 4M 1 

S 4T 1 4 mm 

OS B 190 m 

S5 T 14 

5M 1pp 

m 

00 

06 T 1 9 4 m 

190 M 

07 T 1 4~rm 

190 M 

08 T 1 40 m 

09 B 190 m 

S9T 14 

gM 'pp 

m 

10B 190m as Y 1~m 

11 B 190M 1' M 1 

11 T 1 40 m 

12 T IT T 

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May 

1993 1994 

00 

Figure 3.2 .2 . Current meter data recovered for the second year. 
Current Meter Data from Second Field Year 

13B 190m 

3 

11 7' 

40 M _~4 

m 

MM 

16B 18M 

16T 11 m 

17B 6m 17T 3m 

16 T 11 m 

187--10 m8B 20m 

19M 20m 19B 47m 

19T 3m 

20B 13m 

20T 3m 

?i m 

22B 48m 22 M 20m 2 3m 

23B 13m 23T 10m 

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May 

1993 1994 

Figure 3.2 .2 . Current meter data recovered for the second year (continued). 
Current Meter Data from Second Field Year 

~4T 8m 

~5 IVI ~D m 25T 11 m 

48 B 190 m 

48 

49 B 490 m 49M 

49 T 14pmm ~ 

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May 

1993 1994 

N 

O 

Figure 3.2 .2 . Current meter data recovered for the second year (continued). 
21 

Table 3.2 .4 . LATEX Current Meter Data April 1993 - April 1994. 

Mooring Depth S/N Deploy Cruise Recover Cruise Start Data End Data Exceptions 

0113 I lm 10093 93P12 (Ml 1) 93P15 (M12) 09x29/1993 1330 12/1 1/1993 13 :00 

0113 ilm 10092 93P15 (M12) 94S14(M14) !2/11/199313 :30 03/28/199413 :00 K,Q,S 

O1T 14m SSM241 93P04(M08) 93P07 (M09) 03!23/199313 :30 05/21/19931130 

O1T 19m SSM239 93P(Y7 (M09) 93P12 (M11) 05!21/1993 13 :00 09/29/1993 07:00 

O1T Ilm SSM240 93PI2(MI1) 93PI5(M12) 09/29/199314 :30 12/11/199313 :30 

O1T llm SSM250 93P15(M12) 94S14(M14) 12/11/199314 :00 03/28/199413 :00 K,Q 

02B 31m LSU008 93P07 (M09) 93PI2 (M(1) 05/21/1993 14 :30 09/18/1993 19 :25 K,N 

02B 30m ISU030 93P12 (M11) 93P15 (M12) 09!29/1993 18 :30 12J11/1993 16 :25 

02T I lm SSM258 93P04 (MO8) 93P07 (M09) 03/23/1993 16 :30 05/21/1993 12 :00 

02T 12m SSM256 93P07 (M09) 93P12 (M11) 05/21/1993 16 :30 09/29/1993 16 :30 K,Q 

02T lOm SSM239 93P12(M11) 93P15 (M12) 09/29/199319 :00 17J11/199316 :30 

02T lOm SSM040 93P15 (M12) 94514 (M14) 12/11/1993 17 :00 03/29/1994 1230 

03B 58m DMT145 93P07 (M09) 93P12 (M11) 05/21/1993 1830 09/18/1993 0525 K,Q 

03B 58m LSU070 93P15 (M12) 94514 (M14) 12/11/1993 21 :00 03/29/1994 14 :50 D,E 

03M 33m DMT146 93P07 (M09) 93P12 (M11) 05/21/1993 18 :30 09/18/1993 0830 

03M 32m DMT146 93P12(M11) 93P15 (M12) 09/30/199305 :00 12111/199318 :50 

03M 33m DMT145 93P15 (M12) 94514 (M14) 12/11/1993 21 :00 03/29/1994 14 :50 K,N 

03T 13m SSM244 93P01 (M07) 93P07 (M09) 01/20/1993 01 :30 05/21/1993 16 :00 

03T 13m SSM241 93P07 (M09) 93P12 (M11) 05/21/1993 1930 09/29/1993 20:00 

03T lOm SSM232 93P15 (M12) 94514 (M14) 12111/1993 2230 03/29/1994 15 :00 

04B 190m AA10684 93P01 (M07) 93P07 (M09) 01120/1993 07 :30 05/21/1993 23 :00 

04M 100m AA10678 93P01 (M07) 93P07 (M09) 01/20/1993 0730 05/21/1993 23 :00 

04M 100m AA10673 93P12 (M11) 93P15 (M12) 09/30/1993 02:30 17111/1993 23 :00 

04M 100m AA9411 93P15 (M12) 94514 (M14) 12/12/1993 02:00 03/29/1994 19 :00 K,N,Q 

04T 12m SSM255 93P01 (M07) 93P07 (M09) 01/20/1993 0730 05/21/1993 22:30 

04T 14m SSM258 93P(r7 (M09) 93P12 (M11) 05/22/1993 01 :00 09/29/1993 23 :30 

04T 14m SSM256 93P12 (M11) 93P15 (M12) 09/30/1993 02:00 12/11/1993 23 :00 

04T 14m SSM279 93P15 (M12) 94514 (M14) 12/12/1993 02:00 03/29/1994 19 :00 D,E 

05B 190m 7106521 93P01 (M07) 93P07 (M09) 01/20/1993 12 :30 05/20/1993 21 :30 1,K,M 

OSM 100m AA10685 93P01 (M07) 93P07 (M09) 01!20/1993 12 :00 05/20/1993 22 :00 

05M 100m AA10685 93P12 (M11) 93PI5 (M12) 09/29/1993 02 :30 12112/1993 1630 

05M 100m AA10676 93P15(M12) 94514(M14) !2/12/199319 :30 03/27/199418 :30 K,Q 

05T 13m SSM256 93Po1 (M07) 93P07 (M09) 01/20/1993 1230 05/20/1993 22 :00 K,Q,I 

05T 14m SSM240 93P07 (M09) 93P12 (M1 1) 05!21/1993 01:00 09/29/1993 00:00 

05T 14m SSM240 93P15 (M12) 94514 (M 14) 12/12/1993 19 :30 03/27/1994 18 :00 D,E,K 

06B 190m AA 10690 93P01 (M07) 93P07 (M09) 01/19/1993 03:00 05/20/1993 12 :00 A,B,K 

06B 190m AA9410 93P12 (M11) 93P15 (M12) 09!28/1993 22:30 12/12/1993 23 :00 A,B,K 

06B 190m AA9121 93P15 (M12) 94S14(M14) !2/13/199302 :00 03/27/199413 :00 S 

06M 100m AA10688 93P01 (M07) 93P07 (M09) 0!/19/1993 03:00 05/!8/1993 00:00 

06M 100m AA10673 93P07 (M09) 93P12(M11) 05!20/199315 :30 09/28/19931930 

06M 100m AA10670 93P12 (Mil) 93P15 (M12) 09/28/1993 22 :00 12/10/1993 2230 

06M 100m AA10674 93P15 (M12) 94S 14 (M14) 12/13/1993 02:00 03/27/1994 13 :00 

06T 13m SSM239 93P01 (M07) 93P07 (M09) 01/19/1993 03:00 05/20/1993 12 :30 

06T 14m SSM243 93P07 (M09) 93P12(M11) 05/20/199315 :00 09/28/199319 :30 K,N 

06T 14m SSM255 93PI2 (M11) 93P15 (M12) 09/28/1993 22 :00 12/12/1993 23 :00 K,Q 

06T 14m SSM256 93P15 (M12) 945 14 (M14) 12/13/1993 02 :00 03/27/1994 12 :30 

07B 190m AA10175 93P01 (M07) 93P07 (M09) 01/18/1993 09 :00 05/13/1993 19 :00 

07B 190m AA9410 93P07 (M09) 931`12 (M11) 05/2211993 16 :30 09/26/1993 14 :00 i's 

07B 190m AA 10669 93P12(M11) 93P15 (M12) 09!28/199316 :00 11110/199323 :00 K,Q,S 

07B 190m AA 10677 931`15 (M12) 94S14(M14) 12/11/1993 02 :00 03/27/199404 :30 
22 

Table 32.4 . LATEX Current Meter Data April 1993 - April 1994. (continued) 

Mooring Depth SIN Deploy Cruise Recover Cruise Start Data End Data Exceptions 

07M 100m AA 10681 93P01 (M07) 93P07 (M09) 01/(8/(99309 :00 05/22/1993 13 :00 B,K 

07M 100m AA10685 93P07 (M09) 93P12 (M11) 05/22/1993 1630 09/28/1993 14 :00 K,Q 

07M 100m AA10687 93P12 (M11) 93P15 (M12) 09/28/1993 16 :30 12I10/1993 23 :00 

07M 100m AA10681 93P15(M12) 94514(M14) 12/11/199302 :00 03/27/199404 :00 B,K 

07T 14m SSM253 93P01 (M07) 93P07 (M09) 01/18/1993 0930 05/2211993 12 :00 

07T 14m SSM255 93P07 (M09) 93P12 (MI 1) 05/22/1993 16 :00 09/28/1993 13 :30 

07T 14m SSM235 93P15 (M12) 94S14(M14) 12/I1/199302 :00 03/27/199404 :00 D,E 

08B 190m AA10672 93P01 (M07) 93P07 (M09) 01/16/1993 06:00 05/22/1993 20 :30 K,S 

08B 190m AA10674 93P12 (M11) 93P15 (M12) 09!23/1993 22:00 12109/1993 19 :30 A,B,K 

08B 190m AA10678 93P15 (M12) 94514(M14) 12/10/199307 :00 03/2b/199420 :00 

08M 100m AA 10669 93P01 (M07) 93P07 (M09) 01/16/1993 06:00 05/2711993 21 :00 

08M 100m AA10678 93P07 (M09) 931`12 (M11) 05/22/1993 23 :00 09/23/1993 1930 K,W 

08M 100m AA10682 931`12 (Mil) 93P15 (M12) 09/23/1993 22 :00 12/09/1993 19 :00 

08M 100m AA10690 93PI5(M12) 94S14(M14) 12/10/199307 :00 03/26/199420 :00 K,Q,S 

08T 15m SSM233 93P01 (M07) 93P07 (M09) 01/16/1993 06:00 05/22J1993 20:00 

08T 14m SSM244 93P07 (M09) 93P12 (Ml 1) 05!22/1993 23:00 09/23/1993 19 :00 

08T 15m SSM040 93P12 (MI 1) 93P15 (M12) 09/23/1993 22:00 12J09/1993 19 :00 

08T 14m SSM242 93P15 (M12) 94514 (M14) 12/10/1993 07 :00 03/26/1994 1930 D,E 

09B 190m AA 10671 93P01 (M07) 93P07 (M09) 01/15/1993 23:30 05/23/1993 02:00 

09M 100m AA10670 93P01 (M07) 93P07 (M09) 01/15/1993 23:00 05/23/1993 02:30 K,S 

09M 100m AA10684 93P07 (M09) 93P12 (Ml 1) 05!23/1993 0530 09/24/1993 12 :30 K,Q,S 

09M loom AA10677 93PI2 (M11) 93P15 (M12) 09124/1993 14 :30 10/07/1993 05 :45 P 

09M 100m AA 10684 93P15 (M12) 94S14 (M14) 12/09/1993 16 :00 03/26/1994 1230 

09T 14m SSM253 93P07 (M09) 93PI2 (M11) 05!23/1993 05:00 09/24/1993 12 :00 

09T 14m SSM250 93P12 (M11) 93P15 (M12) 09x2,4/1993 15 :00 12109/1993 13 :00 

09T 14m SSM244 93P15 (M12) 94S14(M14) 12/09/199316 :00 03/26/199412 :00 

1013 190m AA10675 93P01 (M07) 93P07 (M09) 01/11/1993 0930 05/25/1993 00 :30 

ION! 100m AA10720 93P01 (M07) 93P07 (M09) 02/0211993 00 :30 05/16/1993 00 :00 K,S 

lOM 100m AA 10669 93P07 (M09) 931`12 (M11) 05!25/1993 03:30 09/24/1993 19 :30 K,Q 

IOM 100m AA10678 93P12(Ml!) 93P15 (M12) 09/24/19932130 12/08/199320 :00 

lOM 100m AA10689 93P15 (M12) 94S14(M14) 12/08/19932230 03/26/199402 :30 

IOT 14m SSM042 93P15 (M12) 94514 (M14) 12/08/1993 2230 03/26/1994 03 :00 

1113 190m AA 10689 93P01 (M07) 93P07 (M09) 01/11/1993 18 :00 05/25/19931130 A,B,K 

11M 100m AA10682 93P0I (M07) 93P07 (M09) 01!20/1993 00:30 05/18/1993 00 :00 

I1M 100m AA10680 93P15(M12) 94S14(M14) 12/08/19930930 03/25/199420 :00 1,K,M 

11T 14m SSM232 93P04 (M08) 93P07 (M09) 01/11/1993 1830 05/25/1993 11 :00 

11T 14m SSM232 93P07 (M09) 93P10 (M10) 05/25/1993 14 :30 06/09/1993 0030 K 

11T 14m SSM241 93P15(M12) 94S14(M14) 12/08/199310:00 03/25/199420 :00 

12M 100m AA10676 93PO1 (M07) 93P10 (M10) 01/12/1993 16 :00 07/18/1993 01 :00 K,Q 

12M 100m AA 10681 93P12(M11) 931`15 (M12) 07/18/199307 :00 12!07/19930530 B,K 

12T 14m SSM250 93PO1 (M07) 93PI0 (M10) 01/1211993 16 :00 07/18/1993 01 :30 

12T 14m SSM235 93P10(M10) 93P15 (M12) 07/18/199308 :30 12107/199305 :00 K,Q,S 

13B 190m AA10674 93P01 (1407) 93P07 (M09) 01/12/1993 20:00 05/26/199302 :00 K,Q 

13M 100m AA 10679 93P01 (M07) 93P07 (M09) 01/27/1993 00 :30 05/21/1993 00 :30 

13M 100m AA 10670 93P07 (M09) 93P12 (M11) 05!26/1993 05 :00 09/25/1993 17 :00 

13M 100m AA10676 93P12(MI1) 93P15 (M12) 09/25/199319 :00 12107/199300 :30 

13M 100m AA 10679 93P15(M12) 94514(M14) 12/07/199304 :30 03/25/199400 :00 K,N 

13T 14m SSM245 93PO1 (M07) 93P07 (M09) 01/12!1993 20:00 05/26/1993 02:00 

13T 15m SSM257 93P07 (M09) 93P12 (M11) 05/26/1993 05 :00 09/25/1993 16 :00 K,Q 

13T 14m SSM247 93P15(M12) 94S14(M14) 12/07/199304 :00 03/25/199400 :00 S 
23 

Table 3 .2 .4 . LATEX Current Meter Data April 1993 - April 1994 . (continued) 

Mooring Depth S/N Deploy Cruise Recover Cruise Start Data End Data Exceptions 

14B 40m I .SU020 93P07 (M09) 93P10 (MIO) 05!26/1993 19 :00 07/17/1993 1920 D,E,K 

14B 40m ISU005 93P10 (M10) 93P12(Ml1) 07/!7/19932230 09/25/199320 :50 D,E,K 

14B 40m DMT015 93P12 (M11) 93P15 (M12) 09!25/199322:30 12106/1993 18 :15 D,E,K,N,O,Q 

14B 40m LSU005 93P15 (M12) 94P02 (M13) 12/07/1993 02:00 02114/1994 2020 D,E 

14B 40m LSU020 94P02 (M 13) 945 14 (M 14) 02115/1994 01 :30 03/24/1994 21 :25 D,E 

14M 26m DMT015 93P04 (MO8) 93Po7 (M09) 03!20/1993 2030 05/26/1993 10 :00 D,E,K,Q 

14M 23m DMT015 93P07 (M09) 93PI0 (M10) 05!26/1993 19 :00 07/17/1993 1925 D,E,F,G,K 

14M 23m DMT015 93P10 (M10) 93P12 (MI 1) 07/17/1993 2230 09/25/1993 20:40 D,E,K,Q 

14M 20m DMT208 93P12(M11) 93P15 (M12) 09!25/199322:30 12/06/199317 :55 

14M 24m L,SU050 93P15 (M12) 94P02 (M13) 12/06/1993 2230 02I14/1994 19 :55 D,E 

14M 24m LSU005 94P02 (M13) 945 14 (M14) 02115/1994 01 :30 03/24J1994 21 :25 D,E 

14T 11m SSM235 93P04 (M08) 93P07 (M09) 03/20/1993 21 :00 05/26/1993 1030 K,Q 

14T lOm SSM245 93P07 (M09) 93P10 (M10) 05/26/1993 1930 07/!7/1993 16 :30 

14T 19m SSM039 93P15 (M12) 94P02 (M13) 12/06/1993 23 :00 02114/1994 1930 

14T lOm SSM258 94P02(M13) 94S14(M14) 02/15/1994 02:00 03/24/1994 21 :00 

15B 24m LSU005 93P04 (M08) 93P07 (M09) 03/19/1993 2330 05/26/1993 20:30 

15B 24m L,SU005 93P07 (M09) 93P10 (M10) 05!26/1993 22:30 07/17/1993 15 :30 D,E,K 

15B 25m DMT215 93P10 (M10) 93P12 (MI 1) 07/17/1993 1730 09/25/1993 20:00 A,K 

15B 24m LSU005 93P12 (MI 1) 93P15 (M12) 09/26/1993 00:00 12106/1993 16 :00 D,E 

15B 24m DMT238 93P15 (M12) 94P02 (M13) 12/06/1993 16 :00 0211M19942225 

15B 24m L.SU055 94P02 (M13) 94S14 (M14) 02/14/199423 :00 03/2411994 16 :15 D,E 

15T IOm SSM247 93P04 (M08) 93P07 (M09) 03/20/1993 00:00 05/26/1993 20:30 1 

IST lOm SSM235 93P07 (M09) 93P10 (M10) 05!26/1993 22:30 07/17/1993 15 :30 

15T lOm SSM285 93P10 (M10) 93P12 (M11) 07/17/1993 18 :00 09/25/1993 23:30 1 

15T IOm SSM257 93P12 (M11) 93P15 (M12) 09!26/1993 00:00 12106/1993 16 :00 K,N 

15T lOm SSM258 93P15 (M12) 94P02 (M13) 12/06/1993 1630 02114/1994 22 :00 

15T lOm SSM233 94P02 (M13) 94S14 (M14) 02/14/19942330 03/24/1994 16 :00 

16B 18m 10096 93P04 (M08) 93P07 (M09) 03/19/1993 2029 05/26/1993 2329 H 

16B 18m 10096 93P04 (M08) 93P07 (M09) 03/19/1993 2129 05/26/1993 23 :29 H,J,T 

16B 14m 10096 93P15 (M12) 94P02 (M13) 12/06/1993 1330 02114/1994 13 :30 

16B 14m 10094 94P02 (M 13) 94S14(M14) 02/!4/199418 :00 03/2M19941230 

16T I lm SSM285 93P04 (MO8) 93P07 (M09) 03/19/1993 19 :30 05/27/1993 00 :00 1 

16T I lm SSM247 93P07 (M09) 93P10 (M10) 05/27/1993 01 :00 05/29/1993 12 :00 

16T 11m SSM285 93P07 (M09) 93P10 (M10) 06!23/1993 18 :55 07/17/1993 11 :45 P 

16T I lm SSM242 93P10 (MIO) 93P12 (Ml 1) 07/17/1993 1330 09/26/1993 1130 

16T 11m SSM285 93P12 (Ml 1) 93P15 (M12) 09/26/1993 14 :30 12106/1993 13 :30 K,N,Q 

16T 11m SSM233 93P15(M12) 94P02(M13) !2/06/199314 :00 02114!19941330 

16T 11m SSM243 94P02(M13) 94514(M14) 02/!4/199415 :00 03/24/199413 :30 

17B 6m 10094 93P04 (M08) 93P07 (M09) 03/18/1993 18 :00 05/27/1993 1230 H,K,T 

17B 7m 10096 93P12 (M 11) 93P15 (M12) 09/27/1993 1230 12105/1993 13 :00 K,T 

17B 6m 10094 93P15 (M12) 94P02 (M13) 12/05/1993 1430 07113/1994 1330 

17B 6m 10093 94P02 (M13) 94S14(M14) 02/!3/199414 :00 03/23/199415 :30 

17T 3m 08111788 (17) 93P04 (M08) 93P07 (M09) 03/18/1993 2029 05/19/1993 18 :59 

17T 3m 08111788(17) 93P07 (M09) 93P10 (M10) 05/27/1993 12 :40 07/16/1993 21 :10 K,N 

18B 19m DMT025 93P04 (M08) 93P07 (M09) 03/18/1993 21 :00 04/25/1993 23 :55 D,E,K 

18B 20m DMT215 93P07 (M09) 93P10 (M 10) 05/24/1993 12 :50 07/16/1993 1725 

18B 20m LSU030 93P10 (M10) 93P12 (M11) 07/16/1993 19 :30 09/26/1993 23 :00 A,K 

18B 20m DMT215 93P12(M11) 93P15 (M12) 09/27/199300:00 12/05/199318 :00 

18B 20m L.SU020 93P15 (M12) 94P02 (M13) 12/05/1993 18 :30 17J13/1993 14 :30 D,E,K 

18B 20m LSU050 94P02(M13) 94S14(M14) 02/15/199413 :30 03/23/199418 :55 D,E 
24 

Table 3.2 .4 . LATEX Current Meter Data April 1993 - April 1994. (continued) 

Mooring Depth S/N Deploy Cruise Recover Cruise Start Data End Data Exceptions 

18T lOm SSM039 93P04 (MO8) 93Po7 (M09) 03/18/1993 21 :30 OS/2M1993 11 :00 

18T lOm SSM280 93P07 (M09) 93P10 (M10) 05124/1993 12 :30 07/16/1993 18 :00 

18T lOm SSM242 93P12 (M11) 93P15 (M12) 09/26/1993 2230 (2/05/1993 17 :00 K,N,Q 

18T lOm SSM254 93P15 (M12) 94P02 (M13) 12/05/1993 18 :30 01113/1994 16 :00 

19B 47m DMT221 93P04 (M08) 93P07 (M09) 03/19/1993 04:00 05/24/1993 16 :00 

19B 49m DMT125 93P07 (M09) 93P10 (M10) 05/24/1993 19 :00 07/16/1993 11 :30 

19B 48m LSU050 93P10 (M10) 93P15 (M12) 07/16/1993 15 :00 11/13/1993 22:15 D,E,K 

19B 47m LSU040 93P15 (M12) 94P02 (M13) 12/06/1993 03 :00 12/13/1993 21 :00 D,E,K 

19B 47m LSU040 94P02(M13) 94514(M14) 02/15/199421 :00 03/23/199423 :10 D,E 

19M 18m LSU030 93P07 (M09) 93P10 (M10) 05/24/1993 19 :00 07/16/1993 11 :30 K,Q,S 

19M 18m DMT238 93P10 (M10) 93P15 (M12) 07/16/1993 1430 08/16/1993 22:30 I,7,K,S 

19M 20m LSU065 93P15 (M12) 94P02 (M13) 12/06/1993 03 :00 01/20/1994 23:00 D,E,K 

19T 3m 00000000 (19) 93P07 (M09) 93P10 (M10) 05/24/1993 18:40 07/16/1993 11 :40 D,E,K 

19T 3m 00001781 (19) 93P10 (MIO) 93P12 (M11) 07/16/1993 14 :36 08/28/1993 14 :06 D,E,K 

20B 13m 10095 93P04 (M08) 93P07 (M09) 03/17/1993 17 :29 05/28/1993 00:29 J,K,T 

20B IOm 10094 93P12 (M11) 93PI5 (M12) 09!22/1993 18 :00 12104/1993 1330 

20B lOm 10093 93P15 (M12) 94P02 (M13) 12/13/1993 15 :00 0211211994 13 :00 

20B llm 10096 94P02 (M13) 94S14(M14) 02/16/1994(8 :00 03/31/199412 :30 

20T 3m 081 l 1779 (20) 93P04 (M08) 93P07 (M09) 03/17/1993 21 :10 05/16/1993 01 :40 

20T 3m 08111779 (20) 93P07 (M09) 93P10 (Ml0) 05!28/1993 02:10 06/30/1993 21 :40 D,E,K 

20T 3m 08111778 (20) 93P10 (M10) 93P12 (M11) 07/15/1993 1324 09!22/1993 14 :24 D,E,K 

21B 21m C.SU030 93P04 (M08) 93P07 (M09) 03/18/1993 00 :30 05/23/1993 17 :00 I'M 

21B 22m DMT208 93P07 (M09) 93P10 (M10) 05/23/1993 17 :30 07/15/1993 13 :45 B,I,K 

21B 22m I.SU010 93P10 (M10) 93P12 (MI 1) 07/15/1993 18 :00 09/2211993 23 :05 

21B 22m DMT208 94P02(M13) 94514(M14) 02/121199419 :00 03/31/199419 :30 1 

21T 13m SSM280 93P04 (M08) 93P07 (M09) 03/18/1993 0030 05/23/1993 17 :00 

21T 14m SSM233 93P07 (M09) 93P10 (M10) 05/23/1993 1730 07/15/1993 16 :30 

21T 14m SSM279 93P10 (MIO) 93P12 (MI 1) 07/15/1993 19 :00 09/22J1993 23 :00 

21T 14m SSM254 93P12 (M11) 93P15 (M12) 09/23/1993 00:00 12104/1993 21 :30 

21T 14m SSM243 93P15 (M12) 94P02 (M13) 12/05/1993 01 :00 02/12!1994 18 :00 

21T 14m SSM285 94P02 (M13) 94514 (M14) 02/12/1994 19 :00 03/31/1994 1930 

22B 48m DMT215 93P04 (M08) 93P07 (M09) 03/21/1993 23 :30 05/23/1993 11 :30 A,K,N 

22B 48m C.SU050 93P07 (M09) 93P10 (M10) 05/23/1993 14 :00 07/15/1993 2225 

22B 48m L,SU010 93P12 (MI 1) 93P15 (M12) 09/23/1993 15 :30 12/09/1993 23 :50 K,N 

22B 48m DMT015 93P15 (M12) 94P02 (M13) 12/10/1993 0230 02/12/1994 00 :00 D,E,K 

22M 20m DMT125 93P04 (M08) 93P07 (M09) 03/21/1993 23 :30 05/23/1993 11 :45 C,D,E,K 

22M 20m DMT238 93Po7 (M09) 93P10 (M10) 05/23/1993 14 :00 07/15/1993 22:00 

22M 20m DMT208 93P10 (M l0) 93P12 (M11) 07/16/1993 00:00 09/15/1993 16 :55 D,E,K 

22M 20m SSM279 93P12 (M11) 93P15 (M12) 09/23/1993 16 :00 12109/1993 2330 

22M 20m DMT208 93P 15 (M12) 94P02 (M 13) 12/10/1993 02:30 02J12J1994 00 :00 

22M 20m LSU030 94P02 (M 13) 94S 14 (M14) 02/12/1994 05 :30 03/31/1994 23 :40 

22T 3m 08111780 (22) 93P04 (MO8) 93P07 (M09) 03/21/1993 23 :50 05/15/1993 0220 

22T 3m 08111781 (22) 93P07 (M09) 93P10(M10) 05/23/1993 17 :10 06/16/1993 17 :40 I,K 

22T 3m 08111777 (22) 93P10 (M l0) 93P12 (Ml 1) 07/15/1993 21 :44 09/23/1993 14 :14 

23B 13m 10092 93P04 (M08) 93P07 (M09) 03/22/1993 14 :30 05/14/1993 12 :30 H,K,Q,T 

23B 13m 10092 93P04 (M08) 93P07 (M09) 03/22/1993 14 :30 05/19/1993 12 :30 H,K,Q,T 

23B 14m 10092 93P12 (M 11) 93P15 (M 12) 10/01/1993 10 :00 12/10/1993 15 :00 

23B 13m 10095 93P15 (M12) 94P02 (M13) 12/10/1993 16 :00 02110/1994 14 :00 

23T lOm SSM243 93P04 (M08) 93P07 (M09) 03/22/1993 17 :30 05/19/1993 1530 D,E,K 

23T lOm SSM042 93P07 (M09) 93P10 (M10) 05/19/1993 16 :30 07/(4/1993 12 :00 D,E,K,Q 
25 

Table 3.2 .4. LATEX Current Meter Data April 1993 - April 1994. (continued) 

Mooring Depth S/N Deploy Cruise Recover Cruise Start Data End Data Exceptions 

23T IOm SSM247 93P10(M10) 93P12(M11) 07/l4/19931430 09/30/199321 :00 

23T lOm SSM257 93P15 (M12) 94P02(M13) 12/10/199317 :00 02/10/1994 09 :00 D,E 

24B 25m DMT145 93P04 (1008) 93P07 (M09) 03/22/1993 19 :30 05/19/1993 19 :55 

24B 22m LSU060 93P10 (M10) 93P12 (MI 1) 07/14/1993 16 :00 09/30/1993 13 :00 D,E,K 

24B 27m LSU060 931`12 (M1 1) 93P15 (M 12) 10/01/1993 0030 12/10/1993 13 :55 D,E,K 

24B 27m LSUOlO 93P 15 (M12) 94P02 (M13) 12/10/1993 17 :30 02111/1994 13 :30 

24B 23m DMT215 94P02 (M 13) 94S14 (M14) 02/11/1994 14:00 03/30/1994 1230 

24T lOm SSM246 93P04 (M08) 93P07 (M09) 03122/1993 20:30 05/19/1993 19 :30 

24T I lm SSM279 93P07 (M09) 93P10 (MIO) 05/19/1993 20:30 07/(4/1993 15 :00 

24T I lm SSM232 93P10 (M10) 93P12 (Ml 1) 07/14/1993 16 :30 09/30/1993 19:00 

24T lOm SSM232 93P12 (M11) 93P15 (M12) 10/01/1993 01:00 12110J1993 16:30 

24T lOm SSM285 931`15 (M12) 94P02 (M13) 12/10/1993 18 :00 02/1 1/1994 1330 

24T 8m SSM255 94P02 (M 13) 94514 (M14) 02/11/1994 14 :00 03/30/1994 12:30 

25B 30m LSU010 93P07 (M09) 93P10 (M10) 05/19/1993 22:30 07/14/1993 1930 

25B 30m I.SU070 93P10 (M10) 931`12 (Ml 1) 07/14/1993 20:00 07/30/1993 1920 F,K 

25B 30m DMT145 931`12 (M11) 931`15 (M12) 09/30/1993 15 :00 12/10/1993 1920 1 

25M 20m DMT146 93P04 (M08) 93P07 (M09) 03/23/1993 00:00 05/19/1993 21 :45 G 

25M 20m LSU070 93P12 (Ml 1) 931`15 (M12) 09/30/1993 17 :30 12110/1993 19 :25 D,E 

25T I lm SSM240 93P04 (M08) 93Po7 (M09) 03/23/1993 00 :30 05/19/1993 22 :00 I,K 

25T I lm SSM242 93P07 (M09) 93P10 (M10) 05/19/1993 22:30 07/1M1993 19 :30 K,O,Q 

48B 190m AA9411 93P01 (M07) 93P07 (M09) 01/12/1993 07 :30 05/11/1993 23 :30 

48M 100m AA10687 93P01 (M07) 93P07 (M09) 01/12/1993 0730 05/25/1993 18 :00 

48M 100m AA10672 93PI5(M12) 94514(M14) 12/08/199305 :00 03/25/199414:00 

48T 14m SSM257 93Po1 (M07) 93P07 (M09) 01/12J1993 07:30 05/25/1993 18 :30 S 

48T 14m SSM253 931`15 (M12) 94514 (M14) 12/08/1993 05:00 03/25/1994 13 :00 

49B 490m AA9410 93P0! (M07) 93P07 (M09) 01/19/1993 09 :30 05/20/1993 17 :00 I's 

49M 100m AA10688 93P07 (M09) 931`15 (M12) 05/20/1993 21 :30 12/1711993 05 :00 

49M 100m AA10682 93P15 (M12) 94514 (M14) 12/12/1993 10 :00 03/29/1994 23 :30 

49T 14m SSM246 93P07 (M09) 931`15 (M12) 05!20/1993 21 :30 1211211993 06:00 A,B,K 

49T 14m SSM239 93P15 (M12) 94S14(M14) 12/(2/199310 :00 03/30/199400:00 D,E 

Exception Descriptions 

A - No Speed Data. K - Partial data. 

B - No Direction data . L - Temp and Cond scrambled; No data . 

C - No Temperature data . M - Temperature data suspect. 

D - No Conductivity data. N - Conductivity goes bad during deployment . 

E - No Salinity Data. O - Meter tangled in line/wire. 

F - Dropped Samples. P - Sample interval 5 minute (should be 30). 

G - Bad self checks. Q - Speed goes bad during deployment . 

H - Possible 180 Abiguity in Direction. R - Failed during deployment . 

I - Conductivity and salinity suspect. S - Speed Suspect. 

J - Direction suspect. T - Pressure data suspect. 
26 

calibration, which includes temperature effects, could be used to convert the data into 

engineering units. A current sensor calibration was attempted at a tow-tank facility at 

Bay St. Louis, MS, just prior to redeployment but the results of this calibration were 

suspect. Table 3.2 .5 shows the data start stop dates and in/out water dates of the five 

MiniSpec directional wave gauges . Figure 3 .2 .3 shows a timeline displaying the 

MiniSpec data return . 

Two of the MiniSpecs, S/N's 10092 and 10096, developed chronic problems that recurred 

during each deployment for the rest of the second field year. The electromagnetic current 

sensor in S/N 10092 failed in mid-deployment three times in three deployments. The 

failure occurred in the U-velocity channel and resulted in a highly noisy wave spectrum 

from this channel; the V-velocity channel did not have this problem. The problem was 

discovered while analyzing the significant wave heights as measured by the pressure 

sensor and the velocity sensor . The current velocity field was zeroed out in the processed 

data set at the time at which the significant wave heights measured by the two sensors 

diverged. 

The pressure sensor of S/N 10096 also failed inmid-deployment during each deployment 

or the second field year. Like the current sensor failure, the problem was discovered 

when analyzing and comparing the burst spectra and significant wave height. The 

pressure field was zeroed at the time at which the pressure-measured wave statistics 

diverge from the velocity statistics . Both the pressure problem or S/N 10096 and the 

current velocity sensor problem of S/N 10092 were brought to the attention of the 

manufacturer (Coastal Leasing, Inc.) and both instruments were removed from the field 

for servicing during the third field year. The onset of the pressure sensor failure was 

accompanied by a drop in battery voltage, which was investigated as the cause of this 

problem . The pressure sensor in S/N 10093 also failed at the end of March 1994, four 

days prior to recovery. This failure seemed to be isolated and did not recur. 

Several of unique situations occurred during the second field year which led to MiniSpec 

data loss . One MiniSpec (S/N 10095) was lost some time in February or March 1994, 

possibly due to a jack-up rig at Mooring 23 ; it was never recovered. LATEX divers 

reported large circular holes in the ocean floor in the vicinity of this mooring . Also, 

during the September - December 1993 deployment, the instrument setup parameters for 

S/N 10095 were mistakenly left the same as those used during the Bay St. Louis current 

sensor calibration . The instrument, therefore, recorded every two minutes in burst mode 

only ; 110 samples were taken at 0.5 second intervals. The instrument continued to record 

until the internal hard drive was filled to capacity-about 7 days total. These data are 

unsuitable for wave and current analysis are considered lost . 

In February 1994, the LATEX Data Office scheduled a comparison study at mooring 16 

between a MiniSpec (S/N 10094) and a Woods Hole Instrument Systems 

(WHISL)SeaPac 2100 directional wave gauge to judge the performance and accuracy of 

the LATEX pressure sensor calibration; the results of this study were presented in 

DiMarco et al . (1994) . The comparison provided 38 days of directional wave data from 

the two instruments, which were positioned one meter above the bottom and three meters 

apart. The SeaPac wave gauge was equipped with a Paroscientitic quartz pressure sensor, 

which has an order of magnitude better resolution than the MiniSpec and provided an 

excellent standard by which to compare the MiniSpec's performance and check its 

calibration. The comparison showed that the MiniSpec's ICS pressure sensor, properly 

calibrated, agreed closely to Paroscientific quartz sensor up to a cutoff frequency of 0.22 

Hz. The rms difference of the significant wave height measured by the two sensors was 
27 

Table 3 .2 .5 . MiniSpec directional wave gauge deployment data. 

MiniSpec - Data Ranges - Second Field Year 

Deploy.-Recov. Cruise Pressure Current Temperature 

Mooring SM In Water Start Data Start Data Start Data Exceptions 

Out Water Stop Data Stop Data Stop Data 

Mll - M12 

1 10093 09/29/9313 :26 09/29/9313 :30 09/29/9313 :30 09/29/9313 :30 

1?111/93 13 :25 12J11/93 13 :00 12111/93 13 :00 12111/93 13:00 

16 10095 09/26/9313 :48 09/26/9313 :48 09/26/9313 :48 09/26/9313 :48 A 

12106/93 13 :20 10/03/93 21 :52 10/03/93 21 :52 10/03/93 21 :52 

17 10096 09/27/9312 :09 09/27/9312 :30 09/27/9312 :30 09/27/9312 :30 B 

12/05/93 13 :24 10/16/93 03:00 12J05/93 13 :00 12J05/93 13 :00 

20 10094 09/22/93 17 :54 09/22/93 18 :00 09/22/93 18 :00 09/22/93 18 :00 

12104/93 14 :11 12104/93 13 :30 1?J04/93 13 :30 12J04/93 13 :30 

23 10092 09/30/93 20:56 10/01/93 10 :30 10/01/93 1030 10/01/93 10 :30 C 

12110/93 15 :29 12110/93 15 :00 10/27/93 00:00 1?J10/93 15 :00 

M12 - M13 

1 10092 12/11/93 13 :27 

recovered CM 14 

16 10096 12106/9313 :23 12106/9313 :30 12106/931330 12106/9313 :30 B 

02/14/9413 :50 12/25/93 13 :30 02/14/94 13 :30 02114/9413 :30 

17 10094 12/05/93 14:03 12!05/93 14 :30 17105/93 14 :30 12!05/93 14 :30 

02/13/9413 :38 02113/941330 02113/9413 :30 02/13/9413 :30 

20 10093 12/13/93 14:53 12/13/93 15 :00 1?J13/93 15 :00 12113/93 15 :00 

02/12/94 13 :35 02/12/94 13 :00 02/12/94 13 :00 02/12/94 13 :00 

23 10095 12/10/93 15 :30 12/10/93 16:00 12/10/93 16:00 12110/93 16:00 

02/10/94 14:20 02/10/94 14 :00 02/10/94 14:00 02110/94 14:00 

M13 - M14 

1 10092 12/11/9313 :27 12111/9313:30 12111/9313 :30 12111/9313:30 C 

03/29/94 13 :40 03/28/94 13 :30 12/24/93 00:00 03/28/94 13 :30 

16 10094 02/14/94 13 :52 02114/94 18 :00 02/14/94 18 :00 02/14/94 18 :00 

03/24/9412:58 03/24/9412 :30 03/24/9412 :30 03/24/9412 :30 

17 10093 02/13/94 13 :42 02113/94 14 :00 02!13/94 14:00 02113/94 14:00 B 

03/23/94 15 :48 03/19/94 22:00 03/23/94 13 :00 03/23/94 13:00 

20 10096 02/16/94 17:45 02116/94 18 :00 02!16/93 18 :00 02/16/93 18:00 B 

03/31/9413 :24 03/13/9410 :00 03/31/9412 :30 03/31/9412 :30 

23 10095 02/10/93 15 :30 no data no data no data D 

lost no data no data no data 

Exception Descriptions 

A - Burst data every 2 minutes (110 samples) 

B - Pressure sensor failure 

C - Current sensor failure 

D - instrument lost 
28 

. . nnoonng 1 ~ 

. . . . . . . . . . . . . P 

V 

U t 

U 

.- .- . . .- . .

Z~ MPoring 16 

c V - 

cg 

L 

Mooring 17 

P 

U 

V 

O 

T 

C 

N 

Mooring 20 

V 

T 

Mooring 23 

P 

V 

T 

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar 

1993 1994 

Figure 3.2 .3 . Timelines of data returns for five MiniSpecs at LATEX Moorings 1, 16, 

17, 20, 23 during the second field year. P = pressure, V = current velocity, 

T = Temperature. The dotted line represents SeaData 635-8 pressure data 

return . 

4.0 cm during the deployment period . Wave heights calculated from the SeaPac's 

velocity data agreed closely with the wave heights calculated from both pressure sensors, 

but wave heights calculated from the MiniSpec's velocity were generally lower. The 

principal differences between the instruments were the sensitivities of their pressure 

sensors, the method of determining their orientations, and the date and the amount of use 

since calibration. 

A SeaData 635-8 Wave Gauge was deployed to replace a MiniSpec pulled from the field 

for service or maintenance. There were three Sea Data wave gauge deployments during 

the second field year. Table 3.2 .6 lists the deployment and data recovery dates and 

provides minor corrections to times and dates for the three deployments reported in 
29 

Jochens and Nowlin (1994b). The SeaData instrument recorded only hydrostatic pressure 

in burst mode. A burst consisted of 1024 samples taken at 1 .0-second intervals. The 

processing of the SeaData data was similar to the processing of the MiniSpec wave data. 

Computer programs were written in both FORTRAN and the PV-Wave programming 

language. The FORTRAN program read in blocks of raw data in units of PSIA and 

corrected for missing or invalid data points . Next, the PV-Wave routines converted the 

pressure data from PSIA to hPa, added appropriate time stamps, performed wave 

statistics, and provided data output . 

Table 3 .2 .6 . SeaData 635-8 wave gauge deployment data. 

Mooring Deployment Cruise Recovery Cruise Start Data End Data 

01 

01 

nl 

16 

17 

17 

M03 

07/26/92 22:30 

M04 

09/0/92 15:25 

M08 

03/23/93 13 :02 

M09 

05/27/93 00 :11 

M06 

12/12/92 21 :15 

M07 

01/14/92 17 :18 

M04 

09/04/92 12 :53 

MOS 

10/15/92 12:53 

M(9 

05/21/93 12:24 

M10 

07/17/93 13:24 

M07 

01/14/93 14:00 

M08 

03/18/93 16:30 

07/27/92 00:15 

09/04/92 17:30 

03/24/93 00 :20 

05/27/93 03 :00 

12/12/92 21 :50 

01/14/93 19 :32 

09/04/92 12 :16 

10/15/92 08 :30 

05/21/93 09 :20 

07/17/93 12 :00 

01/14/93 12 :50 

03/16/93 01 :24 

3.2 .3 .3 Meteorological Data 

Internally-recorded, meteorological data collected during the second year of deployment 

were recovered during mooring maintenance cruises M09 through M14. Table 3.2 .7 

summarizes the recovery results for the second field year. Calibrations and processing of 

the data from the meterological buoys were completed as described in section 2.2 .3 .3 of 

Jochens and Nowlin (1994b). 

During the second year, the plan called for the recovery or 36 data sets . Twenty-eight 

sets of varying quality were recovered. Of the eight not collected, two were due to a 

shortage of parts required for on-site repair . The remaining six were not collected 

because of dead batteries (two), a blown fuse (one), flooding in the battery compartment 

(one), electronics failure (one), and collision (one) . Figure 3 .2 .4 shows data recovery 

timelines. 
30 

Table 3.2.7 . Meteorological data recovered April 1993 - March 1994. 

Mooring Deploy Cruise Recover Cruise Start Data End Data Exceptions 

17 93P04 (MO8) 93P07 (M09) 03/18/1993 19 :00 05/27/1993 11 :00 

17 93P07 (M09) 93PI0 (M10) 05/27/1993 (3 :00 07/(6/1993 21 :00 a 

17 93P10 (M10) 93PI2(M11) 07/16/199322 :45 09/27/199311 :45 a,b,d 

17 93P12 (M11) 93P15 (M12) 09/28/1993 15 :00 12/06/1993 12 :00 f 

17 94P02 (M13) 94514 (M14) 02/13/1994 15 :45 03!23/1994 15 :45 a,b 

19 93P04 (MO8) 93P07 (M09) 03/19/1993 05:00 05/24/1993 13 :00 k 

19 93P12 (M11) 93P15 (M12) 09127/1993 20:05 12!05/1993 21 :05 

19 93P15 (M12) 94P02 (M13) 12/06/1993 01 :40 02115/1994 14 :40 b,d 

19 94P02 (M13) 94514 (M14) 01J15/1994 19 :30 03123/199422 :30 

20 93P04 (M08) 93P07 (M09) 03/17/1993 21 :00 05/28/1993 00:00 

20 93P07 (M09) 93P10 (M10) 05/28/1993 02:00 07/15/1993 12 :00 bj 

20 93P10 (MIO) 93P12 (M11) 07/15/1993 11 :20 09/22/1993 10 :20 b 

20 93P12 (MI 1) 93P15 (M12) 09l22J1993 18 :00 12!04/1993 13 :00 

20 93P15 (M12) 94P02 (M13) 12/13/1993 17 :46 02/1211994 13 :46 e 

20 94P02(M13) 94514(M14) 02/16/19942130 03/31/199416 :30 gj 

22 93P04 (M08) 93P07 (M09) 03/22!1993 00 :00 05!23/1993 11 :00 1 

22 93P10 (M10) 93PI2 (M11) 07/16/1993 01 :45 0923/1993 12 :45 k 

22 93P12 (Mil) 93P15 (M12) 09(13/1993 16 :30 12/09/1993 23:30 

22 93P1S (M12) 94P02 (M13) 12110/1993 0320 02111/1994 2220 i 

22 94P02 (M 13) 94S14 (M14) 02!12/1994 05 :00 03/31/1994 23:00 

50 93P04 (MO8) 931`07 (M09) 03r24/1993 14 :00 05/19/1993 12 :00 

50 93P15 (M12) 94P02 (M13) 12/04/1993 08 :30 02/11/1994 15 :30 a,d,f 

50 94P02(M13) 94S14(M14) 02/11/199416 :30 03/30/199421 :30 

51 93P04 (M08) 93P07 (M09) 03/24/1993 21 :00 05!23/1993 17 :00 

51 93P15 (M12) 94P02 (M 13) 12/04/1993 02 :04 02111/1994 18 :04 

52 93P15 (M12) 94P02 (M13) 12/05/1993 06 :30 02/13/1994 0130 a,b,d 

53 93P15 (M12) 94P02 (M13) 12/06/1993 08 :45 02/15/1994 03 :45 

53 94P02 (M13) 94S14 (M14) 02/15/1994 05 :00 03(24/1994 07 :00 

Exceptions 

a. Significant part of the wind direction record flagged as bad. 

b. Significant part of the wind speed record flagged as bad. 

c. Significant part of the pressure record fl agge d as bad . 

d. Significant part of the air temperature record flagged as bad. 

e. Entire wind direction record flagged as bad. 

f. Entire wind speed record flagged as bad. 

g. Entire pressure record flagged as bad. 

h. Entire air temp erature record flagged as bad. 

i . Entire sea temp erature reco rd flagged as bad. 

j. Suspect wind direction. 

k. Suspect air temperature. 
31 

LATEX-A Meteorological Buoy Data April 1993 - March 1994 

17 

19 

20 

22 

50 

51 

52 

53 

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr 

1993 1994 

Figure 3 .2 .4 . Meteorological buoy data recovered during the second year. 
32 

3 .2 .3 .4 IES Data 

One upward-looking inverted echo sounder (Sea Data Model 1665) was placed with an 

acoustic release within one meter of the sea bed in 3130 m of water depth at mooring 42 

on 23 July 1992 and in 1540 m of water depth at mooring 43 on 23 July 1992. The 

maintenance cycle for these instruments was one year. The acoustic releases were set to 

release automatically 366 days after deployment. The maintenance cruise for the IES 

units was planned to place the vessel on-site before, during, and after the automatic 

trigger was to release. 

The IES at mooring 43 was never recovered. During the recovery attempt there were 

weak acoustic communications between the deck unit and the acoustic release, but the 

instrument failed to surface and was declared lost . The IES at mooring 42 was recovered 

on 25 July 1993; however, the acoustic travel-time data, except for about six days at the 

beginning of the record, were unusable. Temperature and pressure data for the year-long 

deployment were good. After data downloading, the IES was redeployed at mooring 42 

3 .3 Drifting Buoy Measurements 

3 .3 .1 Deployment Times and Locations 

Four satellite-tracked drifting buoys were deployed on 2 May 1993 during hydrographic 

survey HOS. Table 3.3 .1 lists the drifting buoys by their Platform Transmitter Terminal 

(PTT) identification numbers along with their deployment dates and locations and 

associated event records. 

The plan called for LATEX A drifters to be released at four locations: inshore and 

offshore of the coastal boundary frontal zone, mid-shelf, and over the outer shelf near the 

continental shelf break. Because another MMS-sponsored program, the Surface Current 

Lagrangian Program (SCULP), was deploying large numbers of drifting buoys over the 

inner and mid-shelf regions at the same time, LATEX A placed all four drifters over the 

region of the outer shelf. The mean lifetime of the four drifters was 168 days with a 

range of 71 to 251 days. 

Table 3 .3 .1 . LATEX A drifter deployment dates and disposition. 

ARGOS Date and Time Deployment 

ID yymmddhhmm Locations Event 

06938 9305020604 94°10.5'W 27°51 .0'N Deployed (active 168 days) 

9310172313 86°54.3'W 28°20.5'N Last message (lost) 

06935 9305020744 94°08.3'W 27°57 .1'N Deployed (active 184 days) 

9311021018 80°02.3'W 26°09.4'N Last message (lost) 

06937 9305021013 94°037W 28°09.0'N Deployed (active 251 days) 

9401081441 83°56.9'W 26°45 .6'N Last message (lost) 

06939 9305021310 93°59.7'W 28°22.0'N Deployed (active 71 days) 

9307121412 94°06 .4W 29°19.4'N Last message (lost) 
33 

3 .3 .2 Instrumentation and Samnline Procedur 

A physical description of the drifting buoys, their internal instrumentation, data recovery 

methods, pre-deployment tasks, and bench testing were described in section 9 .5 of 

Nowlin et al . (1991) and section 2.3 .2 of Jochens and Nowlin (1994b) . Beginning with 

the May 1993 deployment, a hand-held transmitter test unit was used immediately prior 

to the release of the buoys to verify that the internal transmitters were active . The release 

method adopted during this deployment was for two crew members to heave the unboxed drifting buoy over the side of the vessel while underway at 1-2 knots . This 

ensured that the drogue uncoiled well behind the vessel . 

3 .3 .3 Summary of Data Collection 

Details of the data processing steps used to process the drifting buoy data can be found in 

section 2 .3 .3 of Jochens and Nowlin (1994b). The performance and longevity of the four 

drifters released in May was superior to that or the previous deployments . The drifters 

transmitted for 71, 168, 184, and 251 days. One or the drifting buoys (06935) was 

captured briefly but released without communication with the LATEX Data Office . 

None of the drifters were returned and all are considered lost . 

3 .4 Hvdroi!ranhic Measurements 

3 .4 .1 Svnonsis of Hvdroeranhic Surveys 

During the second field year, three hydrographic cruises were conducted over the full 

shelf of Texas-Louisiana west of 90.5°W. Table 2.2 .1 gives the cruise dates. All cruises 

were aboard the R/V J. W. Powell. Over 200 CTD-Rosette stations were occupied on each 

cruise ; station positions were nearly identical each time, with nine lines of stations 

perpendicular to the isobaths and two lines parallel to the coast along the 50-m and 200-m 

isobaths . No major problems were encountered during these cruises. The following is a 

summary of major events for each or the three cruises. 

3.4 .1 .1 Cruise HOSCPW9306 

The fifth LATEX A hydrography cruise (HOS) was conducted from the RN J. W. Powell 

25 April - 11 May 1993. Dr. Denis A. Wiesenburg was Chief Scientist. The cruise was 

divided into two legs . Figure 3.4 .1 shows the station locations and the cruise track; Table 

3.4.1 gives station number, date, time, location, water depth, and number of bottles 

tripped at each station. Two hundred fifteen stations were completed, three more than 

planned, including three located in about 1000-m water depth in the western half of the 

survey area within the anticyclonic Loop Current Eddy V. A representative of the 

National Weather Service participated on each leg to conduct LATEX weather 

operations . Four ARGOS-tracked drifters were deployed for Task A-2 (Table 3 .4 .2) . 

This cruise also accommodated four complementary research efforts. Three MetOcean 

ARGOS-tracked drifters were launched in Eddy V in cooperation with Dr. David Sheres 

of USM and Dr. Harry Selsor of the Naval Research Laboratory. Primary productivity 

measurements were made at 12 stations by Khaled Al-Abdulkader and Gaston Gonzales 

(students of Dr. Sayed El-Sayed, TAMU Dept. or Oceanography). Phytoplankton net 

hauls were taken at 11 stations and two horizontal net tows were conducted for Dr. Greta 

Fryxell (TAMU Dept. of Oceanography). Coccolithophorid data were collected at 15 

stations for Vita Pariente (student of Dr. Stefan Gartner, TAMU Dept. or Oceanography). 
W 

30 

"151 ! 1000 L .. 

Y15: " Z1/ " " ,~ " 41J 

I I I 

ISIANA 

.. .. ..~ .. ... .. ... ... .... ... ... ... ... ... ..r.. ; ... . ... .... . .. .

.V. ... .. 

New Orleans_ 

29 

28 

2/ 

26 

.as 

iooo 

LATEX Cruise Track 

H05CPW9306 

26 April - 10 May, 1993 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

Figure 3 .4 .1 . CTD stations and cruise track, LATEX HOS. 
35 

Table 3 .4 .1 . Station times and positions for LATEX A cruise HOS. 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

1 26APR93 138 28°25 .30' 93°51 .04' 48 7 

2 26APR93 2145 28°25 .07' 93°37.27' 48 7 

3 27APR93 0005 28°25 .98' 93°24.01' 47 7 

4 27APR93 0150 28°25 .33' 93°10.18' 47 8 

5 27APR93 0446 28°26.48' 92°45.66' S0 8 

6 27APR93 0632 28°27 .61' 92°31 .80' S0 8 

7 27APR93 0807 28°29 .40' 92°17.36' S0 7 

8 27APR93 0920 28°29 .39' 92°06.59' 49 7 

9 27APR93 1129 28°28 .79' 91°51 .60' S0 7 

10 27APR93 1310 28°28 .76' 91°37.23' S1 7 

11 27APR93 1501 28°26.42' 91°24.03' 49 7 

12 27APR93 1709 28°23 .70' 91°08.90' 48 7 

13 27APR93 1923 28°20.47' 90°54.15' 49 7 

14 27APR93 2056 28°20.42' 90°42.59' 47 8 

15 28APR93 0127 28°58.09' 90°30.59' 10 4 

16 28APR93 0156 28°55 .72' 90°30.86' 12 5 

17 28APR93 0234 28°52.69' 90°30.61' 16 5 

18 28APR93 0304 28°49.97' 90°30.58' 16 5 

19 28APR93 0336 28°46.72' 90°30.63' 16 5 

20 28APR93 0405 28°43 .3' 90°30.36' 16 6 

21 28APR93 0455 28°37.93' 90°30.29' 19 6 

22 28APR93 0552 28°31 .63' 90°30.16' 36 7 

23 28APR93 0653 28°25.43' 90°29 .6' 44 7 

24 28APR93 0734 28°21 .61' 90°29.97' 48 8 

25 28APR93 0825 28'16.82' 90°2999' 60 8 

26 28APR93 003 28°13.54' 90°30.02' 75 12 

27 28APR93 1000 28`10.47' 90°30.15' 92 12 

28 28APR93 1049 28°07.68' 90°30.16' 115 12 

29 28APR93 1153 28°04.65' 90°30.20' 147 12 

30 28APR93 1302 28°01 .27' 90°30.07' 251 12 

31 28APR93 1411 27°5798' 90°30.18' 435 12 

32 28APR93 1510 27°55.45' 90°30.47' 496 12 

33 28APR93 1655 28°02.72' 90°38 .59' 162 12 

34 28APR93 1845 28°0138' 90°52.40' 187 12 

35 28APR93 2037 28°00.39' 91°05 .84' 134 12 

36 28APR93 2236 27°58.15' 91°19.49' 264 12 

37 29APR93 0022 27°56.61' 91°32.70' 223 12 

38 29APR93 0202 27°54.77' 91°45 .89' 167 12 

39 29APR93 0410 27°44.93' 91°59.89' 491 12 

40 29APR93 0538 27°47.52' 92°00.02' 389 12 

41 29APR93 0656 27°50.67' 91°59.98' 196 12 

42 29APR93 0821 27°53.57' 92°00.07' 166 12 

43 29APR93 0934 27°56.80' 92°00.05' 98 10 

44 29APR93 1058 27°59.97' 92°00.04' 118 12 

45 29APR93 1156 28°02.69' 91°59.96' 103 11 

46 29APR93 1348 28°08.3' 91°59.92' 81 10 

47 29APR93 1524 28°14.71' 91°59.89' 67 7 

48 29APR93 1727 28°21 .13' 91°59.82' S9 7 

49 29APR93 1812 28°26 .78' 91°59.85' S7 8 

50 29APR93 1921 28°33 .01' 91°59.84' 43 6 

51 29APR93 2006 28`37 .74' 91°59.88' 38 6 

52 29APR93 2109 28`44 .70' 92°00.09' 32 7 
36 

Table 3.4 .1 . Station times and positions for LATEX A cruise HOS (continued). 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

53 29APR93 2205 28°50.26' 92°00.00' 27 6 

54 29APR93 2240 28°52.96' 91°59.99' 25 5 

55 29APR93 2319 28°56.22' 91°59.98' 22 6 

56 29APR93 2358 28°5933' 92°00.08' 20 6 

57 30APR93 0033 29°02.28' 92°00.11' 17 5 

58 30APR93 0105 29°04.86' 92°00.16' 14 5 

59 30APR93 0136 29°07.98' 92°00.06' 11 4 

60 30APR93 0206 29°10.87' 91°59.99' 7 4 

61 30APR93 0844 29°34.02' 93°00.04' 10 4 

62 30APR93 042 29°27 .93' 92°59.96' 12 4 

63 30APR93 1033 29°22.00' 92°59.96' 13 4 

64 30APR93 1126 29°15 .90' 93°00.01' 16 5 

65 30APR93 1222 29°10.04' 93°00.04' 18 5 

66 30APR93 1355 29°0399' 92°59.95' 22 5 

67 30APR93 1454 28°57 .80' 92°59»' 21 6 

68 30APR93 1549 28°51 .42' 92°59.99' 24 6 

69 30APR93 1643 28°44.93' 92°59.94' 28 6 

70 30APR93 1737 28°38 .41' 92°59.93' 31 7 

71 30APR93 1843 28°31 .87' 92°59.99' 42 7 

72 30APR93 1942 28°25 .39' 92°59.97' 47 8 

73 30APR93 2044 28'18 .48' 92°59.90' 52 8 

74 30APR93 2151 28°10.85' 92°5994' 70 9 

75 30APR93 2307 28°01 .82' 92°59.86' 100 9 

76 O1MAY93 0032 27°52.85' 93°00.12' 188 12 

77 O1MAY93 0147 27`45 .28' 93°00.16' 203 12 

78 O1MAY93 0252 27°39.40' 92°59.91' 316 12 

79 O1MAY93 0836 27°55 .13' 92°0996' 143 12 

80 O1MAY93 1840 27°55 .13' 92°23.41' 82 9 

81 O1MAY93 1238 27°55 .13' 92°37.47' 191 12 

82 O1MAY93 1455 27°52.49' 92°51 .37' 216 12 

83 O1MAY93 1648 27°50.07' 93°05.28' 173 12 

84 O1MAY93 1837 27°49.86' 93°19 .15' 148 12 

85 O1MAY93 2030 27°49.00' 93°32 .57' 198 12 

86 O1MAY93 2227 27°4829' 93°46.27' 187 12 

87 02MAY93 0024 27°49.24' 94°00.01' 197 12 

88 02MAY93 0230 27°39.63' 94°13 .47' 442 12 

89 02MAY93 0352 27°44.25' 94'12.21' 450 12 

90 02MAY93 0450 27°4799' 94°11.41' 266 12 

91 02MAY93 0543 27°5098' 94°10.26' 116 10 

92 02MAY93 0641 27°54.14' 94°0930' 94 10 

93 02MAY93 0729 27°57.05' 94°0832' 82 8 

94 02MAY93 0809 27°59.54' 94°07.50' 79 8 

95 02MAY93 008 28°04.65' 94°05.52' 67 8 

96 02MAY93 1002 28°08.96' 94°03.76' 63 8 

97 02MAY93 1113 28°16.01' 94°01 .30' 56 7 

98 02MAY93 1257 28°21 .93' 93°59 .64' 50 7 

99 02MAY93 1433 28°27.92' 93°59 .99' 41 6 

100 02MAY93 1548 28°33.80' 93`59 .94' 34 6 

101 02MAY93 1657 28°31.65' 93°59 .93' 28 6 

102 02MAY93 1806 28°46.02' 94°00.08' 23 6 

103 02MAY93 1902 28°51 .91' 93°59 .97' 23 6 

104 02MAY93 1959 28°57.93' 94°00.13' 16 5 
37 

Table 3 .4 .1 . Station times and positions for LATEX A cruise HOS (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

105 02MAY93 2040 29°0130' 94°00.05' 18 4 

106 02MAY93 2116 29°03 .79' 94°00.12' 17 5 

107 02MAY93 2158 29°07 .34' 94°00.06' 16 5 

108 02MAY93 2235 29°09 .97' 94°00.07' 15 5 

109 02MAY93 2313 29'13 .02' 94°00.15' 13 4 

110 02MAY93 2344 29'16.19' 94°00.10' 12 5 

111 03MAY93 0016 29°18 .97' 93°59.92' 11 5 

112 03MAY93 0046 29°21 .61' 94°00.12' 9 4 

113 03MAY93 0118 29°24.57' 94°00.02' 9 4 

114 03MAY93 0155 29°28.15' 94°00.12' 10 4 

115 03MAY93 0233 29°32.05' 94°00.16' 9 5 

116 03MAY93 0738 29'10. 19' 94°47.98' 13 4 

117 03MAY93 0827 29°04.50' 94°46.20' 16 5 

118 03MAY93 0915 28°58 .80' 94°44.40' 15 6 

119 03MAY93 1005 28°53 .40' 94°43.20' 18 5 

120 03MAY93 1051 28°48.00' 94°41 .41' 18 6 

121 03MAY93 1137 28`42.59' 94°39.0' 24 7 

122 03MAY93 1226 28°37.20' 94°38.40' 28 8 

123 03MAY93 1317 28°31 .80' 94°36.59' 33 8 

124 03MAY93 1406 28°26.40' 94°35.12' 38 8 

125 03MAY93 1455 28°21 .00' 94°33.60' 41 8 

126 03MAY93 1751 28°22.21' 94°05.41' 47 6 

127 03MAY93 1916 28°18.59' 94°18.02' S6 6 

128 03MAY93 2047 28'15 .60' 94°32.41' 46 6 

129 03MAY93 2219 28'14.41' 94°46.80' 46 6 

130 03MAY93 2354 28'13 .20' 9S°01 .20' 46 6 

131 04MAY93 0248 28°06.62' 95°2698' 46 6 

132 0SMAY93 0433 28°01 .81' 9S°40.79' 47 6 

133 0SMAY93 1400 27°43 .02' 95°00.67' 500 12 

134 0SMAY93 1654 27°45 .82' 95°01 .4' 370 12 

135 0SMAY93 1808 27°48.55' 95°03.57' 258 12 

136 0SMAY93 1915 27°51 .30' 95°04.92' 161 12 

137 0SMAY93 2005 27°54.08' 95°06.41' 106 10 

138 0SMAY93 2111 27°59.66' 95°09 .15' 76 10 

139 0SMAY93 2212 28°05.03' 95°12 .10' S3 8 

140 0SMAY93 2307 28°10.51' 95°15.01' 45 8 

141 06MAY93 0003 28°16.36' 95°17.84' 37 6 

142 06MAY93 0100 28°21 .65' 95°20.84' 31 6 

143 06MAY93 0211 28°27.00' 95°23 .46' 28 6 

144 06MAY93 0246 28°2 .68' 95°25 .05' 26 6 

145 06MAY93 0322 28°32.37' 95°26.34' 23 6 

146 06MAY93 0357 28°34.84' 95°28 .19' 20 4 

147 06MAY93 0430 28°37.44' 95°29 .31' 17 4 

148 06MAY93 0508 28°39.71' 95°30.82' 13 4 

149 06MAY93 0555 28°4230' 95°32.17' 13 4 

150 06MAY93 1136 27°58.20' 95°57 .60' 47 7 

151 06MAY93 1619 27°31 .50' 95°47 .10' 519 12 

152 06MAY93 1753 27°36.12' 95°52.68' 190 12 

153 06MAY93 1903 27`41 .10' 95°58.19' 100 8 

154 06MAY93 2001 27°4529' 96°03 .30' 77 8 

155 06MAY93 2110 27°48.60' 96°07.84' 64 6 

156 06MAY93 2216 27°53.98' 96°13 .50' 48 6 
38 

Table 3 .4 .1 . Station times and positions for LATEX A cruise HOS (continued). 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

157 06MAY93 2313 27°58 .20' 96°18.93' 35 5 

158 07MAY93 0015 28°0239' 96°24.06' 25 5 

159 07MAY93 0112 28°07 .81' 96°30.01' 18 4 

160 07MAY93 0207 28°12.60' 96°36.01' 8 4 

161 07MAY93 0530 27°51 .60' 96°19.20' S0 6 

162 07MAY93 0706 27°44.40' 96°30.00' 49 6 

163 07MAY93 0849 27°34.80' 96°39.61' S0 6 

164 07MAY93 1025 27°24.01' 96°47.39' S0 6 

165 07MAY93 1453 27°05 .99' 96°12.60' 446 12 

166 07MAY93 1554 27°06.88' 96°16.97' 317 12 

167 07MAY93 1654 27°07 .59' 96°20.21' 226 12 

168 07MAY93 1741 27°08 .10' 96°22.80' 185 12 

169 07MAY93 1843 27°08 .85' 96°26.72' 140 12 

170 07MAY93 1952 27°0( ) .10' 96°29.80' 114 10 

171 07MAY93 2033 27°09 .68' 96°33.14' 99 10 

172 07MAY93 2112 27°10.18' 96°3638' 90 10 

173 07MAY93 2207 27'11 .04' 96°42.93' 72 10 

174 07MAY93 2317 27'l 1 .92' 96°49.60' S7 8 

175 07MAY93 2358 27°12.59' 96°5339' 49 8 

176 08MAY>3 0035 27°12.69' 96°56.24' 43 8 

177 08MAY03 0139 27'13 .56' 97°03.15' 32 6 

178 08MAY93 0218 27'14.30' 97°06.27' 29 6 

179 08MAY93 0320 27'14.42' 97°09.58' 25 4 

180 08MAY93 0350 27'15 .38' 97'12.64' 22 4 

181 08MAY93 0421 27'15 .45' 97'16.05' 18 4 

182 08MAY93 073 27`01 .00' 96°55.80' 49 6 

183 08MAY93 0938 26°48 .00' 96°54.61' 49 6 

184 08MAY93 1136 26`36.59' 96°47.26' S0 6 

185 08MAY93 1343 26°24.60' 96°39.00' 47 6 

186 08MAY93 1602 26'13 .22' 96°37.07' S0 6 

187 08MAY93 2116 26°01 .29' 97°06.98' 15 4 

188 08MAY93 2149 26°01 .37' 97°04.55' 21 4 

189 08MAY93 2223 26°01 .20' 97°01 .36' 25 4 

190 08MAY93 2302 26°01 .50' 96°58.12' 30 4 

191 09MAY93 0004 26°00.99' 96°51 .44' 37 6 

192 09MAY93 0103 26°00.99' 96°44.98' 44 6 

193 09MAY93 0203 26°00.98' 96°38.64' 48 6 

194 09MAY93 0320 26°00.97' 96°31 .84' 61 6 

195 09MAY93 0435 26°00.71' 96°2526' 86 8 

196 09MAY93 0523 26°00.84' 96°2194' 121 10 

197 09MAY93 0625 26°00.81' 96°18.67' 210 12 

198 09MAY93 0733 26°00.60' 96'14.69' 504 12 

199 09MAY93 044 26`08 .61' 96'19.94' 230 12 

200 09MAY93 1133 26°19.81' 96°17.85' 245 12 

201 09MAY93 1339 26°31 .81' 96'19.94' 295 12 

202 09MAY93 1558 26°43 .78' 96°26.25' 201 12 

203 09MAY93 1745 26°55 .81' 96°26.25' 205 12 

204 09MAY93 1939 27°07 .S9' 96°20.21' 220 12 

205 09MAY93 2118 27'16.79' 96'15.21' 202 12 

206 09MAY93 2313 27°25 .79' 96°06.25' 200 12 

207 IOMAY93 0222 27°39.03' 95°42.68' 237 12 

208 IOMAY93 0412 27°42.49' 9S°30.12' 304 12 
Table 3.4.1 . Station times and positions for LATEX A cruise HOS (continued) . 

39 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

209 l OMAY93 0613 27°45.68' 95° 17 .21' 263 12 

210 lOMAY93 0937 27°50.15' 94°48.57' 234 12 

211 lOMAY93 1128 27°50.12' 94°35.31' 272 12 

212 lOMAY93 1334 27°50.05' 94°21 .67' 170 12 

213 IOMAY93 1813 27°24.95' 93°49.97' 854 0 

214 lOMAY93 2315 27°25.04' 94°30.03' 996 0 

215 11MAY93 0404 27°26.23' 95°10.44' 1056 0 

Table 3 .4 .2 . Launch locations of LATEX A drifting buoys on cruise HOS. 

Station No. Drifter No. Day/Time (UTC) Latitude (N) Longitude(W) 

091 6938 02 May 1993 0604 27° 51 .02' 94° 10.48' 

093 6935 02 May 1993 0744 27° 57 .08' 94° 08.31' 

096 6937 02 May 1993 1013 28° 09.02' 94° 03.74' 

098 6939 02 May 1993 13 10 28° 21 .94' 93° 59.67' 

3 .4 .1 .2 Cruise H06CPW9311 

The sixth LATEX A hydrography cruise (H06) was conducted aboard the R/V J. W. 

Powell 25 July - 7 August 1993 . Dr. Lauren E. Sahl of Maine Maritime Academy was 

Chief Scientist. Figure 3 .4 .2 shows the locations of the stations occupied and the cruise 

track. Table 3 .4 .3 gives the station number, date, time (UTC), location, water depth, and 

number of bottles tripped at each of the stations . The survey plan called for 211 CTD 

stations ; 215 were completed with the four extra stations located on a seaward extension 

of the transect offshore from Galveston. 

In addition to the LATEX program work, we accommodated four complementary 

research efforts . Primary productivity measurements were made at eight stations by 

Gaston Gonzales, a student of Dr. Sayed El-Sayed (TAMU Oceanography) . Plankton 

tows were made at 43 stations for Paula Bontempi, a graduate student of Dr. Denis 

Wiesenburg (Center for Marine Sciences, University of Southern Mississippi) . 

Coccolithophorid data were collected at 18 stations for Vita Pariente, a graduate student 

of Dr. Stefan Gartner (TAMU Oceanography). Measurements of photosynthesis versus 

irradiance were made at selected stations by Xiaogang Chen, a graduate student of Dr. 

Steven E. Lohrenz (Center for Marine Sciences, University of Southern Mississippi) . 
30 

29 

28 

27 

26 

TEXAS 

00 

UISIANA 0' -, 

... .. ..~... ... . .. . ` ... .... . .. .... .... ... ..r .. .... . ... .. . . ._ .

.V ... ._ . 

Nelnr O~leans_ 

.,n - - 

__ ._ ._. .. .. .. . . ... ... ... ., ...ZO~o. M. ... . .. . .. . ~ . . . .. . 

-129 :llo in .' 

.eo ?p 

.IN se iao 

~ " 137 i70! ;79 ibt .30-(~ 

.1]2 it07 .67 ''+~~'~~ryp,~ ~3 

" 11] -133 aloe 4 

-142 005 .81 ss " ais ia s um ia s~ .iw "zu 

"

-103 

.z,z 84 

162 -97 .96 : %1D 

LATEX Cruise Track 

HO6CPW9311 

26 July - 8 August, 1993 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

.A 0 

Figure 3 .4 .2 . CTD stations and cruise track, LATEX H06. 
41 

Table 3.4.3 . Station times and positions for LATEX A cruise H06. 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

1 26JLJL93 1344 27°58.20' 95°57.59' 47 7 

2 26JLJL93 1538 28°01 .80' 95°40.78' 49 6 

3 26JLJL93 1721 28°06.60' 95°26.96' S0 6 

4 26JLJL93 1957 28°13.20' 95°01.20' 49 6 

5 26JL1L93 2133 28°14.40' 94°46.80' 49 6 

6 26JLJL93 2315 28°15.59' 94°32 .40' 48 6 

7 27JUL93 0052 28° 18.60' 94° 18.01' 49 6 

8 27JUL93 0228 28°22.21' 94°05.41' 49 6 

9 27JLJL93 0406 28°2530' 93°51.02' S0 6 

10 27JIJL93 0536 28°25.06' 93°37.26' S1 6 

11 27JIIL93 0709 28°25.98' 93°23.98' S1 6 

12 27JUL93 0837 28°2532' 93°10.20' S1 7 

13 27JLIL93 1106 28°26.48' 92°45.68' S3 8 

14 27JLTL93 1237 28°27.62' 92°31 .79' S4 8 

15 27JiJL93 1413 28°29.40' 92°17 .36' S2 8 

16 27JiJL93 1524 28°29.39' 92°06.59' S2 7 

17 27JiJL93 1656 28°28.80' 91°51 .60' S2 8 

18 27JLTL93 1825 28°28.76' 91°37.22' S0 7 

19 27JLJI .93 1947 28°26.40' 91°24.02' S0 7 

20 27JUL93 2133 28°23.70' 91°08.91' S0 7 

21 27JtTL93 2312 28°20.45' 90°54 .14' S1 7 

22 28JUL93 0030 28°20.41' 90°42 .58' 48 7 

23 28JLJL93 0442 28°58.08' 90°30.60' 12 4 

24 28JLTL93 0525 28°55.74' 90°30.86' 14 4 

25 28JUL93 0622 28°52.70' 90°30.60' 18 5 

26 28JIJL93 0654 28°49.97' 90°30.5' 19 5 

27 28JUL93 0740 28°46.69' 90°30.62' 18 5 

28 28JLJL93 0815 28°43.93' 90°30.35' 18 5 

29 28JUL93 0908 28°3795' 90°30.27' 21 10 

30 28JLJL93 1024 28°31 .63' 90°30 .16' 37 7 

31 28JIJL93 1123 28°25.43' 90°29.96' 42 7 

32 28JLJL93 1221 28°21 .61' 90°29.97' 48 8 

33 28JLJL93 1310 28° 16.82' 90°29.98' 62 8 

34 28JUL93 1354 28°13 .54' 90°30.02' 76 12 

35 28JLJL93 1505 28°10.48' 90°30.13' 95 12 

36 28JLJL93 1546 28°07.67' 90°30.13' 118 12 

37 28JLJL93 1641 28°04.64' 90°30.20' 151 12 

38 28JLTI.93 1747 28°01 .28' 90°30.06' 254 12 

39 28JLJL93 1926 27°5798' 90°30.17' 438 12 

40 28JLJL93 2009 27°55.43' 90°30.46' 499 12 

41 28JL1L93 2228 28°02.72' 90°38.61' 165 12 

42 29JUL93 0001 28°0135' 90°52.40' 203 12 

43 29JUL93 0132 28`00.38' 91°05.83' 136 12 

44 29JLJL93 0302 27°58.15' 91°19.49' 266 12 

45 29JLJL93 0438 27°56.63' 91°32.72' 227 12 

46 29JLJL93 0618 27°54J8' 91°45.87' 168 12 

47 29JUL93 0814 27°4493' 91°5990' 498 12 

48 29JiJL93 0927 27°47.52' 92°00.01' 391 12 

49 29JLJL93 1014 27°50.66' 91°5998' 200 12 

50 29JLTL93 1053 27`53 .58' 92°00.04' 166 12 

51 29JLJL93 1203 27°56.81' 92°00.05' 100 10 

52 29JLTL93 1304 27°59.97' 92°00.03' 121 12 
42 

Table 3 .4 .3 . Station times and positions for LATEX A cruise H06 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

53 29JUL93 1351 28°02.69' 91°59.95' 106 11 

54 29JiJL93 1447 28°08 .92' 91°59.90' 80 10 

55 29JLTL93 1541 28°14.71' 91°59.89' 62 7 

56 29JiJL93 1653 28°21 .13' 91°59.82' 59 8 

57 29JLJL93 1744 28°26.78' 91°59.85' 55 8 

58 29JiJL93 1853 28°33 .01' 91°59.83' 44 7 

59 29JLTL93 1941 28°37 .73' 91°59.88' 40 6 

60 29JLJL93 2039 28°44.69' 92°00.08' 32 6 

61 29JLJL93 2144 28°50.26' 91°59.98' 27 6 

62 29JLJL93 2213 28°52.98' 92°00.01' 22 6 

63 29JUL93 2251 28°56.22' 91°59.98' 22 5 

64 29JLJL93 2334 28°59.34' 92°00.07' 19 5 

65 30JUL93 0004 29°02.29' 92°00.12' 17 5 

66 30JUL93 0032 29°04.85' 92°00.16' 14 4 

67 30JUL93 0110 29°07 .98' 92°00.14' 10 4 

68 30JUL93 0145 29'10.87' 92°00.00' 7 4 

69 30JUL93 0826 29°34.02' 93°00.01' 12 4 

70 30JUL93 0923 29°27 .93' 92°59.95' 14 4 

71 30JUL93 1023 29°22.00' 92°59.93' 16 4 

72 30JUL93 1128 29°16.00' 92°59.82' 17 5 

73 30JUL93 1312 29'10.04' 93°00.03' 17 5 

74 30JUL93 1415 29°04.01' 92°59.97' 21 5 

75 30JUL93 1510 28°57.80' 93°00.00' 21 5 

76 30JUL93 1604 28°51 .47' 92°59.93' 23 6 

77 30JUL93 1705 28°44.93' 92°59.95' 28 7 

78 30JUL93 1757 28°38.41' 92°59.93' 32 7 

79 30JUL93 1850 28°31 .88' 92°59.99' 41 7 

80 30JUL93 1942 28°25 .40' 92°59.97' 49 8 

81 30JUL93 2053 28°18.48' 92°59.89' 51 8 

82 30JUL93 2152 28'10.84' 92°59.98' 69 8 

83 30JUL93 2314 28°01 .80' 92°59.87' 105 9 

84 31JUL93 0021 27°52.83' 93°00.11' 194 12 

85 31JiTL93 0222 27°45 .28' 93°0017' 217 12 

86 31JiJL93 0320 27`39.41' 92°5993' 314 12 

87 31JiJL93 0858 27°55.15' 92°09.95' 145 12 

88 31JUL93 1037 27°55.13' 92°23 .40' 80 9 

89 31JIJL93 1212 27°55.13' 92°37 .45' 195 12 

90 31JIJL93 1408 27°52.48' 92°5137' 218 12 

91 31JIJL93 1551 27°50.07' 93°05 .29' 173 12 

92 31JLJL93 1730 27°49.86' 93°19.15' 147 12 

93 31JIJL93 1903 27°49.00' 93°32.57' 201 12 

94 31JIJL93 2144 27°48.29' 93°46.27' 187 12 

95 31JUL93 2317 27°49.26' 94°00.02' 201 12 

96 OlAUG93 0105 27°39.63' 94°13.47' 402 12 

97 OlAUG93 0227 27°44.25' 94`12.22' 450 12 

98 OlAUCY93 0321 27°47.99' 94°11.44' 265 12 

99 OlAUG93 0410 27`50.98' 94°10.26' 118 10 

100 OlAUU)3 0448 27°54.14' 94°0934' 96 10 

101 OlAUU)3 0529 27°57.06' 94°0833' 85 8 

102 OlAUC03 0556 27°59.54' 94°07.49' 80 8 

103 OlAUC793 0643 28°04.65' 94°05.45' 69 8 

104 OlAUG93 0721 28°08.95' 94°03.76' 63 8 
43 

Table 3.4.3 . Station rimes and positions for LATEX A cruise H06 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

105 OIAUG93 0828 28°16.01' 94°01.29' 58 7 

106 OIAUG93 0914 28°21 .92' 93°59.61' 52 7 

107 OIAUG93 1000 28°27.91' 93°59.98' 42 6 

108 OIAUG93 1047 28°33.80' 93°59.95' 36 5 

109 OlAUC~)3 1147 28°39.65' 93°59.93' 29 6 

110 OIAUG93 1242 28°46.03' 94°00.08' 25 6 

111 OIAUG93 1333 28°51 .92' 93°59.97' 25 6 

112 OlAUG93 1424 28°57.93' 94°00.13' 17 5 

113 OIAUG93 1459 29°01 .30' 94°00.05' 18 4 

114 OIAUG93 1528 29°03.78' 94°00.13' 18 5 

115 OIAUG93 1611 29°07.34' 94°00.05' 16 5 

116 OIAUG93 1643 29°09.97' 94°00.06' 16 5 

117 OlAUG93 1718 29°13.02' 94°00.15' 15 4 

118 OlAUG93 1750 29°16.17' 94°00.08' 13 5 

119 OIAUG93 1817 29°18.97' 93°59.91' 12 5 

120 OIAUG93 1849 29°21 .62' 94°00.14' 9 4 

121 OlAUCY93 118 29°24.60' 94°00.03' 9 4 

122 OIAUG93 1954 29°28.15' 94°00.11' 12 4 

123 OIAUG93 2036 29°32.03' 94°00.15' 10 4 

124 OlAUG)3 0137 29°10.21' 94°47.97' 13 4 

125 02AUC93 0232 29°04.50' 94°4618' 17 4 

126 02AUC,93 0317 28°58J8' 94°44.36' 17 4 

127 02AUG93 0401 28°53 .39' 94°43.22' 20 5 

128 02AUG93 0446 28°48.00' 94°41 .41' 20 5 

129 02AUG93 0541 28°42.59' 94°39.89' 26 6 

130 02AUG93 0633 28°37.20' 94°38.40' 30 6 

131 02AUCfl3 0720 28°31 .81' 94°36.58' 34 7 

132 02AU&)3 0805 28°26.40' 94°35.11' 39 7 

133 02AUC~J3 0909 28°21 .00' 94°33.59' 43 7 

134 02AUCY( )3 1451 27°43 .02' 95°00.66' 500 11 

135 02AUC,( )3 1610 27°45 .81' 95°01 .94' 374 12 

136 02AUC,~~3 1707 27°48 .55' 95°03.56' 266 12 

137 02AUC7( )3 1756 27°51 .29' 95°04.89' 163 10 

138 02AUG93 1846 27°54.08' 95°06.38' 108 10 

139 02AUC,~l3 1947 27°59.67' 95°0916' 78 10 

140 02AUG)3 2044 28°05 .04' 95°12.10' 55 7 

141 02AUG93 2151 28'10.51' 95° 15.02' 47 8 

142 02AUC,93 2246 28'16.36' 95'17.84' 38 8 

143 02AUC,93 2339 28°21 .65' 95°20.82' 33 7 

144 03AUC*93 0033 28°27 .01' 95°23.47' 31 6 

145 03AUG93 0114 28°29 .68' 95°25.04' 28 6 

146 03AUG93 0143 28°3238' 95°26.35' 25 9 

147 03AUG93 0213 28°34.83' 95°28.18' 22 5 

148 03AUC~93 0242 28°37 .42' 95°29.31' 18 4 

149 03AUCfl3 0310 28°39 .68' 95°30.79' 14 4 

150 03AUC793 0340 28°42.31' 95°32.18' 14 4 

151 03AUG93 1330 27°31 .50' 95°47.09' 520 12 

152 03AUC,93 1444 27°36.12' 95°52.69' 192 12 

153 03AUG93 1556 27°41 .10' 95°58.21' 105 9 

154 03AUG93 1653 27°45 .29' 96°03.29' 80 9 

155 03AUG93 1744 27°48 .60' 96°07.84' 68 7 

156 03AUG93 1906 27°53 .97' 96'13 .48' 50 6 
44 

Table 3.4.3 . Station times and positions for LATEX A cruise H06 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

157 03AUG93 2005 27°58.19' 96°18.92' 36 6 

158 03AUG93 2058 28°0238' 96°24.04' 27 5 

159 03AUG)3 2159 28°07.81' 96°30.02' 19 4 

160 03AUCfl3 2256 28°12.57' 96°35.98' 4 4 

161 04AUG93 0154 27°51.57' 96°19.20' 49 6 

162 04AUG93 0317 27°44.41' 96°29.99' 49 6 

163 04AUO)3 0448 27°34.79' 96°39.62' 49 6 

164 04AUG93 0614 27°24.01' 96°47.40' 49 6 

165 04AUG93 1015 27°05 .98' 96'12.58' 445 12 

166 04AUG93 1149 27°06.88' 96°16.96' 316 12 

167 04AUG93 1313 27°07 .59' 96°20.20' 226 12 

168 04AUG93 1401 27°08 .08' 96°22.77' 185 12 

169 04AUU)3 1450 27°08 .85' 96°26.73' 140 12 

170 04AUG93 1623 27°09 .09' 96°29.79' 115 11 

171 04AUG93 1704 27°09 .68' 96°33.12' 99 10 

172 04AUG93 1806 27°10.17' 96°36.35' 90 10 

173 04AUC93 1907 27'11 .04' 96°42.93' 72 10 

174 04AUC,( 2007 27'l 1 .92' 96°49.59' 57 8 

175 04AUG93 2046 27°12.58' 96°53.41' 49 8 

176 04AUCr~~3 2149 27°12.71' 96°56.23' 43 8 

177 04AUC,93 2253 27'13 .55' 97°03.17' 32 7 

178 04AUC93 2325 27'14.30' 97°06.25' 29 5 

179 04AUCj( )3 2357 27'14.39' 97°09.58' 25 5 

180 05AUC,03 0029 27` 15 .39' 97'12.64' 22 5 

181 OSAUC~~3 0106 27'15 .43' 97'16.05' 18 4 

182 05AUC793 0348 27°01 .01' 96°55.77' 49 6 

183 05AUG93 0530 26°47.98' 96°54.63' 49 6 

184 05AUG)3 0711 26°36.58' 96°47.26' 52 6 

185 05AUG93 08.55 26°24.60' 96°39.00' 48 6 

186 05AUG93 1137 26°13 .22' 96°37.06' 50 6 

187 05AUG93 1502 26°01 .30' 97°06.98' 15 4 

188 05AUG)3 1540 26°0138' 97°04.53' 21 4 

189 05AUCfl3 1612 26°01 .20' 97°01 .35' 25 5 

190 05AUG)3 1644 26°01 .53' 96°58.10' 30 6 

191 05AUU)3 1736 26°00.99' 96°51.44' 37 6 

192 05AUG93 1837 26`00.99' 96°4498' 44 6 

193 05AUG93 1924 26°0098' 96°38.62' 49 7 

194 OSAUC,~~3 2018 26°00.98' 96°31 .84' 61 7 

195 OSAUC,~)3 2123 26°00.71' 96°25.25' 86 9 

196 05AUG93 2156 26°00.83' 96°21 .94' 121 10 

197 05AUG93 2248 26°00.81' 96°18.67' 210 12 

198 05AUG93 2334 26°00.59' 96'14.68' 504 12 

199 06AUG93 0122 26°08.63' 96'19.91' 230 12 

200 06AUG93 0254 26'19.82' 96'17 .81' 237 12 

201 06AUG93 0430 26°31 .83' 96°19 .94' 272 12 

202 06At1C93 0616 26°43.80' 96°2621' 202 12 

203 06AUU>3 0747 26`55.83' 96°26.19' 206 12 

204 06AUC93 1010 27'16.78' 96'15 .20' 203 12 

205 06AUC93 1140 27°25.79' 96°06.21' 206 12 

206 06At1G)3 1426 27°39.03' 95`42 .68' 237 12 

207 06AUCT( )3 1619 27°42.50' 95°30.12' 301 12 

208 06AUCT03 1749 27°45.68' 95°17.19' 264 12 
Table 3.4 .3 . Station rimes and positions for LATEX A cruise H06 (continued) . 

45 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

209 06AUG93 2033 27°50.13' 94°48.59' 241 12 

210 06AUG93 2204 27°50.12' 94°35.30' 279 12 

211 06AUUI3 2346 27°50.05' 94°21.68' 170 12 

212 07AUG93 0056 27°56.01' 94°27.71' 106 12 

213 07AUG93 0140 28°00.94' 94°29.03' 68 7 

214 07AUG93 0225 28°05.46' 94°29.99' 56 6 

215 07AUG93 0303 28°10.20' 94°31.51' 56 6 

3.4 .1 .3 Cruise H07CPW9314 

The seventh LATEX A hydrography cruise (H07) was conducted on the R/V J. W. Powell 

6-22 November 1993. Figure 3 .4.3 shows the location of the stations occupied and the 

cruise track. Ms. Carrie A. Neuhard of TAMU was Chief Scientist. Table 3_4.4 gives the 

station number, date, time (UTC), location, water depth, and number of bottles tripped at 

each of the stations. The plan called for 212 normal stations to he occupied on the TexasLouisiana shelf and 33 additional stations along the Sn-m isobath with only CTD 

measurements . All 212 normal stations were completed ; only 23 of the CTD-only 

stations were completed before the Chief Scientist discontinued them due to adverse 

weather conditions and problems with ship operations. Stations 230 and 234 on Line 9 

were sampled twice. A deep station (740 m) was added at the end of the survey for 

intercruise CTD comparison. A total of 238 stations were completed. 

In addition to LATEX program work, three complementary research efforts were 

accommodated . Primary productivity measurements were taken by Gaston Gonzales a 

graduate student of Dr . Sayed El-Sayed (TAMU Dept. or Oceanography) . 

Coccolithophorid data were collected at eight stations for Vita Pariente a graduate student 

of Dr. Stefan GaRner (TAMU Dept. of Oceanography) . Measurements of photosynthesis 

versus irradiance were made at selected stations by Xiaogang Chen a graduate student of 

Steven Lohrenz (Center for Marine Science, University of Southern Mississippi) . 
30 

TEXAS 

0 0 

29 

28 

27 

26 

-148 #07 

_ . .. . ,T .. Zo . 

Z~ too :nl ", 

.,52 .,3, i,ao 

.153 .132 lm 

.is4 i131 .1a¢ 

-155 

.ise aeniuzaxi2zxax4 s iez~ze .iu 

.

:~~ :ia 

a ii ~ Q~ ias 

V 162 " 167 : " 1j! .in s 

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2 .i 3 4 

~ iio 

185 -120 1

. 

'~ .°.-119 

in~ x"100017 

16- 

iw 

C~ 

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-10 

10 

-63 

4i 4243.45 

-e 

LATEX Cruise Track 

H07CPW9314 

6 - 22 November, 1993 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

Figure 3 .4 .3 . CTD stations and cruise track, LATEX H07. 
47 

Table 3.4.4 . Station times and positions for LATEX A cruise H07. 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

1 07NOV93 1630 27°5639' 96'10.83' 48 0 

2 07NOV93 1843 27°58.19' 95°57 .59' 49 7 

3 07NOV93 1948 28°00.01' 95°49 .18' 49 0 

4 07NOV93 2046 28°01 .82' 95°40.77' 49 8 

5 07NOV93 2149 28°04.20' 95°33 .90' 49 0 

6 07NOV93 2238 28°06.62' 95°26.97' 49 7 

7 08NOV93 0100 28°09.91' 95°14.07' 49 0 

8 08NOV93 0217 28°13.20' 95°01 .19' 49 7 

9 08NOV93 0306 28'13.82' 94°54.00' S0 0 

10 08NOV93 0357 28°14.41' 94°46.80' 49 7 

11 08NOV93 0448 28°14.99' 94°39.60' 49 0 

12 08NOV93 0538 28°15 .59' 94°32.42' 49 7 

13 08NOV93 0644 28'17 .11' 94°25.21' 48 0 

14 08NOV93 0738 28°18 .57' 94°18.02' 48 7 

15 08NOV93 0847 2820.41' 94°11 .73' 49 0 

16 08NOV93 0935 28°22.21' 94°05.43' 49 7 

17 08NOV93 1032 28°23 .76' 93°58.23' S0 0 

18 08NOV93 1122 28°25.30' 93°51 .05' S0 7 

19 08NOV93 1215 28°25.19' 93°44.16' S0 0 

20 08NOV93 1304 28°25.06' 93°37 .27' S1 7 

21 08NOV93 1408 28°25.54' 93°30.66' S1 0 

22 08NOV93 1501 28°2596' 93°24.02' S0 7 

23 08NOV93 1602 28°25.65' 93°17 .11' S0 0 

24 08NOV93 1658 28°25.32' 93°10.18' S0 7 

25 08NOV93 1829 28"25.90' 92°57.92' S1 0 

26 08NOV93 1950 28°26.48' 92°45 .66' S3 6 

27 08NOV93 2041 28°27 .04' 92°38.74' S2 0 

28 08NOV93 2143 28°27 .61' 92°31 .80' S3 6 

29 08NOV93 2237 28°28 .50' 92°24.58' S4 0 

30 08NOV93 2332 28°29 .40' 92'17.36' S3 7 

31 09NOV93 0029 28°29 .39' 92°11 .98' S3 0 

32 09NOV93 0115 28°29 .39' 92°06.59' S2 7 

33 09NOV93 0218 28°29 .08' 91°59.10' S2 0 

34 09NOV93 0317 28°28.79' 91°51 .61' S3 7 

35 09NOV93 0417 28°28.77' 91°44.42' S2 0 

36 09NOV93 0513 28°28.76' 91°3723' S1 8 

37 09NOV93 0616 28°27.59' 91°30.65' S2 0 

38 09NOV93 0713 28°26.43' 91°24 .03' S1 7 

39 09NOV93 0836 28°25.06' 91°16 .48' S2 0 

40 09NOV93 0937 28°23.71' 91°08 .93' S1 7 

41 09NOV93 1047 28°22.08' 91°01 .53' S1 0 

42 09NOV93 1149 28°20.47' 90°54.17' S2 7 

43 09NOV93 1324 28°20.45' 90°48 .38' S0 0 

44 09NOV93 1430 28°20.42' 90°42.62' S0 7 

45 09NOV93 1606 28°21 .01' 90°36.29' S0 0 

46 lONOV93 0147 28°58.11' 90°30.61' 13 4 

47 lONOV93 0218 28°55.72' 90°30.86' 15 4 

48 IONOV93 0310 28°52.69' 90°30.61' 19 5 

49 lONOV93 0341 28°4999' 90°30.59' 20 5 

50 10NOV93 0413 28°46 .72' 90°30.64' 19 4 

51 lONOV93 0456 28`43 .93' 90°30.36' 19 6 

52 lONOV93 0623 28°3795' 90°30.33' 22 5 
48 

Table 3.4.4 . Station times and positions for LATEX A cruise H07 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

53 10NOV93 0827 28°31 .63' 90°30.18' 36 6 

54 lONOV93 1041 28°25.42' 90°29 .97' 45 7 

55 lONOV93 1152 28°21 .61' 90°29 .97' 50 7 

56 lONOV93 1259 28'16.81' 90°30.00' 62 9 

57 lONOV93 1347 28°13.53' 90°30.05' 77 9 

58 lONOV93 1502 28°10.47' 90°3030' 95 11 

59 lONOV93 1553 28°07.68' 90°30.16' 118 12 

60 lONOV93 1653 28°04.65' 90°30.21' 151 12 

61 lONOV93 1741 28°01 .26' 90°30.06' 256 12 

62 lONOV93 1857 27°57.97' 90°30.14' 441 12 

63 lONOV93 1950 27°55.45' 90°30.46' 503 12 

64 lONOV93 2145 28°02 .72' 90°38.59' 163 12 

65 lONOV93 2323 28°01 .39' 90°52.41' 189 12 

66 11NOV93 0059 28°00.39' 91°05 .83' 136 12 

67 11NOV93 0232 27°58 .15' 91°19.49' 267 12 

68 11NOV93 0408 27°56.60' 91°32.70' 230 12 

69 11NOV93 0539 27°54.77' 91°45.89' 172 12 

70 11NOV93 0757 27°44.94' 91°59.90' 493 12 

71 11NOV93 0938 27°47 .51' 92°00.02' 396 12 

72 11NOV93 1105 27°50.68' 91°59.98' 200 12 

73 11NOV93 1221 27°53 .54' 92°00.08' 170 12 

74 11NOV93 1313 27°56.80' 92°00.07' 101 10 

75 11NOV93 1409 27°5999' 92°00.05' 123 12 

76 11NOV93 1453 28°02.71' 91°59.97' 106 11 

77 11NOV93 1613 28°08.94' 91°5993' 83 10 

78 11NOV93 1735 28°14.69' 91°59 .89' 70 7 

79 11NOV93 1902 28°21 .13' 91°5 .82' 62 7 

80 11NOV93 1958 28°26.77' 91°59 .86' 56 7 

81 11NOV93 2052 28°33.01' 91°59 .85' 46 6 

82 11NOV93 2135 28°37.73' 91°59 .88' 39 6 

83 11NOV93 2231 28°44.70' 92°00.09' 33 6 

84 11NOV93 2323 28°50.26' 92°00.00' 28 6 

85 11NOV93 2353 28°5296' 91°59 .99' 25 5 

86 12NOV93 0026 28°56.23' 91°5998' 22 5 

87 12NOV93 0058 28°59.33' 92°00.07' 20 5 

88 12NOV93 0128 29°0229' 92°00.11' 17 5 

89 12NOV93 0156 29°04.87' 92°00.16' 14 5 

90 12NOV93 0228 29°07.99' 92°00.06' 11 4 

91 12NOV93 0255 2J°10.87' 91°59.99' 7 4 

92 12NOV93 0824 29°34.05' 93°00.07' 12 4 

93 12NOV93 0917 29°2793' 92°59.96' 13 4 

94 12NOV93 1018 29°22.00' 92°5 .97' 15 4 

95 12NOV93 1116 29°15.91' 93°00.01' 17 5 

96 12NOV93 1213 29°10.04' 93°00.05' 19 5 

97 12NOV93 125 29°03.98' 92°5997' 22 5 

98 12NOV93 1352 28°57.81' 92°5999' 23 5 

99 12NOV93 1448 28°51 .41' 92°5999' 26 5 

100 12NOV93 1555 28°44 .92' 92°59.4' 31 6 

101 12NOV93 1649 28°38 .41' 92°59.93' 34 7 

102 12NOV93 1810 28°31 .87' 92°5998' 44 7 

103 12NOV93 1911 28°25 .38' 92°5994' 50 9 

104 12NOV93 2024 28'18 .48' 92`59.88' 53 8 
49 

Table 3 .4.4. Station rimes and positions for LATEX A cruise H07 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

105 12NOV93 2142 28°10.85' 92°59.92' 73 10 

106 12NOV93 2315 28°01 .82' 92°59.86' 102 12 

107 13NOV93 0040 27°52.85' 93°00.11' 190 12 

108 13NOV93 0201 27°45.27' 93°00.15' 207 12 

109 13NOV93 0310 27°39.41' 92°59 .91' 315 12 

110 13NOV93 0504 27°52.49' 92°51 .37' 217 12 

111 13NOV93 0645 27°55.13' 92°37 .46' 195 12 

112 13NOV93 0826 27°55.14' 92°23 .40' 83 9 

113 13NOV93 1001 27°55.13' 92°09.94' 145 12 

114 13NOV93 1500 27°50.08' 93°05 .29' 176 12 

115 13NOV93 1638 27°49.87' 93°19.13' 151 12 

116 13NOV93 1810 27°49.00' 93°32.57' 201 12 

117 13NOV93 2001 27°48 .29' 93°46.23' 192 12 

118 13NOV93 2153 27°49 .23' 93°5999' 199 12 

119 14NOV93 0111 27°31 .62' 94°13.46' 452 12 

120 14NOV93 0115 27°44.25' 94°12.19' 442 12 

121 14NOV93 0216 27°4799' 94°11 .40' 269 12 

122 14NOV93 0302 27°50.8' 94°10.27' 121 12 

123 14NOV93 0343 27°54.14' 94°09.29' 96 10 

124 14NOV93 0424 27°57 .05' 94°08.32' 85 9 

125 14NOV93 0500 27°59.54' 94°07.51' 82 9 

126 14NOV93 0549 28°04.65' 94°05.52' 70 8 

127 14NOV93 0639 28°0897' 94°03.73' 66 8 

128 14NOV93 0744 28'16.02' 94°01 .31' 58 7 

129 14NOV93 0834 28°21 .94' 93°59.64' 51 7 

130 14NOV93 0930 28°27.94' 93°59.99' 43 6 

131 14NOV93 1023 28°33.82' 93°59 .94' 37 6 

132 14NOV93 1118 28°39.64' 93°5993' 29 6 

133 14NOV93 1225 28`46.01' 94°00.09' 25 6 

134 14NOV93 1315 28°51 .90' 93°5997' 25 6 

135 14NOV93 1404 28°57.93' 94°00.14' 17 5 

136 14NOV93 1438 2J°01 .31' 94°00.06' 18 4 

137 14NOV93 1505 29°03.78' 94°00.14' 19 5 

138 14NOV93 1539 29°0734' 94°00.07' 18 5 

139 14NOVJ3 1607 29°09.99' 94°00.07' 16 5 

140 14NOV93 1655 29'12.99' 94°00.10' 15 5 

141 14NOV93 1725 29'16.21' 94°00.10' 13 5 

142 14NOV93 1753 29'18 .97' 93°5 .92' 13 4 

143 14NOV93 1821 29°21 .61' 94°00.13' 12 4 

144 14NOV93 1850 2J°24.57' 94°00.03' 12 4 

145 14NOV93 1923 29°28 .15' 94°00.13' 12 4 

146 14NOV93 1956 29°32.04' 94°00.16' 12 4 

147 15NOV93 0613 29°10.18' 94°4798' 14 4 

148 15NOV93 0700 29°04.50' 94°46.23' 18 4 

149 15NOV93 0853 28°58 .78' 94°44.41' 17 4 

150 15NOV93 0936 28°53 .40' 94°43.22' 20 5 

151 15NOV93 1021 28°48.01' 94°41 .43' 18 5 

152 15NOV93 1108 28°42.58' 94°39.89' 26 6 

153 15NOV93 1152 28°37.18' 94°38.41' 29 6 

154 15NOV93 1246 28°31 .77' 94°36.60' 34 7 

155 15NOV93 1333 28°26.40' 94°35.15' 39 7 

156 15NOV93 1424 28°21 .00' 94°33.58' 43 7 
50 

Table 3.4.4 . Station times and positions for LATEX A cruise H07 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

157 17NOV93 1001 28°42.21' 95°32.21' 16 4 

158 17NOV93 1034 28°39.71' 95°30.82' 13 4 

159 17NOV93 1102 28°37.45' 95°29.30' 18 4 

160 17NOV93 1135 28°34.82' 95°28.19' 21 5 

161 17NOV93 1215 28°3238' 95°26.35' 26 7 

162 17NOV93 1256 28°29.66' 95°25.07' 27 6 

163 17NOV93 1330 28°27.00' 95°23 .48' 30 6 

164 17NOV93 1429 28°21.63' 95°20.86' 33 7 

165 17NOV93 1522 28°1635' 95°17.86' 38 8 

166 17NOV93 1623 28°10.50' 95°15.02' 47 8 

167 17NOV93 1725 28°05 .03' 95°12.12' S6 7 

168 17NOV93 1836 27°59 .64' 95°09.11' 76 9 

169 17NOV93 1925 27°54.08' 95°06.41' 108 11 

170 17NOV93 2005 27°51 .30' 9S°04.93' 164 11 

171 17NOV93 2105 27°48 .55' 95°03.59' 265 11 

172 17NOV93 2154 27°45 .83' 95°0196' 377 11 

173 17NOV93 2241 27°43 .02' 95°00.69' 508 11 

174 18NOV93 0320 27°31 .50' 95°47.11' 521 12 

175 18NOV93 0448 27°36.12' 95°52.69' 196 12 

176 18NOV93 0612 27°41 .09' 95°58.19' 104 10 

177 18NOV93 0813 27°45 .30' J6°03.31' 80 9 

178 18NOV93 0907 27°48 .60' 96°07.85' 68 7 

179 18NOV93 1008 27°53 .98' 96'13.52' S0 6 

180 18NOV93 1101 27°58.22' 96°18.93' 36 6 

181 18NOV93 1153 28°02.40' 96°24.06' 27 6 

182 18NOV93 1255 28°07 .82' 96°30.02' 19 4 

183 18NOV93 1359 28°12.62' 96°36.02' 10 4 

184 18NOV93 1631 27°51 .61' 96°19.21' S0 6 

185 18NOV93 1753 27°44.39' 96°30.00' S0 6 

186 18NOV93 1914 27°34.80' 96°39.62' S2 6 

187 18NOV93 2037 27°24.01' 96°47.3' S0 6 

188 19NOV93 0006 27°0599' 96°12.59' 447 12 

189 19NOV93 0102 27°06.88' 96° 16 .96' 316 12 

190 19NOV93 0151 27°07.58' 96°20.20' 224 12 

191 19NOV93 0236 27°08.10' 96°22.81' 187 12 

192 19NOV93 0321 27°08.84' 96°26.72' 140 12 

193 19NOV93 0403 27°09.09' 96°29.80' 114 12 

194 19NOV93 0442 27°09.68' 96°33.14' 98 10 

195 19NOV93 0519 27°10.17' 96°36.38' 90 10 

196 19NOV93 0619 27'l 1 .04' 96°4292' 72 10 

197 19NOV93 0718 27° 11 .92' 96°49.60' S7 8 

198 19NOV93 0802 27'12.59' 96°53.38' 49 8 

199 19NOV93 0834 27'12.69' 96°56.24' 43 8 

200 19NOV93 0930 27'13.56' 97°03.13' 32 7 

201 19NOV93 1004 27°14.29' 97°06.28' 29 5 

202 19NOV93 1045 27°14.42' 97°09 .60' 25 5 

203 19NOV93 111 27°15.38' 97°12 .64' 23 5 

204 19NOV93 11 S2 27'15.45' 97'16.05' 17 4 

205 19NOV93 1405 27°01 .00' 96°55 .81' 48 6 

206 19NOV93 1528 26`48.01' 96°54 .62' 48 6 

207 19NOV93 1652 26°36.59' 96°47 .24' S1 6 

208 19NOV93 1821 26°24.59' 96°39 .00' 47 6 
51 

Table 3.4.4 . Station times and positions for LATEX A cruise H07 (continued) . 

Station Date Time (UTC) Latitude N Longitude W Depth Niskins 

209 19NOV93 1937 26°13.20' 96°37 .06' 51 6 

210 19NOV93 2230 26°01 .29' 97°06.97' 15 4 

211 19NOV93 2256 26°01 .37' 97°04.55' 21 5 

212 19NOV93 2324 26°01 .20' 97°0135' 25 5 

213 20NOV93 0011 26°01 .50' 96°58.11' 30 6 

214 20NOV93 0051 26°00.98' 96°51 .44' 38 6 

215 20NOV93 0145 26°00.97' 96°44.97' 46 6 

216 20NOV93 0235 26°00.97' 96°38.62' 50 7 

217 20NOV93 0326 26°00.96' 96°31 .84' 60 7 

218 20NOV93 0413 26°00.71' 96°25 .26' 85 8 

219 20NOV93 0449 26°00.83' 96°21 .95' 120 10 

220 20NOV93 0549 26°00.80' 96°18.66' 203 12 

221 20NOV93 0712 26°00.61' 96°14.69' 504 12 

222 20NOV93 1056 26°08.61' 96'19.94' 230 12 

223 20NOV93 1350 26°19 .80' 96°17.87' 245 12 

224 20NOV93 1612 26°31 .80' 96°1995' 295 12 

225 20NOV93 2106 26°43 .74' 96°26.29' 204 12 

226 20NOV93 2320 26°55 .80' 96°26.23' 207 12 

227 21NOV93 0144 27°07 .59' 96°20.22' 223 12 

228 21NOV93 0315 27°16 .7' 96°15.21' 203 12 

229 21NOV93 0500 27°25 .79' 96°06.24' 203 12 

230 21NOV93 0709 27°36.10' 95°52.67' 194 12 

231 21NOV93 0918 27°39 .04' 95°42.67' 252 12 

232 21NOV93 1059 27°42 .49' 95°30.12' 301 12 

233 21NOV93 1237 27°45 .68' 95°17.20' 266 12 

234 21NOV93 1415 27°48 .55' 95°03.56' 265 12 

235 21NOV93 1643 27°50.15' 94°48.55' 241 12 

236 21NOV93 1822 27°50.12' 94°35.29' 276 12 

237 21NOV93 1959 27`50.05' 94°21 .66' 173 12 

238 21NOV93 2151 27`34.48' 94°18.07' 738 12 

3 .4 .2 Instrumentation . Calibration, and Sampling Procedures 

The instrumentation and sampling procedures for the hydrographic surveys were 

described in section 2.4.2.1 of Jochens and Nowlin (1994b). Some minor variations from 

the procedures set nut in these references occurred due to time constraints and the actual 

instruments used. The only significant variation was that a Chelsea fluorimeter was used 

on these cruises . The Chelsea instrument has a logarithmic output which provides better 

fluorescence resolution in rapidly changing coastal waters . 

At each cast continuous profiles with depth were taken of temperature, conductivity 

dissolved oxygen, transmissometry, fluorescence, optical back- scatterance, and 

downwelling irradiance. Routine meteorological data were collected during the cruise 

and were sent to the National Weather Service via the SEAS III system. Secchi disk 

depth readings were taken at every daylight station. Instrumentation used is shown in 

Table 3.4.5 . 
52 

Table 3.4.5 . Hydrographic equipment available on each hydrography cruise . 

Instrument T y~ Quantity 

CTD System + oxygen Sea-Bird SBE-911 plus 2 

Rosette General Oceanics 12 place 2 

Rosette frame TAMU fabrication 2 

Niskin Bottles GO Level Action, lO liters 12 

Niskin Bottles GO Standard, 10-12 liter 12 

Transmissometer SeaTech 2000 m 2 

Fluorometer SeaTech 3000 m 1 

Fluorometer Chelsea Instruments 1 

Backscatter Sensor D&A Instruments OBS-3 2 

Altimeter Datasonics PSA-900 2 

PAR Sensor Biospherical QSP-200L 2 

Secchi Disk TAMU fabrication 2 

3 .4 .3 Summary of Data Collection 

On each hydrographic cruise, more data were collected than required by the contract . 

Table 3.4.6 summarizes data collected and scientific participation from the three fullshelf hydrography cruises conducted in the second year. In addition, visiting researchers 

nn each cruise collected complementary data for use in their individual research 

programs . Information relative to these complementary programs is given in Table 3.4.7 . 

3 .5 Autistic Doppler Current Profiler Measurements (ADCP) 

3 .5 .1 SvnoDSis of ADCP Surv 

Underway ADCP surveys were made on all three hydrographic surveys during the second 

field year. Dates are shown in Table 2.2 .1 . Survey tracks are shown in Figures 3.4 .1 

through 3.4 .3 . The HOS survey used the same self-contained 150-kHz RDI NarrowBand 

ADCP employed on LATEX A cruise H03 in the first field year. Surveys H06 and H07 

used the 150-kHz RDI NarrowBand ADCP from R/V Gyre employed on cruise H04 in 

the first field year. Prior to each cruise, the ADCP was connected to a quadrapod 

mounting carriage that was installed in the through-ship well aboard the R/V J.W. Powell 

and aligned as described by Murphy et al . (1992) . 

3 .5 .1 .1 Cruise H0SCPW9306 

Underway ADCP data were collected from 10:15 GMT on 26 April through 13 :53 GMT 

on 11 May, using RDI's "TRANSECT" software. This was generally successful, 

although nn 30 April, 3 May, and 7 May this software stuck at "checking Configuration 

and Data Path" . There were two other periods of down time occasioned by shipboard 

power failures nn 8 May; each was less than an hour. 
53 

Table 3 .4 .6 . Summary of data collected and scientific participation in the LATEX A 

standard grid hydrography surveys in the second field year. 

Description 

HOS 

May 199 

H06 

3 Aug- 1993 

H07 

Nov. 1993 

Cruise Duration (days) 17 13 16 

Cruise Track (km) 3680 3632 3720 

Total Hydro Stations 215 215 238 

CTD Stations 215 215 238 

Nutrient Stations 212 215 212 

Oxygen Stations 145 148 144 

Salinity Stations 134 133 133 

Pigment Stations 153 154 152 

Particulate Stations 107 109 108 

Secchi Disk Stations 105 115 97 

Weather Obs 64 48 60 

Nutrient Samples 1682 1704 1685 

Salinity Samples 1058 1044 1054 

Oxygen Samples 1129 1155 1125 

Pigment Samples 1204 1211 1217 

Particulate Samples 214 221 214 

Total Scientific Party 23 17 20 

LATEX Scientists 19 15 18 

Guest Investigators 4 2 2 

Graduate Students 9 4 6 

Complementary Studies 4 4 3 

Table 3.4.7 . Complementary programs nn LATEX A hydrography surveys. 

HOS H06 H07 

Description May 1993 Aug, 1993 Nov. 1993 

Guest Investigators 2 2 2 

Phytoplankton Stations 28 61 8 

Productivity Stations 12 8 9 

Drifter Launches 3 0 0 

3 .5 .1 .2 Cruise H()6CPW9311 

At the beginning of the cruise, the ADCP deck unit had difficulty receiving heading 

information from the gyrocompass on the R/V Powell . This was corrected by 15 :57 

GMT on 26 July . There were no difficulties with subsequent operation, and underway 

ADCP data were collected from 16:18 GMT nn 26 July through 10:35 GMT on 7 August. 
54 

3.5 .1 .3 Cruise H07CPW9314 

Underway ADCP data were collected from 05:53 GMT on 7 November through 18:53 

GMT on 14 November, from 09 :30 GMT on 15 November through 12 :30 GMT on 16 

November, and from 09:56 GMT on 17 November through 05 :52 GMT on 22 November. 

Gaps in data collection were occasioned by mid-cruise port stops. Except for data gaps 

when the computer hung up (8 h on 11 November and 1 .5 h on 20 November), there were 

nn major problems in data collection . 

3.5 .2 Instrumentation, Calibration, and Sampling Procedures 

Instrumentation and sampling procedures for ADCP were described in section 9.7 of 

Nowlin et al. (1991) and in section 2.5 of Jochens and Nowlin (1994b) . Some variations 

from those procedures occurred due to time constraints and the actual instruments used. 

Calculation of the mounting alignment error and first level and second level quality 

control were performed as detailed in sections 3.5.1 .3 through 3 .5.1 .5 of Jochens and 

Nowlin (1994b). Most parameter settings were unchanged from those of LATEX A 

cruise H04; the time set between pings was changed to 0.67 seconds on H06 and H07. 

3.5 .3 Summary of Data Collection 

The configurations recorded for each ADCP cruise are shown in Table 3.5.1 . The dates 

of data collection are stated in section 3 .5.1 above. Quantities of ADCP data collected 

are: 150 Mbytes nn cruise HOS, 293 Mbytes nn H06, and 281 Mbytes on H07. 

Table 3.5 .1 . ADCP configurations . 

System Parameter HOS H(K H07 

Averaging interval (min) 5 

Depth cell length (m) 4 

Number of depth cells 100 

Time between pings (sec) 1 .75 

Transmit pulse length (m) 4 

Blank after transmit (m) 4 

Navigation type GPS 

Data recorded Raw data; 

averaged data; 

navigation 

5 

4 

100 

0.67 

4 

4 

GPS 

Raw data; 

averaged data; 

navigation 

5 

4 

100 

0.67 

4 

4 

GPS 

Raw data; 

averaged data; 

navigation 

3.6 Collateral Data 

The assembly of collateral data consists of the collection of information from other 

programs that are collecting physical oceanographic data nn the Texas-Louisiana shelf 

during the LATEX field years and from pertinent historical reports. These data will be 

used to assist in the analysis of the LATEX A data set and in the development of the final 

synthesis report . The collateral data assembly has followed the plan given in Nowlin et 

al . (1991) . This section summarizes the progress made in assembling (1) a bibliography 
55 

on the physical oceanography of the Gulf of Mexico, (2) the physical oceanographic data 

collected over the Texas-Louisiana shelf by non-LATEX programs during the LATEX 

field years (the concurrent data), and (3) the historical data from the Gulf of Mexico that 

may be pertinent to the analysis and synthesis of the LATEX and concurrent data sets . 

3.6 .1 Bibliography 

The LATEX Gulf of Mexico bibliography continues to be maintained and augmented. It 

contains 687 entries related to the physical and hydrographic characteristics of the Gulf. 

Notice of the availability of the bibliography was posted twice in this report year to the 

GULF.MEX bulletin board and is promoted in every issue of the LATEX Fortnightly. 

Ninety-eight copies of the bibliography were distributed in the second year of the 

program in response to requests from the public . Four individuals requested and received 

diskette versions . 

3 .6 .2 Concurrent Data Collection 

LATEX A has established links with other programs that are collecting data on the 

physical oceanography of the Texas-Louisiana shelf and adjacent waters during the 

LATEX field years . Many of these data sets have been obtained through data sharing 

agreements that limit further distribution of the data. The major data sets obtained in the 

second field year are briefly described in Table 3 .6.1 . Those obtained in the first field 

year are described in Table 2.6.1 of Jochens and Nowlin (1994b). 

3 .6 .3 Historical Data Collection 

As part or the collateral data assembly, LATEX A acquired available historical data from 

the Gulf of Mexico that could he useful in interpreting the LATEX data sets . These were 

discussed in section 2.6 .3 of Jochens and Nowlin (1994b). Additional data sets obtained 

are included in Table 3.6 .1 . 
56 

Table 3 .6 .1 . Collateral data assembled. 

Entity Description of Data Obtained 

LATEX B Preliminary Data from cruise P932 

LSU AVHRR images posted to GULF.MEX April 1993 through March 1994 

LATEX C XBT and drifter data posted to GULF.MEX April 1993 through March 1994 

SAIC 

T'IGER/SOOP Tech. Report 93-04-T, TAMU Oceanography 10 May 1993 

TAMU Hyclrographic data reports 1988-1993 for SOOP data in the LATEX region 

Technical Report 94-O1-T, TAMU Oceanography 17 January 1994 

Hydrographic data from continental shelf & slope of the NW Gulf of Mexico 

NOAA-NWS-GTS Surface land and sea weather observations, waves from fixed sites and from 

the Volunteer Observing Ships program in and around the Gulf of Mexico 

4/92-3/94 extracted from the Global Telecommunications System 

NOAA-NDBC Wave date transmitted over the GTS, April 1993 through March 1994 

NDBC moored data base for the Atlantic and Gulf of Mexico 

Conrad Blucher Institute Coastal water level data for Gulf of Mexico stations for April 1993 

through March 1994 

NECOP Agreement and password to provide access to their data base (all data) 

NOAA COASTWATCH Approximately 2500 AVHHR sea surface temperature images 

Army Corps of Engineers Daily discharge of the Atchafalaya River at Sunmesport, Louisiana and 

Mississippi River at Tarbert Landing, MS (April 1993 - March 1994) 

USGS For Texas and Louisiana rivers : 

-All USGS data for water year 1992 (9/1991-9/1992) 

-Preliminary data for water year 1993 (9/1992 -9/1993) 

-All USGS data for Texas rivers, October 1989 - September 1991 

NOAA-NOS Gulf of Mexico tidal hourly heights for 1991 and 1992 

NOAA-NWS-NMC Final Analysis Cycle Gridded Flux Data archive 4 tunes daily 2/93-3/94 

3-hourly surface weather maps, April 1993 - March 1994 

Daily weather map: weekly series, April 1993 - March 1994 

GULFCET Hydrographic and XBT data from GULFCET cruises Ol through 07 

TAMUG 

NOAH-SEAMAP Temperature and salinity data from SEAMAP Gulf of Mexico cruises 

JPL Satellite-derived multi-channel sea surface temperature and phytoplankton 

pigment concentration data (5 CD ROMs) 
57 

4 DATA QUALITY ASSURANCE AND CONTROL 

4.1 Introduction 

Section 4 provides a discussion of the data processing efforts and quality 

assurance/quality control (QA/QC) methods for each type of data and a summary of the 

results of the QA/QC processing. The data processing was conducted in accordance with 

the procedures set out in section 9 of Nowlin et al. (1991) and section 3 of Jochens and 

Nowlin (1994b). 

Data QA/QC and preliminary analyses are performed by the LATEX A Data Office . The 

primary responsibility for QA/QC and analysis of different types of data are handled by 

different individuals in the Data Office as shown in Table 4.1 . l . 

Table 4.1 .1 . Personnel performing QA/QC. 

Individual 

Dr. Norman L. Guinasso, Jr 

Dr. Matthew K. Howard 

Dr. Steven F. DiMarco 

Mr. Linwood L. Lee III 

Mr. Frank J. Kelly, Jr. 

Data Type 

Hydrographic data 

Meteorological data & Drifter data 

Directional wave data 

Current meter data 

ADCP data 

In general, data sets are grouped by the name of the cruise nn which the data are 

recovered. Data are processed into engineering units and stored in hierarchical 

directories on hard disks. Preliminary data products are produced, examined, and 

obvious errors corrected. The preliminary data products then are given to other principal 

investigators for examination. These investigators inform the Data Office of further 

corrections. After all corrections are made the data are transferred to a distribution 

directory where investigators can have access to the data set. 

4.2 Moored Measurements 

The QA/QC processing procedures for the current meter, wave gauge, and meteorological 

data sets were discussed in sections 3.2 .1, 3 .2 .2, and 3 .2 .4, respectively, of Jochens and 

Nowlin (1994b). 

The first retrieval of data from the IES instruments was completed on mooring cruise 

M10 in July 1993 . The IES on mooring 43 was never recovered. The IES on mooring 42 

was recovered but the acoustic travel-time data were unusable with the exception of a few 

days at the start of the record . The data at the start of the record is not useful for analyses 

because it is so short and during most of that time the instrument and electronics were 

still equilibrating to the ambient pressure and temperature. The temperature and pressure 

records were good. The entire data set-acoustic travel-time, temperature, and pressure, 

along with the calibration coefficients for the thermistor and Paroscientific pressure 

sensor-were sent to Earl F. Childers, a technician at Woods Hole Instrument Systems, 
58 

Ltd. (WHISL), the authorized service provider, for processing. Mr. Childers is very 

familiar with the instrument and the software for processing the resulting data and 

graciously processed the data for LATEX. He could not, however, offer any insight to 

the failure of the instrument to collect good acoustic data. 

4.3 Drifting Busy Measurements 

The methodology for data analysis and QA/QC for the drifting buoys is provided in 

Nowlin et al . (1991) and in section 2 .3 of Jochens and Nowlin (1994b) . A summary of 

times of operation is given in Table 3.3 .1, and an example trajectory is given in section 

6.5 . Drifter trajectories were posted to the GULF.MEX electronic bulletin board on a 

weekly basis. 

4.4 Hvdrographic Measurements 

Hydrographic data were processed following methodologies described in section 3 .4 of 

Jochens and Nowlin (1994b) with the following exception : During cruises H06 and H07, 

duplicate phytoplankton pigment samples were collected, filtered, and analyzed for 

chlorophyll a_ and phaeophytin using a Turner Model 10 Fluorometer. The methods of 

Smith et al. (1981) were followed for these analyses. Prior to analysis, sample collection, 

filtration, and storage processes were handled in the same manner as filters collected for 

HPLC. Similar to chlorophyll a measurements made by HPLC, data acquired using the 

Turner 10 Model tluorometer was validated by comparing chlorophyll a measurements 

with in situ fluorometric measurements nn the CTD package. Fluorometric data versus 

chlorophyll a bottle data were plotted over each other using the procedures described in 

Jochens and Nowlin (1994b) for chlorophyll a measured by HPLC . To further validate 

the chlorophyll a_ data collected using the Turner fluorometer, duplicate filters from 

selected stations were analyzed nn the HPLC system. Chlorophyll a values determined 

on both systems were plotted on top of each other. When discrepancies are detected, 

stations are flagged for further examination. 

In their section 3.4.4, Jochens and Nowlin (1994b) reported the participation of the 

TAMU Department of Oceanography's Technical Support Services Group in an 

international intercalibration experiment sponsored by Quality Assurance of Information 

for Marine Environmental Monitoring in Europe (QUASIMEME). LATEX samples 

were among those evaluated. Results of the nutrient intercalibration experiment were 

published in a confidential report . Nutrient concentrations submitted by TAMU were 

found to be in very good agreement with actual nitrate, nitrite, phosphate, and ammonia 

concentrations . 

4.5 Acoustic Doppler Current Profiler Measurements 

The QA/QC processing procedures for the ADCP data sets were discussed in section 3.5 

of Jochens and Nowlin (1994b). During the second year or field work, the TRANSECT 

software developed by RD Instruments was used to record both raw and averaged data. 

The initial QA/QC processing for H06 and H07 was routine and the data quality was 

good. Due to the downtime described in section 3 .5 .1 .1 of this report, the processing of 

the HOS ADCP data required additional work. The resulting data set also was of good 

quality. Work continues on the subjective second level QA/QC, described in section 

3 .5 .15 of Jochens and Nowlin (1994b) . 
59 

5 DATA MANAGEMENT AND INFORMATION TRANSFER 

5.1 Introduction 

Section 5 gives an overview of data archival and sharing activities and of information 

transfer activities of LATEX A, including summaries of data archived at the National 

Oceanographic Data Center (NODC) and data provided to others . A summary of 

information transfer activities implemented is provided, including postings to 

GULF.MEX electronic bulletin board, issuance of public notices and notices to 

fishermen, publication of the bi-weekly newsletter, LATEX Fortnightly, and organization 

of LATEX meetings. 

5.2 Data Archival 

The NODC project identification code for LATEX A data is 0212. Data collected from 

current meter moorings (Table 3 .2.4), wave gauges (Tables 3 .2 .5 and 3 .2 .6), 

meteorological buoys (Table 3 .2.7) on mooring cruises M09 through M14, CTD and 

other continuous profile data and bottle nutrients, oxygen, and salinity data collected on 

hydrographic surveys HOS thorugh H07 have been submitted to NODC. Due to poor data 

return from the inverted echo sounder, the pressure and temperature data require further 

QA/QC. Drifting buoy data were posted to GULF.MEX . ADCP data collected during 

the hydrographic surveys are undergoing additional QA/QC. Analyses of filters for 

pigments and total suspended particulates from cruises HOS through H07 have been 

completed. The results are undergoing QA/QC processing . 

5.3 Data Sharing 

There has been substantial interest in the LATEX A data set. A data sharing agreement 

was formulated to allow interested scientists outside the LATEX/MMS community to use 

portions of the data set while protecting the interests or the LATEX A scientists in the use 

of these data. Data provided were those that had been submitted to NODC. Table 5.3 .1 

provides a summary of the data provided by LATEX A to others during the second field 

year. 

Table 5.3 .1 . LATEX A data shared with others . 

Name Data Description Date Sent 

George Forristall current meter data from initial cruises April 1993 

Shell Dev. Corp. 

Eric Noah current meter and wind data in area and time June 1993 

EHI of LATEX B October 1992 cruise 

Michael Dowgiallo surface temperature and salinity data from H06 July 1993 

NOAA comparison or these with same from H02 

John Cortinas corrected met buoy data August 1993 

NSSL 
60 

Table 5 .3 .1 . LATEX A data shared with others (continued) . 

Name Data Description Date Sent 

Marie Neuman CMAN and MOMS meteorological data from September 1993 

LSU April 1992 through September 1993 

Glen Wheless current meter and met data from mooring 22 October 1993 

ODU for October 1992 to March 1993 

William Wiseman meteorological buoy data from April 1992 October 1993 

LSU through March 1993 

Susan Brown selected CTD data from HO 1 through H04 October 1993 

UTMSI 

D. Lopez-Veneroni chlorophyll a data from HO l October 1993 

TAMU 

K. Al-Abdulkader selected bottle data from HO1 through H04 October 1993 

TAMU 

Tom Lee meteorological data from NDBC buoys 42001 November 1993 

RSMAS and 42007 for January through October 1993 

Giulietta Fargion CTD, nutrient, and oxygen data from HO 1 November 1993 

TAMUG-GulfCet through H04 

James Herring NMC archive flux data November 1993 

Dynalysis 

Richard Patchen time history of the mooring locations November 1993 

Dynalysis 

Nan Walker accuracy and precision specifications November 1993 

LSU for the current meters 

Murray Brown selected meteorological and current meter data November 1993 

MMS 

John Lundberg sea surface temperature and CTD data from December 1993 

UT HO1, H02, and H03 

Glen Wheless additional current meter and met data December 1993 

ODU from mooring 22 

David Brooks historical Mississippi and Atchafalaya January 1994 

TAMU river flow data 

John Heideman 

& Wilson Lamb Hurricane Andrew wave data from mooring 16 February 1994 

EXXON 

John Hubertz NMC gridded flux data from September through February 1994 

COE-WES December 1993 

John Hubertz NMC gridded flux data from March 1993 March 1994 

COE-WES 

Doug Evans current meter data from moorings 12 through 19 March 1994 

EHI and met buoy data from moorings 17 and 19 

for August through October 1992 

David Sheres wind, wave, current data from moorings 15, 17, March 1994 

USM and 23 for March through May 1993 

Giulietta Fargion CTD and bottle data from HOS March 1994 

TAMUG-GulfCet 
61 

5.4 Information Sharin g 

5.4 .1 GULF.MEX Bulletin Boar 

LATEX A maintains the GULF.MEX bulletin board on ScienceNet of Omnet, a 

commercial electronic mail service. GULF.MEX received approximately 500 postings in 

this second year. Approximately 70% of the postings consisted of drifter tracks, frontal 

analysis, and OPCplot postings ; 20% were field study reports; and 10% provided general 

information. LATEX A posts to GULF.MEX all cruise plans and reports, meeting 

announcements, weekly drifter trajectories, weekly meteorological summaries, the 

LATEX calendar, and other selected information relative to LATEX A. 

5.4.2 Public Notices 

Whenever there is a substantial change in the position of a mooring located away from 

offshore platforms, LATEX A advises the United States Coast Guard (USCG), the 

Defense Mapping Agency (DMA), and the U.S . Navy Submarine Command (USN). One 

change in position was reported during the second field year: buoy E at mooring 20 was 

reported to the USCG and the DMA and USN were copied 9 September 1993 . Other 

reports were made to the USCG to notify of them or off-station marker buoys (8 April, 26 

April, 6 July, 8 July, 12 October 1993, and 9 March 1994), redeployment or status reports 

(6 July, 30 July, and 13 October 1993 ; DMA and USN copied), and discontinued buoys 

(1 April 1993 ; DMA and USN copied). 

5 .4 .3 LATEX Meetings 

LATEX A organized one meeting on the oceanography or the Texas-Louisiana 

continental shelf. The third general meeting (LATEX III) was held in New Orleans, 27-

28 October 1993. The Science Advisory Panel (SAP) met 26-28 October. Program 

descriptions were presented by the program managers of LATEX A, B, and C, and by 

principals of the MMS-sponsored modeling efforts and other collateral programs . 

Science presentations focused nn the topics of remote sensing and hydrography (27 

October) and shelf kinematics and processes (28 October). Table 5 .4 .1 shows the agenda 

for this meeting. 

5.4 .3 The LATEX Fortnightly 

The LATEX Fortnightly News is sent to approximately 2500 addresses by bulk mail. 

Twice during the period 1 October 1993 - 30 September 1994, address correction flags 

were added to the front of the newsletter to determine the number of publications not 

being delivered for various reasons. This resulted in the removal of approximately 200 

addresses due to inability to contact or lack of information on the addressees . Tables 

5.4 .2 and 5.4 .3 provide a listing of all issues published during the second field year. 
62 

Table 5.4 .1 . Agenda for LATEX III meeting of October 1993 . 

Description Speaker 

October 26, 1993 

Welcome and general remarks M. Brown 

Opening statements R. O. Reid 

Review of LATEX Plume S. Murray 

Review of LATEX Shelf W. Nowlin 

Review of LATEX C T. Berger 

Review of TIGER D. Biggs 

Review of shelf modeling study J. Herring 

Review of Gulf modeling study L. Kantha 

Discussion Speakers and SAP 

October 27, 1993 

First Session: Remote Sensing and Hydrography 

Data assimilation in local circulation model K. Thompson 

Salinity, density, and geopotenaal distributions 

during LATEX A hydrographic cruises J. Cochrane 

Variations in non-conservative properties over the LATEX shelf D. Wiesenburg 

Seasonal variations of hydrographic characteristics 

in the LATEX coastal plume S . Murray 

TOPER & ERS-1 analysis in the Gulf of Mexico G. Born 

The effects of coastal processes nn ocean color measurement 

in the Gulf of Mexico R. Gould 

Aspects of circulation in the NW Gulf of Mexico during 1993 L. Rouse 

Second Session: Reviews of selected collateral efforts 

The NOAH coastal ocean program Nutrient Enhanced Coastal 

Ocean Productivity (NECOP) Program: an overview D. Atwood 

Surface current & Lagrangian drifter program P. Niiler 

Gulf Offshore Satellite Applications Program N. Guinasso 

GulfCet hydrography cruises, April 1992 - August 1993 G. Fargion 

NE Gulf study sorkshop A. Clarke 

NOAA's activities in the Gulf of Mexico J. Lamkin 

SEAMAP D. Donaldson 

Oil spill risk analysis program G. Wheless 

Estuaries modeling in the Gulf of Mexico M. Inoue 

Paleocirculation M. moue 

Historical oil industry eddy surveys (EJIP) K. Schaudt 

October 28, 1993 

Third Session: Kinematics and Processes 

Numerical simulation of warm core and secondary eddies 

in the western Gulf of Mexico D. Dietrich 

Hyclro/drifter data at the shelf edge P. Hamilton 

ADCP observations of shelf edge currents F. Kelly 

Issues in modeling continental shelf flow fields J . Allen 

Wind-driven circulation in Bay of Cainpeche; distinct patterns of 

western Gulf circulation R. O. Reid 

Near-inertial oscillation over the Texas-Louisiana shelf C. Chen 

Variability in the velocity structure of the LATEX coastal current S. Murray 
63 

Table 5 .4 .2 . Volume 2 LATEX Fortnightly News, 12 April - 20 December 1993 . 

Volume 2: Date: Title(s) : 

Iss . 8 4/12/93 Inertial Currents (story) 

MMS Reports Available (story) 

Correction (story) 

LATEX Mooring 14/East-West Current (figure) 

Winds from 25 March - 8 April 1993 (hack map) 

Iss . 9 4/26/93 The Blizzard of 1993 (story) 

Blizzard Storm Track (back map) 

Iss . 10 5/10/93 May is a Busy Month for Field Work in the GOM (story) 

LATEX-C May Surveys (story) 

Mooring Service Cruise (story) 

GulfCet Spring Survey (story) 

Winds from 26 April - 10 May 1993 (hack map) 

Iss . 11 5/24/93 ADCP Currents for Cruise 92C (story) 

ADCP Currents (figure) 

Winds from IU May - 24 May 1993 (hack map) 

Iss . 12 6/7/93 LATEX Assists Kids with Drift Bottles (story) 

Ninth Mooring Cruise Completed (story) 

Winds from 25 May - 7 June 1993 (hack map) 

Iss . 13 6/21/93 SOOP and Whoppers (story) 

Depth of Isotherms/June 2-3 1993 (figure) 

XBT Station Track and Drifter Trajectories (figure) 

Winds from 7 June - 20 June 1993 (back map) 

Iss . 14 7/5/93 Second Field Activity Completed for GOOMEX (story) 

GOOMEX Study Sites (figure) 

Winds from 21 June - 4 July 1993 (hack map) 

Iss . 15 7/19/93 Humidity Data Flows Through GTS (story) 

VOS Reporting Locations June 1993 (figure) 

Relative Humidity at VOS Locations (figure) 

Winds from 5 July - 18 July 1993 (hack map) 

Iss . 16 8/2/93 Sixth LATEX A Hydrography Cruise Underway 

in Gulf (story) 

Oceanographic Charting Software for the World's Seas (story) 

Winds from 19 July - 27 July 1993 (hack map) 

Iss . 17 8/1(/93 LATEXans Research Raging River Runoff (story) 

Surface Salinity July-August 1993 (figure) 

Winds from 28 July - 15 August 1993 (back map) 

Iss . 18 8/30/93 ONR Adds Plankton Study to LATEX (story) 

Winds from 16 August - 29 August 1993 (hack map) 

Iss . 19 9/13/93 LSU Scientists Describe 1993 Hypoxia (story) 

Winds from 29 August - 12 September 1993 (hack map) 

Iss . 20 9/27/93 LUMCON Scientists Describe 1993 Hypoxia (story) 

Current Meter Service Cruise Underway (story) 

Winds from 13 September - 26 September 1993 (hack map) 
64 

Table 5.4 .2 . Volume 2 LATEX Fortnightly News, 12 April - 20 December 1993 (continued). 

Volume 2: Date: Title(s): 

Iss. 21 10/11/93 LATEX III Meeting October 26-28, 1993 (story) 

Directions to MMS Regional Offices for the LATEX III Meeting (back story) 

Information about Hotel Accommodations (back sorry) 

Lss . 22 10/25/93 Surface Current and Lagrangian-Drift Program (SCULP) (story) 

SCULP Drifters July-Sept 1993 (figure) 

Winds from 11 October - 24 October 1993 (back map) 

Iss . 23 11/8/93 Seventh LATEX-A Hydrographic Cruise Underway in Gulf (story) 

LATEX III is a Success (story) 

Winds from 25 October - 7 November 1993 (back map) 

Iss . 24 11/22/93 Loop Current Eddy Shedding Cycle 1981 through 1993 (story) 

Winds from 8 November - 21 November 1993 (back map) 

Iss . 25 12/6/93 Loop Current Eddies (story) 

Most GTS Reporting of LATEX Data to Stop (sorry) 

Loop Current Eddies (figure) 

Winds from 22 November - 6 December 1993 (back map) 

Iss. 26 12/20/93 LATEX Talks Given at MMS Meeting (story) 

Seventh LATEX A Survey Completed (story) 

LATEX Mooring Cruise Returns (story) 

Winds from 6 December - 20 December 1993 (back map) 

Table 5 .4 33 . Volume 3 LATEX Fortnightly News, 1 January - 28 March 1994. 

v 

Iss . 1 1/3/94 Ocean Sciences 1994 A LATEX Jamboree (sorry) 

Winds from 20 December - 3 January 1994 (back map) 

Iss . 2 1/17/94 Numerical Model Reproduces Small-Scale Features of Gulf Circulation (story) 

Top Level Temperature from DieCAST Model (maps) 

Iss . 3 1/31/94 Story of Texas and the Sea on Display at the Texas Maritime Museum (story) 

LATEX Mooring Service Cruise (story) 

Winds from 17 January - 30 January 1994 (back map) 

Iss . 4 2/14/94 LATEX Measures Large Waves During Hurricane Andrew (story) 

Significant Wave Height - Hurricane Andrew (figure) 

Winds from 1 February - 14 February 1994 (back map) 

Iss . 5 228/94 USM Scientists Study Phytoplankton Production on LATEX Hydro 

Cruises (sorry) 

Winds from 14 February - 27 February 1994 (back map) 

Iss . 6 3/14/94 Net-/Nano-/Picoplankton Contributions to Primary Productivity on the 

LATEX Shelf (story) 

Winds from 28 February - 13 March 1994 (back map) 

Iss . 7 32,8/94 Dissolved Organic Nitrogen Studies in LATEX (story) 

Information Highway Used to Send LATEX Data to NODC (story) 

Winds from 14 March - 27 March 1994 (back map) 
65 

6 TECHNICAL DISCUSSION 

6.1 Introduction 

Section 6 provides a brief technical discussion of early results of the data collection from 

the second field year as the vehicle for providing a representative selection of standard 

computer-produced graphics. Additional graphical products will be contained in the 

microfiche packet that will accompany the Final Report, which will be completed in 

1996. Included in the discussion are representations of time series from the moored 

measurements, drifting buoy trajectories, plots of hydrographic properties, and 

preliminary plots of ADCP-measured currents . The preliminary results of the second 

year of the cyclogenesis study are presented. A comparison is made of observed currents 

with those simulated by a simple barotropic wind-driven model. The activities of the 

LATEX Science Advisory Panel are described. 

Although the data shown in this section have received quality control and assessment, 

they are still preliminary; users should expect that subsequent corrections will be made to 

the data sets prior to the final submission to the NODC . THIS SAME CAVEAT 

APPLIES TO ALL DATA REPORTED IN THIS DOCUMENT. 

6.2 Scales Analyses for the LATEX Shelf Based on Hvdrouanhic Observation 

One important result of the LATEX Program will be a description of the spatial and 

temporal scales of energetic variability over the Texas-Louisiana continental shelf. Y. Li, 

W. Nowlin, and R. Reid are completing an analysis of the spatial scales based on 

hydrographic observations. In particular, this analysis examines horizontal scales of 

temperature, salinity, and geopotential anomaly distributions . 

Our procedure is to identify, describe, and remove reference fields corresponding to the 

shelf-wide patterns of density and circulation . We have examined both Fourier and 

polynomial representations of the reference fields, including terms of order necessary to 

include the major large-scale variability as determined by applying an F-test . The results 

for individual May cruises were compared to the mean May fields based on multiple 

cruises described in section 6 .3 . The May mean reference fields are fit reasonably well 

by a quadratic in cross-shelf direction or in along-shelf direction for half the shelf length . 

(A higher order is necessary to represent the along-shelf variability of the mean or 

individual fields when full shelf length is considered.) After removing the reference 

fields, the remaining anomaly fields are analyzed to describe the scales of the smaller 

scale variability over the LATEX region . 

The variability from a spatial mean of the reference fields obtained by fitting quadratics 

to data from individual May cruises agreed well with those of the May mean fields . 

Moreover, the length scales and associated variability of the anomaly fields (determined 

by use of both autocorrelations and structure functions) of individual and mean May data 

agreed well. Therefore, we have decided to remove reference fields from all individual 

LATEX A cruises using quadratic fits . 

Figure 6.2 .1 shows 3-m salinity observed at each station on cross-shelf transect 4 

(approximately 94° W) during the May 1992 LATEX A hydrographic cruise and 3-m 

salinity from the mean May field interpolated to the May 1992 station positions. The 

shelf-scale shape of both individual and mean fields are seen to be quite similar-a 
66 

quadratic with cross-shelf variation in salinity of near 10. Removing the mean field from 

the May 1992 cruise yields an anomaly field that can be used to describe the smaller 

energetic spatial scales of variability. Figures 6.2 .2 and 6.2 .3 show the autocorrelation 

coefficients and structure function, respectively, as functions of cross-shelf separation for 

the anomaly field . The first zero crossing of the autocorrelation function is 

approximately 25 km ; the structure function indicates the magnitude of cross-shelf 

variability in the salinity anomaly to be about 1 .3 . Also indicated in Figure 6.2 .3 is that 

the measurements are not adequate to resolve smaller scale variability in surface salinity 

of amplitudes 0.5 or less . Note that the magnitude of variability of this anomaly field is 

almost an order of magnitude less than that of the background or reference field removed. 

Table 6 .2 .1 gives spatial scales of anomaly fields for most of the LATEX A hydrographic 

cruises . Transects 2, 4, and 7 are cross-shelf, located at 92° W, 94° W, and 27.4° N 

respectively ; transects 9 and 10 are along the 200-m and 50-m isobaths respectively 

(values for the eastern shelf from 90.5° W to 94° W). All scale values are based on first 

zero crossings or autocorrelation coefficients of anomaly fields after background 

quadratic fits were removed. Salinity and temperature values were observed at 3 m; the 

geopotential anomaly is for 3 db relative to 70 db, calculated as described in section 6.3 . 

Over the eastern and central portions of the Texas-Louisiana shelf, the cross-shelf 

anomaly scales for surface salinity, surface temperature, and geopotential anomaly all 

average to values near 20 km . Temperature scales seem slightly less . By contrast, the 

cross-shelf anomaly scales at transect 7 (although represented by fewer realizations) 

range from 8 to 15 km with averages or 8 to 14 km-again, temperature scales are 

slightly shorter. 

The average of along-shelf anomaly scales over the east-central shelf are 30 to 38 km . 

There seems to be no real difference between scales at the shelf edge (transect 9) and 

those at mid-shelf (transect 10). The surface salinity scales are somewhat shorter than 

those for temperature and geopotential anomaly, which seem equal. 

It is important to note that our LATEX hydrographic station spacing on cross-shelf 

transects normally varied from 10 km at mid-shelf to 5 km at inner and outer shelf 

locations, and our along-shelf hydrographic station spacing was normally 20 km. On one 

cruise, however, we decreased the station spacing to 10 km along-shelf. Usable 

underway surface temperture and salinity measurements were obtained on many cruises. 

We have examined the data from the In-km along-shelf stations and thermosalinograph 

surface data at 1-km separations for cross-shelf transects. These examinations showed no 

significant differences in spatial scales from those given in Table 6.2 .1 . Thus, it seems 

unlikely that significant variability is present in spatial scales shorter than indicated by 

Table 6.2 .1 but missed in our analysis because of the LATEX A sampling intervals. 
36 

34 

32 

30 

a 2 

26 \ 

24 

22 

20 

18 

16 

0 20 40 60 80 100 120 140 160 180 200 220 

Separation from St. l (km) 

Figure 6.2 .1 . (-) 3-m salinity observed at each station on cross-shelf transect 4 (94°W) 

during LATEX May 1992 hydrographic cruise HO1; (---) 3-m salinity 

from mean May field interpolated to May 1992 station positions. 

v 
o~ 00 

1 .0 

0.8 

0 .6 

CIO 

0.4 

U 

w 

0.2 

U 

C 

0 0.0 

cd 

-0 .2 

O 

U i 

-0 .4 

a 

Q 

-0 .6 

-0.8 

-1 .0 

0 10 20 30 40 50 60 70 80 90 100 

Separation (km) 

Figure 6.2 .2 . Autoconelation function for difference between May 1992 and mean May 

3-m salinities as funcion of cross-shelf separation. 
3.5 

3.0 

2.5 

2.0 

" r1 ` 

.~ 1 .J 

vJ 

1 .0 

0.5 

0.0 

0 10 20 30 40 50 60 70 80 90 100 

Separation (km) 

Figure 6.2.3 . Structure function as for Figure 6.2.2. 

110 
0 

Table 6.2 .1 . Spatial scales of anomaly field of selected transects and variables as described in the text . 

Salinity Geopotentlal Anomaly Temperature 

Transect 2 4 7 10E 10W 9 2 4 7 10E 10W 9 2 4 7 10E 10W 9 

LATEX - H01 20.5 1 7 30 23 23 24 ' 64 38 1 8 1 5 1 8 36 

LATEX - H02 1 8 20 37 1 9 7 21 38 36 14.5 14 .5 32 38 

LATEX - H03 27 28 38 41 24 1 8 28 50 23 1 6 46 50 

LATEX - H04 1 5 24 35 30 24 23 44 36 22 21 27 23 

LATEX - H05 1 8 30 .5 14 .5 31 37.5 1 5 28 1 0 37 33 1 1 28.5 10.5 30 45 

LATEX - H06 1 6 32.5 1 3 26 32 22 20 1 7 36 37 16 9 9 26 43 

LATEX - H07 11 .5 19.5 15 26 22 18 .5 17 .5 14.5 20 38 23 22 8 .5 26 35 

Mean 18 22 14 31 38 30 20 21 .5 14 35 40 38 17 18 9 30 31 37 

# of Cruises 7 7 3 7 3 7 7 7 3 7 3 7 7 7 33 7 3 7 
71 

6.3 . Seasonal and Interannual Variability over the Texas-Louisiana Continental Shelf 

As described in Jochens and Nowlin (1994b), we are pursuing a study of the general 

circulation patterns (and property distributions) over the Texas-Louisiana continental 

shelf based on combining historical and LATEX hydrographic data. We began last year 

by examining all pre-LATEX hydrographic cruises over the region and selecting some 60 

cruises that either covered most or the shelf or constituted intensive repeats over a portion 

thereof. We then examined distributions of temperature (T), salinity (S), and geopotential 

anomaly (surface relative to 70 db, after the approach of Csanady (1981)) to assess in a 

general way whether these patterns conform to the seasonal patterns hypothesized by 

Cochrane and Kelly (1986) . Indeed, they generally do, although there are significant 

deviations, e.g ., at times of anomalous river discharge. We also examined for the same 

purpose the LATEX A hydrographic cruises ; as discussed in Jochens and Nowlin 

(1994b), the conformation is good. 

During the past year we have composited LATEX and historical data for two distinctly 

different seasons (according to Cochrane and Kelly 1986): for May, when the shelf is 

dominated by a large cyclonic circulation with relatively fresh water flowing downcoast 

(west and southwest) in the surface layers of the nearshore portion or the gyre; and for 

August, when the cyclonic gyre has been disrupted by the annual shift in the wind 

regime. These two seasons were chosen for initial examination because they characterize 

the typical shelf-wide patterns, ignoring atypical patterns generated by extreme events, 

e.g., hurricanes. 

Mean May and August patterns or 3 db relative to 70 db geopotential anomaly are shown 

in Figures 6.3 .1 and 6.3 .2 . These were constructed by gridding data from 9 and 8 cruises, 

respectively, using the objective analysis package incorporated in GMT (Generic 

Mapping Tools) software. The objective analysis package in GMT is based on an 

extension of the minimum curvature method of gridding described by Smith and Wessel 

(1990) . Gridded values were obtained at 15-minute separations in latitude and longitude. 

Then we began a cruise-by-cruise comparison of the LATEX A May and August patterns 

(geopotential anomaly and 3-m salinity) with the corresponding mean patterns . We 

constructed gridded fields from the individual LATEX cruise data in the same manner, 

using GMT. An example is shown in Figure 6.3 .3 for LATEX A May cruise H05. For a 

quantitative comparison we constructed difference fields between the individual fields 

and the corresponding mean field (shown in Figure 6.3 .4 for cruise HOS) . This difference 

was compared to the field of standard deviations for the mean field obtained by 

differencing that field from the individual fields from which it was constructed (shown in 

Figure 6.3 .5 for the May mean field of geopotential anomaly). 

If the difference field or individual cruise data from the mean field (e.g ., Figure 6.3 .4) 

was larger than the standard deviation field (e.g ., Figure 6.3 .5), we judged that the 

individual field evidenced a significant interannual difference from the mean. For those 

cases we have begun to examine the differences in synoptic wind fields and river 

discharge histories for the individual cruises as compared with the longer term wind and 

river discharge patterns. In this manner we expect to be able to describe and understand 

the underlying mechanisms responsible for changes in shelf-wide circulation and property 

distributions. We have a draft manuscript or results. During the next two years, we will 

complete this study and submit a manuscript for publication that will constitute a portion 

of our final LATEX A synthesis. 
N 

Figure 6.3 .1 . Average geopotential anomaly at sea surface relative to 70 db for nine May cruises. 
Figure 6.3 .2 . Average geopotential anomaly at sea surface relative to 70 db for eight July-August cruises . 

v 

w 
Figure 6.3 .3 . Geopotential anomaly at sea surface relative to 70 db for LATEX HOS cruise (26 April - 10 May 1993). 
Figure 6.3 .4 . Differences of geopotential anomalies at sea surface relative to 70 db for LATEX 

HOS cruise (26 April - 10 May 1993). 

~1 
Figure 6.3 .5 . Standard deviation of geopotential anomaly at sea surface relative to 70 db for nine May cruises. 
77 

6.4 Coastal Upwelling and Related Currents in Spring and Summer off South Texas 

In this section we report on a preliminary analysis to describe and explain the winddriven coastal upwelling and related currents off south Texas (Cochrane et al . 1995) . 

Figure 6.4 .1 shows the annual progression of monthly mean wind stress in 2° quadrangles 

along the western boundary coast of the Gulf of Mexico from 20°-30° N, based on 

Hellerman and Rosenstein (1983) . Along the coast, the zonal component of the means is 

predominantly westward throughout the year, exclusively so north of about 24° N. The 

meridional component undergoes an annual cycle, being northward April through August 

and southward October - March. In March and September north of 20° N, the stress is 

almost westward. Since the alongshore component of stress provides the primary driving 

force for coastal upwelling, it may be seen from Figure 6.4 .1 that the mean stress is 

favorable for upwelling along much of the coast from April through August. 

The NOAA/NOS/OPC Oceanographic Features Analyses (NOAA 1994) of infrared 

imagery indicate that upwelling is present along the western boundary coast of the Gulf 

of Mexico at least from 21' N to 29° N. Figure 6.4 .2 shows an example of an analysis for 

the Gulf of Mexico. The twice weekly analyses from 1992-1994 have been used in this 

study. Browsing through these analyses makes clear that particularly cool spots are often 

found in places where the coastline is oriented more nearly parallel to the mean wind 

stress direction, e.g ., north of the mouth of the Rio Grande . 

For a more precise evaluation of the prevalence of reduced coastal temperature, we have 

determined the number of days in which a band with temperature at least 2°C below that 

of the adjacent open Gulf extended at least 4° of latitude along the coast. Table 6.4.1 

gives the results for June, July, August, and September in terms of relative frequencies ; 

the 3-year means for months not listed are lower. July shows the highest incidence. 

August has the defined conditions for more than half the days analyzed . The July 

maximum and the high August value are not surprising in view of the strong upcoast 

mean stress in those months. September's relatively small incidence agrees with the low 

upcoast mean for that month. On the other hand, the low incidence of coastal cool bands 

for April, May, and June seems inconsistent with the strong upcoast stresses in the longterm mean given in Figure 6.4 .1, a paradox still awaiting resolution. 

Near-surface hydrographic data, while not as extensive in time or space as infrared 

imagery, provides a closer view of temperature and includes salinity . For April through 

September, nearly all the presently available data of this kind south of 28° N are from off 

the coast of south Texas. Readily available inner shelf data are from (1) the southernmost 

GUS III monthly stations for 1963-1965 (Temple et al ., 1977), (2) the tide station at 

Brazos Santiago, which is exposed to the Gulf, for 1958-1971 (U.S . Dept. of Commerce, 

1973), (3) the top current meters (10-14 m depth) of LATEX A moorings 1 and 2 for 

1992-1993, and (4) inner shelf stations of LATEX A hydrographic cruises in May and 

August of 1993 and 1994. Information for the outer shelf, slope, and open Gulf is based 

on Etter and Cochrane's (1975) discussion of Texas-Louisiana Shelf water temperatures . 

Figure 6.4 .3 shows the locations where the above data were obtained. 

Figure 6.4 .4 shows monthly means of temperature for April through October for each of 

the above data sources except the LATEX A hydrographic data. The April, May, and 

June means for the inner shelf sources are higher or about the same as the outer shelfopen Gulf means (Etter and Cochrane 1975); they do not suggest upwelling. The July 

and August means, however, fall considerably below the outer shelf-open Gulf meannearly 3°C in July when a secondary temperature minimum is indicated; upwelling surely 
7s 

is present. The September means for inner shelf sources are close to that for the outer 

shelf-open Gulf sources, suggesting insignificant upwelling. For October, the lower inner 

shelf means seem to be due to the more rapid autumnal cooling there. 

The relations between the inner shelf and the outer shelf-open Gulf temperature means 

from July through October seem quite compatible with the mean stresses for those 

months (Figure 6.4 .1). However, the absence of upwelling indicated by the temperature 

means in April through June is in conflict with the upcoast alongshore stress component 

that implies to upwelling . The low mean salinity in the inner shelf data for April and 

May also is in conflict with the alongshore stress (Figure 6.4 .4(b)) . Thus, the near-shore 

hydrography leads to the same conclusion as the Oceanographic Features Analyses of 

infrared imagery : paradox for the April - May period, but good agreement with wind 

stress in July - August. 

Figure 6.4.5 shows the shallowest CTD temperatures (1-3 m depth) for the western 

portion of the Texas-Louisiana Shelf during the period 2-7 August 1993 and 1994. In 

both years, a band of cool water extended north along the coast to about 28° N from a 

coldest spot (temperature near 26 C) at the most inshore station of the line along 26° N. 

The tonguelike form of the band suggests northward flow. 

Figure 6.4.6 gives the distributions for the same region of shallowest CTD salinities for 

3-11 May and 2-8 August 1993 . In May, the shallowest CTD salinity was generally less 

than 32, and in August it was generally above 36. Similar salinities were encountered in 

early May and early August of 1994. Thus, the near-surface salinities in both years show 

the same change as the mean salinities (Figure 6 .4.4(b)) for the inner shelf sources . 

Consequently, they lead to the same situation for May, little or no upwelling and 

downcoast current in disagreement with an upcoast component of the long-term mean 

wind stress . 

Looking beneath the sea surface one finds that off south Texas the slope of the isopycnals 

changes from predominantly downward toward the coast in early May 1993 to 

predominantly upward in early August. A similar change between May and August was 

found in 1994. The May slope data in both years indicate against upwelling and for 

downcoast geostrophic flow; the August slope data in both years indicate the opposite . 

As an example of the change, Figure 6 .4 .7 provides the topographies of the 6e = 25.0 

surface for May and August. In August, somewhat north of where the lowest surface 

temperature was encountered, the surface is considerably shallower than in May. The 

topography illustrates clearly that the onshore rise in isopycnals has a three-dimensional 

form with a downslope to the north and east of the crest. To illustrate further the vertical 

structure for early May and early August, vertical sections of 6e based on measurements 

made in 1993 along Line 7 are shown in Figure 6 .4 .8 . 

The geopotential anomaly of 3 over 400 decibars (1 db = 10 kPa) for the early May 1993 

and August 1993 observations is shown in Figure 6.4 .9. In May, the indicated 

geostrophic velocity is directed downcoast, while in August it is upcoast. The change in 

direction is the same in 1994. The downcoast flow in May is to be expected in the 

absence of upwelling; the upcoast flow in August is consistent with upwelling. 

Further information regarding the mean currents on the south Texas shelf is supplied by 

records for the period April through September from the top current meters (10-14 m 

depth) of LATEX moorings 1, 2, and 3 (Figure 6.4 .3). Records with some gaps exist and 
79 

have been processed for 1992 and 1993 . Records for 1994 have been processed only 

through 27 July . Table 6.4 .2 provides mean alongshore components for six-week 

periods . Means are given for each year so far as data are available. Although the 

variability of the currents is so great that confidence limits can be expected to be wide, 

the current records represent the only direct measurements available. 

From 8 April - 19 May, the alongshore component was downcoast in all years and had 

the only downcoast mean taken over the three years. The downcoast direction agrees 

with the evidence of the inner shelf temperatures and salinities for April and May in 

indicating that upwelling is not dominant in this period . From 20 May - 30 June, the 

multi-year mean is upcoast but quite small. This indicates that the period is a plausible 

time for transition to the higher positive means for 1 July - 11 August. For the latter 

period no disagreement exists between the upwelling condition, upcoast current, and 

upcoast mean stress . Finally, the relatively small mean from 12 August - 23 September 

(no 1994 data) indicates that this period is at least a plausible time for transition to mean 

downcoast flow accompanying mean downcoast wind stress . 
29N 

29N . ' .,~ .,~. . . 

_as 

27N 

27N 

26N~ . . . : . . . ; . . . . . : . . . . . ; . ; . . . . : . . ; . . . 

25N z5N 111 

24N 

24N ~ . . . . 

. . 

23N 

23N 1 111 

22N 

22N . . . : . : . . : . . _ . . . : : . . 

21N . 

21N- . . . : . .

.1 r . ~ . . l l, 

99W 98 : 5W 98W 97 . 5W 97W 96 . 5W 96W 95 . 5W 95W 

0 

Figure 6.4 .1 . Climatic monthly mean wind stress for 2° squares along the western boundary of the Gulf of 

Mexico between 20° and 30° N. 
OCEANOGR,APHSC .FEATURES ± ANALYSIS TErQ NQAA/NDSE,/OPC, 5200 AUTH :RD, #100 

WASHINGTiON, DC 20233 : 32 

TELEVHQI~ : '(301) 763-829 - 31 

To ORDER CHARTS : (704) 211-4619 2°-

., .r?_~~_. . . .. . ; . . .. . . . _. . . .. .. .. . . . . .. .. . .. .._ .. 

7-

26 ANALYST ANALYST : : JENIFER CLARK 25 

24- GS GULF STREAM SEMI SHELF HATER 23 LC LOOP Cu12.REtdT SLIT SLOPE ~~jATER 

CF.- (:OLD F. .I!t?Y - SAR~ SARGASSO HATER 

iTE HARPS F:C?DY LAB LABRADOR CURRENT 

FRO,1dTS LO ATIQ21 

0-~ Days Old 

-' - -' 4-7 Days Old 

- "-' " >? Ws Old 

DIRECT7,0t~1 OF FI.OT~i (NOT ILYTS) 

80 

LC SSTS STILL 

., 

"SI 

I-- 

I 

I 

t 

r2.9 

i 30 

C061 31 

. : . . . 

~o 

2~9 

s`~ `.'a _-~- 

30 

PARTIALLY INVERTED 

3 0 

T r, 

C) - 

Iz 30 31 

30 L 

z 

0 

3 

'1 

3 

31 -3 

1 

2 

30 

L 

7 30 

29 . 

-30- . \ . 

~-]2 9 COO L" 

28- 

n C) 

81 

6.4 .2 . Example of NOAA/NOS/OPC Oceanographic Features Analysis 

showing the cool band along the western boundary of the Gulf. 
82 

Table 6.4 .1 . Relative frequency of coastal cool bands that are cooler by 2° C 

or more than the adjacent open Gulf and extend 4° or more in 

latitude along the western boundary. 

June July Aug Sep 

1992 0.33 0.78 0.33 <0.11 

1993 <0.11 0.89 0.44 0.22 

1994 0.33 0.89 0.89 0.44 

Mean 0.22 0.85 0.56 0.22 
83 

30° 

I 29° 

I 28° 

I 27° 

I 26° 

970 W 96'W 950 W 

Measurement Locations 

K 

1 

r 1 h 1 G IVIGLGVI VIVVIliQl %7lCllIV11 / I ' 1 

Figure 6.4 .3 . Locations of measurement stations discussed in the text . 
84 

Near-Surface Mean Temperatures 

30 

29 a:. . . ........ ... . . . . . ....... . .. . . . . . . . . . . . ....... . . . . . ....... . .. . . . . . . . . . .... . .. . . . . ..... . . . . . . . . . . ..... . . . . . .... . 

28 . ..... . ... ........ . . . . . ... .... . .. . . . . . ... r i.. . . . . . .v.... . . . .... .~.~. . . ~.~ . .~ .... . . . . . ..... . . . . . . .i....... . 

~27 

./ .o U . .......t . . . ... ........ ... .',~. .y,...~P, . .`... . . . . . . . . .... ... .y . . . . .. . . . . . . . . ., . ..... . . . . . . ...... . . ... . . . . .v... .. . . . .t' 

...... . 

... 

m 26 . ....... . . . . . . . . ;X ... . .. . . .I . . . 0.... . .T . . . ; ~ .0 . . . . . .p....... . . . . . . . . . : . ...... . . . . . . ..... . ... . .... . 

ru 25 . . ...... . . . f..... .. . . . . . . . . . . ....... . . . . . . . . ....Q. . . . ....... . . . . . . ........ . .. . . . . . . . ....... . . . . . ..... . . . .... . . . . . . ?....... 

m .~. . 

: .t .. . . . . 

a 24 . ...... . ... .......~ : Inner-Shelf ~ ..... . .4....... 

H 23 ~. 

0 , -r- Brazos Santiago Tide Station, 1958-1971 

..... ... . 

' - K- - GUS III Stas W60 8 W61,1963,1964,1965 

.. 

22 . . ....R . . . . . .. . ........... . O LATEX-A Moorings 1 & 2 Top Meter, 1992 & 1993 . . ..... . . . . . . . .. 

' Outer- and Off-Shelf 21 . . ...... :. . . . . . . . . . ........... . : . . ...... .. . ;. . ... .. 

D Etter and Cochrane, 1975 (Bathythertnograms) 

20 

Apr May Jun Jul Aug Sep Oct Nov 

Month 

Near-Surface Mean Salinities 

37 b:- --.. . . . . . . . . .... . . . . . . . . .. . ..... . ... ..... . . . . . ... . . . . . . . . . ....... . . . . . . ....... . . . . . . . . .... . . . . . .. ... . . 

36 . . . . . _ . ... . . . . . . . . .... . . . . . . . . . . . . . ...... . . . . . . . . .... . . . . . . . . . . . ........ 

_ 

-'..\ . . . . . . ... . . . . . ..... . . . . . . . . ..... . . 

.~ 

35 .. . . . ..b...... . . . . . . . . ... ....i. . . . . . . ..' 5 . . . .. ...... . . . . . . . . ..i. ... . . . . . . . . .. . ......5 . .. . . . . . ..... ~.~.. . . . . . .... ... . . . . . .o..... . . 

'c 34 . . . . . . .. ..~. . . . . . . . . . .. . . . . ...... .. . . . . . . . . . . . . . . . . . ... . . . . . . . . . . .... . . . ... 

~ 33 ... . . _ ......... . . . . . . . . . . . . 

e 

,.. . . . . . . . . . . . .. _ . . . . ........ . . . . . .... ... . . . . . . . . . . . ... . . . . . . . . . . .... . . . .. `~f... .~. r.... 

32 ... . . . . e.. ....... . . . . . . . . , e...... . . . . . . . . . . . ....d . . . . . . ........ . . . . . . .e .... . .. . . . . . . . . . . . ...e... . . . . . . . . .... . . . . . . ..... . . . . . ..... . . . . . .e ....... 

t Brazos Santiago Tide Station, 195&1971 

31 ... . . . . ;.. ....... . . .

.I 

. . . . . . ;. . .. ... . . . . . .... . . . . . . ;. 

- t -GUS III Stas W60 8 W61, 1963,1964,1965 

30 -`-r 

Apr May Jun Jul Aug Sep Oct Nov 

Month 

Figure 6.4 .4 . Monthly or fortnightly means of (a) near-surface temperature for 

inner shelf and outer or off-shelf locations, and (b) near-surface 

salinity for inner shelf locations. 
Sha llowest 1 -3m) CT D Temperature (C) 

30° N 30° N 

a. Early August 1993 b. Early August 1 994 

°31 

" 28 

29° N ; 29'N , 

0 28 

. 40 m ~ W . 40 m 

L 

. . 

28° N ° 

8 

100 m . 28 N 100 m 

500 m boo m 

30 

0- 29 /

2 7 29 

. . . 

. , !! 

° 27 N 9 27 ° N 

.W 

29 

i 26° N * 2 1 it I I I I I I I I I J j 

26 

I I I I I 11 

97° W 

- _L 

96° W 

_ 

95° W 97'W 96° W 95° W 

Figure 6 .4 .5 . Shallowest (1-3 m) CTD temperatures measured in (a) early August 1993 and (b) early August 1994. 00 
a I I owe st (1-3 m 

30° 

29° 

28° 

27° 

26° 

30° 

29° 

28° 

27° 

26* 

alinity 

v 

97° W 96° W 95° W 

00 

Figure 6.4 .6 . Shallowest (1-3 m) CTD salinities measured in (a) early May 1993 and (b) early August 1993 . 

97° W 96' W 95° W 
Figure 6.4 .7 . Topography of the 68 = 25 .0 surface based on measurements made in (a) early May 1993 and 

(b) early August 1993 . °° 
0 

20 

40 

60 

80 

E 

L100 

0 

120 

140 

160 

200 

240 

20 

40 

60 

80 

E 

n 100 

0 

120 

140 

160 

200 

240 

20' 10' 970 50' 40' 30' 20' 10' 

W. Longitude 

Vertical Section of GO Along Line 7 

19 2021 22 23 O 23 .5 

00 

00 

Figure 6 .4 .8 . Vertical section of 68 along line 7 made in (a) early May 1993 and (b) early August 1993 . 

20' 10' 97° 50' 40' 30' 20' 10' 

W. Longitude 
eopotential Anomaly o 

30° 

29° 

28° 

27° 

26° 

30° 

29° 

28° 

27° 

26° 

over 400 

Figure 6 .4 .9 . Geopotential anomaly of 3 over 400 db based on measurements made in (a) early May 1993 and 

00 (b) early August 1993 . 

97° W 96° W 95° W 97° W 96° W 95° W 
90 

Table 6.4 .2 . Six-week means of the alongshore component of currents at top 

current meters (10-14 m depth) of moorings 1, 2 and 3 combined 

(cm-s-1). 

1992 1993 1994 Mean 

08 Apr - 19 May -0.65 -1 .08 -8.09 -3.27 

20 May - 30 Jun <5.52> 3 -4.44 2.57 1 .22 

0 1 Jul - 11 Aug <4.80> 3 <4.76>2 6.72` 5.43 

12 Aug - 23 Sep -5.11 I <5.62>2 I - I 0.26 

< > Indicates that a six-week mean for one of the moorings is missing. 

The subscript indicates which mooring was missing. 

* Indicates that the records ended with 27 July. 

All entries in the table have been given equal weight in computing 

the multiyear means. 
91 

6.5 Phenomena at the Outer Shelf Bound 

Phenomena at the outer shelf boundary are being studied using hydrographic, current 

meter, and drifter data, as well as collateral data such as AVHRR and altimetric fields 

from satellites . One such phenomenon observed with the LATEX A data set was the 

anticyclonic Loop Current eddy, Eddy Vazquez (Eddy V) . Satellite altimeter data from 

the TOPEX/POSEIDON mission, not shown here, provided important information in 

developing the history of this eddy (Jochens et al . 1994). 

In summer 1992, Eddy V was observed in the Gulf of Mexico, adjacent to the TexasLouisiana Shelf (e.g ., Jochens and Nowlin 1994b) . During the fall and winter of 1992, 

Eddy V migrated along the base of the north slope into the northwestern corner of the 

Gulf. Eddy V spun down during December 1992 through February 1993, probably 

through interaction with another anticyclonic Loop Current eddy, Eddy Unchained (Eddy 

U), located in the southwestern Gulf (Jochens et al . 1995). By the end of February, the 

two eddies were separated completely. In March and April 1993, Eddy V and Eddy U 

interacted again . By May, Eddy V again separated from Eddy U. Each of these 

interactions weakened Eddy V, which dissipated in summer 1993, perhaps as early as 

June. 

The LATEX A hydrographic survey HOS provided observations of Eddy V adjacent to 

the shelf in early May 1993 and of a cyclonic eddy at the shelf edge to the west of Eddy 

V. Figure 6.5 .1 shows the geopotential anomaly of 3 db with respect to 200 db; station 

numbers are provided in Figure 3.4 .1 . The northern portion of Eddy V is apparent as the 

high in geopotential anomaly at about 27.5°N 95°W. The cyclonic eddy adjacent to Eddy 

V is apparent as a low in geopotential anomaly at about 27 .3°N 96 .3°W. Eddy V and the 

cyclonic eddy can be identified in the contour section of potential temperature taken 

along the 200-m isobath between approximately 97° and 94° W (Figure 6.5 .2). Eddy V is 

seen approximately between stations 207 and 211, and the cyclonic eddy is seen between 

stations 202 and 206 . Note that the cyclonic eddy has no expression in the upper 100 m. 

Figure 6 .5 .3 provides examples of potential temperature-salinity diagrams for 

hydrographic stations influenced by Eddy V (208, 136, and 91) and the cyclonic eddy 

(168) . Station 208 has a salinity maximum greater than 36 .5 at temperatures around 20 

C; this is indicative of the Subtropical Underwater that occurs in Loop Current eddies and 

suggests that water from Eddy V is found near the outer shelf. Stations 136 and 91, 

located progressively east of station 208, show an erosion of the salinity maximum 

present at station 208 . Station 91 shows the influence of fresher shelf waters, suggesting 

that shelf water is flowing off the shelf at the eastern edge of Eddy V; based on the 

temperature-salinity diagram, the offshelf flow of freshwater extended to depths near 50 

m. By comparison, station 168 is located within the cyclonic eddy. 

Current meter data from along the 200-m isobath show flow at approximately 12-m water 

depths consistent with the local flow indicated by the geopotential anomaly map. Figure 

3.2 .1 shows the locations of moorings 4, 6, 7, and 8 discussed in this section. Figure 

6.5 .4 shows the data from mooring 4, which in early May was located in the region of 

southward flow for the cyclonic eddy. Hydrographic station 168 is located next to this 

mooring. Figure 6.5 .5 shows the data from mooring 6, which was heavily influenced by 

Eddy V. It shows northward flow in early May, which, coupled with the Subtropical 

Underwater signature from the adjacent hydrographic station 208, suggests that water 

from the eddy was being moved onto the shelf. Figures 6.5 .6 and 6 .5 .7 show data from 

moorings 7 and 8, respectively . These moorings are next to hydrographic stations 136 
92 

and 91, respectively . Mooring 7, located in the region of high geopotential anomaly, 

shows strong eastward flow indicative of influence by Eddy V. Mooring 8, located at the 

eastern edge of the region of high geopotential anomaly, shows weaker flows varying 

from east to southeast. This, coupled with the potential temperature-salinity diagram for 

station 91, indicates flow off the shelf. 

LATEX A drifter 06938 was deployed at 27'51 .02'N, 94'10.48'W on 2 May 1993 at the 

200-m isobath near station 91 and mooring 8. It immediately was drawn off the shelf into 

the east flank of Eddy V, confirming an exchange of shelf water (Figure 6 .5 .8) . It 

circulated anticyclonically throughout May, confirming the separation of Eddy V and 

Eddy U. The circuits of the drifter moved progressively westward, showing that Eddy V 

was translating westward during this time. In early June, the trajectory of the drifter 

changed to a cyclonic loop as it was drawn into a cyclonic eddy that had been to the 

southeast of Eddy V. Satellite altimeter data showed that this cyclonic feature had moved 

northwest into portions or the Eddy V region, suggesting that Eddy V had become 

disorganized and may have dissipated in June 1993 (Jochens et al . 1994). 

The presence of Eddy V at the edge of the shelf and the cyclonic eddy to its west may 

have been factors in driving an offshore cross-shelf flow on the south Texas shelf. The 

cross-shelf flow can he seen in Figure 6.5.9 showing the salinity distribution at the sea 

surface from cruise HOS in May 1993. Between Corpus Christi and Brownsville, water 

with salinities less than 31 extended across the shelf. The surface salinities suggest that 

Eddy V spilled a tongue of higher salinity water onto the shelf near 95° W, and drew 

lower salinity water off the shelf farther east. 

This cross-shelf flow affected particle and nutrient distributions on the outer shelf (Sahl et 

al . 1994) . The waters of the offshore flow were low in temperature, nutrients, and 

density, as well as salinity, and, as shown in Figure 6.5 .10, high in particle beam 

attenuation coefficient (PBAC) . The tongue or water from Eddy V that spilled onto the 

shelf had lower PBAC and higher temperature, nutrients, and density, as well as salinity, 

than adjacent shelf waters . 

The primary impact of this cross-shelf flow nn particles was to transport a surface 

nepheloid layer (SNL) across the shelf. Cruise line 7 was the cross-shelf line closest to 

the axis or the cross-shelf flow . A vertical section of PBAC along this line illustrates the 

change in the SNL across the shelf (Figure 6.5 .11) . From mid-shelf to slope waters, the 

thickness of the SNL decreased from 25 m to 2.5 m. The particle concentration also 

decreased from the middle to the outer shelf. 

The structure or the SNL suggests that some of the particles contained in it were eroded 

from the sea floor. On the middle shelf, the SNL had a PBAC maximum located close to 

the base or the SNL. This structure would be created by the transport of a bottom 

nepheloid layer from the inner shelf into deeper water. Preliminary analysis of PBAC 

and fluorimetry data indicate that some, but not all, or the particles carried in the SNL 

were phytoplankton. 
30 

29 

28 

27 

26 

44 

1 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

Figure 6.5 .1 . Geopotential anomaly of 3 db relative to 200 db for the LATEX HOS cruise, May 1993. 

w 
Sta. 197 199 200 201 

0 

50 

100 

a 

N 

Q 

150 

200 

202 203 204 205 206 207 208 209 210 211 212 

\_ 24 q a_ 

22 

22 22 

\ 2 4 

O 

~~ 

20 

0 20 ~ \` 

11 

~ \8 

`'0 27, 

16 

22 

,8 do 

?o J 

/// \\` ~\/ V , ///'~ 16 

16 

50 100 150 200 250 

Distance along cruise track (km) 

300 350 

Figure 6.5 .2 . Vertical section of potential temperature along the 200-m isobath for the 

LATEX HOS cruise, May 1993. 
95 

25 

a u 

a 

0 

a 

20 

15 

10 ` 

33 33 .5 34 34 .5 35 

Salinity 

35 .5 36 36 .5 37 

° b :o a 

--~.. 

ww 

" Station 208 (10 May 1993) 

= Station 136 (5 May 1993) 

" Station 91 (2 May 1993) 

" Station 168 (7 May 1993) 

Figure 6.5 .3 . Potential temperature - salinity diagrams for stations 91, 136, 168, 

and 208, located in the western half of the LATEX Shelf along the 

200-m isobath. 
96 

so 

^ 4°-h LP May, 1993 

40 - 

v 

20 - w 

0 

0 0 

-20 

-40 

North 

V 

-80 

80 9-h LP I 

^ 40-h LP (heavy line) ifs 

40- 

20- 

~ o M 74AX 4 

V 

-20 m 

-40 

-80 

80 3-h LP 

40-h LP { heavy line) 

40 

v 20 

7 

- 

1 

O 

- -P - -q J A I lt ~ Y 

A~ 

o Vwvu~'~~-1 

.V . ._ 

a a 

F°, -40 

U 

-80 

30 3-h LP (dash: S; solid: T) 40 

40-h LP (heavy line) 

U 0 

v 25 '~J,J/~y!1 35 A 

20 30 ~ 

u F 

15 25 

0 5 10 15 20 25 30 

Time (Day) 

Figure 6 .5 .4 . Monthly plot of current velocity, temperature, and salinity for 

mooring 4 at 12 m for May-1993. 
97 

so 

40-h LP May, 1993 

40 

U 

20- 

w 

0 

U 

d 

p 

-20 North V 

Olf 

-40 

1 

3" , 

60 

) 

U74'T 

80 3-h LP 

40-h LP (heavy Una) 

40- 

20- 

:1 0 

2 0- 

tie - 

0 40- 

-60 d 

60- 3-h LP 

40-h LP ( heavy line) 

40 - 

v 20 - > 

0 

,°, -40 

V 

U 

-80 

30 3-h LP (dash: S; solid: T) 40 

40-h LP (heavy line) 

U 0 

25 35 

d 

20- 

u 

E15 25 

0 5 10 15 20 25 30 

Time (Day) 

Figure 6 .5 .5 . Monthly plot of current velocity, temperature, and salinity for 

mooring 6 at 13 m for May- 1993. 
98 

so 4o-h LP May, 1993 

40 - 

U 

~' 20 - 

r. 0 

v 0 

o I ~ 

q -20 North 

-40 

V 

3W5sn 

U 

-80 Uas~r 

80 3- I 

40 - 

n P 

v 20 - 

::3 0 ~w ~ pyrr 

j -20 

-40 - 

-60- 

60 3-h LP 

40-h LP ( heavy line) 

40 - 

Q 

20 - 

0 u 

a 

~ -20 - 

1, 

r N ~ N Y Vv v ~ r + 

0 -40 - 

-60 

30 3-h LP (dash: S; solid: T) 

40 

40-h LP (heavy line) 

U 0 

v 

25- 35 

E 

P-20- -30 

H 

15 25 

0 5 10 15 20 25 30 

Time (Day) 

Figure 6.5 .6 . Monthly plot of current velocity, temperature, and salinity for 

mooring 7 at 14 m for May. 1993. 
99 

so 

40-h LP May, 1993 

40 

U 

20- 

w 0 

0- 

\\- -20 - q North 

-40 

On V 

Vr 

U 

99'f 

80 9-h LP 

40-h LP (heavy line) 

40 - 

20 - 

:1 0 

-zo 

m 

-40 - 

-60- 

60- 3-h LP 

40-h LP ( heavy Une) 

40- 

20- 

- . kk - A . A , :4 

0 - 7T V-V-V-Y V T v \rV V J10 V 

w -7 

2 oW 

0 -40- 

1 -60 

30- 3-h LP (dash: S; solid: T) 

40 

40-h LP (heavy line) 

U 0 

a~ 25 35 v, 

J 

CU 20 - 

w y . 

-3U 

u 

E 

15 25 

0 5 10 15 20 25 30 

Time (Day) 

Figure 8 .5 .7 . Monthly plot of current velocity, temperature, and salinity for 

mooring 8 at 15 m for May, 1993. 
inn 

LATEX-A Drifter 6938 02 May to 17 Oct 1993 

30 

Deployed 02 May 

25 

-100 -95 -90 -85 -80 

150 

75 

O 

G'. 

U -' - - --° 

-75 . . ..... . . . ... . . ... . .._ . ._ . . ._. . . ........ . . . . . . . . .. . .... . . . . . . . ..---.- . .---- .----.... . . . . .... . . . . . . . . . . . . .-- .-- .-.--.... ..... .. . . . . . . .------------- .---- .-- .1 ." . . . 

-iso 

May/2 May/30 Jun/27 

150 

75 - -

0 

> `-' ~ Irlr ~y 

-75 

150 

Jul/25 Aug/22 Sep/ 19 Oct/ 17 

May/2 May/30 Jun/27 

200 

150 

U 

TJ 

-- . . . . . . - ~-- . . . . . . . . . . . Q. 50 

0 

Jul/25 Aug/22 Sep/19 Oct/ 17l 

May/2 May/30 Jun/27 Jul/25 Aug/22 Sep/19 Oct/17 

Figure 6.5 .8 . Trajectory of drifter 6938, May to October 1993, with U (east) and 

V (north) velocity components and speed. Circles in the trajectory 

trace represent the drifter's position at midnight each day. The 

record is 168 days long. 
,1 ~ vv 

d~ . 

30 __ Il . ... .... .. . _ . . ~ _ .. 

~. 

, 29 ~. . _ _ .~. 3 ~ ..~ . . . : . 

1 ~ 

o e ~ 

Yy' 

3? ~--~ 3Z 

\ ~7 

V 

~ g / 

~ ?6 ~Ql 

~ O , v~.r 

3 ; 34 

e 0 34 ~-.i 

28 

32 . 

_ . 3 .. .. .a . . _ 

^~°, 

a ._ __ ... . . . ._sJ ..3e ...., . ~3 .. .. _ . . .. ... . . 

e o d > 1 

. . °° 

\~1 

26 __ ~.e .. . . > _ .. . . ... .. . 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

Figure 6.5 .9 . Salinity at 3 m depth for the LATEX HOS cruise, May 1993. 

0 
30 

29 

28 

27 

26 

e 

7!v; 

5~! 

. . 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

0 

N 

Figure 6.5 .10. Distribution of particle beam attenuation coetncient ~m-l) at L m aepcn ror me i.Hir-Anva cruise, may lyyI. 
103 

Sta.181 180179 178177 

0 

50 

a. 

Q 

100 

150 

Distance along cruise track (km) 

176175 174 173 172 171 170169 168167 166 165 

r 

0.6 p. 

^ 0.2 0.2 

Q~'L 

~5 

\ 

2 

1 

~ C .60,1f~ 

1 

00 

oa 

0 0 

a 

o 

N 

0 

a 

N 

O 

50 100 

Figure 6.5 .11 . Vertical section of particle beam attenuation coefficient (m-1) 

along transect 7 for the LATEX HOS cruise, May 1993. 
104 

6.6 Analysis of Wind Fields over Texas-Louisiana Shelf 

Surface winds significantly influence the ocean environment of the Texas-Louisiana 

Shelf. Wind stress serves as a primary driving force affecting the pattern of shelf 

circulation, while evaporation and surface heat flux related to wind modify the 

distributions of water properties and thus the vertical stability . The wind fields over this 

region display a marked seasonal march (Hastenrath 1968). During summer, the 

atmospheric circulation over the region is dominated by the western end of the North 

Atlantic Anticyclone and the downstream portion of the trades (Elliott 1979); winds are 

northwestward and relatively weak compared with those in other seasons. In fall and 

winter, the polar front moves to the south, generating a series of intense cold fronts that 

pass over the shelf region ; winds are dominated by westward or southwestward 

components. 

Cochrane and Kelly (1986) showed a clear seasonal pattern of ocean circulation in this 

region . They indicated the dominant feature of the shelf circulation is a cyclonic gyre 

elongated along the shelf. The inshore limb of the gyre is a coastal current. West of 

92 .5° W, the coastal current is driven primarily by the along-shore component of wind 

stress. They stated " . . . the western or southern end of the gyre migrates seasonally with 

the direction of the prevailing wind, reaching south of the Rio Grande mouth in fall and 

[off] Cameron in July. The gyre is normally absent in July, but reappears in AugustSeptember when a down-coast wind component develops." The coherence between shelf 

circulation and wind stress has been examined by others ; e.g ., Lewis and Reid (1985) 

studied the response of the coastal current off the Texas coast to the local wind in the 

summer and fall of 1978 and the winter of 1979. Their results showed that in fall and 

winter, the current is driven by local wind forcing ; in summer, it is driven by a 

combination of local wind plus non-locally generated shelf wave phenomena due to weak 

local wind. 

In addition to the seasonal variation, wind fields have large spatial and temporal 

variability at periods of a few days to a few weeks. Extreme events, such as hurricanes, 

frontal passages, cyclogenesis, and severe cold-air outbreaks, often occur over the 

LATEX shelf. Such extreme events affect the circulation and water mass distributions 

over the shelf. Accurate, high-resolution wind fields are needed for the study of such 

effects. 

To date, there have been several compilations of wind stress fields over the Gulf of 

Mexico, including the Texas-Louisiana shelf; e .g ., Elliott (1979) calculated seasonally 

averaged wind stress fields for the Gulf of Mexico with 1°-grid resolution using historical 

ship data through 1972; Rhodes et al . (1985) calculated corrected geostrophic winds for 

the period 1967-1982 using surface pressure analysis with 280- to 300-km grid 

resolution and 12-hour temporal resolution. 

The National Meteorological Center (NMC) analyzes the global surface wind fields with 

1 ° spatial resolution and 6-hour temporal intervals using their Global Data Assimilation 

System (GDAS). GDAS consists of several parts, including the processing of observed 

data, objective analysis, initialization, numerical forecasting, and post-processing 

(Kanamitsu 1989). The NMC analyzed fields differ from fields produced by analyzing 

observed data alone. The regional NMC analyzed surface wind field for 0600 UTC on 4 

November 1992 is shown in Figure 6.6 .1 . 
105 

From April 1992 through November 1994, the LATEX meteorological buoys provided 

data over the mid Texas-Louisiana Shelf, measuring hourly sea level pressure, sea surface 

wind speed and direction, sea surface temperature, and surface air temperature. In 

addition, there were seven National Data Buoy Center (NDBC) buoys and nine CoastalMarine Automated Network (C-MAN) buoys operative in the area. Four land weather 

stations along the coast were chosen to supplement the buoy stations . The locations of all 

twenty-eight stations are shown in Figure 6.6 .2 ; on the shelf, the mean separation of 

observations was about 0.8°. 

Directed by Professors R.O. Reid and W.D. Nowlin, Ms . Wensu Wang, a Ph.D. student, 

is analyzing selected surface meteorological fields for the LATEX region and field 

period . Gridded values will be obtained at 0.5° spatial resolution over the TexasLouisiana shelf and adjacent regions by using all observed data from the 28 stations . The 

principal objectives of this research are: 

1) To produce time series, probably at 3-hour intervals, of surface meteorological fields 

for selected episodic atmospheric events over the Texas-Louisiana Shelf. These might 

include hurricane Andrew, cyclogenesis of a major storm, and frontal passages . This 

work also will serve to examine the effectiveness of selected distinct objective analysis 

procedures by comparing analyzed fields with those obtained by subjective analyses 

using the same data. 

2) To apply the chosen objective analysis procedures to produce seasonal patterns of 10-

m wind and pressure, surface wind stress, and perhaps wind stress curl, SST, and surface 

air temperature for the LATEX shelf during the field period. 

Winds were measured at different heights during the LATEX field period: LATEX 

buoys measured them at 3.6 m; some NDBC buoys measured at 5 m, others at 10 m; 

measurement heights at C-MAN buoys varied from station to station. To be compared 

and used as surface wind, the observed wind must be adjusted to a common height, 

usually to 10 m. The shape of the vertical wind profile over the sea depends on the 

aerodynamic surface roughness length and the air stability in the marine boundary layer 

(Smith 1988). Surface roughness is a function of wind speed. Stability depends on the 

temperature difference between air and sea and wind speed as well. Using empirical 

formulae, the wind profile can be calculated if the wind, surface sea and air temperature, 

and humidity are given at the height of observation. A number of variants of these 

empirical formulae are in use. Among the adjustment methods, those of Smith (1988), 

Liu et al. (1979), and Large and Pond (1981) are commonly used. These published 

empirical formulations have been compared over a broad range of temperatures, winds, 

and stability; a preferred algorithm has been selected. Based on examination of surface 

humidity measured on Voluntary Observing Ships (VOS) and at platforms over the 

LATEX area, a mean humidity was estimated for use in the algorithms . 

The surface meteorological fields are measured at irregularly distributed stations over the 

shelf and adjacent regions. However, for many purposes it is necessary to use regularly 

arrayed data sets . This is true for contouring fields of these variables or for their use as 

the boundary conditions in numerical model of shelf circulation. 

There are various methods of gridding the data. The basic principle is to estimate the 

value at a grid point from a weighted average of nearby observed data. The simplest 

methods, such as that of Barnes (1964, 1973), use a known function of distance as the 

weighting function. This method is commonly used for mesoscale analysis in 
106 

meteorology (Koch et al. 1983) and it is in the General Meteorological Data Assimilation, 

Analysis, and Display (GEMPAK) software package. Another method is the "minimum 

curvature" method (Smith and Wessel 1990). A modification of this method is used in 

the Generic Mapping Tool (GMT) software, a package commonly employed in 

oceanography. A third method is statistical interpolation (SI) based on an estimation 

theory known as optimal estimation and used in meteorological data analysis (Gandin 

1963). It was first applied in oceanographic analysis by Bretherton et al . (1976) . 

A set of wind events were selected and subjectively analyzed fields prepared. Using the 

same data sets, three objective analysis methods were used to prepare corresponding 

fields : GMT, GEMPAK, and the SI method. These results were compared to one 

another and to the subjectively analyzed fields . The comparisons showed that the SI 

method has distinct advantages ; this method was chosen to analyze the surface 

meteorological fields . At this stage of our analysis, we are estimating covariances for the 

meteorological fields for which we intend to produce gridded and contoured fields . 

For the month of November 1992, observed winds at each station (Figure 6.6 .2) for 6-hr 

intervals were corrected to 10 m and components were averaged. Then the SI method 

was applied to obtain gridded fields of components, which were combined to produce the 

mean 10-m wind field shown in Figure 6.6.3 . For contrast, we show in Figure 6.6 .4 the 

10-m wind field produced by the same objective method for 0600 UTC on 4 November 

1992 during a major cyclogenesis event. Figure 6.6.4 should be compared with the NMC 

wind field for the same time shown in Figure 6.6 .1 . 

We show another comparison between our analyzed 10-m wind field at 1700 UTC on 7 

November 1992 (Figure 6.6 .5) and the NMC analyzed field for the same time (Figure 

6 .6 .6). One major difference in those fields is the trend toward decreased speed and 

southward winds over the far western shelf in our analysis . For comparison, we show 

(Figure 6.6 .7) the wind field for that western region at the same time as derived from the 

scatterometer data from ERS-1 (Freilich and Dunbar 1994) . This ERS-1 field agrees 

more closely with our analysis . 
30 

29 

28 

z, 

26 

I Is velocity : m/s LOUISIANA 

. . ; ... .. ... . ... ... .. ...... ;.. ... ... . Y ~ _ 

~

. 

0 25 50 Houston : 

... ... ..

.NeVv Orleans

...r.. ... . . .... . ... ... .... . . ... .... ... .... ... 

S 

Galvestori 

TEXAS 

... . ... .. .... ... ... ._ Q . . ... .. .... ... .... ... .. .... .. ... .... ... . .. .... ... . ~(~ 

cr ~- 0 o y 

... . ~ O .... . . . ~ . .. . . ... 

- 

vO: .c~ 

50 ZO . 

-- , . 

1000 

d 1 0 

Vr 4 T t , 

O ~ y ~ O 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

Figure 6.6 .1 . National Meteorological Center analyzed wind field at 0600 UTC on 4 November 1992. 

0 

~1 
30 

5~ ~-

/ .-.- 220 

29 

28 

27 

26 

-97 -96 -95 -94 -93 -92 -91 -90 -89 -88 

0 

00 

Figure 6.6 .2 . The distribution of observing stations used in analysis of surface meteorological variables. 
Figure 6.6 .3 . Mean 10-m wind field for November 1992. 

0 ~a 
0 

Figure 6.6 .4 . 10-m wind field at 0600 UTC on 4 November 1992 . 
30 

29 

28 

27 

26 

. . .. r 

b 

`~tY 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

Figure 6.6 .5 . Wind field at 1700 UTC, 7 November 1992. 
N 

Figure 6.6 .6 . NMC analyzed wind field at 1700 UTC, 7 November 1992. 
Figure 6.6 .7 . ERS-1 wind field at 1700 UTC, 7 November 1992. 

w 
114 

6.7 Summary of Cyclogenesis Study 

Cyclogenesis is defined as any development or strengthening of cyclonic circulation in 

the atmosphere . The term is applied here to the development of low-pressure systems 

over the northwestern Gulf of Mexico. Between 1972 and 1982 an average of 10.4 

winter cyclones developed each year over the LATEX region . Of these, 5 .5 cyclones per 

year developed central pressures at or below 1010 mb. The 1983 winter season 

(November to March, inclusive) was by far a more active cyclone season for the Gulf 

than during the preceding 11-year period . A total of 26 surface cyclones affected the 

region . Of these, 21 attained central pressures at or below 1010 mb; five of these 

cyclones were "meteorological bombs", i.e., the pressure drop exceeded 0.5 mb per hour, 

or 12 mb for a 24-hour period, at latitudes of approximately 28° N. 

From November 1993 through May 1994, there were 13 winter cyclogeneses over the 

LATEX region (Table 6.7 .1). The 1994 winter season (November to March, inclusive) 

had nine cyclogeneses, which was close to the average ten discussed above. Of these, 

five attained central pressures of or below 1010 mb or at least Class 2 in Hsu's 

classification (1993), and two were "meteorological bombs" (13 December 1993 and 27 

March 1994). 

At LATEX mooring/buoy station 22 (Figure 6.7 .1) between 22Z (UTC) on 12 December 

and 06Z on 13 December 1993, the atmospheric pressure dropped from 1012.8 mb to 

1003.95 mb, an 8 .8 mb decrease in eight hours (Figure 6.7 .2), indicating the development 

of a meteorological bomb during this period. This characteristic was widespread over the 

LATEX region, as shown for NDBC buoys 42002, 42019, 42020, and 42035, as well as 

C-MAN station PTAT2. The wind speed increased from around 5 ms-1 in the morning 

hours of 12 December to over 14 ms-1 twenty-four hours later (Figure 6.7.3) . Note that 

the precipitous decrease in wind speed around 12Z on 13 December at both PTAT2 and 

NDBC buoy 42020 occurred about six hours later than the pressure minimum, indicating 

that the center of this cyclogenesis was located in the south LATEX region between 

PTAT2 and buoy 42020. 

The development or significant wave height (H,), at buoys 42002, 42020, and 42035 are 

shown in Figure 6.7 .4 . At buoy 42020, HS increased approximately 3 m within 24 hours. 

Because cyclogenesis was initiated in the vicinity or that buoy, HS increased more rapidly 

there than at 42002 and 42035. 

Wave steepness is defined as the ratio of wave height to wave length . From linear wave 

theory, the steepness is Hy/gTP2 = k, where Hs is the significant wave height, g is gravity, 

Tp the dominant wave period, and k is assumed to he a constant for a given wave 

condition (e.g ., Gilhousen 1993) . Buckley (1988) reviewed the entire archive of the 

NDBC for all stations and Canadian oil rig observations and obtained an extreme 

steepness value of k = 0.00776 . Gilhousen (1993), using NDBC buoys 42019 and 42020, 

plotted a chart with the vertical axis as H5 in meters and the horizontal axis as T in 

seconds for the "Storm of the Century" nn 12 March 1993 over the LATEX region . ~is 

results show that some measurements were located to the left of Buckley's Extreme 

Steepness Curve, indicating phenomenal wave growth and confirming the presence of 

strong winds and a rapidly deepening storm . According to Gilhousen (1993), these steep 

waves also portend the type of widespread maritime calamity that followed, where the 

U.S . Coast Guard conducted 111 search and rescue efforts from Texas to Appalachee Bay 

related to these storm effects. 
115 

Figure 6.7 .5 provides added evidence to show that winter cyclogenesis over the LATEX 

region can produce a wave steepness that exceeds the statistical extreme steepness value 

obtained by Buckley (1988). Because the storm on 13 December 1993 was only 

moderate, it is very surprising to see that so many measurements exceeded the Buckley 

limit. We checked the data at NDBC 42035 and found no case in which the waves were 

under either shoaling or fully-developed conditions, indicating more steep waves existed 

in the shallower water (= 20 m) for 42035 than at the deeper water (= 200 m) along the 

shelf break at 42020. More studies on this subject and its effect on the drag coefficient 

formulation for shallower waters induced by winter cyclogenesis are recommended. 

The wind stress or the flux of momentum at the sea surface affects nearly all aspects of 

air-sea interactions, including the growth of surface gravity waves, the generation of 

surface currents, and the development of the mixed layer. Wind stress, 'C, is often 

estimated by ti = pCdU 102, where p is the air density, Cd the drag coefficient, and U to the 

wind speed at 10 m above the mean sea surface. Since ti is directly proportional to Cd, it 

is crucial to get as accurate a formulation as possible . 

Because published equations of Cd varied greatly in the literature, a proper Cd 

formulation for the LATEX region was needed. Since Cd is related to the aerodynamic 

roughness length, Zo, which in turn is related to the wind waves, any Cd formulation must 

include the wave parameters (Hsu 1994x) . Most recently, Donelan et al. (1993) proposed 

a formulation in which Zo is directly proportional to the significant wave height and 

inversely proportional to the 2.6 power of the wave age. Therefore, Cd can he estimated 

from both wind and wave data. During an extreme winter cyclogenesis period in March 

1993 (the "Storm of the Century"), simultaneous measurements of wind and waves were 

made in the LATEX region. The results are shown in Figures 6.7.6 and 6.7.7 . While the 

variation of Cd with U to along the shelf break was published in Hsu (1994b) as shown in 

Figure 6.7.6, its variation over the deep Gulf is shown in Figure 6.7 .7 . Figure 6.7 .8 

shows the comparisons of both equations or Cd over the northwest Gulf of Mexico and 

other areas. It can be seen that over the LATEX region, the closest popular formulation is 

that or Wu (1982), whereas usage of both open ocean (e.g ., Large and Pond 1981) and 

lake environment (Donelan 1982) formulations can lead to large errors. 
116 

Table 6.7 .1 . Winter cyclogenesis over the northwestern Gulf of Mexico from 

November 1993 through May 1994. 

Year Month Day Intensity* 

1993 November 9 1 

December 13 3 

December 19 1 

December 22 2 

1994 January 11 1 

February 5 1 

February 10 2 

March 1 2 

March 27 4 

April 19 1 

April 22 2 

May 2 1 

May 14 2 

* The intensity classification is based on Hsu (1993) . The data source is "Daily Weather 

Maps", published weekly by NOAA. 
117 

32N 

*NDBC BUOYS 

A C-MAN STATIONS 

Q LATEX BUOYS 

uvu ; 

d 

0 

0 

ssw 

42035 e o '' 

@#22 

. . . . . . 

r 

t42020 GULF OF MEX'CO 

I 

42002 

. . . -20 METERS 

j ---200 METERS 

96 94 92 90 

30 

28 

2s 

J 24N 

saw 

Figure 6.7 .1 . Locations for the winter cyclogenesis case study, 

12-14 December 1993. 
118 

December 1993 Air Pressure mb 

1024 

1020 

0 1016 

o 

d~ 

1012 

1008 

r 

1004 ~ 

1025 

1020 

1015 L 

o ` 

1010 

1005 

r 1000 

1025 

1020 

1015 

0 

1010 

1005 

1000 

12 13 14 15 

Day GMT 

Figure 6.7 .2 . Characteristics of atmospheric pressure over the LATEX region during 

the winter cyclogenesis case of 12-14 December 1993. 
119 

December 1993 Air Pressure mb 

1025 

1020 

`n 1015 

o ' 

1010 

r 

1005 I 

1 

1000 

1025 

1020 , 

1015 F 1010 

1005 

1000 ~ 

1025 

1020 - 

i 

1015 

C\2 

1010 

1005 

I 

I 

1000 i 

12 13 14 15 

Day GMT 

Figure 6.7 .2 . Characteristics of atmospheric pressure over the LATEX region during 

the winter cyclogenesis case of 12-14 December 1993 (continued). 
120 

December 1993 Wind Speeds m/s 

16 

14 

cQ 12 

0 

0 10 

c\2 

~r g 

f 

6 

4 . 

16 

14 ~ 

12 - U 

10 -

6 

4 ; 

16 

14 

12 

v 

C\2 1 0 

O 8 ; 

C\2 j 

6 

v 

4 ~ I I 

12 13 14 15 

Day GMT 

Figure 6.7 .3 . Characteristics of wind speeds over the LATEX region during the 

winter cyclogenesis case of 12-14 December 1993. 
121 

December 1993 Wind Speeds m/s 

16 ; 

14 

12 

LO -

c~ 10 

c~\2 8. w 

I 

4 

14 

12 

10 v 

S 

6 v 

4 ~/ 

z o 

14 

12 V 

10 

C\2 

C\2 8 

V 

6 

4 

2 

12 13 14 15 

Day GMT 

Figure 6.7 .3 . Characteristics of wind speeds over the LATEX region during the 

winter cyclogenesis case of 12-14 December 1993 (continued). 
122 

December 1993 Hs m 

4 . 5 

i 

3 .5 

c\2 

0 

0 2 .5 

1 .5 

0 .5 ~ ' i 

3 .5 

0 2.5 

o 

c\2 

-1' 1 .5 

i 

0.5 i 

3 .0 

~n 2A ~ I i cY'D 

0 

am d "1 .0 i 

0 .0 

12 13 14 15 

Day GMT 

Figure 6.7 .4 . Characteristics of H5 over the LATEX region during the winter 

cyclogenesis case of 12-14 December 1993. 
123 

H vs. Wave Period December 12-14 1993 s 

5 

~E 0 3 

r 

eS~eeQ 

31E 

O ~ ~E ~ 

c\2 2 )E 

MOK N( 

I 

0 

4 

o 

S~eeQ°~ ~ ~~ CIE 

d" . '~ ~~~e~`e )K '` ~ jlE 1 ' c~, ~~IEE 

4 ; 

cY'D ~ )E 

0 2 = oe¢ )E)E 

C\2 

e 3191E 

I I I ~ 0 2 4 6 8 10 12 

Dominant Wave Period (s) 

Figure 6.7 .5 . Measurements of H, and TP from NDBC buoys #42002, #42020, and 

#42035 during the cyclogenesis period 12-14 December 1993 . 
5 .0 

For Buoys 1142019 b M42020 i 

i 

103 Cd= 0.69 . 0.081 Up 

With Correlation Coefficient : 0 .97 

2 .5 

lr, 

.d I 

`w 2 .0 i 

u 

N 

o 's 

U 

`. 

" 

q 

.C 

N 1 .5 .~i . 

c "/ . 

t /. 

Data Source : 

i~ North Sea (Geernaert Et AI ., 1987) " Buoy ff42019 

" Buoy M42020 

/ ~ East China Sea (MSU,1994b) *Occurred Twice At A42020 iy NOBC Data Set For 

Gulf Of Mexico (Along The Continental Shelf Break, March 11-14,1993 (During A 

Winter Cyclogeneaia Period) HSU, 1994b) 

0 . 5 

0 5 10 15 20 25 30 

Wind Speed At 70m Above The Mean Sea LevsI,Ulp,m/a 

N 

Figure 6.7 .6 . A relationship between Cd and Ulp based on the wind-wave interaction method for 

the LATEX region and its comparison to the North Sea and East China Sea. 
3.0 

I I I I I .' 

For Buoy 1142002 In The Gulf Of Mexico 

i 

1o3 ca : o.76 . o.o7o u ,a 

With Correlation Coefficient= 0 .98 

i 

2 .5 

i i i i i 

U 

O 

0 2 .0 

u 

o 

o 

U 

d 

rn 1.5 " j 

v 

r 

o 

r 

:r 

i i 

Q ~ ~ Gull Of Mexico (Along The Continental Shelf Break) Oats Source : 

" NDBC Data Set For 

Gulf Of Mexico (Deep Gulf) Match 11-14,1995 (During A 

Winter Cyclogeneals Period) 

Occurred More Than Once 

0.5 

0 5 10 15 20 25 30 

Wind Speed At 10m Above The Mean Sea LavsI,U1o,m/s 

Figure 6.7 .7 . A relationship between Cd and Ulo based on the wind-wave interaction method for 

the LATEX region . 
3 .0 

25 

,2,9~i Jai~i 

1w" ,i S~ 

e~~ " ~~~~~ rr~0q1 

2.0 t i o 

NZ 0- b 

a . : i i''' '4° . .` 9° 

1 .5 

z 

r 

. . .. . . ..y . . .. . . ..... . . ... . . . ..... . . . . .. . . . . : 

1.0 

0.50 5 10 15 20 25 30 

Wind Speed At 10m Above The Mean Sea Surface, U , m/s 

N 

Figure 6.7 .8 . A comparison of Cd formulations over the LATEX region and others published in 

the literature . 
127 

6.8 Summary of LATEX Wave Observations during Hurricane Andrew 

On 24 August 1992, the LATEX program had four bottom-mounted wave gauges in the 

northwestern Gulf of Mexico as Hurricane Andrew moved westward across the southern 

tip of Florida (Figure 6.8 .1) . As the storm entered open water in the eastern Gulf, this 

relatively small but intense Category 4 hurricane followed a northwesterly arc and made 

landfall on the south-central Louisiana coast near Cypremort Point, LA, on 26 August 

1992. The easternmost wave gauge was located at mooring 16, within 30 km of 

Andrew's eye as the hurricane crossed the eastern edge of the Texas-Louisiana Shelf. 

The wave gauges deployed during the hurricane's passing were three Coastal Leasing, 

Inc. (CLI) MiniSpec directional wave gauges at moorings 16, 20, and 23, and one 

SeaData 635-8 non-directional wave gauge at mooring 1 . All four gauges were mounted 

approximately one meter above the bottom and recorded hydrostatic pressure ; the 

MiniSpecs also recorded current velocity and temperature. 

As Andrew traveled westward across the west Florida shelf into the deeper eastern Gulf, 

the hurricane quickly generated fast-moving long period waves that propagated westward 

and reached the Texas-Louisiana Shelf (DiMarco et al. 1995). Long period waves, i .e., 

waves of period 10 seconds and greater, are rare in the Gulf of Mexico for all but the 

most extreme weather events. Such long period waves are of particular interest because 

larger orbital velocity added to mean flow can resuspend sediments at much greater 

depths than under normal conditions. Arriving several hours before the storm's eye, the 

long period waves first reached the easternmost mooring 16. Although considerable 

distances from the storm center, the wave gauges at the more western locations also 

recorded longer period waves. 

The significant wave heights (HS) at each LATEX mooring during the 48-hour period, 

centered on the time of highest waves at mooring 16, are shown in Figure 6.8 .2 . The 

most striking feature is the peak height of 9 .09 m at mooring 16 at approximately the time 

the eye was closest to this location . The maximum wave heights observed at moorings 

20, 23, and 1 occurred when long period waves represented a large percentage of spectral 

energy, i .e ., at 2:OOZ, 3:OOZ, and 9:OOZ on 26 August, respectively . The waves traversed 

broad shelf regions before arriving at moorings 23 and 20 . Wave heights were lower at 

these locations than at mooring 1 even though the distances traveled were shorter. The 

phasing of the HS peaks at each mooring indicates that the long period swell generated by 

the hurricane propagated westward in agreement with linear wave theory . Further, by 

knowing the arrival times at each location of the long period waves and the wave celerity, 

one can extrapolate back to the location at which they were generated. This analysis 

obtained a generation zone in the southeastern Gulf of Mexico that extended from 26 .2° 

N, 85 .0° W to a point on the edge of the west Florida shelf around 25.8° N, 83 .1° W. If 

waves had been generated at locations east or west of this range, they could not have 

arrived at the LATEX wave gauges at the observed times. 

The frequency of the peak spectral value for each wave burst is shown as a function of 

time in Figure 6 .8 .3 . Early in the 24-hour period preceding Andrew, the spectra at 

moorings 20, 23, and 1 were generally dominated by locally generated high-frequency 

waves. Peak frequency dropped abruptly as the swell created by Andrew reached each 

mooring . The dramatic shift to low frequency was accompanied by a rise in the wave 

height at each mooring (Figure 6.8 .2). After the shift, peak frequency increased gradually 

with time because of the frequency dependent celerity of the waves . In a few cases, the 

wave spectra became multi-modal and showed peaks at both high and low frequencies. 
128 

In constructing the curves of Figure 6 .8 .3 for the case of a multi-modal spectra, we chose 

the peak whose frequency corresponded to swell and had a period greater than eight 

seconds, thus focusing on energy derived from the distant storm. The phasing of the 

arrival times of the long period waves is evident in this figure, with the waves arriving 

earlier at the eastern moorings. 

The spectral contour plot in Figure 6.8 .4 shows that when Andrew made its closest 

approach to mooring 16 the spectrum was multi-modal and exhibited significant energy 

density at higher frequencies (>0 .15 Hz). This figure also shows the evolution of the 

correlation between significant wave height and the spectral distribution of wave energy . 

At mooring 16, long period waves outran the storm center by several hours. The storm 

advanced at a speed of 14 km per hour while in the deep eastern Gulf (Stone et al . 1993). 

Low frequency waves continued to contribute to the energy spectra after the eye passed 

(after 6 :OOZ on 26 August) . During the eight-hour period when the storm center was 

closest to mooring 16 (20:OOZ on 25 August to 4:OOZ on 26 August), the spectra had 

considerable energy in the high frequency range (0.15-0.22 Hz). For example, at 1 :OOZ 

on 26 August, the spectrum consisted of locally generated wind waves and swell 

generated by the storm in the deeper Gulf. The spectra at mooring 16 were 

fundamentally different than the spectra recorded at the three other moorings, where the 

wave energy due to the hurricane was present only as swell. 

Because of its bi-modal structure, the spectra recorded at mooring 16 deserves special 

attention. This structure differs from many observations in deeper water of hurricane 

spectra that are characterized by a modified JONSWAP type distribution having a single 

low-frequency peak (Ochi 1994). Two major factors probably contributed to the 

significant energy involved in the frequency range (>0.15 Hz) of the spectrum of mooring 

16 when Andrew approached. The wave spectrum essentially represents a resultant wave 

field of a steep and narrow-banded long period wave train propagating to mooring 16 

from earlier Andrew wave generation, superposed by a locally generated long period 

wave field when Andrew passed nearby mooring 16. In addition, a significant portion of 

wave energy in the higher frequency range (0.14-0.17 Hz) results from second-order sumfrequency nonlinear effects of the steep long wave train (Longuet-Higgins and Stewart 

1960; Zhang et al . 1992). The nonlinear effects became more significant in this shallow 

(20 m) area because of the large spectral peak at low frequency and because the 

significant wave height approached half the water depth. A specific study to quantify the 

nonlinear wave effects in the high frequency range of the Hurricane Andrew data is 

underway. 
Louisiana 

~/ 

Mississippi 

Texas sits 1 8:00Z 

sits 12 :ooz --

30N 

IeL 

~looring 20 8/26 06:OOz 

o in o 

8/260 O:DOf 

28N ti . e . Y° 

8/25 18:00z 

0 00i g1 8/25 12 :00z 

2sN o 

Gulf of Mexico 42001 

98W 96W 94W 92W 90W 88W 

Figure 6.8 .1 . Map of the northwestern Gulf showing 50-, 100-, and 200-m isobaths, Hurricane 

Andrew storm track, and LATEX wave gauge and NDBC buoy locations. 

N 
10 

- , 

Mooring 1 

Mooring 16 

E 6- -~ Mooring 20 

---- Mooring 23 

CO 4 

2 

O . . ._ -. . .- .- . . _. . .- . ._~. . .~-" 

_ ~" .. - - _- 

20: 0: 4: 8: 12: 16 : 20: 0: 4: 8: 12: 16: 20: 0 : 

24 25 26 27 

August 

1992 

w 0 

Figure 6.8 .2 . HS measured at LATEX moorings 1, 16, 20, and 23 during Hurricane Andrew . 
0.25 

0.20 

0.15 

U 

C 

0.10 

0.05 

J 

1 / \/ 

. . . . Mooring 1 

0.00 1 1 

20: 0: 

24 25 

August 

1992 

4 : 8: 12: 16: 20: 0: 4: 8: 12 : 16 : 20: 0: 

26 27 

Figure 6.8 .3 . Spectral peak periods at LATEX moorings 1, 16, 20, and 23 during Hurricane Andrew . 

Mooring 16 

., . . . 

--~--- Mooring 20 

- - - - Mooring 23 

w 
0 20 0 

50 

. 

0 

o 

40 

0 .15 - 

N V 

s~ - 30, 

a 

U ° `r 

D 

0 .10 

a 20c" L k~+ `i/ 

`b~ " u 

0 .05 10 

0 .00 1 0 

OO :OOz 12:OOz OO:OOz 12:OOz OO :OOz 

8/25/1992 8/26/1992 8/27/1992 

W 

N 

Figure 6.8 .4 . Contour plot of energy density versus time with significant wave height (SWH) 

superimposed at mooring 16. 
133 

6.9 Acoustic DonDler Current Profiler Measurement 

Some of the limitations in the use of ADCP data on the Texas-Louisiana Shelf have been 

discussed in 7ochens and Nowlin (1994b) . The most serious of these is that the velocity 

vectors, such as that shown in Figure 6.9 .1 for cruise H06, do not represent a synoptic 

pattern of near-surface current. Based on the moored current meter data, considerable 

variability of the flow is known to occur at periods less than the two-week period 

required for the shelf-wide hydrographic cruise . Much of this variability is caused by 

winds on the inner and mid-shelf (see section 6.11), which tend to produce a nearly 

barotropic response for depths of 50 m or less . The ADCP measures this response which 

is not readily detected in the CTD measurements. 

One of the primary uses of ADCP is in assessing the vertical profiles of current, since the 

measurements over the water column at any given location do give a synoptic pattern 

with resolution superior to that provided by the current meter moorings. As part of his 

dissertation research, H-W. Chen has carried out analyses of the dominant vertical 

structures of current for selected ADCP cruises, of which H06 is one . The method of 

treating the velocity vector as a complex number allows evaluation or vector empirical 

orthogonal functions (EOFs) as first employed by Kundu and Allen (1976) . 

Figure 6.9 .2 shows the locations of ADCP transects AB along the 50-m isobath and 

transects CD, EF, and GH along the 200-m isobath during cruise H06. Dates, timeintervals, and number of ADCP vertical profiles along each of these transects are given in 

Table 6 .9 .1 . Complex EOF modes were computed from the complex covariance matrix 

formed by summing contributions over all profiles along the nominal 50-m transect AB . 

Vertical levels were restricted to those having a common range for all profiles . The 

resulting first, second, and third dominant modes are shown as vector stick plots in Figure 

6.9 .3 for each four meters in the depth range 10 to 38 m below the surface. The percent 

of the total variance (kinetic energy) explained by each of these modes is shown at the top 

of each profile. Similar EOF computations were carried out for the transects along the 

200-m isobath for a common depth range of 10 to 106 m. The resulting EOF modes 

based on combining covariance contributions from all three sections are shown in Figure 

6.9 .4 . 

The dominant empirical structures in each case are nearly unidirectional profiles that 

characterize about 68 and 85 percent of the kinetic energy along the 50-m and 200-m 

transects, respectively . The second and third modes, which contain one and two null 

vectors respectively, contribute much less to the kinetic energy. Representation of the 

currents in terms of the first few modes can provide a spatially filtered version of the flow 

across the transect. 

One of the objectives or Chen's research is to compare the vertical shear derived from the 

ADCP data with the vertical shear derived from the temperature and salinity data using 

the "thermal wind" (geostrophic shear) relation . The use of EOF mode representation of 

profiles may he helpful in that task . 
TEXAS LOUISIANA 

3

a _ .... . ... .. ... ... .... .... ... ... ... . . ... ... .. ... ... ... ... ... ... ... .. 

Houston 

. ... ... ... .... .!. ... ... ... ... .. ... ... ... .... .... . ... .... ..... .... ..... ...>_ ... ... . C~ 

~ ~ .... ... ...

.Neiiv Orleans

.. ...: .... .. 

~ 

w 

. . ..... . .. ....~. . . .; . .. ., ... ... . 

0 moo 

Galvestori 

29 _

..._ ..._ .... ..... .... . - _..------- _i .... ... . ..... . " . ... .. . ... 

\ ?0 

_ -~``` -~ I 

Y , 

' 

r 

i 00 

v 

28 .. . . .... . . . _. .. . .... .. . . .. .... ... ... .. ... .... ... 

10 1000 

w 

27 . ... . ... . ..... . 

i I I 

. .. ... .... .... 

'\ \ ~V 26 Depth: 10 m 

, .... ... . .... ... .. . .. ... ... ...~ ... ... ... .. . .... .... ... ... ;i . ... ... ... ... .. ... .... ...a ... ... .... ... .... ..... . ..... ..j~ . ... ... . 

~ ... ... ... ... . . . . , ~... .... ... . . . .. .. ... . .... . Velocity (cm-s-1 I t j mm~ 

0 50 100 

-97 -96 -95 -94 -93 -92 -91 -90 -89 

w 

Figure 6.9 .1 . Vector stick plots of currents at 10 m, measured by ADCP during cruise H06, 25 July - 7 August 1993. 
LOUISIANA 

30°N (` ~ Q 

C 

TEXAS 

29°N yl~!'- 

-" l/ 

S` C 

28°N ~ H F 

:/ 

d D 

27°N 

0 0 0 0 

N ~ N 

26°N 

98°W 97°W 96°W 95°W 94°W 93°W 92°W 91°W 90°W 89°W 

Figure 6.9 .2 . Transects along the 50-m and 200-m isobaths along which ADCP data from cruise H06 were 

employed to evaluate empirical othogonal profiles of current. w 
136 

Table 6.9 .1 . Dates, time-intervals and number of ADCP vertical profiles along 

the 50-m and 200-m isobaths during the LATEX cruise H06. 

Decimal Day Date and Time Length of Time (hr) No. of Locations 

A 207 .666100 Ju12615 :59:11 

B 209 .035394 Jul 28 00 :50:58 32.86 269 

C 209 .912454 Jul 28 21 :53:56 

D 210 .383692 Jul 29 09 :12:31 11 .31 86 

E 212 .369271 Ju13108:51 :45 

F 212 .985833 Ju13123:39:36 14.80 103 

G 218 .391076 Aug 6 09 :23:09 

H 218 .982928 Aug 6 23 :35:25 14.20 ~ 121 
137 

Eigenmode 

1 2 3 

67.76% 21 .51% 4.58% 

10 - ---~ \ 

12- 

14- 

16 

18 

20- 

22 

.r 

-B 24 

a 

~1 26 - 

28 

30 

32 

34 ~ 

36 

38 T --- 

Figure 6.9 .3 . The first three EOFs derived from ADCP data along the 50-m transect 

of cruise H06. 
138 

Eigenmode 

1 2 3 

85 .21% 8.49% 2.66% 

12 

-~ ~-- 

E- 

- 

16 

-~ F-- 

20 F24 

-~ E28 

-~ f- F 

32 

36 

40 

--~ F F44 - 

-~ E E48 

< E-- 

52 - 56 

60 

G1 64 

68 

72 

76 

80 

84 

88 

-- 

92 

96 

100 ~ 

104 

Figure 6.9 .4 . The first three EOFs derived from ADCP data along the 200-m transect 

of cruise H06. 
139 

6 .10 Maximum Currents 

The MMS wishes to determine the maximum likely distance that spilled oil over the 

Texas-Louisiana shelf could move in a 48-hour period . To assist in this assessment, the 

maximum speeds and associated directions measured at the upper instruments were 

determined from the second-year records of each of the LATEX A moorings. These 

maxima were selected from the 40-hour, low-passed current records that will be included 

in the microfiche packet that will accompany the Final Report. Table 6.10.1 gives 

mooring number, location, instrument depth, maximum speed, direction, and date for 

each current meter site measured over the Texas-Louisiana shelf. The types of 

instruments used at each location are given in section 3.2 . 

For the second LATEX field year, the table shows that the maximum low-passed 

currents, at a nominal 10-m depth, range from about 29 to 86 cm-s-1, directions vary 

around the compass, and maxima occur around the calendar. This may make 

interpretation of these results difficult. Additionally, instruments did not record at all 

locations year round due to instrument losses, malfunctions, lack of spares, and removal 

of moorings . Moreover, these records often contain several relative speed maxima of 

similar values (for an example, see section 5 .2.1 in Jochens and Nowlin, 1994b) . 
140 

Table 6.10.1 . Maximum speeds and corresponding directions observed in 40-hr lowpassed current record from each LATEX A mooring during the second 

field year. 

Depth Smax Amax 

Mooring Latitude N Long itude W (,m) (cm .s 1) (°T) Date 

1 270 15 .39' 970 14.81' 19 86 196 20 June 1993 

2 27 0 17 .09' 960 58.81' 10 81 204 10 Nov. 1993 

3 270 17 .35' 960 44.18' 13 69 222 13 Mar. 1993 

4 270 07 .76' 960 21 .63' 12 77 358 13 Feb. 1993 

5 270 27 .82' 960 04.12' 14 64 63 12 Aug. 1993 

6 270 42.59' 950 39 .85' 13 83 94 15 Feb. 1993 

7 270 50.12' 950 04.19' 14 83 99 4 Aug. 1993 

8 270 49.47' 940 10.77' 15 61 144 10 Mar. 1993 

9 270 48.92' 930 31 .91' 14 51 94 6 Jan. 1994 

10 270 56.07' 920 44.70' 14 39 88 8 Mar. 1994 

11 270 50.64' 920 00.45' 14 32 29 17 Jan. 1994 

12 270 55.76' 900 29.64' 14 68 103 27 Oct. 1993 

13 280 03 .48' 900 29.18' 15 54 87 17 Aug. 1993 

14 280 23 .74' 900 29.65' 19 42 262 8 Jan. 1994 

15 280 36 .49' 900 29.53' 10 59 80 7 Aug. 1993 

16 280 51 .96' 900 29.50' 11 52 268 8 Oct. 1993 

17 290 11 .82' 910 57.89' 3 62 304 20 June 1993 

18 280 57 .74' 910 59.01' 10 69 271 8 Apr. 1993 

19 280 27 .92' 920 02.06' 3 52 309 11 Aug. 1993 

20 290 15 .67' 940 03.82' 3 73 12 13 Sept. 1993 

21 280 50.28' 940 04.79' 14 46 264 19 June 1993 

22 280 21 .39' 930 57 .34' 3 59 22 20 July 1993 

23 280 42.77' 950 32 .13' 10 72 246 19 June 1993 

24 280 32.21' 95° 23 .61' 10 83 240 9 Nov. 1993 

25 280 19.33' 950 21 .57' 11 36 87 2 Apr. 1993 

44 Removed 

45 Removed 

46 Removed 

47 Removed 

48 270 58.98' 910 16.99' 14 42 85 7 Jan. 1994 

49 270 23 .13' 950 53.96' 14 29 240 2 Mar. 1994 
141 

6.11 Observations/Model Comparison 

A perception emerging from the LATEX A hydrographic and current meter 

measurements is that the energetic variable circulation on the inner shelf (< 50 m water 

depth) at frequencies within the weather band (about 0.05 to 0.3 cycles/day) is locally 

wind-induced barotropic motion. This variability is superimposed on a much more stable 

but less energetic baroclinic circulation over the whole shelf that varies seasonally, as in 

the Cochrane and Kelly (1986) schema, and whose patterns can be quantified from the 

hydrographic data. Even casual inspection of wind and current records for the inner 

LATEX shelf shows a remarkable consistency between reversals in direction of the 

longshore current and reversals in direction of the longshore wind during weather events . 

Wind-driven currents on the west Florida shelf have been quantifed by Mitchum and 

Sturges (1982) and modeled by Mitchum and Clarke (1986) . We (R.O. Reid and C.L. 

Current) have employed a simple barotropic wind-driven model similar to that of 

Mitchum and Clarke in a pilot experiment for the Texas-Louisiana shelf. The weather 

event or 11-14 March 1993 was selected for this test . It has some unique features first 

recognized by Lee et al . (1994) . 

The model/data comparison discussed below should he considered more as a model/data 

assimilation experiment because from it we deduce a field of bottom friction 

characterization that produces a reasonably optimum match or simulated and observed 

(40-hr low passed) currents, using measured winds to estimate the (40-hr low passed) 

wind stress evolution. 

The model used is a generalization of the simple barotropic shelf model or Gill and 

Schumann (1974) in which the field of flow is represented as a linear combination of 

cross-shelf structure functions, whose amplitudes are predicted versus longshore position 

and time for specified longshore wind stress . Bottom friction is included as 

parameterized by Clarke and Brink (1985) and implemented in a manner similar to 

Mitchum and Clarke (1986) . The primary dynamical constraints of the model are that it 

is barotropic and the horizontal volume transport non-divergent. The latter implies that a 

stream function exists whose horizontal gradient (divided by local depth) gives the 

current. The subsurface pressure anomaly (SSP) can also re related to the stream 

function since the longshore flow is very nearly geostrophic. Another constraint is that 

the scale or variation alongshore is considered large compared to the cross-shore scale. 

In the present application of the model, the bathymetry is approximated by a simple 

exponential form as employed by Buchwald and Adams (1968) and Gill and Schumann 

(1974) but with an offshore scale parameter that depends on alongshore position . Using 

this approximation, the rms error in the offshore distance or a given isobath is about 6% 

of the offshore distance to the 200-m isobath . The domain of the model is from the coast 

(taken as the 6.2-m isobath) to the 200-m isobath (Figure 3.2 .1). The Mississippi Delta is 

replaced by a wall extending fully across the shelf, so it and the coastal wall are 

streamlines of flow. The model extends along the coast to about 26° N, at which there is 

no constraint on the flow. At the seaward boundary (200-m isobath) the flow is allowed 

to pass across, but the longshore flow is considered zero, a constraint that clearly limits 

the model application to wind-driven inner shelf response. Vital geometrical parameters 

that are specified versus longshore position are the distance from the 6 .2-m "shore" to the 

200-m isobath (which varies from 80 km to 220 km) and the direction of the alongshore 

orientation of the 6 .2-m "shoreline." 
142 

Following Mitchum and Clarke (1986) and others, the resisting bottom stress divided by 

water density (TO is taken proportional to the depth-averaged flow (V) : 

Th = rV (1) 

where r has dimensions of speed . The value of r depends, among other factors, on 

background high frequency currents due to surface waves as discussed by Clarke and 

Brink (1985) . As such, r depends on offshore distance and surface wave energy level. In 

the present model application, we take 

r = ro(1-y/L) (2) 

where y is offshore distance, L is the local distance to the 200-m isobath, and ro is the 

nearshore value or r. The dependency of L on longshore position is known. The value of 

ro for the coastal region east of 96.5° W is allowed to differ from the coastal region 

southwest or 96.5° W (Figure 3.2 .1) . We will refer to these two regions as the upcoast 

and downcoast regions, respectively . The values of ro for these regions are selected in the 

optimal tuning of the model. 

The March 1993 storm was formed by cyclogenesis in the northwest Gulf, and at 1200h 

on 12 March was centered near 27° N and 95 .5° W. It intensified as it propagated 

eastward to 90° W, then northeastward, later producing very severe weather along the 

eastern seaboard. The average eastward propagation speed from 95.5° W to 91° W was 

20.6 ms-1 based nn the National Weather Service analyses. 

Wind records at LATEX meteorological moorings 50 and 53 were used to estimate wind 

stress ; time series or speed and direction are shown as Figures 5 .6 .11 and 5.6.12 of 

Jochens and Nowlin (1994h). Locations of these moorings are given here in Figure 3.2 .1 . 

The methodology of Smith (1988) was employed to estimate wind stress from the 

observed wind velocity at a mast height of 3 .6 m above the sea surface. The drag 

coefficient (for neutral stability) based nn wind speed W at 3 .6 m was taken as: 

cd = 0.80+0.081W. (3) 

The east and north components or wind stress were calculated for the period 9-16 March 

1993 for moorings 50 and 53 and then smoothed with a 40-hr low pass filter . The 

resulting filtered stress components are shown for a three-day window in Figure 6.11 .1 . 

These plots indicate very similar east and north components at the two inner shelf 

locations but with a time lag of about 5 hours and an intensification in stress magnitude 

from about 0.3 Pa at mooring Sn to 0.5 Pa at mooring 53 . 

In the model runs, the east and north components or wind stress over the shelf domain are 

taken as: 

)Fe ~t) 

(4) 

. = G(~~)Fn(t~) 

in which k' is west longitude from mooring 53 and t' is t+k'/cu, where c) is the eastward 

angular speed (0.75 deg/hr) of the storm . The functions Fe and Fn are those shown in 

Figure 6 .11 . l . for mooring 53, and G is a gain factor relative to mooring 53 taken as an 
143 

exponential whose e-folding scale is consistent with a gain of 0.60 for mooring 50 

relative to mooring 53. 

The model forcing employs the local longshore component of the wind stress . In the 

early stages of the storm, the direction of the stress is toward the west and rotates 

cyclonically toward the south and southeast in the later stages on 14 March. This 

sequence causes the maximum downcoast longshore stress to propagate downcoast with 

time; i.e ., we should expect the maximum downcoast flow in the southwest part of the 

shelf to lag behind that at the central and east shelf-even though the storm is moving to 

the east. 

Observed currents for moorings l, 23, and 18 were selected as representative of near 

coast conditions at downcoast, midcoast, and upcoast locations (Figure 3.2 .1). The 

depths at these locations lie between about 15 to 22 m. The upper current meter at these 

locations is about 10 m below the surface, and hence, at about mid-depth. We regard 

this, therefore, as an estimate of the depth-averaged current. The only midshelf mooring 

having data at mid-depth (and, in fact, at top, middle, and bottom) spanning the March 

1993 storm event is mooring 25, at a depth of about 40 m (Figure 3 .2 .1). In comparing 

the measured and simulated current, it is important to hear in mind that the model 

simulation provides only the depth-averaged or barotropic part of the current. 

The current meter records at moorings 1, 23, 18, and 25 were smoothed with a 40-hr low 

pass filter, and the longshore component of the estimated depth-averaged current was 

obtained for each . Plots of the estimated depth-averaged longshore current from 

measurements at the three near coastal moorings are shown in the top panel of Figure 

6 .11 .2, while that for mooring 25 is shown with mooring 23 in Figure 6.11 .3. The sign 

convention for longshore flow is such that positive is upcoast (toward the Mississippi 

delta), while negative is downcoast (toward the Rio Grande). This is consistent with the 

monthly current plots. 

The simulated depth-averaged longshore current from the model is shown in lower panels 

in Figures 6.11 .2 and 6.11 .3 to facilitate direct comparison . The values of ro employed in 

the simulated runs shown here are 2.4x10-4 ms-1 and 3 .7x10-4 ms-1 for the upcoast and 

downcoast domains, respectively . These provided the optimal simulation of range and 

phase of current variability shown for the common three day time window in these 

figures. 

Figure 6.11 .2 shows that there is over 12 hours lag of the energetic downcoast flow at 

mooring 1 compared with that at mooring 23 in the measurements and this is mimicked 

quite well in the model simulation . Mooring 18, which is well upcoast from mooring 23, 

is less energetic but nearly in phase with mooring 23. This is simulated reasonably well 

by the model, but one notes some phase error. 

Comparison or mooring 25 with 23 (Figure 6.11 .3) indicates a decay and phase lag in the 

observations . The lag is mimicked well in the simulation, but the offshore decay of the 

simulated flow is more pronounced . 

In the simulations, the initial current for a given mooring was taken as that of the 

observations at 1200h nn 11 March 1993 . The effect or initial condition produces a 

transient that dies away exponentially in time, leaving purely forced motion after about 

two e-folding times . For the upcoast region, the model e-folding decay time is about 26 

hours, but only 17 hours for the downcoast region . 
144 

Not shown here are the observed near surface currents at moorings 24 and 25 or at 

moorings 2 and 3 . These currents reach magnitudes comparable to and even larger than 

those nearer the coast. This suggests that a significant vertical shear exists at these 

moorings. Indeed, for mooring 25, the speed at the time of maximum downcoast flow 

varies from about 0.2 ms-1 near the bottom to about 0.7 ms-1 near the surface and is 

directed downcoast at all three levels . 

Caveats: The observation model comparisons shown in Figures 6.11 .2 and 6.11 .3 look 

almost too good to be true . Recall, however, that we have in effect fit the dynamics to the 

data for these selected moorings and for this very short (3-day) event. The fitting for this 

event involved tuning the bottom friction parameter ro for two regions of the shelf, 

assuming that the wind stress field derived from two meteorological moorings is 

adequate. 

A nagging feature of the simulations, not mentioned earlier, is that in the downcoast 

region (moorings 1, 2, 3), the computed response for moorings 2 and 3 showed an 

unreasonably large time lag compared with the longshore current measured at the near 

surface meters. Possible reasons for this discrepancy between simulation and 

observations are: improper parameterization of friction versus y in this region ; inaccurate 

time sequence or wind stress for this region (taken essentially as that at mooring 50); 

improper account of the effect of coastal curvature in the model; or perhaps there is a 

large phase difference between the depth-averaged and surface current for this region of 

the shelf. 

The above questions require further follow-on data assimilation experiments . This, 

together with confirmation of the bottom friction parameterization and tuning over many 

more weather events, is one of several objectives of C .L. Current in her proposed 

dissertation research. 
145 

0.5 

0.4 

a 0.3 

c 0.2 

m 

c 

a 0.1 0. - 

E p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ._ 

CO -0 .1 -- 

m , ' 

in -0 .2 

-0 .3 ~'----, 

-0 .4 - 

-0.5 - 

11 .5 12 12 .5 13 L13 .5 14 14.5 

Day of March, 1993 

0.5 - 

0.4 - 

Ca 0.3 - 

N 

C 0.2 - 

m 

c 

0.1 CO 

0 ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

in -0 .2 " .' 

v 

~ -0.3 

` 

~ ' 

-0.4 

11 .5 12 12.5 13 13.5 14 14 .5 

Day of March, 1993 

Figure 6.11 .1 . Eastward (-) and northward (---) 40-hr low pass wind stress 

components from moorings 50 (upper panel) and 53 (lower panel) 

for the three-day March 1993 storm. Upcoast is positive. 
146 

i 

o.s 

o .s 

~ 0.4 

0.2 

U 

m 

N -0.2 

-Q° -0.4 

-0 .6 

-0 .8 

-Y 

,-- 

- . - . . - .-. .T . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

. ` ' . 

. ~ '. 

. 

.J 

.` I 

11 .5 12 12.5 13 13 .5 

Day of March. 1993 

1 

0.8 

0.6 

0.4 

0.2 t 

U 0 

m 

0 

N -0.2 

m 

c 

.2-0.4 

-0.6 

-0 .8 

-1 

14 14.5 

' .' . , 

~ . 

11 .5 12 12.5 13 13.5 14 14 .5 

Day of March, 1993 

Figure 6.11 .2 . Observed 40-hr low pass (upper panel) and simulated (lower panel) 

longshore currents for moorings 1 (-), 18 (---), and 23 (-~-) for the 

three-day March 1993 storm. Upcoast is positive. 
147 

i 

0 .8 - 

0.6 - 

N 

E 0.4 

0.2 , ' t 

U 0 ' -. . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., .' . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

m 

` o

N -0 .2 

c 

-Q°-0.4 ~----' 

-0 .6 - 

-0 .8 

- 1 

11 .5 12 12.5 13 13 .5 14 14 .5 

-Day of Marsh, 1993 

1 

0.8 - 

0.6 - 

W 

0.4 

U 0 '- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

m 

` o 

s N -0.2 

~--- --, .0-0 Q .4 - 

- 

-0.6 - 

-0.8 

1 

- 

- 

11 .5 12 12.5 13 13.5 14 14.5 

Day of March, 1993 

Figure 6.11 .3 . Observed 40-hr low pass (upper panel) and simulated (lower panel) 

longshore currents for moorings 23 (-) and 25 (---) for the three-day 

March 1993 storm. Upcoast is positive. 
148 

6.12 LATEX Science Advisory Panel 

During this year, both George Forristall (Chairman) and Denny Kirwan (member) 

resigned from the LATEX Science Advisory Panel because of changes in their situations . 

With the concurrence of LATEX B and C program managers and the MMS COTR, John 

Allen was asked, and agreed, to assume the chair and Gabriel Csanady and Richard 

Garvine were appointed as new Panel members. The members of the SAP and their 

affiliations are listed in Table 6 .12.1 . 

October 26-28, 1993, Panel members attended the LATEX III Meeting at MMS Regional 

Headquarters in New Orleans. They reviewed the LATEX Program and prepared draft 

recommendations which were circulated to the program managers. 

Table 6.12.1 . Members of the LATEX Science Advisory Panel from 1 April 1993 

through 31 March 1994. 

Member 

John S . Allen, Chairman 

John D. Cochrane 

Gabriel T. Csanady 

Richard W. Garvine 

Dong-Ping Wang 

Clinton D. Winant 

William J. Wiseman, Jr. 

Affiliation 

Oregon State University 

Texas A&M University, retired 

Old Dominion University 

University of Delaware 

SUNY - Stony Brook 

Scripps Institution or Oceanography 

Louisiana State University 
149 

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118(4) :401-416. 
Pty, NT OF T,y~ y~ The Department of the Interior Mission 

a w ' p As the Nation's principal conservation agency, the Department of the Interior has responsibility for 

most of our nationally owned public lands and natural resources. This includes fostering sound 

- use of our land and water resources; protecting our fish, wildlife, and biological diversity; 

9 e 

preserving the environmental and cultural values of our national parks and historical places; 

ACH 3 ~ and providing for the enjoyment of life through outdoor recreation . The Department assesses our 

energy and mineral resources and works to ensure that their development is in the best interests 

of all our people by encouraging stewardship and citizen participation in their care . The 

Department also has a major responsibility for American Indian reservation communities and for 

people who live in island territories under U.S . administration . 

The Minerals Management Service Mission 

6xr or 

As a bureau of the Department of the Interior, the Minerals Management Service's (MMS) primary 

' responsibilities are to manage the mineral resources located on the Nation's Outer Continental Shelf 

Y (OCS), collect revenue from the Federal OCS and onshore Federal and Indian lands, and distribute 

those revenues . 

°p s 

~ <4M,~hAGENfJ' b ~ Moreover, in working to meet its responsibilities, the Offshore Minerals Management Program 

administers the OCS competitive leasing program and oversees the safe and environmentally sound 

exploration and production of our Nation's offshore natural gas, oil and other mineral resources. 

The MMS Royalty Management Program meets its responsibilities by ensuring the efficient, timely 

and accurate collection and disbursement of revenue from mineral leasing and production due to 

Indian tribes and allottees, States and the U.S . Treasury . 

The MMS strives to fulfill its responsibilities through the general guiding principles of : (1) being 

responsive to the public's concerns and interests by maintaining a dialogue with all potentially 

affected parties and (2) carrying out its programs with an emphasis on working to enhance the 

quality of life for all Americans by lending MMS assistance and expertise to economic development 

and environmental protection .