OCS Study 

MMS 2000-078 

Northeastern Gulf of Mexico 

Chemical Oceanography and 

Hydrography Study 

Annual Report: Year 3 

MMA19M U"S. Dewrtament of the Interior 

i -W 

Minerals 

an 

gernent Service 

Gulf of Mexico OCS Region 
OCS Study 

MMS 2000-078 

Northeastern Gulf of Mexico 

Chemical Oceanography and 

Hydrography Study 

Annual Report: Year 3 

Editors 

Ann E . Jochens 

Worth D . Nowlin, Jr. 

Prepared under MMS Contract 

1435-01-97-CT-30851 

by 

Texas A&M University 

Department of Oceanography 

College Station, Texas 77843-3146 

Published by 

U.S. Department of the Interior 

Minerals Management Service New Orleans 

Gulf of Mexico OCS Region November 2000 

iii 

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 it has been approved for publication. Approval does not 

signify that the contents necessarily reflect the views and policies of the MMS, nor does 

mention of trade names or commercial products constitute endorsement or 

recommendation for use. It is, however, exempt from review and compliance with the 

MMS editorial standards. 

REPORT AVAILABILITY 

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

5034) at the following address: 

U.S. Department of the Interior 

Minerals Management Service 

Gulf of Mexico OCS Regional Office 

Public Information Office (MS 5034) 

1201 Elmwood Park Boulevard 

New Orleans, Louisiana 70123-2394 

Telephone: (504) 736-2519 or 

1-800-200-GULF 

CITATION 

Suggested citation : 

Jochens, A.E., and W.D. Nowlin, Jr., eds. 2000. Northeastern Gulf of Mexico Chemical 

Oceanography and Hydrography Study, Annual Report : Year 3 . OCS Study MMS 

2000-078, U.S . Dept. of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA . 89 pp . 

V 

ACKNOWLEDGMENTS 

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

people . Each NEGOM-COH principal investigator (PI) contributed portions of the text, 

many participated in the cruises and in data reduction and processing . The principal 

investigators, their affiliations, and their tasks are : 

Worth D. Nowlin, Jr. TAMU Program Manager, PI for Task 3 

Ann E. Jochens TAMU Deputy Program Manager, PI for Program 

Management and Task 2 

Douglas C. Biggs TAMU Co-PI for Task 1 

Norman L. Guinasso, Jr. GERG/TAMU Co-PI for Task 1 

Matthew K. Howard TAMU Co-PI for Task 2 

M. C. Kennicutt II GERG/TAMU Co-PI for Tasks 1 and 3 

Robert O. Reid TAMU Co-PI for Task 3 

Additionally, Dr. Steven F. DiMarco and Ms. Christina Bernal contributed to the 

authorship of this report. 

To all who participated on the four NEGOM-COH cruises (N6, N7, N8, and N9), both 

ship's crew and scientific teams, we extend our great appreciation. We also thank the 

voluntary contributions of the scientists and students at University of Colorado (CU), 

University of South Florida (USF), University of Southern Mississippi (USM), as well as 

Texas A&M University (TAMU) who participated in these cruises. The science 

members, affiliations, and cruises are listed below. 

Leila Belabbassi (TAMU; N6) 

Christina Bernal (TAMU; N6, N7, N8, N9) 

Dr. Doug Biggs (TAMU; N6, N7, N8, N9) 

Scott Birkhead (TAMU; N8) 

Marty Bohn (TAMU; N9) 

Ken Bottom (TAMU; N6, N7, N8, N9) 

Amy Bratcher (TAMU; N8) 

Greg Breed (TAMU; N9) 

Bob Brown (retired ; N8) 

Yesim Buyukakis (TAMU; N6) 

Dr. Piers Chapman (TAMU; N6) 

Paul Clark (TAMU; N6, N7, N8, N9) 

Roland Clark (TAMU; N7) 

Robyn Conmy (USF; N7, N9) 

Dr. Carlos del Castilla (USF; N6, N8) 

Miranda Dettwyler (TAMU; N9) 

Kristie Elston (TAMU; N8) 

Yue Fang (TAMU; N8) 

Will Fletcher (TAMU; N9) 

Chad Fox (CU; N8) 

Mike Fredericks (TAMU; N6, N7, N8, N9) 

Bill Green (TAMU; N6, N7, NS) 

Dwight Gledhill (TAMU; N6) 

Dennis Guffy (TAMU; N6, N8, N9) 

Dr. Norm Guinasso (TAMU; N6, N7, N8, N9) 

Karie Holtermann (USM; N9) 
VI 

Alexey Ivanov (TAMU; N6, N7) 

Bill Kopesky (TAMU; N6) 

Lisa Lathem (TAMU; N9) 

Rob Masserini (USF ; N7) 

Dr. Alexey Mishonov (TAMU; N8) 

Jeff Morin (TAMU; N6) 

Bisman Nababan (USF; N6, N7, N8, N9) 

Lucia Odriozola (USF; N9) 

Francisco Ollervides (TAMU; N6) 

Erik Quiroz (TAMU; N6, N7, N8, N9) 

Patrick Ressler (TAMU; N6) 

Emma Roscow (TAMU; N9) 

Rebecca Scott (TAMU; N7, N8) 

Laurie Sindlinger (TAMU; N9) 

Antoya Stovall-Leonard (USF; N8, N9) 

Ryan Thomas (TAMU; N7, N8) 

Toshi Uozumi (USM; N6) 

Lisa Vanderbloemen (USF; N8) 

Jennifer Waggoner (TAMU; N9) 

John Walpert (TAMU; N6, N7, N8, N9) 

Elise Waltman (TAMU; N6) 

Eddie Webb (TAMU; N6, N7, N8, N9) 

Xiang-Dong Xia (TAMU; N7) 

Thanks go to those who helped prepare equipment and process the data on shore, 

including many named above, Bob Albers, Woody Lee, Dr. Yaorong Qian, and Ou 

Wang . Finally, thanks go to Dr. Joseph Yip for preparation of hourly surface wind and 

wind stress fields for the NEGOM field period and to Dr. Robert L. Leben, Colorado 

Center for Astrodynamics Research, University of Colorado, for production of the daily 

sea surface height anomaly fields from satellite altimeter data. 

Ann E. Jochens 

Worth D. Nowlin, Jr . 
vii 

ABSTRACT 

The Northeastern Gulf of Mexico Physical Oceanography Program (NEGOM) is 

supported by the Minerals Management Service (MMS) of the U. S. Department of the 

Interior . Through a contract between MMS and the Texas A&M Research Foundation, 

several components of the Texas A&M University System are conducting the Chemical 

Oceanography and Hydrography study of NEGOM (NEGOM-COH). This report covers 

activities from July 1999 through August 2000. Data were collected from hydrographic 

and acoustic Doppler current profiler (ADCP) surveys conducted in the Gulf of Mexico 

over the continental shelf and upper slope between the Mississippi delta and Tampa Bay 

in water depths of 10 to 1000 m. Additionally, historical and concurrent data from other 

programs in this region were collected. 

Four hydrographic/ADCP surveys, N6, N7, N8, and N9, were conducted with 98, 98, 

101, and 98 hydrographic sampling stations and 89, 84, 78, and 75 expendable 

bathythermograph stations on respective cruises . Each survey also included continuous 

ADCP measurements along the cruise track. At each hydrographic sampling station 

continuous profiles were made of conductivity, temperature, pressure, downwelling 

irradiance, fluorescence, and light transmission . Up to twelve water samples were taken 

at each station and analyzed for dissolved oxygen and six nutrients : nitrate, nitrite, 

phosphate, silicate, ammonium, and urea. At approximately 60 stations on each cruise, 

water samples were filtered and analyzed for phytoplankton pigments at the surface, from 

the chlorophyll maximum determined from fluorescence, and from the low light regime 

immediately below the maximum. Pigments were determined using high performance 

liquid chromatography . At about 60 stations on each cruise, water samples were filtered 

and analyzed for particulate matter concentrations at surface, middle, and bottom water 

depths and for particulate organic carbon and particulate organic nitrogen concentrations 

at surface and bottom (N6) or chlorophyll maximum (N7-N9) water depths . Bottle 

salinity was measured routinely at the most inshore and offshore stations on each crossshelf line. Surface bucket salinity samples were taken in regions expected to have river 

water influences. The instrumentation as well as calibration and sampling procedures are 

described in this report. The collected data were subjected to stringent quality 

assurance/quality control procedures, which also are described. 

On each cruise there were a number of complementary research programs . N6 had seven 

programs, including coring, bio-optical sampling, color dissolved organic material 

(CDOM) measurements, and flow cytometry sampling. There were five programs on N7, 

consisting of drifter deployments for MMS, bio-optical sampling, CDOM measurements, 

flow cytometry, and experimental measurements using a 38 kHz ADCP. On N8, ten 

complementary programs were pursued; the major ones were coring, a NASA over-flight 

for concurrent airborne and sea water flow-through bio-optical measurements, standard 

bio-optical and CDOM sampling, flow cytometry, benthic trawl samples, and 38 kHz 

ADCP measurements . Five complementary research efforts were accommodated on 

cruise N9, including bio-optical sampling, CDOM measurements, benthic trawls, and 38 

kHz ADCP measurements. Graduate student training and research was conducted on all 

cruises for various academic institutions . 

1X 

TABLE OF CONTENTS 

PAGE 

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v 

ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii 

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

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii 

ACRONYMS AND ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv 

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

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

1 .2 Field Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

1 .3 Third Annual Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

2 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

2 .1 Overview of Cruise Schedule and Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

2 .2 Programmatic Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

2 .3 Report Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

3 DATA ACQUISITION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

3 .1 General Description of Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

3.1 .1 Cruise N6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

3.1 .2 Cruise N7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

3.1 .3 Cruise N8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

3.1 .4 Cruise N9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 

3 .2 Instrumentation, Calibration, and Sampling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 40 

3 .2 .1 Continuous Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 

3 .2 .2 Discrete Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 

3 .2 .3 Acoustic Doppler Current Profiler Measurements. . . . . . . . . . . . . . . . . . . . . . . 42 

3 .2 .4 XBT Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 

3 .2 .5 Underway Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 

3.3 Summary of Field Data Collected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 

3.4 Summary of Historical and Collateral Data Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 

4 DATA QUALITY ASSURANCE AND CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 

4.1 Continuous Profile Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 

4.2 Discrete Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 

4.2 .1 Nutrients, Oxygen and Salinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 

4.2.2 Particulates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 

4.2 .3 Pigments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 

4.3 Acoustic Doppler Current Profiler Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 

4.3 .1 Standard ADCP Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

4.3 .2 Ensemble Processing Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

4.3 .3 Results of QA/QC for NS through N9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 

4.4 XBT Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 

4.5 Underway Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 

5 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 

X1 

LIST OF FIGURES 

FIGURE PAGE 

1 .2 .1 Station locations and cross-shelf line numbers for NEGOM 

hydrographic/ADCP cruises and geographic locations in the study area. . . . . . . . . . . . 3 

3.1 .1 Station locations for cruise N6 conducted 15 - 28 August 1999. . . . . . . . . . . . . . . . . . . . . . . . . 8 

3 .1 .2 Station locations for cruise N7 conducted 12 - 25 November 1999 . . . . . . . . . . . . . . . . . . . 17 

3 .1 .3 Station locations for cruise N8 conducted 15 - 26 April 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 

3 .1 .4 Station locations for cruise N9 conducted 28 July - 8 August 2000. . . . . . . . . . . . . . . . . . . 32 

3 .2 .1 Locations of ADCP data for cruises N6, N7, N8, and N9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 

3 .2 .2 Locations of near-surface, flow-through temperature, salinity, and 

fluorescence data logged every 2 minutes on cruises N6, N7, N8, and N9 . . . . . . . . . 46 

3 .2 .3 Locations of discrete samples filtered for calibration at sea of near-surface, 

flow-through fluorometer data on cruises N6, N7, N8, and N9 . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 

4 .1 .1 Composite potential temperature-salinity diagram for stations from cruise 

NS (May 1999). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 

4.1 .2 Composite potential temperature-salinity diagram for stations from cruise 

N6 (August 1999) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 

4.1 .3 Composite potential temperature-salinity diagram for stations from cruise 

N7 (November 1999). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 

4.1 .4 Composite potential temperature-salinity diagram for stations from cruise 

N8 (Apri12000) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 

4.1 .5 Composite potential temperature-salinity diagram, using preliminary data, 

for stations from cruise N9 (July/August 2000) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 

4.2.1 Phosphate versus nitrate for 1999 cruises NS (spring), N6 (summer), and 

N7 (fall) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 

4.2 .2 Phosphate versus nitrate for 2000 cruises N8 (spring) and N9 (summer). . . . . . . . . . . 58 

4.2 .3 Frozen versus fresh nutrient concentrations (gM) from station 32 on 

NEGOM cruise N8 (April 2000). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 

4.2 .4 Frozen versus fresh nutrient concentrations (gM) from station 33 on 

NEGOM cruise N8 (April 2000) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 

4.2 .5 Ensemble upcast CTD salinity versus bottle salinity for cruises NS through 

N9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

4.2 .6 Dissolved oxygen versus upcast sigma-theta for 1999 cruises NS (spring), 

N6 (summer), and N7 (fall) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 

4 .2 .7 Dissolved oxygen versus upcast sigma-theta for 2000 cruises N8 (spring) 

and N9 (summer). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 

4 .5 .1 Flow-through fluorometer calibration for cruise N6 (August 1999). . . . . . . . . . . . . . . . . . . 69 

4.5 .2 Flow-through fluorometer calibration for cruise N7 (November 1999) . . . . . . . . . . . . . . 70 

4.5 .3 Flow-through fluorometer calibration for cruise N8 (Apri12000).. . . . . . . . . . . . . . . . . . . . . . 71 

4.5 .4 Flow-through fluorometer calibration for cruise N9 (July/August 2000). . . . . . . . . . . . 72 

X111 

LIST OF TABLES 

PAGE 

2.1 .1 Cruise identifiers and dates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

3.1 .1 Times and locations for CTD stations on cruise N6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

3.1 .2 Number of bottles sampled by variable on cruise N6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

3.1 .3 Launch times and locations for XBT drops on cruise N6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

3 .1 .4 Times and positions for CTD stations on cruise N7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

3 .1 .5 Number of bottles sampled by variable on cruise N7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

3 .1 .6 Launch times and locations for XBT drops on cruise N7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 

3 .1 .7 Times and positions for CTD stations on cruise N8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

3 .1 .8 Number of bottles sampled by variable on cruise N8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

3 .1 .9 Launch times and locations for XBT drops on cruise N8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

3 .1 .10 Times and positions for CTD stations on cruise N9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 

3 .1 .11 Number of bottles sampled by variable on cruise N9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 

3 .1 .12 Launch times and locations for XBT drops on cruise N9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 

3 .2 .1 Hydrographic equipment available on cruises N6, N7, N8, and N9. . . . . . . . . . . . . . . . . . 40 

3 .2 .2 Bottle tripping locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 

3 .2 .3 Dates and quantity of 150 kHz ADCP data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 

3 .2 .4 ADCP configuration summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 

3 .3 .1 Summary of data collection and scientific participation on NEGOM-COH 

cruises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 

3 .3 .2 Complementary programs on NEGOM-COH hydrography surveys. . . . . . . . . . . . . . . . . 49 

3 .4 .1 Gulf of Mexico collateral data assembled in support of NEGOM-COH. . . . . . . . . . . 49 

4.2 .1 POC and PON from two depths at station 35 on NEGOM cruise N6. . . . . . . . . . . . . . . 64 

4.3 .1 Complex regression statistics for GPS velocity versus bottom-track 

velocity from 150 kHz ADCP data on cruises NS through N9 . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

4.3 .2 Results of evaluation of 150 kHz ADCP data for external factors on 

cruises NS through N9 and number of data segments rejected. . . . . . . . . . . . . . . . . . . . . . . . . . 66 

xv 

ACRONYMS AND ABBREVIATIONS 

ADCP acoustic Doppler current profiler 

AVHRR advanced very high resolution radiometer satellite 

CCAR Colorado Center for Astrodynamics Research 

CTD conductivity-temperature-depth 

DGPS differential global positioning system 

GPS global positioning system 

HPLC high performance liquid chromatography 

NEGOM Northeastern Gulf of Mexico Physical Oceanography Program 

NEGOM-COH NEGOM Chemical Oceanography and Hydrography Study 

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

NASA National Aeronautics and Space Administration 

OS Ocean Surveyor 

PAR photosynthetically available radiation 

PI principal investigator 

PM particulate matter 

POC particulate organic carbon 

PON particulate organic nitrogen 

QA/QC quality assurance/quality control 

RDI RD Instruments, Inc. 

R/V research vessel 

SAIL Serial ASCII Interface Loop system 

S/N serial number 

SSHA sea surface height anomaly 

TAMU Texas A&M University 

USF University of South Florida 

USM University of Southern Mississippi 

UTC universal coordinated time 

XBT expendable bathythermograph probe 

1 EXECUTIVE SUMMARY 

11 Introduction 

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

supports the Northeastern Gulf of Mexico Physical Oceanography Program (NEGOM) . 

NEGOM is divided into six study units, one of which is the Chemical Oceanography and 

Hydrography Study (NEGOM-COH). NEGOM-COH covers the east LouisianaMississippi-Alabama-west Florida continental shelf and upper slope from the Mississippi 

River delta to Tampa Bay in water depths of 10 to 1000 m. This report focuses on the 

third year of work of NEGOM-COH covering the period July 1999 through August 2000. 

It does not contain detailed syntheses or interpretation of data collected ; those will be 

detailed in the Final Synthesis Report at the conclusion of the program . 

The contract for NEGOM-COH was awarded to the Texas A&M Research Foundation on 

30 September 1997 . Through the contract, components of the Texas A&M University 

System, a combination of Texas institutions of higher learning and Texas state agencies 

dedicated to training, research, and extension, conduct the NEGOM-COH study. In 

addition to support from the MMS, financial backing for NEGOM-COH is provided by 

Texas A&M University (TAMU), a component of the System. TAMU is assisted in this 

program by a subcontract with Dr. Robert R. Leben of the University of Colorado. 

The major objective of NEGOM-COH is to describe spatial and temporal distributions 

and variations of hydrographic variables, and the processes that contribute to them. It 

will be met through completion of a three-year field program of hydrographic/acoustic 

Doppler current profiler (ADCP) cruises in the spring, summer, and fall seasons, after 

which observations will be synthesized, interpreted, and reported to provide a more 

complete understanding of circulation and distribution of properties over the study area. 

Program management is provided by Dr. Worth D. Nowlin, Jr., Program Manager, and 

Dr. Ann E. Jochens, Deputy Program Manager. Study tasks are: 

" Task l, Field Work and Data Collection 

Dr. Douglas C. Biggs, Co-principal investigator (Co-PI) 

Dr. Norman L, Guinasso, Jr., Co-PI 

Dr. M. C. Kennicutt II, Co-PI 

" Task 2, Data Reduction/Analysis and Synthesis 

Dr. Ann E. Jochens, Principal Investigator (PI) 

Dr. Matthew K. Howard, Co-PI 

" Task 3, Information/Data Synthesis and Technical Reports 

Dr. Worth D. Nowlin, Jr., PI 

Professor Robert O . Reid, Co-PI 

Dr. M. C. Kennicutt II, Co-PI 

1 .2 Field Data 

Four hydrographic/ADCP survey cruises were conducted in the report period : cruise N6 

during 15-28 August 1999 ; cruise N7 during 13-25 November 1999 ; cruise N8 during 

15-26 April 2000, and cruise N9 during 28 July-8 August 2000. Conductivitytemperature-depth (CTD) and bottle sampling were completed at 98, 98, 101, and 9 8 

stations and expendable bathythermographs (XBT) were launched successfully at 89, 84, 
2 

78, and 75 stations. ADCP data were recorded continuously along track. The standard 

pattern of station locations and line numbers, as well as bathymetry and geographic 

locations, are shown in Figure 1 .2.1 . 

At each CTD/bottle station, continuous profiles were made of conductivity, temperature, 

dissolved oxygen, downwelling irradiance, backscatterance, fluorescence, and percent 

light transmission . Up to 12 water samples were taken at each station and analyzed for 

dissolved oxygen and six nutrients : nitrate, nitrite, phosphate, silicate, ammonium, and 

urea. Typically at 60 stations, water samples were analyzed for phytoplankton pigments, 

particulate matter, and particulate organic carbon/particulate organic nitrogen. Bottle 

salinities were measured at the innermost and seawardmost stations of each cross-shelf 

line, as well as at supplemental stations for problem solving associated with bottle 

sampling . Surface bucket salinity samples were taken in regions expected to be 

influenced by river water. XBT stations were taken between cross-shelf CTD stations to 

increase the resolution of the temperature data to -10 km. Near-surface temperature, 

salinity, and fluorescence were logged every two minutes while the ship was underway or 

stopped at stations. To calibrate the underway fluorescence, 101, 99, 99, and 101 

underway water samples were analyzed for chlorophyll content . After collection, the 

data sets were processed for compliance with quality assurance and quality control 

(QA/QC) criteria. 

On each cruise there were a number of complementary research programs. For cruises 

N6, N7, N8, and N9, there were seven, five, ten, and five complementary programs, 

respectively . The type of programs included coring, bio-optical sampling, color 

dissolved organic material measurements, flow cytometry sampling, experimental 

measurements using a 38 kHz ADCP, drifter deployments for MMS, a NASA over-flight 

for concurrent airborne and sea water flow-through bio-optical measurements, and 

benthic trawl sampling. Graduate student training and research was conducted on all 

cruises for various academic institutions, including TAMU, University of South Florida, 

University of Southern Mississippi, and University of Colorado. 

1 .3 Third Annual Report 

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

NEGOM-COH. It contains no detailed analyses of the data. Examples of products can 

be found in the first and second annual reports (Jochens and Nowlin, 1998 and 1999, 

respectively). 

The NEGOM-COH Synthesis Report, in preparation, will contain discussions of all data 

analyses carried out. The final synthesis report is expected to be available from MMS 

about September 2001 . 
31°N 

30°N 

29°N 

28°N 

0 

o ° 

9 ° 

" CTD/Bottle Stations 10 

o XBT Stations 11 00 o n o 0 0 ~ o 0 o 

27°N L90°W 89°W 88°W 87°W 86°W 85°W 84°W 83°W 82°W 

Figure 1 .2 .1 . Station locations and cross-shelf line numbers for NEGOM hydrographic/ADCP cruises and geographic 

locations in the study area. Line numbers are given at the offshore end of the lines. 

f ~ o v o o .o o 

- ~ , o 04 ~ o 

i p ° 4 ° o o `~ --

~ 5 ' 0 0o" 

0 

o o Q 2 G o 0 0 ~ ' 

e~ o 0 0 

ss, ~ 

7* 

: 

0

.o . o ~ o 

'odr,~ - o 

w 

2 INTRODUCTION 

The first annual report for NEGOM-COH detailed the program objectives, tasks, and 

participants, activities from October 1997 through June 1998, the data collection and 

processing for cruises N 1 and N2, and the results of preliminary examination of the N 1 

data set (Jochens and Nowlin, 1998). The second annual report described the activities 

from July 1998 through June 1999 and included data acquisition on cruises N3, N4, and 

N5, and QA/QC and analysis for selected data from cruises N2, N3, and N4 (Jochens and 

Nowlin, 1999) . This third annual report focuses on the period from July 1999 through 

August 2000 and includes information on data acquisition on cruises N6 through N9 and 

on QA/QC for data from cruises NS through N9. Information on the NEGOM-COH 

program is provided on a publicly accessible web page on the Internet at 

http ://negom.tamu.edu/negom . 

2.1 Overview of Cruise Schedule and Nomenclature 

Four hydrographic/ADCP cruises were conducted aboard R/V Gyre during this report 

period. The cruises, their various designators, and their start and end dates are given in 

Table 2.1 .1 . The NEGOM ID is the shorthand identifier used in this report . The cruise 

ID number is the standard cruise identifier widely used in the U.S . oceanographic 

community. The first two characters are the year of the cruise, the third character is the 

ship identifier, G for Gyre, and the last two characters are the number of the ship's cruise 

for that year. Typical station locations and cross-shelf line numbers are shown in Figure 

1 .2.1 . 

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

Survey 

No. 

Start Date End Date NEGOM ID Cruise ID 

6 15 August 1999 28 August 1999 N6 99-G-08 

7 13 November 1999 25 November 1999 N7 99-G 12 

8 15 April 2000 26 April 2000 N8 00-G-04 

9 28 July 2000 8 August 2000 N9 00-G-08 

2 .2 Programmatic Chance 

For the first six cruises, particulate organic carbon samples were taken from the top and 

bottom Niskin bottles. There was little relationship found between particulate organic 

carbon values and the particulate matter concentrations or beam attenuation for the 

bottom samples . Therefore, for the final three cruises, samples were taken from the 

bottles at the surface and chlorophyll maximum. 

Antheraxanthin was added to the suite of pigments determined by high performance 

liquid chromatography (HPLC) after equipment and an analytic standard became 

available for identification of this pigment. This occurred for N6 and subsequent cruises. 
6 

To better assess off-shelf currents and to make full use of the available ship time on 

cruise N8, line 2 was extended approximately 45 km offshore into a cyclonic eddy and an 

additional three CTD and three XBT stations were taken. 

2.3 Report Organization 

This is the third annual report of the NEGOM-COH study . It reports on: data-gathering 

efforts; equipment, measurement and analytical methodologies employed; and results of 

quality control procedures and results. Extensive results and syntheses of the information 

will be provided in the final Synthesis Report at the conclusion of the field work and 

analyses . Section 3 of the report details the acquisition of the chemical oceanography, 

hydrography, and ADCP measurements, as well as collateral data assembly. Section 4 

discusses data processing efforts and data quality control methods and results . All times 

are reported in Universal Coordinated Time (UTC) unless stated otherwise. 
3 DATA ACQUISITION 

Data acquisition activities for cruises N6, N7, N8, and N9 described here include a 

discussion of in situ sampling efforts and the instrumentation, calibration, and sampling 

procedures. Summaries of field data collection and collateral data assembly are given. 

3.1 General Description of Surveys 

From July 1999 through August 2000, four hydrographic/ADCP surveys (N6 through 

N9) were conducted aboard the R/V Gyre. A Sea-Bird SBE-91 1p1us CTD was used on 

each cruise . CTD-Rosette stations were occupied on each cruise at nearly identical 

station locations. Test stations, at which all bottles were tripped in the salinity minimum 

water at 700-800 m, were made to test instrumentation and equipment. XBT probes 

were launched between CTD stations . ADCP data were collected along the track . 

Navigation data and station locations were determined using a differential Global 

Positioning System (DGPS). 

The surveys consisted of eleven lines of CTD and XBT stations perpendicular to the 

bathymetry (cross-shelf lines) . The lines are numbered from 1 to 11 going from west to 

east (Figure 1 .2 .1) . The naming convention for cross-shelf lines is : 

First and second characters: 

Third character : 

Fourth and fifth characters : 

Sixth character : 

Seventh and eighth characters : 

Ninth character: 

NEGOM cruise number (N6, N7, N8, or N9) 

L = Line 

Line number (1 through 11) 

S = Sequence 

Sequence number of station on the line 

C = CTD station type; X = XBT station type 

Stations on each cross-shelf line are numbered sequentially from innermost to outermost 

station regardless of station type. As an example, station N6L06S03C is the third station 

from the coast on line 6 and is a CTD station taken on cruise N6. On cruise N6, XBTs 

also were deployed between pairs of cross-shelf lines along portions of the 1000-m 

isobath. For these stations the third character is "X", denoting a segment between two 

cross-shelf lines; the fourth and fifth characters give the starting cross-shelf line number 

and the sixth and seventh give the ending cross-shelf line number. The eighth character 

is "M", denoting the station is midway between the two cross-shelf lines . In the tables 

below, where it is clear whether the station type is a CTD or an XBT, the ninth character 

is not included. 

3 .1 .1 Cruise N6 

The sixth NEGOM-COH hydrography cruise (N6) was conducted on the R/V Gyre during 

15 - 28 August 1999. It was staged out of Galveston, TX, and returned to Panama City, 

FL. Dr. Douglas C. Biggs and Dr. Norman L. Guinasso, Jr., were co-chief scientists . 

One hundred CTD stations, including one test station (Station 000, N6TEST00) and one 

supplementary station (Station OOA, N6CORE00), were completed. The test station was 

located in deep water near Mississippi Canyon. The supplementary station was taken 

outside the NEGOM study area in about 35 m water depth west of the Mississippi River 

Delta. Eighty-nine successful XBT drops were made. The locations of the CTDs and 

XBTs and the cruise track are shown in Figure 3 .1 .1 . 
31 °N 

30°N 

29°N 

28°N 

27°N 

90°W 89°W 88°W 87°W 86°W 85°W 84°W 83°W 82°W 

00 

Figure 3 .1 .1 . Station locations for cruise N6 conducted 15 - 28 August 1999 . The cruise ran in order along lines 

1, 2, 3, 4, 11, 10, 9, 8, 5, 6, and 7. The thick line shows the cruise track, which began at the 

location of the most seaward station on line 1 . 
9 

The cruise started at the seaward end of line 1 and completed the CTD/XBT stations 

along lines 1, 2, 3, and 4 . Collecting XBT data, it then ran along the 1000-m isobath to 

the most seaward station on line 11 . The cross-shelf CTD/XBT station sampling then 

resumed and was completed for lines 11, 10, 9, and 8 . Due to illness, the cruise diverted 

to complete line 5 and then to evacuate the ill person via water taxi to Destin, FL. Lines 

6 and 7 then were run to complete the cruise . Station number, date, time, location, water 

depth, and number of bottles tripped at each CTD station are given in Table 3 .1 .1 . 

Stations at which bottle samples were taken are summarized in Table 3 .1 .2. Nutrients 

and oxygen were measured from every Niskin bottle sampled . Salinity was measured at 

the inner-most and 1000-m isobath stations on each cross-shelf line, the test station, the 

supplemental station, and station 86 for a total of 25 stations . Surface bucket salinity 

samples were taken at 58 of the CTD stations in regions expected to be influenced by 

river water. Pigment samples were taken at the top, in the chlorophyll-maximum as 

estimated from the downcast fluorescence trace, and in the low light regime immediately 

below the chlorophyll-maximum at 60 stations . Total particulate matter (PM), particulate 

organic carbon (POC), and particulate organic nitrogen (PON) were measured from the 

shallowest and deepest bottles and, for PM, from a middle, "clear water" bottle at 60 

stations. Duplicate POC/PON samples were taken at station 35. 

The location, date, time, total water depth, and probe type of the XBT drops are given in 

Table 3 .1 .3 . A 150kHz broadband ADCP was operated continuously along the track 

(Section 3 .2.3) . Flow-through near-surface temperature, conductivity, and fluorescence 

were logged every 2 minutes (Section 3 .2.5) . Surface samples were filtered and analyzed 

at 101 locations for chlorophyll a content to calibrate the flow-through fluorometer . 

Seven complementary research efforts were accommodated on summer cruise N6. With 

ship support provided by the state of Texas, Mr. Jeff Morin, TAMU, took gravity box 

core samples at the supplementary station and Mr. Dwight Gledhill, TAMU, took piston 

core samples at the test station . Both then assisted with NEGOM sampling for the 

remainder of the cruise . Mr. Bisman Nababan, from the remote sensing group of Dr. 

Frank Muller-Karger at the University of South Florida (USF), conducted irradiance casts 

and collected dissolved organic carbon data for comparison with SeaWiFS data . Dr. 

Carlos del Castilla, working for Dr. Paula Coble of USF, operated an underway Safire 

system to collect dissolved organic material fluorescence and absorbance data. Mr. Bill 

Kopesky collected samples for the flow cytometry program of Dr. Lisa Campbell, 

TAMU. Ms. Yesim Buyukates, graduate student of Dr. Dan Roelke of TAMU, 

participated in the cruise for purposes of looking at NEGOM data for her study of red 

tides . Two salinity samples were taken at each of three stations for Dr. Donald Shive of 

Muhlenberg College, Allentown, PA, for use in training chemistry students . Further 

information on these complementary research programs can be obtained from the 

scientists involved. 
10 

Table 3.1 .1 . Times and locations for CTD stations on cruise N6. 

Station 

Number 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

OOA N6CORE00 17- AUG- 1999 16:33:44 28 .953063 -89.889853 37. 12 

000 N6TEST00 18- AUG- 1999 00:23:46 28 .132920 -89.130395 1061 . 11 

001 N61-01S07 18- AUG- 1999 09:03:07 28 .662875 -88.900053 1004. 12 

002 N6LO1S05 18-AUG- 1999 11 :08:50 28 .805220 -88.948680 500. 12 

003 N61-01S04 18- AUG- 1999 12:38:36 28 .894520 -88.973960 205 . 12 

004 N61-01S03 18- AUG- 1999 13 :45 :27 28 .956055 -88 .997812 97. 12 

005 N61-01S01 18- AUG- 1999 14:55:59 29 .059043 -89.030423 19. 4 

006 N61-02S00 18- AUG- 1999 20:27 :49 29 .800647 -88.753902 15 . 4 

007 N61-02S01 18- AUG- 1999 21 :41 :14 29 .662818 -88.692392 19. 4 

008 N6L02S03 18- AUG- 1999 23:52 :49 29 .397653 -88.570245 58. 4 

009 N6L02S05 19- AUG-1999 01 :28 :51 29224697 -88.497543 111 . 12 

010 N6L02S06 19- AUG- 1999 02:24 :06 29 .173675 -88.473805 189. 12 

011 N61-02S08 19- AUG- 1999 03:51 :49 29 .047793 -88.416757 493. 12 

012 N6L02S10 19- AUG- 1999 05:37 :00 28 .869780 -88.336602 999. 12 

013 N61-03S10 19- AUG- 1999 09:47 :40 29 .153288 -87.859850 999. 12 

014 N6L03S09 19-AUG- 1999 11 :23 :46 29218220 -87.875755 459. 12 

015 N61-03S08 19- AUG-1999 12 :43 :51 29281913 -87.888493 207. 12 

016 N61-03S07 19- AUG- 1999 13 :48 :59 29.345993 -87.900927 98. 12 

017 N6L03S05 19- AUG- 1999 15 :50:14 29.558238 -87.948152 42. 5 

018 N61-03S03 19- AUG- 1999 18 :04:09 29.804197 -87.997625 36. 5 

019 N6L03S01 19- AUG- 1999 20:22 :56 30.103062 -88 .074298 21 . 4 

020 N6L03S00 19- AUG- 1999 21 :06:58 30.156823 -88.088667 12 . 4 

021 N6L04S00 20- AUG- 1999 01 :52 :39 30.279632 -87.324707 13 . 4 

022 N6L04S01 20-AUG-1999 02:35 :43 30221458 -87.351032 19 . 5 

023 N6L04S03 20- AUG- 1999 04:29 :04 29.979590 -87.349012 29. 5 

024 N6L04S05 20- AUG- 1999 06:25 :26 29.729037 -87.348882 80. 12 

025 N6L04S07 20-AUG-1999 08:01 :36 29.567942 -87.350190 110. 12 

026 N6L04S08 20- AUG- 1999 08:55 :40 29.531815 -87.350138 213. 12 

027 N6L04S10 20- AUG- 1999 10 :33 :17 29.371678 -87.346672 511 . 12 

028 N6L04S12 20- AUG- 1999 12 :34:44 29.194363 -87.348157 987. 12 

029 N6L11S18 21- AUG- 1999 05:57 :26 27.499055 -85.395352 996. 12 

030 N6L11S16 21- AUG- 1999 07:57 :09 27.498827 -85.225350 755. 12 

031 N61-11S14 21-AUG-1999 09:48 :13 27.499177 -85.076073 496. 12 

032 N61-11S12 21- AUG- 1999 11 :36:57 27.499573 -84.890750 300. 12 

033 N61,11S10 21- AUG-1999 13:32:58 27.499237 -84.681222 201 . 12 

034 N6L11S08 21- AUG- 1999 16 :07:08 27.500280 -84.342913 100. 12 

035 N6L11S06 21- AUG- 1999 18 :52:14 27.500453 -83.940733 58 . 9 

036 N61,11S04 21-AUG-1999 21 :35:42 27.499728 -83.496557 43 . 4 

037 N6L 11 S02 22- AUG- 1999 00:33:00 27.501252 -83.022510 22 . 5 

038 N61-11S01 22- AUG- 1999 01 :46:45 27.497312 -82.853122 13 . 4 

039 N6L10S01 22- AUG- 1999 10 :10:17 28.608993 -83 .074212 12. 4 

040 N6LIOS03 22- AUG- 1999 12 :03:18 28.521138 -83 .329595 20. 4 

041 N61-10S05 22- AUG- 1999 14:40:40 28.400475 -83 .702083 32. 6 

042 N61-10S07 22- AUG- 1999 17 :23:59 28286815 -84.059065 39. 4 

043 N6L10S09 22-AUG-1999 19:57 :47 28 .177022 -84.404055 60. 5 

044 N6L I OS 11 22 -AUG- 1999 22:24 :27 28 .076480 -84.706150 102. 12 

045 N6L10S13 23 -AUG- 1999 00:02 :08 28 .022188 -84.876767 200. I1 

046 N6L10S15 23-AUG- 1999 01 :49 :15 27 .959797 -85.069868 313 . 12 

047 N61-10S17 23 -AUG- 1999 03 :46 :30 27 .895870 -85.276100 495. 12 

048 N61-10S19 23 -AUG -1999 05 :07 :35 27 .852303 -85.412990 655. 12 

049 N6L10S21 23 -AUG -1999 07:27 :31 27 .782912 -85.631008 994. 12 
11 

Table 3.1 .1 . Times and locations for CTD stations on cruise N6 (continued) . 

Station 

Number 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

050 N6L09S21 23- AUG- 1999 11 :31 :56 28.019132 -86 .042420 979. 11 

051 N6L09S19 23- AUG- 1999 13 :43:12 28.115022 -85 .876547 682 . 12 

052 N6L09S17 23- AUG- 1999 15 :37:31 28.190858 -85 .753908 502 . 12 

053 N6L09S15 23- AUG- 1999 17 :49:33 28.310348 -85 .560443 304. 12 

054 N6L09S13 23- AUG- 1999 19 :36:00 28.412758 -85 .393618 200. 12 

055 N6L09S11 23- AUG- 1999 21 :12:34 28.510907 -85234182 162. 11 

056 N6L09S09 23- AUG- 1999 22:53:21 28.627353 -85 .043788 98 . 12 

057 N6L09S07 24- AUG- 1999 01 :35:40 28.839780 -84.693920 46. 6 

058 N6L09S05 24- AUG- 1999 04:43:46 29.105440 -84.256075 27 . 5 

059 N6L09S03 24- AUG- 1999 07 :42:56 29.342655 -83 .861285 20. 5 

060 N6L09S01 24- AUG- 1999 09:41 :40 29.491292 -83 .625663 12. 4 

061 N6L08S01 24- AUG- 1999 16:47:47 29.602123 -84.780017 14. 4 

062 N6L08S03 24- AUG- 1999 19:01 :52 29.386823 -85 .019942 25 . 4 

063 N6L08S05 24- AUG- 1999 21 :05:22 29.203973 -85 .274593 40. 4 

064 N6L08S07 24- AUG- 1999 23 :29:45 28.986182 -85.528882 121 . 12 

065 N6L08S09 25- AUG- 1999 01 :17:41 28.825528 -85.719160 199. 12 

066 N6L08S11 25- AUG- 1999 04:00 :50 28 .605627 -85 .973177 308. 12 

067 N6L08S13 25- AUG- 1999 06:21 :25 28 .402348 -86.215092 496. 12 

068 N6L08S15 25- AUG- 1999 08:06 :21 28 .295305 -86.339145 672. 12 

069 N6L08S17 25- AUG- 1999 10:41 :51 28 .132228 -86.530562 998. 12 

070 N6LOSS17 25-AUG- 1999 20:30:46 29 .050862 -87 .200947 995. 12 

071 N6LOSS15 25-AUG- 1999 23:00:40 29277745 -87.101618 708. 12 

072 N6LOSS13 26- AUG- 1999 00:59 :02 29.470788 -87.016340 480. 12 

073 N6LOSS11 26- AUG- 1999 02:43 :02 29.608477 -86.945093 263. 12 

074 N6LOSS09 26- AUG- 1999 03:59 :41 29.725840 -86.885920 199. 12 

075 N6LOSS07 26-AUG-1999 05:25 :35 29.882902 -86.811590 147. 12 

076 N6LOSS05 26- AUG- 1999 06:53 :27 30.027678 -86.737165 99. 12 

077 N6LOSS03 26-AUG-1999 08:34:00 30.204820 -86.655707 27. 5 

078 N6LOSS01 26- AUG- 1999 10 :02:41 30.365935 -86.578790 19 . 4 

079 N6L06S01 26-AUG-1999 15 :10:19 30.178808 -85.883368 21 . 4 

080 N6L06S03 26- AUG- 1999 16 :46:53 30.018252 -86.021422 32. 5 

081 N6L06S05 26- AUG- 1999 18 :25 :37 29.853597 -86.166260 47. 5 

082 N6L06S07 26- AUG-1999 20:09:10 29.682588 -86.310030 100. 12 

083 N6L06S09 26- AUG- 1999 22:01 :55 29.496432 -86.470868 204 . 12 

084 N6L06S11 26- AUG- 1999 23:59:34 29.310330 -86.632468 384 . 12 

085 N6L06S13 27- AUG- 1999 01 :59:54 29.133015 -86.789645 498 . 12 

086 N6L06S15 27- AUG-1999 04:01 :05 28.984517 -86.917517 610. 12 

087 N6L06S17 27- AUG- 1999 05:46:09 28.827078 -87.052560 767 . 12 

088 N6L06S19 27- AUG-1999 08:08:21 28.653437 -87201165 994. 12 

089 N6L07S17 27- AUG- 1999 11 :17:56 28.370637 -86.987340 1009 . 12 

090 N6L07S15 27- AUG- 1999 13 :54:31 28.557317 -86.772570 668 . 12 

091 N6L07S13 27-AUG- 1999 15 :53:00 28.701253 -86.612705 499. 12 

092 N6L07S11 27-AUG- 1999 18 :11 :05 28.861955 -86.422038 382. 12 

093 N6L07S09 27- AUG- 1999 20:29:49 29.010635 -86245705 317. 12 

094 N6L07S07 27- AUG- 1999 22:48:16 29207753 -86.029408 200. 12 

095 N6L07S05 28-AUG-1999 00:13 :38 29 .298890 -85.921008 94. 12 

096 N6L07S03 28-AUG-1999 02:29 :56 29 .499793 -85.693047 31 . 5 

097 N6L07S01 28 -AUG -1999 04:27 :12 29.686492 -85.478688 20. 4 

098 N6L07S00 28 -AUG -1999 05 :09 :25 29.735563 -85.427490 11 . 3 
12 

Table 3 .1 .2 Number of bottles sampled by variable on cruise N6. Blank = no sample. 

Station Station Nutrient Oxygen Salinity Bucket Pigment PM* POC & 

No. Name Salinity PON* 

OOA N6CORE00 12 12 3 1 

000 N6T'EST00 11 11 11 

001 N6LO1S07 12 12 12 1 3 3 2 

002 N61-01S05 12 12 1 3 3 2 

003 N6LO1S04 12 12 1 4 3 2 

004 N61-01S03 12 12 1 4 3 2 

005 N6LO1S01 4 4 4 1 3 3 2 

006 N6L02S00 4 4 4 1 

007 N6L02S01 4 4 1 3 3 2 

008 N61-02S03 4 4 1 

009 N6L02S05 12 12 1 3 3 2 

010 N61,02S06 12 12 1 4 3 2 

011 N6L02S08 12 12 1 4 3 2 

012 N6L02S10 12 12 12 1 3 3 2 

013 N6L03S10 12 12 12 1 3 3 2 

014 N6L03S09 12 12 1 3 3 2 

015 N6L03S08 12 12 1 3 3 2 

016 N6L03S07 12 12 1 3 3 2 

017 N6L03S05 5 5 1 

018 N61-03S03 5 5 1 

019 N6L03S01 4 4 1 3 3 2 

020 N6L03S00 4 4 4 1 

021 N61-04S00 4 4 4 1 

022 N6L04S01 5 5 1 2 3 2 

023 N61-04S03 5 5 1 

024 N61-04S05 12 12 1 

025 N6L04S07 12 12 3 3 2 

026 N6L04S08 12 12 3 3 2 

027 N61-04S10 12 12 2 3 2 

028 N6L04S12 12 12 12 3 3 2 

029 N6L11S18 12 12 12 3 3 2 

030 N6L11S16 12 12 

031 N6LI1S14 12 12 3 3 2 

032 N6L11S12 12 12 

033 N61,11S10 12 12 3 3 2 

034 N6L11S08 12 12 1 4 3 2 

035 N6LI1S06 9 9 1 6 

036 N6L11S04 4 4 1 3 3 2 

037 N6L11S02 5 5 1 2 3 2 

038 N6L11S01 4 4 4 1 

039 N61-10S01 4 4 4 1 

040 N61-10S03 4 4 1 2 3 2 

041 N61-10S05 6 6 1 2 3 2 

042 N61-10S07 4 4 1 2 3 2 

043 N61-10S09 5 5 1 

044 N6L10S11 12 12 1 3 3 2 

045 N6L10S13 11 11 3 3 2 

046 N61-10S15 12 12 

047 N6L10S17 12 12 3 3 2 

048 N6LlOS19 12 12 

049 N6L10S21 12 12 12 3 3 2 
13 

Table 3 .1 .2 Number of bottles sampled by variable on cruise N6 (continued) . 

Station Station Nutrient Oxygen Salinity Bucket Pigment PM* POC & 

No. Name Salinity PON* 

050 N61-09S21 11 11 11 3 3 2 

051 N61-09S19 12 12 

052 N61-09S17 12 12 3 3 2 

053 N6L09S15 12 12 

054 N61-09S13 12 12 3 3 2 

055 N61-09S11 11 11 

056 N61-09S09 12 12 1 3 3 2 

057 N6L09S07 6 6 1 2 3 2 

058 N61-09S05 5 5 1 2 3 2 

059 N61-09S03 5 5 1 2 3 2 

060 N61-09S01 4 4 4 1 

061 N6L08S01 4 4 4 1 

062 N6L08S03 4 4 1 2 3 2 

063 N6L08S05 4 4 1 

064 N6L08S07 12 12 1 3 3 2 

065 N61-08S09 12 12 3 3 2 

066 N6L08S11 12 12 

067 N6L08S13 12 l2 3 3 2 

068 N61-08S15 12 12 

069 N6L08S17 12 12 12 3 3 2 

070 N61-05S17 12 12 12 3 3 2 

071 N61-05S15 12 12 

072 N61,05S13 12 12 3 3 2 

073 N61,05S11 12 12 

074 N6LO5S09 12 12 1 3 3 2 

075 N6LO5S07 12 12 1 

076 N6LO5S05 12 12 1 3 3 2 

077 N6LO5S03 5 5 1 

078 N61,05S01 4 4 4 1 2 3 2 

079 N61-06S01 4 4 4 1 4 3 2 

080 N6L06S03 5 5 1 

081 N61-06S05 5 5 1 

082 N61-06S07 12 12 1 3 3 2 

083 N61-06S09 12 12 3 3 2 

084 N61-06S11 12 12 

085 N6L06S13 12 12 3 3 2 

086 N6L06S15 12 12 1 

087 N61-06S17 12 12 

088 N61-06S19 12 12 12 3 3 2 

089 N61-07S17 12 12 12 3 3 2 

090 N6L07S15 12 12 

091 N61-07S13 12 12 4 3 2 

092 N6L07S11 12 12 

093 N6L07S09 12 12 

094 N61-07S07 12 12 3 3 2 

095 N61-07S05 12 12 1 3 3 2 

096 N6L07S03 5 5 1 

097 N6L07S01 4 4 1 2 3 2 

098 N61-07S00 3 3 3 1 

Total 936 936 189 58 175 180 126 

* POC = particulate organic carbon ; PON = particulate organic nitrogen ; PM = total particulate material 
14 

Table 3 .1 .3 Launch times and locations for XBT drops on cruise N6. 

Sequence Station Date Time Latitude Longitude Water Probe 

Number Name (UTC) (LTl'C) (°N) (°W) Depth Type 

001 N6LO1S06 18-AUG-1999 10:32:15 28.730737 -88 .923875 775 . T7 

002 N6LO1S02 18-AUG-1999 14:31 :44 29.015817 -89.016952 54. T10 

003 N6L02S02 18-AUG-1999 22:43:40 29.538170 -88 .635763 30. T10 

004 N6L02S04 19-AUG-1999 00:41 :30 29.316070 -88 .538018 64. T10 

005 N6L02S07 19-AUG-1999 03 :02:09 29.122648 -88.452140 286. T7 

006 N6L02S09 19-AUG-1999 04:53:37 28.955443 -88.376955 764. T7 

007 N6X0203M 19-AUG-1999 08 :12:13 29 .036410 -88.104570 1112. T7 

008 N6L03S06 19-AUG-1999 15 :00:33 29 .453058 -87.927990 62. T10 

009 N6L03S04 19-AUG-1999 17:01 :08 29 .677448 -87.971885 40. T10 

010 N6L03S02 19-AUG-1999 19:18 :24 29 .953342 -88.038065 25. T10 

011 N6L04S02 20-AUG-1999 03:32 :37 30.102882 -87.350898 30. T10 

012 N6L04S04 20-AUG-1999 05:28 :54 29.856562 -87.350963 46. T10 

013 N6L04S06 20-AUG-1999 07:20:16 29.656693 -87.351025 80. T10 

014 N6L04S09 20-AUG-1999 09:55 :35 29.449695 -87.351757 356. T10 

015 N6L04S 11 20-AUG-1999 11 :53 :16 29.282025 -87.350887 814. T7 

016 N6X0405M 20-AUG-1999 14 :05 :10 29.135822 -87.261080 1011 . T7 

017 N6LO5S17 20-AUG-1999 14 :42:52 29.054725 -87205087 999. T7 

019 N6X0506M 20-AUG-1999 15 :57:27 28.860145 -87.198792 970. T7 

020 N6L06S19 20-AUG-1999 17 :16:54 28.653150 -87201557 1004. T7 

021 N6X0607M 20-AUG-1999 18:22:44 28.491198 -87.117947 1004. T7 

022 N6L07S17 20-AUG-1999 19 :21 :17 28.371050 -86.988298 1004 . T7 

023 N6X0708M 20-AUG-1999 20:39:34 28.260988 -86.759383 1004 . T7 

024 N6LO8S17 20-AUG-1999 21 :59:10 28.132252 -86.532263 1004 . T7 

025 N6X0809M 20-AUG-1999 23:19:08 28.057017 -86.304250 1004 . T7 

026 N6L09S21 21-AUG-1999 00:49:00 28.018963 -86.042978 976 . T7 

027 N6X0910M 21-AUG-1999 02:15:59 27.902095 -85 .819495 992 . T7 

031 N6L10S21 21-AUG-1999 03 :43:45 27.768318 -85 .610183 1154 . T7 

033 N6X1011M 21-AUG-1999 04 :43:51 27.648197 -85 .495332 1008 . T7 

035 N6L11S17 21-AUG-1999 07 :27:55 27.499743 -85 .294338 836. T7 

036 N6L11S15 21-AUG-1999 09 :13:21 27.500162 -85 .145767 624. T7 

037 N61-11S13 21-AUG-1999 10:55:40 27.500100 -84.986097 391 . T7 

038 N6L11S11 21-AUG-1999 12:45:21 27 .498930 -84.791440 236. T7 

039 N6L11S09 21-AUG-1999 14:57 :08 27 .500353 -84.523513 140. T10 

040 N6L11S07 21-AUG-1999 17 :31 :03 27 .499980 -84.159887 74. T10 

041 N6L11S05 21-AUG-1999 20:10:47 27 .498963 -83.732930 50. T10 

042 N6L11S03 21-AUG-1999 23 :06 :33 27 .500055 -83249920 34. T10 

043 N6L10S02 22-AUG-1999 11 :06:51 28 .564000 -83.195000 17 . T10 

044 N6L10S04 22-AUG-1998 13 :28 :14 28 .456167 -83.528000 30. T10 

045 N6L10S06 22-AUG-1999 16 :06:53 28.343208 -83.887577 40. T10 

046 N6L10S08 22-AUG-1999 18 :51 :35 28228363 -84.240790 48. T10 

047 N6L10S10 22-AUG-1999 21 :20:24 28.122778 -84.569115 74. T10 

048 N6L10S12 22-AUG-1999 23:18:02 28.048992 -84.799125 150. T10 

049 N6L l OS 14 23-AUG-1999 00:57:41 27.992635 -84.976133 248 . T7 

050 N6L10S16 23-AUG-1999 02 :47:34 27.930763 -85 .167107 374 . T7 

051 N6L10S18 23-AUG-1999 04 :30:48 27.877480 -85 .333083 586. T7 

052 N6L10S20 23-AUG-1999 06 :32:34 27.817543 -85 .522470 791 . T7 

053 N6L09S20 23-AUG-1999 13 :04:42 28.071937 -85 .950745 804. T7 

055 N6L09S18 23-AUG-1999 15 :06:50 28 .157765 -85 .811520 588 . T7 

056 N6L09S 16 23-AUG-1999 16:58 :31 28 .253977 -85 .652872 380. T7 

057 N6L09S 14 23-AUG-1999 18 :51 :16 28 .360028 -85 .478887 246. T7 

058 N6L09S12 23-AUG-1999 20:29 :49 28 .457780 -85 .318993 180. T10 
15 

Table 3.1 .3 Launch times and locations for XBT drops on cruise N6 (continued) . 

Sequence 

Number 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Water 

Depth 

(m) 

Probe 

Type 

059 N6L09S10 23-AUG-1999 22:04:50 28.567043 -85.138688 130. T10 

060 N6L09S08 24- AUG-1999 00:10:54 28.724622 -84 .882418 52. T10 

061 N6L09S06 24- AUG-1999 03:09:55 28.971995 -84 .476187 34. T10 

063 N6L09S04 24- AUG-1999 06:20:13 29.232880 -84.048080 26. T10 

064 N6L09S02 24- AUG-1999 08:49:53 29.427677 -83 .728733 16. Tl0 

065 N6L08S02 24- AUG-1999 17 :46:46 29.522655 -84.872518 16. T10 

066 N6L08S04 24- AUG-1999 19 :55:25 29.327688 -85 .128325 28 . T10 

067 N6L08S06 24- AUG-1999 22:20:53 29.094632 -85 .403573 50. T10 

068 N6L08S08 25- AUG-1999 0029:48 28.902450 -85 .628025 170. T10 

069 N6L08S10 25-AUG-1999 02:46:58 28.710045 -85 .853997 254. T7 

070 N6L08S 12 25- AUG-1999 05 :21 :44 28 .496532 -86.104515 374. T7 

071 N6L08S14 25 -AUG-1999 07:27 :35 28 .352118 -86.274125 568. T7 

072 N61,08S16 25-AUG-1999 09:48 :25 28 .214348 -86 .436180 833. T7 

073 N6L05S16 25-AUG-1999 21 :5929 29.181382 -87.149327 826. T7 

074 N6L05S14 26 -AUG-1999 00:01 :34 29.374463 -87.056307 694. T7 

075 N6LO5S12 26 -AUG-1999 01 :46:21 29.534427 -86 .978903 348. T7 

076 N6LO5S 10 26 -AUG-1999 03:25 :41 29.670997 -86.912642 224. T7 

077 N6LO5S08 26 -AUG-1999 04:48 :18 29.808423 -86.847217 170. T10 

078 N6L05S06 26 -AUG-1999 06:18 :13 29.959827 -86.773887 124. T10 

079 N6L05S04 26 -AUG-1999 07:49:14 30.112803 -86.700062 47. T10 

080 N6LO5S02 26 -AUG-1999 09:24:26 30.292765 -86.613012 28. T10 

081 N6L06S02 26 -AUG-1999 15 :57:57 30.097510 -85.952788 28. T10 

082 N6L06S04 26 -AUG-1999 17 :35:43 29.942333 -86.090112 40. T10 

083 N6L06S06 26 -AUG-1999 1922:11 29.760362 -86.247053 68. T10 

084 N6L06S08 26 -AUG-1999 21 :03:48 29.600773 -86.385437 134 . T10 

085 N6L06S 10 26 -AUG-1999 22 :57:05 29.410407 -86.549257 290. T7 

086 N6L06S12 27 -AUG-1999 00:58:28 29226358 -86.708507 442. T7 

088 N6L06S14 27 -AUG-1999 03 :04:43 29.043020 -86.866280 554. T7 

090 N6L06S16 27 -AUG-1999 05 :03:11 28 .906617 -86.983492 698. T7 

091 N6L06S18 27 -AUG-1999 07 :15:57 28 .741793 -87.125132 906. T7 

092 N6L07S 16 27 -AUG-1999 13 :01 :05 28 .464108 -86.880533 716. T7 

093 N6L07S14 27 -AUG-1999 15 :15 :46 28 .638195 -86.682493 574. T7 

094 N6L07S12 27 -AUG-1999 17 :13 :13 28 .784548 -86.513858 420. T7 

095 N6L07S 10 27 -AUG-1999 19 :18 :43 28 .944783 -86.329412 338. T7 

096 N6L07S08 27 -AUG-1999 21 :53 :19 29.120413 -86.127943 258. T7 

097 N6L07S06 27 -AUG-1999 23:36:29 29.251550 -85.979040 158. T10 

098 N6L07S04 28 -AUG-1999 01 :19:32 29.387523 -85.822905 50. T10 

099 N6L07S02 28 -AUG-1999 03:30:17 29.593492 -85.586598 28. T10 

Launches at missing sequence numbers were failures or deemed bad data during QA/QC or were 

where the counter erroneously advanced . 

3.1 .2 Cruise N7 

The seventh NEGOM-COH hydrography cruise (N7) was conducted aboard the RN Gyre 

during 12-25 November 1999 on two legs. Leg one, with an 18-member science party, 

was from Gulfport, MS, to St. Petersburg, FL, and consisted of the hydrographic 

sampling program for lines 1 through 11 . Leg two, with a 4-member science party, 
16 

consisted of an ADCP run along the 1000-m isobath. Dr. Douglas C. Biggs and Dr . 

Norman L. Guinasso, Jr., were co-chief scientists . Ninety-nine CTD stations, including 

one test station, were completed and 84 successful XBT drops were launched. CTD and 

XBT locations and cruise track are shown in Figure 3 .1 .2 . Station number, date, time, 

location, water depth, and number of bottles tripped at each CTD station are shown in 

Table 3 .1 .4 . 

The test station was taken approximately at the location of the most seaward CTD station 

on line 1 . The cruise track started at this location and ran along the cross-shelf lines 1 

through 11 in order. Due to weather-related time constraints, the 10-m isobath station on 

line 8 (station 58, N7LA8SOIC) was moved to the 10-m isobath between line 7 and 8 and 

the innermost XBT station on line 8 was eliminated. The water sampling contingent of 

the science crew disembarked at St. Petersburg on 22 November 2000 . Leg two began in 

St. Petersburg, FL, ran seaward along line 11 and then along the 1000-m isobath to line l . 

The cruise ended at the completion of the 1000-m isobath ADCP run. XBTs were 

dropped along the 1000-m isobath at the ends of each cross-shelf line . 

Stations at which bottle samples were taken are summarized in Table 3 .1 .5 . Nutrient and 

oxygen concentrations were measured from every Niskin bottle depth sampled. Salinity 

was measured at all bottles only at the most shoreward and most offshore stations and at 

the test station for a total of 23 stations . Surface bucket salinity samples were taken at 81 

stations with possible influence by river water. Pigment measurements were collected at 

the top bottle, the chlorophyll-maximum as determined by the downcast fluorescence 

trace, and the low light regime immediately below the chlorophyll-maximum at 59 

stations . PM samples were taken from the top, mid-depth "clear water", and bottom 

bottles at 52 stations . POC and PON were measured from the top and chlorophyllmaximum bottles at 52 stations . 

The location, date, time, total water depth, and probe type of the 84 successful XBT 

drops are listed in Table 3.1 .6. ADCP data were collected continuously along the survey 

track (Section 3 .2.3). Two ADCPs were operated. A 38 kHz ADCP was operated 

throughout the N7 cruise in water depths greater than -40 m. A broadband 150 kHz 

ADCP was operated continuously from the beginning of the cruise to the shoreward end 

of line 10 . The broadband ADCP then was replaced with a narrowband 150 kHz ADCP 

as part of a scheduled comparison between the narrowband and 38 kHz instruments . The 

broadband ADCP was reinstalled after the ship put into port prior to the final run on line 

11 and the 1000-m isobath. Flow-through, near-surface temperature, conductivity, and 

fluorescence were logged every 2 minutes (Section 3 .2.5) during Leg 1 . Surface samples 

were filtered and analyzed for chlorophyll a content to calibrate the flow-through 

fluorometer at 99 locations . 

Five complementary research efforts were accommodated on autumn cruise N7 . Thirty 

ARGOS-tracked drifters were launched for Dr. James M. Price of MMS. Mr. Bisman 

Nababan, graduate student of Dr. Frank Muller-Karger at USF, and Ms . Robyn Conmy, 

graduate student of Dr. Paula Coble of USF, conducted irradiance casts and collected 

dissolved organic carbon data for comparison with SeaWiFS data and operated an 

underway Safire system to collect dissolved organic material fluorescence and 

absorbance data. Samples were collected for the flow cytometry program of Dr. Lisa 

Campbell, TAMU. A 38kHz ADCP, which samples to 500-1000 m, was operated by Dr. 

Guinasso in cooperation with RD Instruments (RDI) for a comparison with a 150 kHz 

ADCP, which samples to 100-200m. Further information on these complementary 

research programs can be obtained from the scientists involved . 
31°N 

30°N 

29°N 

28°N 

27°N 

Mississi 

.. y 

Y 

o 

Florida 

City 

Georgia 

3 C'4' 5 

22 

- 0 w 0 

7 

8 

9 

" CTD/Bottle - 98 Stations 10 ' o XBT - 84 Stations 

* Test Station 11 rooo3 g 

90°W 89°W 88°W 87°W 86°W 85°W 84°W 83°W 82°W 

Figure 3.1 .2 . Station locations for cruise N7 conducted 12 - 25 November 1999 . The cruise ran along lines 1 through 

11 in order. The thick line shows the cruise track, which began with at test station near the most seaward 

station on line 1 . XBTs were deployed at the offshore ends of the lines at cruise end. 
18 

Table 3.1 .4 . Times and locations for CTD stations on cruise N7 . 

Station 

No. 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

000 N7T'EST00 13- NOV- 1999 16 :27 :47 28 .662690 -88.899048 1000. 12 

001 N7LO1S07 13- NOV- 1999 18:28 :53 28 .662892 -88.900270 1002. 12 

002 N7LO1S05 13-NOV- 1999 20:59:55 28 .805990 -88.949197 504. 12 

003 N7LO1S04 13- NOV- 1999 22:24:06 28 .893882 -88.973517 207. 12 

004 N7LO1S03 13- NOV- 1999 23:26:04 28 .952613 -88.996395 106. 12 

005 N7LO1S01 14- NOV- 1999 00:43 :43 29.057675 -89.028092 21 . 4 

006 N7L02S00 14- NOV- 1999 06:23 :07 29.800955 -88.754447 15 . 4 

007 N7L02S01 14-NOV- 1999 07:33 :18 29.661690 -88.691905 19 . 4 

008 N7L02S03 14- NOV- 1999 09:43 :05 29.393505 -88.573053 58 . 6 

009 N7L02S05 14-NOV- 1999 11 :13:32 29.225252 -88.498328 110. 12 

010 N7L02S06 14- NOV- 1999 12:13:09 29.172503 -88.473820 190. 12 

011 N7L02S08 14-NOV- 1999 13 :34:44 29.045738 -88.417888 493. 12 

012 N7L02S10 14- NOV- 1999 15 :37:46 28.867812 -88.339902 950. 12 

013 N7L03S10 14-NOV- 1999 20:26:42 29.149988 -87.860715 1032. 12 

014 N7L03S09 14- NOV- 1999 22:09:07 29218975 -87.879465 453 . 12 

015 N7L03S08 14- NOV- 1999 23 :16:06 29.282748 -87.891930 201 . 12 

016 N7L03S07 15- NOV- 1999 00:13 :08 29.347867 -87 .902533 95 . 12 

017 N7L03S05 15- NOV- 1999 01 :59:40 29.558600 -87.947050 43 . 5 

018 N7L03S03 15- NOV- 1999 03 :50:56 29.804268 -87.995943 35 . 5 

019 N7L03S01 15- NOV- 1999 06:26:20 30.123222 -88 .076577 19 . 5 

020 N7L03S00 15-NOV- 1999 07:13:26 30.154995 -88 .087455 11 . 4 

021 N7L04S00 15-NOV- 1999 11 :49:56 30.273440 -87.327028 11 . 4 

022 N7L04S01 15- NOV- 1999 12:23:37 30.219653 -87.352223 22. 5 

023 N7L04S03 15- NOV- 1999 14:10:52 29.978493 -87.352708 30. 5 

024 N71,04S05 15- NOV- 1999 16:03:13 29.728818 -87.352553 75 . 6 

025 N7L04S07 15- NOV- 1999 17:31 :13 29.567372 -87.353410 104. 12 

026 N7L04S08 15- NOV- 1999 18 :26:00 29.530210 -87.352177 177. 12 

027 N7L04S10 15- NOV- 1999 20:12:59 29.369450 -87.351455 508 . 12 

028 N7L04S12 15-NOV- 1999 22:01 :52 29.192213 -87.351393 1014. 12 

029 N7LO5S17 16- NOV- 1999 00:15:35 29.054842 -87204893 996. 12 

030 N7LO5S15 16- NOV- 1999 03 :10:45 29.273787 -87.104755 710. 12 

031 N7LO5S13 16- NOV- 1999 05 :49:12 29.465822 -87.013115 485 . 12 

032 N7L05S11 16- NOV- 1999 07:58:38 29.605508 -86.946357 264. 12 

033 N7LO5S09 16- NOV- 1999 09:52:18 29.721987 -86.888860 201 . 11 

034 N7LO5S07 16- NOV- 1999 11 :51 :12 29.879738 -86 .812887 148 . 11 

035 N7L05S05 16- NOV- 1999 13 :33:11 30.028668 -86.738750 100. 8 

036 N7LO5S03 16-NOV- 1999 15 :15:05 30.205975 -86.655687 28 . 5 

037 N7LO5S01 16- NOV- 1999 16:35 :59 30.366022 -86 .579042 19. 4 

038 N7L06S01 16- NOV- 1999 20:48:08 30.177853 -85.881745 20. 4 

039 N7L06S03 16- NOV- 1999 22:29:30 30.019093 -86.024020 32. 5 

040 N71,06S05 17- NOV- 1999 00:01 :10 29.852153 -86.168018 47. 6 

041 N7L06S07 17- NOV- 1999 01 :31 :46 29.685480 -86.312593 100. 12 

042 N7L06S09 17- NOV- 1999 03:24:35 29.500403 -86.474382 202. 12 

043 N7L06S11 17- NOV- 1999 05:26:05 29.314737 -86.633180 384. 11 

044 N7L06S13 17- NOV- 1999 07:36:32 29.133575 -86.789858 498. 12 

045 N7L06S15 17- NOV- 1999 09:34:22 28.979363 -86.923813 618. 12 

046 N7L06S17 17- NOV- 1999 11 :37:47 28.826920 -87.053660 768. 12 

047 N7L06S19 17- NOV- 1999 13 :53 :40 28.652945 -87.202738 993. 12 

048 N7L07S17 17- NOV- 1999 17 :21 :39 28373960 -86.985653 994. 12 

049 N7L07S15 17- NOV- 1999 20:04:10 28.556108 -86.769557 663. 12 

050 N7L07S13 17-NOV- 1999 22:10:06 28.702852 -86.611245 495. 12 

051 N7L07S11 18 -NOV- 1999 00:09:55 28.864117 -86.422472 381 . 12 
19 

Table 3.1 .4 . Times and locations for CTD stations on cruise N7 (continued) . 

Station 

No. 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

052 N7L07S09 18 -NOV-1999 02:04:14 29.017605 -86.247480 315. 12 

053 N7L07S07 18 -NOV-1999 04:13:07 29207778 -86.029015 199 . 12 

054 N7L07S05 18 -NOV-1999 05:28:46 29.298820 -85.922390 94. 12 

055 N7L07S03 18-NOV-1999 07:40:54 29.499633 -85.695953 31 . 4 

056 N7L07S01 18 -NOV-1999 09:52:44 29.686902 -85.479673 21 . 4 

057 N7L07S00 18 -NOV-1999 10 :36:47 29.736817 -85.426638 IL 4 

058 N7LA8S01* 18-NOV-1999 15 :20:25 29.510475 -85.101652 14 . 4 

059 N7L08S03 18 -NOV-1999 16 :44:26 29.381810 -85.000883 25. 5 

060 N7L08S05 18 -NOV-1999 18 :56:47 29.206452 -85.273090 37. 4 

061 N7L08S07 18 -NOV-1999 21 :07:20 28.986720 -85.526430 96. 11 

062 N7L08S09 18 -NOV-1999 22:58:56 28.824778 -85.719092 198. 12 

063 N7L08S11 19 -NOV-1999 01 :24:35 28.604627 -85.977277 308. 12 

064 N7L08S13 19 -NOV-1999 03:46:31 28.400655 -86.216298 498. 12 

065 N7L08S15 19 -NOV-1999 05:20:29 28.294923 -86.340587 675. 12 

066 N7L08S17 19 -NOV-1999 07:33:34 28.131185 -86.532438 1003. 12 

067 N7L09S21 19 -NOV-1999 11 :39:46 28.018270 -86.044197 978. 12 

068 N7L09S19 19-NOV-1999 14:09:02 28.118267 -85.879067 674. 12 

069 N7L09S17 19 -NOV-1999 16 :01 :32 28.192272 -85.753760 496. 12 

070 N7L09S15 19 -NOV-1999 18:15:23 28.309668 -85.563302 303. 12 

071 N7L09S13 19 -NOV-1999 19 :55:53 28.411183 -85.396510 199. 12 

072 N7L09S11 19 -NOV-1999 21 :38:51 28.508007 -85235188 161 . 12 

073 N7L09S09 19 -NOV-1999 23:20:50 28.627435 -85.045478 98. 12 

074 N7L09S07 20 -NOV-1999 02:06:28 28.839893 -84 .695093 46. 5 

075 N7L09S05 20 -NOV-1999 05:08:13 29.105590 -84256910 27. 4 

076 N7L09S03 20 -NOV-1999 08:14:55 29.341962 -83 .861582 19. 4 

077 N7L09S01 20 -NOV-1999 10:03:39 29.492247 -83 .626153 11 . 4 

078 N7L10S01 20 -NOV-1999 16 :52:21 28.610233 -83.073583 11 . 4 

079 N7L10S03 20 -NOV-1999 18:37:31 28.518478 -83 .332417 19. 4 

080 N7L10S05 20 -NOV-1999 20:56:26 28.400387 -83 .701760 30. 4 

081 N7L10S07 20 -NOV-1999 23:16:58 28.284727 -84 .059953 39. 5 

082 N7L10S09 21-NOV-1999 01 :35:22 28.176533 -84 .403280 59. 6 

083 N7L10S11 21 -NOV-1999 03:37:03 28.077852 -84 .708583 102. 12 

084 N7L10S13 21 -NOV-1999 04:52:35 28.023395 -84.879220 201 . 12 

085 N7L10S15 21-NOV-1999 06:26:51 27.961443 -85 .074738 314. 12 

086 N7L10S17 21 -NOV-1999 08:12:22 27.897020 -85 .278182 493 . 12 

087 N7L10S19 21 -NOV-1999 09:47:59 27.853492 -85 .413820 653. 12 

088 N7LIOS21 21 -NOV-1999 11 :51 :28 27.783585 -85 .632173 986. 12 

089 N7L11S18 21 -NOV-1999 15 :02:43 27.499818 -85 .394512 997. 12 

090 N7L11S16 21-NOV-1999 16:48:04 27.500225 -85 .225898 751 . 12 

091 N7L11S14 21 -NOV-1999 18 :40:35 27.500603 -85 .075908 496. 12 

092 N7L11S12 21 -NOV-1999 20:17:46 27.500210 -84.888698 296. 12 

093 N7L11S10 21 -NOV-1999 21:55:30 27.501265 -84.681113 200. 12 

094 N7L11S08 22 -NOV-1999 00:12:53 27.500410 -84.342758 100. 12 

095 N7L11S06 22-NOV-1999 02:46:09 27.499500 -83 .943988 58 . 5 

096 N7L11S04 22 -NOV-1999 05 :40:45 27.500968 -83 .498420 42. 4 

097 N7L11S02 22 -NOV-1999 08 :49:47 27.500712 -83.022935 21 . 4 

098 N7L11S01 22 -NOV-1999 10:09:04 27 .497340 -82.854247 13 . 4 

* N7LA8SOIC (station 58) is on the 10-m isobath between lines 7 and 8, not on line 8 as usual for 

N7L08S01C. 
20 

Table 3 .1 .5 Number of bottles sampled by variable on cruise N7. Blank = no sample. 

Station Station Nutrient Oxygen Salinity Bucket Pigment PM POC & 

No. Name Salinity PON 

000 N7TEST00 12 12 12 

001 N7LO1S07 12 12 12 3 3 2 

002 N7LO1S05 12 12 1 3 3 2 

003 N7LO1S04 12 12 1 3 3 2 

004 N71-01S03 12 12 1 3 3 1 

005 N7LO1S01 4 4 4 1 2 

006 N7L02S00 4 4 4 1 

007 N7L02S01 4 4 1 3 3 2 

008 N7L02S03 6 6 1 

009 N7L02S05 12 12 1 

010 N7L02S06 12 12 1 3 

Oil N7L02S08 12 12 1 3 3 2 

012 N7L02S10 12 12 12 1 3 3 2 

013 N7L03S10 12 12 12 1 3 3 2 

014 N7L03S09 12 12 1 3 3 2 

015 N7L03S08 12 12 1 3 3 2 

016 N7L03S07 12 12 1 3 3 2 

017 N7L03S05 5 5 1 

018 N7L03S03 5 5 1 

019 N7L03S01 5 5 1 3 3 2 

020 N7L03S00 4 4 4 1 

021 N7L04S00 4 4 4 1 

022 N7L04S01 5 5 1 3 3 2 

023 N7L04S03 5 5 1 

024 N7L04S05 6 6 1 

025 N7L04S07 12 12 1 5 3 2 

026 N7L04S08 12 12 1 3 3 2 

027 N7L04S10 12 12 1 3 3 2 

028 N7L04S12 12 12 12 1 3 3 2 

029 N71-05S17 12 12 12 1 3 3 2 

030 N7LO5S15 12 12 1 

031 N71-05S13 12 12 4 3 2 

032 N71-05S11 12 12 

033 N7LO5S09 11 12 1 3 

034 N7LO5S07 11 11 1 

035 N7LO5S05 8 8 1 3 

036 N71-05S03 5 5 1 

037 N7L05S01 4 4 4 1 2 3 2 

038 N7L06S01 4 4 4 1 1 3 1 

039 N71,06S03 5 5 1 

040 N71-06S05 6 6 1 

041 N7L06S07 12 12 1 l 3 1 

042 N71-06S09 12 12 1 3 3 2 

043 N71-06S11 11 11 1 

044 N71-06S13 12 12 3 3 2 

045 N7L06S15 12 12 

046 N71,06S17 12 12 

047 N7L06S19 12 12 12 3 3 2 

048 N7L07S17 12 12 12 1 3 3 2 

049 N71-07S15 12 12 1 

050 N7L07S13 12 12 1 3 3 2 

051 N7L07S11 12 12 1 
21 

Table 3 .1 .5 Number of bottles sampled by variable on cruise N7 (continued) . 

Station 

No. 

Station 

Name 

Nutrient Oxygen Salinity Bucket 

Salinity 

Pigment PM POC & 

PON 

052 N71-07S09 12 12 1 

053 N71-07S07 12 12 1 3 3 2 

054 N71-07S05 12 12 1 3 3 2 

055 N71-07S03 4 4 1 

056 N71-07S01 4 4 1 3 

057 N7L07S00 4 4 4 1 

058 N7L08S01 4 4 4 1 

059 N7L08S03 5 5 1 3 3 2 

060 N7L08S05 4 4 1 

061 N71-08S07 11 12 1 3 3 2 

062 N7L08S09 12 12 1 3 3 2 

063 N71-08S11 12 12 1 

064 N7L08S13 12 12 1 3 3 2 

065 N7L08S15 12 12 1 

066 N7L08S17 12 12 12 3 3 2 

067 N7L09S21 12 12 12 3 3 2 

068 N7L09S19 12 12 

069 N71-09S17 12 12 3 3 2 

070 N7L09S15 12 12 1 

071 N7L09S13 12 12 1 3 3 2 

072 N7L09S11 12 12 1 

073 N7L09S09 12 12 1 3 3 2 

074 N71-09S07 5 5 1 2 3 2 

075 N7L09S05 4 4 1 1 3 1 

076 N71-09S03 4 4 1 3 3 2 

077 N7L09S01 4 4 4 1 

078 N7L10S01 4 4 4 1 

079 N71-10S03 4 4 1 2 3 2 

080 N7L10S05 4 4 1 2 3 2 

081 N7L10S07 5 5 1 2 3 2 

082 N7L10S09 6 6 1 

083 N71,10S11 12 12 1 3 3 2 

084 N71-10S13 12 12 1 3 3 2 

085 N71-10S15 12 12 

086 N7L10S17 12 12 3 3 2 

087 N7L10S19 12 12 

088 N71-10S21 12 12 12 3 3 2 

089 N7L11S18 12 12 12 3 3 2 

090 N7L11S16 12 12 

091 N7L11S14 12 12 1 3 3 2 

092 N7L11S12 12 12 1 

093 N71-I1S10 12 12 1 3 3 2 

094 N7L11S08 12 12 1 3 3 2 

095 N7L11S06 5 5 1 

096 N7L11S04 4 4 1 3 

097 N7L11S02 4 4 1 3 

098 N7L11S01 4 4 4 1 

Total 911 913 188 81 168 156 100 
22 

Table 3 .1 .6 Launch times and locations for XBT drops on cruise N7. 

Sequence Station Date Time Latitude Longitude Water Probe 

Number Name (iTl'C) (UTC) (°N) (°W) Depth Type 

(m) 

001 N7LO1S06 13- NOV- 1999 20:19:17 28.732722 -88 .926232 734. T7 

002 N7LO1S02 14- NOV- 1999 00:19:27 29.015290 -89.018363 55 . T10 

003 N71-02S02 14- NOV- 1999 08 :30:46 29.538745 -88 .635680 32. T10 

004 N71-02S04 14- NOV- 1999 10:3024 29.316217 -88.537800 64. T10 

005 N7L02S07 14- NOV- 1999 12:56:21 29 .122958 -88.450952 294. T7 

006 N7L02S09 14- NOV- 1999 14:53:56 28 .955520 -88.376845 764. T7 

007 N7L03S06 15- NOV- 1999 01 :17 :10 29 .459065 -87.927525 60. T10 

008 N7L03S04 15- NOV- 1999 03:00:10 29 .685475 -87.974040 40. T10 

009 N71-03S02 I5- NOV- 1999 05:08 :13 29 .954318 -88.038960 34. T10 

010 N7L04S02 15- NOV- 1999 13 :16 :16 30.102538 -87.350375 30. T10 

011 N71-04S04 15- NOV- 1999 15:07 :30 29.856785 -87.350797 46. T10 

013 N71-04S06 15- NOV- 1999 16 :55 :05 29.637500 -87.349833 82. T10 

014 N7L04S09 15- NOV- 1999 19 :37 :18 29.449278 -87.350915 361 . T7 

015 N7L04S11 15- NOV- 1999 21 :35 :00 29.253795 -87.349912 838. T7 

016 N71-05S16 16- NOV- 1999 02:18 :48 29.181378 -87.148928 826. T7 

017 N7LO5S14 16- NOV- 1999 04:58 :19 29.377815 -87.056148 694. T7 

018 N7LO5S12 16- NOV- 1999 07:14:28 29.534165 -86.978822 345. T7 

019 N7LO5S10 16- NOV- 1999 09:13 :08 29.671335 -86.913023 220. T10 

020 N7LO5S08 16- NOV- 1999 11 :10:08 29.808158 -86.846675 166 . T10 

021 N7LO5S06 16- NOV- 1999 12:55:38 29.960223 -86.774277 124 . T10 

022 N7LO5S04 16- NOV- 1999 14 :30:16 30.111228 -86.700307 48 . T10 

023 N71-05S02 16- NOV- 1999 15 :57:07 30283368 -86.617747 28 . T10 

024 N7L06S02 16-NOV- 1999 21:47:28 30.098900 -85 .954642 30. T10 

025 N7L06S04 16- NOV- 1999 23 :14:22 29.941690 -86.089383 40. T10 

026 N71-06S06 17- NOV- 1999 00:54:08 29.758407 -86.247870 68 . T10 

027 N71-06S08 17- NOV- 1999 02 :30:55 29.598487 -86.381692 134. T10 

028 N7L06S10 17-NOV- 1999 04 :35:30 29.407623 -86.544470 284. T7 

029 N7L06S12 17- NOV- 1999 06:45:49 29225935 -86.708222 436. T7 

030 N71-06S14 17- NOV- 1999 08 :54:56 29 .047407 -86.859042 560. T7 

033 N71-06S16 17- NOV- 1999 10:57 :35 28 .892910 -86.986937 694. T7 

034 N71,06S18 17- NOV- 1999 13 :04 :45 28 .740768 -87.120828 835. T7 

036 N7L07S16 17- NOV- 1999 19:04 :42 28 .469790 -86.873387 716. T7 

039 N7L07S 14 17- NOV- 1999 21 :37 :31 28 .645062 -86.676505 584. T7 

040 N7L07S12 17-NOV-1999 23 :24:02 28 .784732 -86 .514657 428. T7 

042 N7L07S10 18- NOV- 1999 01 :25 :20 28 .949132 -86.326033 346. T7 

044 N7L07S08 18- NOV- 1999 03:25 :17 29.122703 -86.125283 258. T7 

045 N7L07S06 18- NOV-1999 05:03 :16 29259515 -85.966938 146. T7 

046 N7L07S04 18- NOV-1999 06:32:07 29.387545 -85.822733 49. T10 

047 N71,07S02 18- NOV- 1999 08:46:58 29.591703 -85.585798 28. T10 

048 N7L08S04 18- NOV-1999 17 :37:25 29.327398 -85.128333 26. T10 

049 N7L08S06 18- NOV- 1999 20:05:15 29.093402 -85 .402383 50. T10 

050 N7L08S08 18- NOV- 1999 22 :12:31 28.901622 -85 .626098 170. T10 

051 N7L08S10 19 -NOV-1999 00:24:55 28.707173 -85 .856067 258 . T7 

052 N7L08S12 19-NOV-1999 02 :48:54 28.497252 -86.103677 375 . T7 

053 N71-08S14 19-NOV -1999 04:47:39 28 .349655 -86.277893 579. T7 

056 N7L08S16 19 -NOV-1999 06:50 :53 28 .197165 -86.453415 819. T7 

057 N7L09S20 19-NOV -1999 13 :27 :00 28 .073352 -85 .950960 808. T7 

059 N7L09S18 19 -NOV-1999 15 :29 :01 28 .157055 -85.809555 578. T7 

060 N7L09S 16 19 -NOV-1999 17 :31 :29 28 .253847 -85.652530 332. T7 

061 N7L09S14 19 -NOV-1999 19 :16:55 28.360322 -85.478943 246. T7 

062 N71-09S12 19 -NOV -1999 20:58 :57 28.458023 -85.319400 178. T10 
23 

Table 3 .1 .6 Launch times and locations for XBT drops on cruise N7 (continued). 

Sequence 

Number 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Water 

Depth 

(m) 

Probe 

Type 

063 N7L09S10 19- NOV- 1999 22:37:43 28.567215 -85 .139172 129. T10 

064 N7L09S08 20- NOV- 1999 00:40:07 28.723627 -84.882417 103. T10 

065 N7L09S06 20 -NOV- 1999 03 :34:40 28 .969807 -84.475163 36. T10 

066 N7L09S04 20 -NOV- 1999 06:49:31 29 .230257 -84.051957 26. T10 

067 N7L09S02 20- NOV- 1999 09:16:16 29 .426018 -83.727403 17 . T10 

068 N7L10S02 20 -NOV- 1999 17:41 :30 28 .563987 -83.195318 17 . T10 

069 N7L10S04 20 -NOV- 1999 19:52 :39 28 .456228 -83.527585 26. T10 

070 N7L10S06 20 -NOV- 1999 22:08 :34 28 .342570 -83.881702 36. T10 

071 N7L10S08 21 -NOV- 1999 00:32 :07 28227327 -84239238 50. T10 

072 N7L10S10 21 -NOV- 1999 02:44:52 28 .122608 -84.568510 74. T10 

073 N7L10S12 21 -NOV- 1999 04:29 :15 28 .040252 -84.823017 164. T10 

074 N7L10S14 21 -NOV- 1999 05:45 :48 27.992237 -84.976698 248. T7 

076 N7LIOS16 21 -NOV- 1999 07:30:01 27.927988 -85.174098 402. T7 

077 N7L10S18 21 -NOV- 1999 09:09:12 27.877543 -85.333142 552. T7 

078 N7L10S20 21 -NOV- 1999 11 :08 :02 27.816452 -85.524130 794. T7 

079 N7L11S17 21 -NOV- 1999 16 :20:31 27.500395 -85294075 835. T7 

080 N7L11S15 21 -NOV- 1999 18 :05 :46 27.500225 -85.146202 634. T7 

081 N7L11S13 21-NOV- 1999 19 :50:43 27.498678 -84.957468 394. T7 

082 N7L11S11 21 -NOV- 1999 21 :13 :39 27.499958 -84.792195 236. T7 

084 N7LI1S09 21-NOV- 1999 23:12:08 27.500340 -84.516025 140 . T10 

086 N7L11S07 22 -NOV- 1999 01 :30:39 27.499808 -84.156487 72. T10 

087 N7L11S05 22 -NOV- 1999 04:12:06 27.500337 -83.733435 50. T10 

088 N7L11S03 22 -NOV- 1999 07:21 :59 27.490553 -83251368 34 . T10 

089 N7L11S18 24 -NOV- 1999 21 :48:45 27.499648 -85.398903 996 . T7 

090 N7L10S21 25 -NOV- 1999 00:07:57 27.786322 -85.634550 1000. T7 

096 N7L08S17 25 -NOV- 1999 05 :38:29 28.131430 -86.532773 1005 . T7 

097 N7L07S 17 25 -NOV- 1999 08 :40:06 28.371037 -86.988458 1004. T7 

098 N7L06S 19 25 -NOV- 1999 10:56:49 28.647342 -87.195407 1000. T7 

099 N7L05S17 25 -NOV- 1999 13 :35:45 29.054165 -87205153 997. T7 

100 N71,04S 12 25 -NOV- 1999 14 :51 :48 29202367 -87.365348 1037. T7 

101 N7L03S10 25 -NOV- 1999 17 :29:45 29 .153342 -87.861518 998. T7 

102 N7L02S 10 25 -NOV-1999 20:31 :55 28 .869717 -88.337332 997. T7 

103 N7L01S07 25 -NOV- 1999 23 :54 :26 28 .663202 -88.899552 997. T7 

Launches at missing sequence numbers were failures or deemed bad data during QA/QC or were 

where the counter erroneously advanced . 

3 .1 .3 Cruise N8 

The eighth NEGOM-COH hydrography cruise (N8) was conducted aboard the R/V Gyre 

during 15 - 26 April 2000. It was staged out of St. Petersburg, FL, and returned to 

Pascagoula, MS. Dr. Douglas C. Biggs and Dr. Norman L. Guinasso, Jr., were co-chief 

scientists . There were 102 CTD stations, including a test station, and 78 successful XBT 

launches. CTD and XBT locations and the cruise track are shown in Figure 3 .1 .3 . 

The cruise track began with the innermost station on line 11 and ran along lines 11 

through 3, then 1, and 2. The test station was made after sampling on the most seaward 
31°N 

30°N 

29°N 

28°N 

27°N 

Mississippi lab a Florida ~ Georgia 

M bil 

Pascag ula Pensa 1 

_ a n City tea `' -- 

° 

hi l 

~^ 

pa 

- 

co 

v 

3 

e -1 

o ; 3 5 . . 

G '7 O h 

o Q ono 

7 

`" 

o 

i 

g - ampa 

9 

" CTD/Bottle - 101 Stations 10 ' o XBT - 78 Stations 

# Test Station 11 ' 

90°W 89°W 88°W 87°W 86°W 85°W 84°W 83°W 82°W 

N 

-41 

Figure 3.1 .3 . Station locations for cruise N8 conducted 15 - 26 April 2000. The cruise ran in order along 

lines 11, 10, 9, 8, 7, 6, 5, 4, 3, 1, and 2. The thick line shows the cruise track, which began 

at the location of the innermost station on line 11 . 
25 

station on line 11 was completed. Three non-standard CTD and three non-standard XBT 

stations were added to extend line 2 approximately 45 km through a cold core eddy 

located over the upper slope . The station number, date, time, location, water depth, and 

number of bottles tripped at each CTD station are shown in Table 3 .1 .7 . 

Stations at which bottle samples were taken are summarized in Table 3 .1 .8 . Nutrients 

and oxygen were measured from every Niskin bottle depth sampled. Duplicate sets of 

nutrient samples were taken and frozen at stations 32 and 33 . Salinity was measured 

from all bottles at the most shoreward, most offshore, and test stations and from selected 

bottles at five diagnostic stations for a total of 28 stations . Pigment measurements were 

collected from the top bottle, the chlorophyll-maximum as determined by the downcast 

fluorescence trace, and the low light regime immediately below the chlorophyllmaximum at 60 stations. PM samples were taken from the top, mid-depth "clear water", 

and bottom bottles at 59 stations . POC and PON were measured from the top and 

chlorophyll-maximum bottles at 60 stations. Surface bucket salinity samples were taken 

at 68 CTD/XBT stations over the inner shelf to better define the freshwater gradients that 

might be associated with spring river discharge. 

The location, date, time, total water depth, and probe type of the 78 successful XBT 

drops are listed in Table 3.1 .9. Two ADCPs (38 kHz and 150 kHz) ran continuously 

along the track. Flow-through, near-surface temperature, conductivity, and fluorescence 

were logged every 2 minutes. Surface samples were filtered and analyzed at 99 locations 

for chlorophyll a content to calibrate the flow-through fluorescence . 

Ten complementary research efforts were accommodated on spring cruise N8 . Ryan 

Thomas, graduate student in geological oceanography at TAMU, and Scott Birkhead, 

geology undergraduate student at TAMU, took 32 gravity cores and 40 shipek-type grab 

samples (shallow water/sandy bottom) at selected stations after completion of CTD work. 

NASA conducted over-flights during the cruise to make airborne bio-optical 

measurements using Lidar and other instrumentation for Dr. Bob Swift (NASA) and Dr. 

Greg Mitchell (University of California-San Diego). As part of this effort, Lisa 

Vanderbloemen, graduate student of Dr. Frank Muller-Karger (USF), operated a 

Shipboard Laser Fluorometer and a Chelsea Fast Repetition Rate Fluorometer, which 

both sampled the flow-through surface water stream. She and Bisman Nababan, another 

USF graduate student of Dr. Muller-Karger, and Dr. Carlos del Castillo and Antoya 

Stovall-Leonard, post-doc and graduate student of Dr. Paula Coble (USF), conducted 

irradiance casts and collected dissolved organic carbon data for comparison with 

SeaWiFS data and operated an underway Safire system to collect dissolved organic 

material fluorescence and absorbance data. Samples were collected for the flow 

cytometry program of Dr. Lisa Campbell, TAMU. Surface whole phytoplankton samples 

were collected at daytime stations for Yesim Buyukates, graduate student of Dr. Daniel 

L. Roelke of TAMU, for her study of trigger mechanisms for blooms of possible harmful 

algae species. An otter trawl was pulled in three different locations on the west Florida 

shelf in water depths of 20 m, 25 m, and 55 m for Dr. Gil Rowe, TAMU, to provide 

shallow-water collections for comparison with deep water samples being collected as part 

of the MMS-sponsored Deep Gulf of Mexico Benthic study. Secchi disk depth readings 

were taken at stations during daylight. The 38kHz ADCP again was operated by Dr. 

Guinasso in cooperation with RDI for a comparison with the 150 kHz ADCP . Dr. Chad 

Fox, postdoc of Dr. Robert Leben of the Colorado Center for Astrodynamics Research, 

University of Colorado, participated as part of TAMU-CCAR cooperative analyses of 

ship and satellite altimeter data. Further information on these complementary research 

programs can be obtained from the scientists involved. 
26 

Table 3 .1 .7 . Times and locations for CTD stations on cruise N8. 

Station 

No. 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

001 N8L 11 SO1 15-APR-2000 15 :22:36 27.498613 -82 .852110 11 . 4 

002 N8L11S02 15-APR-2000 16 :40:21 27.501405 -83 .022138 20. 4 

003 N8L11S04 15-APR-2000 19 :45:46 27.501668 -83 .496660 42 . 5 

004 N8L11S06 15-APR-2000 22:46:43 27.501687 -83 .944585 56. 5 

005 N8L11S08 16-APR-2000 01 :22:53 27.499530 -84.344237 101 . 12 

006 N8L11S10 16-APR-2000 04:03:33 27.500972 -84.682873 200. 12 

007 N8L11S12 16-APR-2000 06:09:13 27.500233 -84.890083 297 . 12 

008 N8L 11 S 14 16-APR-2000 08 :18:54 27.500590 -85 .076398 493 . 12 

009 N8L 11 S 16 16-APR-2000 10:06:41 27 .501248 -85225688 479. 11 

010 N8L 11 S 18 16-APR-2000 12:46:53 27 .498620 -85.397088 1006. 12 

000 N8T'EST18 16-APR-2000 14 :45 :21 27.491665 -85.401368 1137. 12 

011 N8L10S21 16-APR-2000 18 :25 :05 27.783828 -85.630590 979. 12 

012 N8L10S19 16-APR-2000 21 :41 :33 27.851758 -85.412593 654. 12 

013 N8L10S17 16-APR-2000 23:49:12 27.897527 -85.276540 489. 10 

014 N8L10S15 17-APR-2000 02:25 :10 27.960522 -85.073483 314. 11 

015 N8L10S13 17-APR-2000 04:35 :33 28.023657 -84.878132 198. 12 

016 N8L lOS 11 17-APR-2000 06:33:19 28.077020 -84.708455 102. 12 

017 N8L10S09 17-APR-2000 09:10:54 28.175070 -84.402160 58. 6 

018 N8LlOS07 17-APR-2000 11 :37:24 28.286365 -84.057472 37. 4 

019 N8L10S05 17-APR-2000 13 :54:46 28.400088 -83.700188 30. 4 

020 N8L10S03 17-APR-2000 16:16:12 28.522132 -83.330668 19. 4 

021 N8L10S01 17-APR-2000 18 :09:56 28.608013 -83.072348 10. 4 

022 N8L09S01 17-APR-2000 01 :19:21 29.491948 -83 .625337 10. 4 

023 N8L09S03 18-APR-2000 03:19:22 29.343265 -83 .859850 18 . 4 

024 N8L09S05 18-APR-2000 07:36:35 29.103283 -84 .254505 27. 4 

025 N8L09S07 18-APR-2000 11 :05:28 28.835675 -84 .695327 45. 5 

026 N8L09S09 18-APR-2000 14 :06:40 28.623618 -85 .045740 98. 12 

027 N8L09S 11 18-APR-2000 16:29:54 28.502810 -85 .234925 164. 12 

028 N8L09S 13 18-APR-2000 18 :28:00 28.410238 -85 .395443 199. 12 

029 N8L09S 15 18-APR-2000 20:29:44 28.308412 -85 .560697 304. 12 

030 N8L09S 17 18-APR-2000 22:47:14 28.191940 -85 .754313 495. 12 

031 N8L09S 19 19-APR-2000 00:51 :03 28.118712 -85 .875748 666. 12 

032 N8L09S21 19-APR-2000 03 :36:04 28.019367 -86.041962 971 . 12 

033 N8L08S17 19-APR-2000 08:31 :14 28.132555 -86.532390 1003 . 12 

034 N8L08S15 19-APR-2000 12:00 :17 28 .293995 -86.341747 678. 12 

035 N8L08S 13 19-APR-2000 14 :32 :20 28 .401742 -86.216342 497. 12 

036 N8L08S 11 19-APR-2000 17 :58 :17 28 .608558 -85.977438 306. 12 

037 N8L08S09 19-APR-2000 21 :00:51 28 .825823 -85.719617 197. 12 

038 N8L08S07 19-APR-2000 23:19 :46 28 .987452 -85.528048 104. 12 

039 N8L08S05 20-APR-2000 02:32:00 29.204387 -85.272990 37. 4 

040 N8L08S03 20-APR-2000 04:43 :20 29.403162 -84.995498 21 . 4 

041 N8L08S01 20-APR-2000 06:48 :53 29.600187 -84.777725 12 . 4 

042 N8L07S00 20-APR-2000 12 :48:41 29.738027 -85.428767 11 . 4 

043 N8L07S01 20-APR-2000 13 :27:24 29.687317 -85.479662 19 . 4 

044 N8L07S03 20-APR-2000 17 :12:22 29.500362 -85.694900 30. 4 

045 N8L07S05 20-APR-2000 19 :20:45 29.297947 -85.921085 94. 12 

046 N8L07S07 20-APR-2000 20:45:14 29.208422 -86.028608 198 . 12 

047 N8L07S09 20-APR-2000 23:18:42 29.017553 -86.246555 313 . 12 

048 N8L07S11 21-APR-2000 01 :38:34 28.862890 -86.423432 378 . 11 

049 N8L07S13 21-APR-2000 04:19:12 28.701672 -86.611742 495 . 12 

050 N8L07S15 21-APR-2000 07 :05:32 28 .558112 -86.770803 662. 12 

051 N8L07S 17 21-APR-2000 10:37 :49 28 .371175 -86.987520 1008. 12 
27 

Table 3.1 .7 . Times and locations for CTD stations on cruise N8 (continued) . 

Station 

No. 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

052 N8L06S 19 21- APR-2000 14 :52:14 28.651430 -87 .203368 999. 12 

053 N8L06S 17 21- APR-2000 18 :41 :18 28.823227 -87 .049807 766. 12 

054 N8L06S 15 21- APR-2000 21 :30:07 28.983963 -86 .914385 605. 12 

055 N8L06S 13 21- APR-2000 23:52:43 29.134413 -86 .786252 493. 12 

056 N8L06S 11 22- APR-2000 02:30:55 29.313750 -86 .631267 380. 12 

057 N8L06S09 22- APR-2000 05:17:36 29.499603 -86.476150 204. 12 

058 N8L06S07 22-APR-2000 08:13:12 29.684088 -86.315612 99. 12 

059 N8L06S05 22- APR-2000 10:33:17 29.853705 -86.167353 46. 6 

060 N8L06S03 22- APR-2000 12 :21 :23 30.019445 -86.023692 30. 4 

061 N8L06S01 22- APR-2000 13:56:38 30.179972 -85.882888 19. 4 

062 N8LOSS01 22- APR-2000 18 :27:43 30.364127 -86.576278 18 . 4 

063 N8LOSS03 22- APR-2000 19 :54:05 30.201700 -86.650568 27. 4 

064 N8LOSS05 22- APR-2000 21 :27:13 30.027203 -86.739188 97. 12 

065 N8LOSS07 22-APR-2000 23:05:27 29.880793 -86.811628 147. 12 

066 N8LOSS09 23-APR-2000 00:49:12 29.722933 -86.885463 197. 12 

067 N8LOSS11 23- APR-2000 02:20:52 29.603747 -86.943705 266. 12 

068 N8LOSS13 23- APR-2000 04:04:07 29.465820 -87.012897 497. 12 

069 N8LOSS15 23- APR-2000 06:29:05 29.273863 -87.102320 713. 12 

070 N8LOSS17 23- APR-2000 09:06:12 29.053720 -87.203862 995. 12 

071 N8L04S12 23- APR-2000 12 :11 :16 29.193778 -87.353577 1021 . 12 

072 N8L04S 10 23- APR-2000 15:05:29 29.371743 -87.351477 497. 11 

073 N8L04S08 23- APR-2000 17 :13:06 29.532667 -87.349963 211 . 12 

074 N8L04S07 23- APR-2000 18 :15:42 29.569273 -87.350700 108. 12 

075 N8L04S05 23- APR-2000 20:14:26 29.730082 -87.349865 77. 12 

076 N8L04S03 23-APR-2000 22:18:19 29.980355 -87.350057 26. 4 

077 N8L04S01 23- APR-2000 23:59:38 30222798 -87.349028 18 . 4 

078 N8L04S00 24- APR-2000 00:34:09 30.272813 -87.325970 9. 4 

079 N8L03S00 24- APR-2000 05:55:28 30.156275 -88.091010 11 . 4 

080 N8L03S01 24- APR-2000 06:53:14 30.106373 -88.075713 19 . 5 

081 N8L03S03 24- APR-2000 09:32:13 29.803070 -87.996015 34. 5 

082 N8L03S05 24- APR-2000 11 :35:21 29.557057 -87.946453 42. 5 

083 N8L03S07 24- APR-2000 13 :29:01 29.346312 -87.900237 95. 12 

084 N8L03S08 24- APR-2000 14 :27:13 29.281675 -87.888892 211 . 12 

085 N8L03S09 24-APR-2000 15 :47:43 29.217805 -87.875533 499. 12 

086 N8L03S 10 24- APR-2000 17 :24:24 29.151123 -87.858395 1034. 12 

087 N8LO1S01 25-APR-2000 02:43:34 29.060142 -89.029900 15 . 4 

088 N8LO1S03 25-APR-2000 04:02:15 28.951987 -88.998362 101 . 12 

089 N8LO1S04 25-APR-2000 05:07:12 28.894297 -88.977922 205. 12 

090 N8LO1S05 25-APR-2000 06:31 :34 28.805352 -88.951353 515. 12 

091 N8LO1S07 25- APR-2000 08:53:14 28.660592 -88.901180 992. 12 

092 N8L02S16 25-APR-2000 16 :44:50 28.299803 -88.088913 2306. 12 

093 N8L02S 14 25-APR-2000 19 :35:06 28.497407 -88.181165 989. 12 

094 N8L02S 12 25- APR-2000 22:10:33 28.702412 -88 .262810 989. 12 

095 N8L02S 10 25- APR-2000 23:59:58 28.824593 -88 .317540 924. 22 

096 N8L02S08 26- APR-2000 03:12:02 29.047250 -88 .417458 486. 12 

097 N8L02S06 26-APR-2000 05:11 :30 29.173472 -88 .474350 187. 12 

098 N8L02S05 26- APR-2000 06:34:10 29.224315 -88 .497520 110. 12 

099 N8L02S03 26- APR-2000 08:28:02 29.392788 -88 .572327 57. 5 

100 N8L02S01 26- APR-2000 10:41 :31 29.662327 -88 .693227 17 . 4 

101 N8L02S00 26-APR-2000 11 :50:31 29.802500 -88 .755347 13 . 4 
28 

Table 3.1 .8 Number of bottles sampled by variable on cruise N8. Blank = no sample. 

Station 

No. 

Station 

Name 

Nutrient Oxygen Salinity Bucket 

Salinity 

Pigment PM POC & 

PON 

001 N8L11S01 4 4 4 1 

002 N81- 11S02 4 4 1 2 3 2 

003 N8L11S04 5 5 1 2 3 2 

004 N8LI1S06 5 5 1 

005 N8L11S08 12 12 1 3 3 2 

006 N8L11S10 12 12 3 3 2 

007 N8L11S12 12 12 

008 N8L11S14 12 12 3 3 2 

009 N8L11S16 11 11 

010 N81-11S18 12 12 12 3 3 2 

000 N8TEST18 12 12 12 

Oil N8Ll0S21 12 12 12 3 3 2 

012 N8L10S19 12 12 

013 N8LIOS17 10 10 10 3 1 1 

014 N8L10S15 11 11 

015 N81-10S13 12 12 3 3 2 

016 N8L10S11 12 12 1 3 3 2 

017 N8L10S09 6 6 1 

018 N81-10S07 4 4 1 2 3 2 

019 N8LlOS05 4 4 1 2 3 2 

020 N8LIOS03 4 4 1 2 3 2 

021 N8L10S01 4 4 4 1 

022 N81-09S01 4 4 4 1 

023 N8L09S03 4 4 1 2 3 1 

024 N81,09S05 4 4 1 3 3 2 

025 N81-09S07 5 5 1 3 1 2 

026 N8L09S09 12 12 1 3 3 2 

027 N8L09S11 12 12 

028 N8L09S13 12 12 3 3 2 

029 N8L09S15 12 12 

030 N81-09S17 12 12 3 3 2 

031 N8L09S19 12 12 

032 N8L09S21 24 12 12 3 3 2 

033 N8L08S17 24 12 12 3 3 2 

034 MUM 15 12 12 

035 N8L08S13 12 12 3 3 2 

036 N81-08S11 12 12 2 

037 N81-08S09 12 12 3 3 2 

038 N8L08S07 12 12 1 3 3 2 

039 N81-08S05 4 4 1 

040 N81-08S03 4 4 1 2 3 2 

041 N81-08S01 4 5 6 1 

042 N81-07S00 4 4 4 1 

043 N8L07S01 4 4 1 2 3 2 

044 N8L07S03 4 4 1 

045 N81-07S05 12 12 1 3 2 

046 N8L07S07 12 12 1 3 3 2 

047 N81-07S09 12 12 

048 N8L07S11 11 11 

049 N8L07S13 12 12 3 3 2 

050 N8L07S15 12 12 

051 N8L07S17 12 12 12 3 2 
29 

Table 3 .1 .8 Number of bottles sampled by variable on cruise N8 (continued) . 

Station 

No. 

Station 

Name 

Nutrient Oxygen Salinity Bucket 

Salinity 

Pigment PM POC & 

PON 

052 N8L06S19 12 12 12 3 3 2 

053 N8L06S17 12 12 

054 N8L06S15 12 12 

055 N8L06S13 12 12 1 3 3 2 

056 N8L06S11 12 12 1 

057 N8L06S09 12 12 1 3 4 2 

058 N8L06S07 12 12 1 3 4 2 

059 N8L06S05 6 6 1 

060 N8L06S03 4 4 1 

061 N8L06S01 4 4 4 1 2 3 2 

062 N8LO5S01 4 4 4 1 2 3 2 

063 N8L05S03 4 4 1 

064 N8LO5S05 12 12 1 3 3 2 

065 N81,05S07 12 12 1 

066 N8LO5S09 12 12 1 3 3 2 

067 N8L05S11 12 12 1 

068 N81,05S13 12 12 1 3 3 2 

069 N8L05S15 12 12 1 

070 N8L05S17 12 12 12 1 3 3 2 

071 N8L04S12 12 12 12 1 3 3 2 

072 N8L04S10 11 11 1 3 3 2 

073 N8L04S08 12 12 1 3 3 2 

074 N8L04S07 12 12 1 3 3 2 

075 N8L04S05 12 12 1 

076 N8L04S03 4 4 1 

077 N8L04S01 4 4 1 2 3 2 

078 N8L04S00 4 4 4 1 

079 N8L03S00 4 4 4 1 

080 N8L03S01 5 5 1 2 3 2 

081 N8L03S03 5 5 

082 N8L03S05 5 5 1 

083 N8L03S07 12 12 1 3 3 2 

084 N8L03S08 12 12 1 3 3 2 

085 N8L03S09 12 12 1 3 3 2 

086 N8L03S10 12 12 12 1 3 3 2 

087 N8LO1S01 4 4 4 1 2 3 2 

088 N8L01S03 12 12 1 3 3 2 

089 N8L01S04 12 12 1 3 3 2 

090 N8L01S05 12 12 1 3 3 2 

091 N8L01S07 12 12 12 1 3 3 2 

092 N8L02S16 12 12 2 

093 N8L02S14 12 12 2 

094 N8L02S12 12 12 2 

095 N8L02S10 Il 11 11 1 3 2 2 

096 N81,02S08 12 12 1 3 3 2 

097 N8L02S06 12 12 1 3 3 2 

098 N8L02S05 12 12 1 3 3 2 

099 N8L02S03 5 5 1 

100 N8L02S01 4 4 1 2 3 2 

101 N8L02S00 4 4 4 1 

Total 972 949 207 68 163 174 118 
30 

Table 3 .1 .9 Launch times and locations for XBT drops on cruise N8 . 

Sequence 

Number 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Water 

Depth 

(m) 

Probe 

Type 

001 N8L11S03 15- APR-2000 18 :06:22 27.500043 -83250137 28. T10 

002 N8L11S05 15- APR- 2000 21 :29:51 27.498655 -83.733028 46. T10 

003 N8L11S07 16- APR- 2000 00:16:49 27.499582 -84.159795 67. T10 

004 N8L11S09 16- APR- 2000 02:58:05 27.500583 -84.526968 136. T10 

005 N81-11 S 11 16- APR- 2000 05:23:11 27.500065 -84.792275 227. T7 

006 N8L11S13 16- APR- 2000 07:37:36 27.500398 -84.986430 381 . T7 

007 N8L 11 S 15 16- APR- 2000 09:28:54 27.500013 -85 .146188 606. T7 

008 N81-11S17 16- APR- 2000 11 :58:25 27.500232 -85 .295007 815 . T7 

009 N8L10S20 16- APR- 2000 20:52:06 27.817333 -85 .522750 791 . T7 

010 N8L10S18 16- APR- 2000 23:21 :58 27.877490 -85 .332907 586. T7 

011 N81-10S16 17- APR- 2000 01 :39:31 27.930895 -85 .167003 401 . T7 

012 N81-10S14 17- APR- 2000 03 :51 :40 27.992205 -84.976165 262. T10 

013 N8L10S12 17- APR- 2000 05 :48:15 28.048842 -84.798845 144. T10 

014 N81-10S10 17- APR- 2000 07 :58:53 28.122340 -84.568752 70. T10 

015 N81-l OS08 17- APR- 2000 10:29:04 28.228300 -84.239902 45. T 10 

016 N81-10S06 17- APR- 2000 12:48:31 28.343113 -83.881952 32. T10 

017 N81-10S04 17-APR- 2000 15:03:37 28 .454860 -83.526827 21 . T10 

018 N8L10S02 17-APR- 2000 17:17 :59 28 .564300 -83.194052 12 . T10 

019 N81-09S02 18- APR- 2000 02:13 :20 29 .426017 -83.729467 13 . T10 

020 N8L09S04 18-APR- 2000 06:00:37 29230162 -84 .052062 22. T10 

021 N8L09S06 18- APR- 2000 09:25 :44 28 .971020 -84.475747 31 . T10 

022 N81-09S08 18- APR- 2000 12:43 :56 28 .724955 -84.882792 48. T10 

023 N8L09S 10 18- APR- 2000 15 :23 :45 28 .567443 -85.139260 129. T 10 

024 N81-09S12 18-APR- 2000 17 :45 :57 28 .456313 -85.318972 175. T10 

025 N8L09S 14 18-APR- 2000 19 :44:22 28 .359738 -85.478803 240. T7 

026 N8L09S 16 18- APR- 2000 21 :55 :08 28.250392 -85.652907 378. T7 

027 N8L09S 18 19- APR- 2000 00:14:29 28.153643 -85.815750 577. T7 

028 N81-09S20 19- APR- 2000 02:49:10 28.071435 -85.950790 795. T7 

029 N8L08S16 19- APR- 2000 11 :01 :15 28.214712 -86.435825 833. T7 

030 N8L08S 14 19- APR- 2000 13 :55:25 28.352558 -86.274295 570. T7 

031 N8L08S 12 19- APR- 2000 16 :41 :33 28.496905 -86.104092 372. T7 

032 N81-08S 10 19- APR-2000 19 :43:38 28.710235 -85.853915 252 . T7 

033 N81-08S08 19 -APR- 2000 22:23:55 28.902703 -85.627845 165. T10 

034 N81-08S06 20 -APR- 2000 00:41 :56 29.094282 -85 .402743 45 . T10 

035 N81-08S04 20 -APR- 2000 03 :47:08 29.327933 -85 .128093 22 . T10 

036 N8L08S02 20 -APR- 2000 05 :57:18 29.533560 -84.887002 10 . T10 

037 N81-07S02 20 -APR- 2000 14 :24:09 29.593310 -85 .587012 23 . T10 

038 N81-07S04 20-APR- 2000 18 :21 :07 29 .387345 -85.823247 47 . T10 

039 N81-07S06 20 -APR- 2000 20:14:49 29 .251327 -85.979182 155 . T10 

040 N8L07S08 20 -APR- 2000 22:11 :54 29 .119188 -86.130648 258 . T10 

041 N8L07S10 21 -APR- 2000 00:44 :50 28 .944983 -86.330267 334. T7 

042 N81-07S 12 21 -APR- 2000 03:20:48 28 .784158 -86.514233 415. T7 

043 N8L07S14 21 -APR-2000 06:09:17 28 .635573 -86.682833 560. T7 

044 N81-07S16 21 -APR-2000 09:33 :22 28.464230 -86.881345 807. T7 

045 N81-06S18 21 -APR -2000 17 :38 :14 28.742460 -87.124993 845. T7 

046 N81-06S 16 21 -APR-2000 20:48:23 28.911705 -86.978795 673. T7 

047 N81-06S14 21 -APR -2000 23:03:39 29.048837 -86.861460 548 . T7 

048 N81,06S 12 22 -APR -2000 01 :38:24 29.226153 -86.707753 425 . T7 

049 N8L06S 10 22 -APR -2000 04 :17:01 29.409780 -86 .546575 284. T7 

050 N8L06S08 22 -APR -2000 07 :11 :24 29.600795 -86 .385448 129 . T10 

051 N8L06S06 22 -APR -2000 09 :35:45 29.760275 -86.246170 62. T10 
31 

Table 3.1 .9 Launch times and locations for XBT drops on cruise N8 (continued). 

Sequence Station Date Time Latitude Longitude Water Probe 

Number Name (UTC) (iJTC) (°N) (°W) Depth Type 

052 N8L06S04 22- APR-2000 11 :37:50 29.942445 -86.089875 35 . T10 

053 N8L06S02 22- APR-2000 13 :12:36 30.099042 -85 .954870 24. T10 

054 N8LOSS02 22- APR-2000 19 :12:05 30.278782 -86.618752 22. T10 

055 N8LOSS04 22- APR-2000 20:44:28 30.110895 -86.700923 44. T10 

056 N8LOSS06 22- APR-2000 22:22:02 29.959608 -86.774202 120. TIO 

058 N8LOSS08 23- APR-2000 00:11 :23 29.798412 -86.851632 170. T10 

059 N8LOSS10 23-APR-2000 01 :47:00 29.670798 -86.913160 216. T10 

060 N8LOSS 12 23- APR-2000 03:30 :07 29 .530722 -86.980952 340. T7 

062 N8LOSS14 23- APR-2000 05:40:40 29 .369457 -87.059068 604. T10 

063 N8LOSS 16 23- APR-2000 07:59 :20 29 .181425 -87 .147605 850. T7 

067 N8L04S 11 23- APR-2000 14 :23 :22 29.282232 -87.350963 814. T7 

065 N8L04S09 23- APR-2000 16 :33 :57 29.450105 -87.351028 351 . T7 

066 N8L04S06 23- APR-2000 19 :38 :58 29.657093 -87.349987 76. T7 

067 N8L04S04 23- APR-2000 21 :27 :21 29.857167 -87.351065 40. T10 

068 N8L04S02 23- APR-2000 23:13 :10 30.103115 -87.350908 26. T10 

069 N8L03S02 24- APR-2000 08:15 :13 29.954877 -88.030585 30. T10 

070 N8L03S04 24-APR-2000 10 :40:16 29.678003 -87.971988 37. T10 

071 N8L03S06 24- APR-2000 12 :34:47 29.452928 -87.927208 58. T10 

072 N8LO1S02 25- APR-2000 03:14:34 29.015493 -89.016728 53. T10 

073 N8LO1S06 25-APR-2000 08:13:36 28.730370 -88.923632 780. T7 

075 N8L02S 15 25- APR-2000 18 :37:57 28.402917 -88.133520 2178 . T7 

076 N8L02S 13 25 -APR-2000 21 :21 :19 28.600458 -88.220243 1942 . T7 

077 N8L02S I 1 25-APR-2000 23 :38:18 28.773873 -88 .295727 1352. T7 

078 N8L02S09 26-APR-2000 0228:16 28.955883 -88 .376738 764. T7 

079 N8L02S07 26 -APR-2000 04:40:07 29.123293 -88 .451200 277. T10 

080 N8L02S04 26-APR-2000 07 :46:09 29 .316283 -88.537733 58. T10 

081 N8L02S02 26 -APR-2000 09 :46 :02 29 .540152 -88.636140 24. T10 

Launches at missing sequence numbers were failures or deemed bad data during QA/QC, or had no 

XBT launch although the counter advanced . 

3.1 .4 Cruise N9 

The ninth NEGOM-COH hydrography cruise (N9) was conducted aboard the R/V Gyre 

during 28 July - 8 August 2000. It was staged out of Pascagoula, MS, and returned to 

Panama City, FL. Dr. Douglas C. Biggs and Dr. Norman L. Guinasso, Jr., were co-chief 

scientists . Ninety-nine CTD stations, including one test station, were completed and 75 

successful XBT drops were made. CTD and XBT locations and the cruise track are 

shown in Figure 3 .1 .4 . 

The cruise track began with innermost station on line 1 and ran along lines 1 through 11 

in order. The test station was made along the 1000-m isobath between lines 1 and 2 . The 

station number, date, time, location, water depth, and number of bottles tripped at each 

CTD station are shown in Table 3 .1 .10. 
31°N 

30°N 

29°N 

28°N 

27°N 

90°W 89°W 88°W 87°W 86°W 85°W 84°W 83°W 82°W 

W 

N 

Figure 3 .1 .4 . Station locations for cruise N9 conducted 28 July - 8 August 2000. The cruise ran in order along 

lines 1 through 11 . Station 6 was the test station. The thick line shows the cruise track, which began 

at the location of the most shoreward station on line 1 . 
33 

Stations at which bottle samples were taken are summarized in Table 3.1 .11 . Nutrients 

and oxygen were measured from every Niskin bottle depth sampled. Salinity was 

measured at all bottles at the most shoreward and most offshore stations, the test station, 

and one station for diagnostic purposes for at total of 24 bottle salinity stations . Pigment 

measurements were collected from the top bottle, the chlorophyll-maximum as 

determined by the downcast fluorescence trace, and the low light regime immediately 

below the chlorophyll-maximum at 60 stations . PM samples were taken from the top, 

mid-depth "clear water", and bottom bottles at 60 stations . POC and PON were measured 

from the top and chlorophyll-maximum bottles at 60 stations. Surface bucket salinity 

samples were taken at 95 CTD stations to better define the freshwater gradients that 

might be associated with summer river discharge . 

The location, date, time, total water depth, and probe type of the 75 successful XBT 

drops are listed in Table 3.1 .12 . Two ADCPs (38 kHz and 150 kHz) ran continuously 

along the track. Flow-through, near-surface temperature, conductivity, and fluorescence 

were logged every 2 minutes. Surface samples were filtered and analyzed at 101 

locations for chlorophyll a content to calibrate the flow-through fluorescence . 

Four complementary research efforts were accommodated on cruise N9. Mr. Bisman 

Nababan and Ms. Lucia Odriozola, graduate students of Dr. Frank Muller-Karger at USF, 

and Ms. Robyn Conmy and Ms. Antoya Stovall-Leonard, respectively, research assistant 

and graduate student of Dr. Paula Coble of USF, made bio-optic measurements and 

characterized the colored dissolved organic material (CDOM) . They used a flow-through 

AC-9 fluorometer, tandem chlorophyll and CDOM fluorometry, and irradiance casts for 

the bio-optical measurements, and scanning spectrophometers and an underway Safire 

system to collect CDOM data. Four benthic trawls were conducted by Dr. Doug Biggs of 

TAMU over the outer continental shelf to provide shallow-water collections for 

comparison with deep water samples being collected as part of the MMS-sponsored Deep 

Gulf of Mexico Benthic study. The 38 kHz ADCP again was operated by Dr. Norman 

Guinasso and Mr. John Walpert of TAMU in cooperation with RDI for a comparison 

with the 150 kHz ADCP. Graduate student training and research was provided to Ms. 

Karie Holtermann, graduate student of Dr . Denis Wiesenburg of the University of 

Southern Mississippi, and to Ms . Emma Roscow, graduate student of Dr. Marcus 

Horning of TAMU-Galveston . Entering OCNG graduate students Laurie Sindlinger, 

Will Fletcher, Greg Breed, and Jennifer Wagonner also participated. Further information 

on these complementary research programs can be obtained from the scientists involved. 
34 

Table 3.1 .10. Times and locations for CTD stations on cruise N9. 

Station 

No. 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

001 N9L01 SO 1 29-Jut-2000 10 :30:08 29.060208 -89.030430 16 . 4 

002 N9L01 S03 29-Jut-2000 11 :36:56 28.953500 -88.995500 101 . 12 

003 N9L01S04 29-Jut-2000 12 :48:10 28.886000 -88 .969333 209. 12 

004 N9LO1S05 29-Jut-2000 14 :00:20 28.805833 -88 .949333 499. 12 

005 N9LO1S07 29-Jut-2000 16 :13:04 28.662000 -88 .900333 1005. 12 

006 N9T'EST00 29-Jut-2000 20:02:00 28.746578 -88 .600357 952. 12 

007 N9L02S 10 29-Jut-2000 22 :38:08 28.869579 -88 .336197 992. 12 

008 N9L02S08 30-Jut-2000 00:57:47 29.047422 -88 .416603 494 . 12 

009 N9L02S06 30-Jut-2000 02 :34:59 29.176256 -88 .471214 185 . 12 

010 N9L02S05 30-Jut-2000 03 :30:12 29.224691 -88 .496910 111 . 12 

011 N9L02S03 30-Jut-2000 06:01 :08 29.393732 -88 .569641 58 . 7 

012 N9L02S01 30-Jut-2000 08 :15:01 29.661352 -88 .690895 19 . 5 

013 N9L02S00 30-Jut-2000 09 :31 :31 29.800344 -88 .750160 16. 4 

014 N9L03S00 30-Jut-2000 13 :51 :52 30.153910 -88 .091370 12. 4 

015 N9L03S01 30-Jut-2000 14:28:47 30.099512 -88 .074333 22. 6 

016 N9L03S03 30-Jut-2000 16:39 :03 29.800547 -87 .995934 37. 6 

017 N9L03S05 30-Jut-2000 18 :26 :47 29.555363 -87 .946251 41 . 

018 N9L03S07 30-Jut-2000 20:47:42 29342562 -87.903191 102. 12 

019 N9L03S08 30-Jut-2000 21 :42:43 29.280462 -87.891701 212. 12 

020 N9L03S09 30-Jut-2000 22:43:57 29.217682 -87.878990 466. 12 

021 N9L03S10 30-Jut-2000 23 :59 :10 29.150761 -87 .862999 1026. 12 

022 N9L04S12 31-Jut-2000 03:54:17 29.195425 -87.350655 988 . 12 

023 N9L04S10 31-Jut-2000 05:56:30 29.371964 -87.350861 501 . 12 

024 N9L04S08 31-Jut-2000 07:38 :28 29.532328 -87.348839 220. 12 

025 N9L04S07 31-Jut-2000 08:35 :56 29.568691 -87.349312 108 . 12 

026 N9L04S05 31-Jut-2000 10:04:48 29.729511 -87.350334 78. 8 

027 N9L04S03 31-Jut-2000 12:06:33 29.978764 -87.352249 31 . 

028 N9L04S01 31-Jut-2000 14 :00:58 30.225126 -87.350876 18 . 4 

029 N9L04S00 31-Jut-2000 14 :41 :51 30.279581 -87.324982 13 . 4 

030 N9LO5S01 31-Jut-2000 19 :03 :28 30365459 -86.577888 18 . 4 

031 N9LO5S03 31-Jut-2000 2022:54 30.204845 -86.655907 26. 5 

032 N9L05S05 31-Jut-2000 21 :50:18 30.028484 -86.736832 97. 11 

033 N9L05S07 31-Jut-2000 23:23 :12 29.881388 -86.809906 147 . 12 

034 N9LO5S09 01-Aug-2000 01 :02:00 29.721792 -86.886116 199. 12 

035 N9LO5S11 01-Aug-2000 04:06:50 29.606558 -86.943741 263. 12 

036 N9L05S13 01-Aug-2000 05:42:31 29.466742 -87.009552 491 . 12 

037 N9LO5S15 01-Aug-2000 07:56:02 29.275093 -87.102364 707. 12 

038 N9L05S 17 01-Aug-2000 10:31 :50 29.055418 -87202850 990. 12 

039 N9L06S19 01-Aug-2000 14 :10:36 28.651148 -87 .197968 985. 12 

040 N9L06S 17 01-Aug-2000 16 :32:23 28.827702 -87 .051094 763. 12 

041 N9L06S15 01-Aug-2000 18 :31 :22 28.983727 -86.916710 611 . 12 

042 N9L06S 13 01-Aug-2000 20:32:27 29.134928 -86.788551 497 . 12 

043 N9L06S11 01-Aug-2000 22:39:56 29.314922 -86.631371 381 . 12 

044 N9L06S09 02-Aug-2000 00:39:36 29.503145 -86.471359 199 . 12 

045 N9L06S07 02-Aug-2000 02:23:13 29.687574 -86.309998 98 . 12 

046 N9L06S05 02-Aug-2000 04:53:46 29.854334 -86.166595 46. 5 

047 N9L06S03 02-Aug-2000 06:34:50 30.019148 -86.023186 32. 5 

048 N9L06S01 02-Aug-2000 08:09:17 30.178259 -85.885010 21 . 4 

049 N9L07S00 02-Aug-2000 12:12 :33 29 .738285 -85.427216 12 . 4 

050 N9L07S01 02-Aug-2000 12:53 :08 29 .686943 -85.479340 20. 4 

051 N9L07S03 02-Aug-2000 14 :53 :52 29 .499537 -85.695427 32. 4 

052 N9L07S05 02-Aug-2000 16 :50:33 29 .298428 -85.920540 92. 12 
35 

Table 3.1 .10. Times and locations for CTD stations on cruise N9 (continued). 

Station 

No. 

Station 

Name 

Date 

(UTC) 

Time 

(UTC) 

Latitude 

(°N) 

Longitude 

(°W) 

Depth 

(m) 

No. of 

Bottles 

053 N9L07S07 02-Aug-2000 18 :13:39 29.206642 -86.027199 199 . 12 

054 N9L07S09 02-Aug-2000 20:26:44 29.016293 -86.247269 316 . 12 

055 N9L07S11 02-Aug-2000 22:24:15 28.862019 -86.423119 381 . 12 

056 N9L07S 13 03-Aug-2000 00:28:00 28.700300 -86.611366 498 . 12 

057 N9L07S 15 03-Aug-2000 02:23:23 28.556828 -86.774529 668 . 12 

058 N9L07S 17 03-Aug-2000 04:45:49 28.370237 -86.987480 1007 . 12 

059 N9L08S17 03-Aug-2000 08 :4526 28.132650 -86.529839 995 . 12 

060 N9L08S15 03-Aug-2000 11 :08:32 28.296984 -86.338554 671 . 12 

061 N9L08S13 03-Aug-2000 12:58:27 28 .402109 -86.214615 496. 12 

062 N9L08S 11 03-Aug-2000 15:25 :27 28 .605288 -85.974167 308. 12 

063 N9L08S09 03-Aug-2000 18:51 :16 28.824873 -85.717896 197. 12 

064 N9L08S07 03-Aug-2000 20:50:08 28.985283 -85.526047 112. 12 

065 N9L08S05 03-Aug-2000 23:57:49 29.204578 -85274460 42. 5 

066 N9L08S03 04-Aug-2000 02:53 :29 29.403296 -84.996284 21 . 4 

067 N9L08S01 04-Aug-2000 04:49:22 29.602659 -84.779228 13 . 4 

068 N9L09S01 04-Aug-2000 11 :10:00 29.490488 -83.623428 11 . 4 

069 N9L09S03 04-Aug-2000 12 :55:00 29.341192 -83.860985 19 . 4 

070 N9L09S05 04-Aug-2000 15 :45:00 29.103357 -84.257545 27. 5 

071 N9L09S07 04-Aug-2000 21 :02:20 28.838102 -84 .694618 46. 5 

072 N9L09S09 04-Aug-2000 23:29:53 28.625866 -85 .046471 99. 12 

073 N9L09S 11 O5-Aug-2000 01 :03:13 28.506580 -85 .236557 164 . 12 

074 N9L09S 13 O5-Aug-2000 02:25:36 28.409250 -85 .397507 202 . 12 

075 N9L09S15 O5-Aug-2000 03:49:38 28.309015 -85 .563095 306. 12 

076 N9L09S17 O5-Aug-2000 05:36:00 28.189022 -85 .754547 506. 12 

077 N9L09S 19 O5-Aug-2000 07:01 :35 28.116503 -85 .879028 677 . 12 

078 N9L09S21 O5-Aug-2000 08 :53:27 28.017967 -86.042618 988 . 12 

079 N9L10S21 O5-Aug-2000 12:48:04 27.783567 -85 .631584 992. 12 

080 N9L10S19 O5-Aug-2000 16:03:34 27.854818 -85.415482 655 . 12 

081 N9L10S17 O5-Aug-2000 17:49:46 27.894672 -85272484 491 . 12 

082 N9L lOS 15 O5-Aug-2000 19:50:07 27 .958378 -85.070610 314. 12 

083 N9L l OS 13 O5-Aug-2000 21 :29 :40 28 .022945 -84.877510 199. 12 

084 N9L10S11 O5-Aug-2000 22:50:33 28 .077909 -84.708313 101 . 12 

085 N9L10S09 06-Aug-2000 01 :42 :53 28 .175903 -84.403267 59. 6 

086 N9L10S07 06-Aug-2000 04:08 :36 28 .288713 -84.059280 38. 4 

087 N9L10S05 06-Aug-2000 06:24:26 28 .401600 -83.699265 31 . 4 

088 N9L10S03 06-Aug-2000 08:41 :41 28.521595 -83.330879 20. 4 

089 N9L10S01 06-Aug-2000 10 :22:16 28.610165 -83.072899 12 . 4 

090 N9L 11 SO1 06-Aug-2000 19 :21 :35 27.497105 -82.851501 12 . 4 

091 N9L11S02 06-Aug-2000 20:40:12 27.503393 -83.024452 22. 4 

092 N9L11S04 06-Aug-2000 23:26:39 27.499905 -83.497421 42 . 5 

093 N9L11S06 07-Aug-2000 02:12:57 27.500595 -83 .943855 57 . 8 

094 N9L11S08 07-Aug-2000 04 :54:11 27.498529 -84.343376 101 . 12 

095 N9L 11 S 10 07-Aug-2000 07 :16:51 27.499632 -84.680130 200. 12 

096 N9L11S12 07-Aug-2000 09:04 :48 27 .499872 -84.889435 297. 12 

097 N9L 11 S 14 07-Aug-2000 10 :44 :18 27 .500814 -85.075706 494. 12 

098 N9L 11 S 16 07-Aug-2000 12 :20:40 27 .499393 -85.226158 755. 12 

099 N9L 11 S 18 07-Aug-2000 14 :08 :20 27 .499550 -85.395569 1003. 12 
36 

Table 3 .1 .11 . Number of bottles sampled by variable on cruise N9. 

Station 

No. 

Station 

Name 

Nutrient Oxygen Salinity Bucket 

Salinity 

Pigment PM POC & 

PON 

001 N9LO1S01 4 4 4 2 3 1 

002 N9LO1S03 12 12 3 3 2 

003 N91-01S04 12 12 1 3 3 2 

004 N9LO1S05 12 12 1 3 3 2 

005 N9LO1S07 12 12 12 3 3 2 

006 N9TEST00 12 12 12 

007 N9L02S10 12 12 12 1 3 3 2 

008 N9L02S08 12 12 1 2 3 1 

009 N9L02S06 12 12 1 2 3 1 

010 N9L02S05 12 12 1 2 3 1 

011 N9L02S03 7 7 1 

012 N9L02S01 5 5 1 2 3 2 

013 N9L02S00 4 4 4 1 

014 N9L03S00 4 4 4 1 

015 N9L03S01 6 6 1 2 3 2 

016 N9L03S03 6 6 1 

017 N9L03S05 5 5 1 

018 N91-03S07 12 12 1 2 3 1 

019 N9L03S08 12 12 1 2 3 1 

020 N9L03S09 12 12 1 2 3 1 

021 N91-03S10 12 12 12 1 2 3 1 

022 N9L04S12 12 12 12 1 2 3 1 

023 N91-04S10 12 12 1 2 3 1 

024 N91-04S08 12 12 1 3 3 2 

025 N9L04S07 12 12 1 3 3 2 

026 N91-04S05 8 8 1 

027 N91-04S03 5 5 1 

028 N9L04S01 4 4 1 3 3 2 

029 N91-04S00 4 4 4 1 

030 N9LO5S01 4 4 4 1 2 3 1 

031 N9LO5S03 5 5 1 

032 N9L05S05 11 11 1 3 3 2 

033 N9LO5S07 12 12 1 

034 N91-05S09 12 12 1 3 3 2 

035 N9L05S11 11 11 1 

036 N9LO5S13 12 12 1 3 3 2 

037 N9L05S15 12 12 1 

038 N9L05S17 12 12 12 1 3 3 2 

039 N91-06S19 12 12 12 1 3 3 2 

040 N9L06S17 12 12 1 

041 N9L06S15 12 12 1 

042 N91-06S13 12 12 1 3 3 2 

043 N91-06S11 12 12 1 

044 N9L06S09 12 12 1 2 3 1 

045 N9L06S07 12 12 1 3 3 2 

046 N9L06S05 5 5 1 

047 N91-06S03 5 5 1 

048 N9L06S01 4 4 4 1 2 3 2 

049 N9L07S00 4 4 4 1 

050 N9L07S01 4 4 1 3 3 2 

051 N9L07S03 4 4 1 

052 N9L07S05 12 12 1 3 3 2 
37 

Table 3.1 .11 . Number of bottles sampled by variable on cruise N9 (continued) . 

Station 

No. 

Station 

Name 

Nutrient Oxygen Salinity Bucket 

Salinity 

Pigment PM POC & 

PON 

053 N9L07S07 12 12 1 3 3 2 

054 N91-07S09 12 12 1 

055 N9L07S11 12 12 1 

056 N91-07S13 12 12 1 2 3 1 

057 N9L07S15 12 12 1 

058 N9L07S17 12 12 12 1 3 3 2 

059 N91-08S17 12 12 12 1 3 3 2 

060 N9L08S15 12 12 1 

061 N9L08S13 12 12 1 3 3 2 

062 N9L08S11 12 12 1 

063 N9L08S09 12 12 1 3 3 2 

064 N91-08S07 12 12 1 3 3 2 

065 N9L08S05 5 5 1 

066 N9L08S03 4 4 1 1 3 1 

067 N91-08S01 4 4 4 I 

068 N9L09S01 4 4 4 I 

069 N91,09S03 4 4 1 3 3 2 

070 N9L09S05 5 5 1 3 3 2 

071 N9L09S07 5 5 1 3 3 2 

072 N9L09S09 12 12 1 3 3 2 

073 N9L09S11 12 12 1 

074 N9L09S13 12 12 1 3 3 2 

075 N9L09S15 12 12 1 

076 N9L09S17 12 12 1 3 3 2 

077 N9L09S19 12 12 1 

078 N9L09S21 12 12 12 1 3 3 2 

079 N9L10S21 12 12 12 1 3 3 2 

080 N9L10S19 12 12 1 

081 N9L10S17 12 12 1 3 3 2 

082 N9L10S15 12 12 12 1 

083 N9L10S13 12 12 1 3 3 2 

084 N91-I0S11 12 12 1 3 3 2 

085 N91-10S09 6 6 1 

086 N91-10S07 4 4 1 2 3 2 

087 N9LIOS05 4 4 1 2 3 2 

088 N9L10S03 4 4 1 2 3 2 

089 N9L10S01 4 4 4 1 

090 N9L11S01 4 4 4 1 

091 N9L11S02 4 4 1 2 3 2 

092 N9L11S04 5 5 1 3 3 2 

093 N9L11S06 8 8 1 

094 N91-11S08 12 12 1 3 3 2 

095 N9L11S10 12 12 1 3 3 2 

096 N9L11S12 12 12 1 

097 N9L11S14 12 12 1 3 3 2 

098 N91,11S16 12 12 1 

099 N91-11S18 12 12 12 1 3 3 2 

Total 925 925 200 95 158 180 106 
38 

Table 3 .1 .12 Launch times and locations for XBT drops on cruise N9 . 

Sequence Station Date Time Latitude Longitude Water Probe 

Number Name (UTC) (UTC) (°N) (°W) Depth Type 

001 N9LO1S02 29-Jut-2000 10:49:29 29 .053000 -89.025833 22. T- 10 

002 N9LO1S06 29-Jut-2000 15:11:48 28 .730230 -88.923890 685. T- 10 

003 N9L02S09 30-Jut-2000 00:06:01 28 .956303 -88.376106 764. T -7 

004 N9L02S07 30-Jut-2000 02:05 :51 29 .121590 -88 .451164 285. T-7 

005 N9L02S04 30-Jut-2000 05:07 :12 29 .316860 -88.538124 63. T- 10 

006 N9L02S02 30-Jut-2000 07:17 :50 29 .541777 -88.631409 25. T- 10 

007 N9L03S02 30-Jut-2000 15:32 :38 29.952791 -88.039505 29. T- 10 

008 N9L03S04 30-Jut-2000 17:34 :44 29.678053 -87.971725 37. T- 10 

009 N91-03S06 30-Jut-2000 20:00:11 29.452667 -87.927238 60. T- 10 

010 N9L04S11 31-Jut-2000 05:16:59 29282431 -87.350838 760. T -7 

011 N9L04S09 31-Jut-2000 07:00:37 29.450132 -87.350548 355. T -7 

012 N91-04S06 31-Jut-2000 09:31 :29 29.657099 -87.351418 75. T- 10 

013 N9L04S04 31-Jut-2000 11 :08 :26 29.857082 -87.351509 40. T- 10 

014 N91-04S02 31-Jut-2000 13 :05 :36 30.103098 -87.352203 26. T- 10 

015 N9LO5S02 31-Jut-2000 19 :46:22 30283710 -86.620110 22. T- 10 

016 N9LO5S04 31-Jut-2000 21 :11 :08 30.111828 -86.700737 43. T- 10 

017 N9LO5S06 31-Jut-2000 22:43 :11 29.960014 -86.773056 118. T- 10 

018 N9LO5S08 O1-Aug-2000 00:18 :57 29.808308 -86.846764 162. T- 10 

019 N91-O5S10 O1-Aug-2000 03:33 :09 29.670635 -86.911133 218. T -7 

020 N9LO5S 12 01-Aug-2000 05:03 :52 29.533445 -86.977081 345. T -7 

021 N9LO5S 14 O1-Aug-2000 07:03 :34 29.374163 -87.055260 610. T -7 

022 N9LO5S16 01-Aug-2000 09:29:56 29.181023 -87.148331 826. T -7 

023 N9L06S18 O1-Aug-2000 15 :47:16 28.742859 -87.125427 860. T -7 

024 N9L06S 16 O1-Aug-2000 17:59:28 28.926500 -86.964333 675. T -7 

026 N9L06S 14 O1-Aug-2000 19 :09:06 28.979321 -86.921303 550. T -7 

028 N91-06S 12 O1-Aug-2000 21 :54:06 29.227182 -86.707001 430. T -7 

029 N9L06S10 O1-Aug-2000 23:52:23 29.410807 -86.549522 283. T-7 

030 N9L06S08 02-Aug-2000 01 :41 :28 29.600485 -86.383972 128. T- 10 

031 N9L06S06 02-Aug-2000 03:11 :12 29.759678 -86.245232 62. T- 10 

032 N91-06S04 02-Aug-2000 05:49:24 29.943398 -86.092522 35 . T- 10 

033 N9L06S02 02-Aug-2000 07:28:52 30.104774 -85.950233 25 . T- 10 

034 N9L07S02 02-Aug-2000 13 :57:48 29.593307 -85.587715 23 . T- 10 

035 N91,07S04 02-Aug-2000 16 :01 :38 29.387260 -85.823051 46. T- 10 

036 N9L07S06 02-Aug-2000 17 :42:49 29.249521 -85.976570 158 . T- 10 

037 N9L07S08 02-Aug-2000 19 :24:41 29.120893 -86.129761 260. T- 10 

038 N91-07S 10 02-Aug-2000 21 :36:19 28.944637 -86.329948 337. T -7 

039 N9L07S 12 02-Aug-2000 23:36:36 28.784597 -86.512451 425 . T -7 

040 N9L07S 14 03-Aug-2000 01 :38:47 28.634785 -86 .686287 568 . T -7 

041 N9L07S 16 03-Aug-2000 03 :49:45 28.463589 -86.880440 780. T -7 

042 N9L08S 16 03-Aug-2000 10:20:16 28.214539 -86.435028 745 . T -7 

043 N9L08S 14 03-Aug-2000 12 :25 :46 28.352448 -86 .273903 566. T -7 

044 N9L08S 12 03-Aug-2000 14 :22:02 28.496943 -86.103432 370. T -7 

045 N9L08S 10 03-Aug-2000 16:47:27 28.710327 -85 .853790 250. T -7 

046 N9L08S08 03-Aug-2000 19 :55:38 28 .908333 -85 .633500 164. T- 10 

047 N9L08S06 03-Aug-2000 22:52:51 29 .094513 -85.403000 45. T- 10 

048 N9L08S04 04-Aug-2000 01 :15 :26 29 .328314 -85.130066 22. T- 10 

049 N9L08S02 04-Aug-2000 03 :59 :58 29 .533381 -84.886749 10 . T- 10 

050 N91-09S02 04-Aug-2000 11 :58 :07 29.426888 -83.728714 12 . T- 10 

051 N9L09S04 04-Aug-2000 14 :15 :04 29230286 -84.052322 21 . T- 10 

052 N9L09S06 04-Aug-2000 19 :29 :42 28 .970110 -84.474701 32. T- 10 

053 N9L09S08 04-Aug-2000 22:23 :06 28 .722008 -84.876007 47. T- 10 

054 MI-09S10 O5-Aug-2000 00:22:53 28 .567778 -85.138489 128. T- 10 

055 N9L09S12 O5-Aug-2000 01 :52:34 28.457289 -85.319191 175. T- 10 

056 N9L09S 14 O5-Aug-2000 03:13 :56 28.359823 -85.478706 228. T- 10 

057 N9L09S 16 O5-Aug-2000 04:54:49 28.239167 -85.678833 400. T -7 

058 N9L09S 18 O5-Aug-2000 06:30:44 28.152674 -85.814011 575. T -7 
39 

Table 3 .1 .12 Launch times and locations for XBT drops on cruise N9 (continued). 

Sequence Station Date Time Latitude Longitude Water Probe 

Number Name (UTC) (UTC) (°N) (°W) Depth Ty pe 

(m) 

060 N9L09S20 O5 -Aug-2000 08:15:42 28 .066885 -85.956367 790. T -7 

061 N9L10S20 O5 -Aug-2000 14:41 :27 27 .815557 -85.523293 749. T -7 

062 N9L10S18 O5 -Aug-2000 17:14 :04 27 .877342 -85.332687 575. T -7 

063 N9L10S16 O5 -Aug-2000 19:00:06 27 .928167 -85.165604 385. T -7 

064 N9L l OS 14 O5 -Aug-2000 20:51 :47 27 .993065 -84.977722 243. T -7 

065 N9L l OS 12 O5 -Aug-2000 22:15 :50 28 .048607 -84.800026 144. T -7 

066 N91-l OS 10 O5-Aug-2000 23:56:08 28 .122587 -84.569199 70. T- 10 

067 N9L10S08 06 -Aug-2000 02:53 :22 28 .227797 -84239891 44. T- 10 

068 N91-10S06 06 -Aug-2000 05:17 :50 28 .342657 -83.881805 38. T- 10 

069 N9L10S04 06 -Aug-2000 07:30:13 28 .456329 -83.527473 27. T- 10 

070 N9L10S02 06 -Aug-2000 09:34:25 28 .564222 -83.194969 13 . T- 10 

071 N9L11S03 06 -Aug-2000 22:10:07 27.499140 -83.269096 29 . T- 10 

072 N9L11S05 07 -Aug-2000 00:56:43 27.499735 -83.732750 46 . T- 10 

073 N9L 11 S07 07 -Aug-2000 03:40:11 27.499660 -84.159904 66. T- 10 

074 N91,11S09 07 -Aug-2000 06:15 :42 27.499928 -84.524269 140. T- 10 

075 N9L 11 S 11 07 -Aug-2000 08:25:29 27.500196 -84.791840 233 . T -7 

076 N9L 11 S 13 07 -Aug-2000 10 :07:51 27.500076 -84.985954 391 . T -7 

077 N9L 11 S 15 07 -Aug-2000 11 :47:39 27.499878 -85.146027 590. T -7 

078 N91-11S17 07 -Aug-2000 13 :28:02 27.499960 -85295410 839. T -7 

Launches at missing sequence numbers were failures or deemed bad data during QA/QC (59), or had 

no XBT launch although the counter advanced (25 & 27). 
40 

3 .2 Instrumentation, Calibration, and Sampling Procedures 

Standard oceanographic instrumentation and sampling procedures were used to collect 

measurements on the NEGOM-COH cruises . Data taken at each station consist of five 

types-continuous profiles, discrete measurements, ADCP measurements, XBT profiles, 

and supplementary underway measurements. The equipment and data collection 

procedures for each were summarized in previous NEGOM-COH reports (Jochens and 

Nowlin, 1998, 1999). Below are given changes in methods or procedures and additional 

information on data collection. At the time of this report, processing of data from cruises 

N6, N7, and N8 was completed, but data processing for cruise N9 was in progress . 

3 .2 .1 Continuous Profiles 

Continuous profiles versus pressure were made of temperature, conductivity, 

downwelling irradiance (with a photosynthetically available radiation (PAR) sensor), 

transmissivity, fluorometry, optical backscatter, and, although not contractually required, 

dissolved oxygen. Instruments were mounted on the Rosette frame below the Niskin 

water bottles and Rosette system to provide unperturbed, obstruction-free flow of water 

to all instruments during the downcast. The various instruments were interfaced with the 

CTD, which transmitted data to the Sea-Bird SBE-11 deck unit for data logging and 

storage. The altimeter allowed the CTD package to be lowered to within 1-5 meters of 

the sea floor. Typically two sets of instruments were taken on each cruise to provide 

back-up instrumentation. This redundancy helped assure collection of complete data sets 

for each parameter . No major CTD equipment failure occurred on these cruises. The 

hydrographic equipment used on the cruises is listed in Table 3 .2.1 . Sensor specifications 

and methods were detailed in Jochens and Nowlin (1998). 

Table 3 .2 .1 Hydrographic equipment available on cruises N6, N7, N8, and N9. 

Instrument Manufacturer 

N6 

Quantity 

N7 N8 N9 

CTD system Sea-Bird SBE-91 1p1us 2 2 2 2 

CTD deck unit Sea-Bird SBE-11 2 2 2 2 

Rosette system General Oceanics 12 place 2 2 1 1 

Carousel system Seabird Carousel 24 place 1 1 

Rosette frame TAMU fabrication 2 2 1 1 

Carousel frame Seabird 1 1 

Niskin bottles GO Lever Action, lO liter 14 14 14 14 

Niskin bottles GO Standard, 10-12 liter 10 10 10 8 

Transmissometer 25-cm SeaTech 2000 m 2 2 1 1 

Transmissometer Wetlabs 6000m CStar 1 1 

Fluorometer Chelsea Instruments 2 2 2 1 

Optical backscatter SeaTech light scattering sensor 2 2 2 2 

PAR sensor Biospherical QSP-200L 2 2 2 2 

Altimeter Datasonics PSA-900 2 2 1 2 

Altimeter Datasonics PSA-916 2500m 1 1 

Oxygen sensor Sea-Bird SBE 13, Beckman 2 2 2 2 

polarographic 
41 

3 .2 .2 Discrete Measurements 

Water samples for discrete measurements were collected from 10-liter Niskin bottles 

mounted on a General Oceanics Rosette sampler. Typically, four to 12 bottles per station 

were used. Bottles were tripped at the maximum CTD depth, the sea surface (-3 m), and 

the chlorophyll maximum as determined from the fluorescence profile by the CTD 

operator . Other bottles were tripped at the sigma-theta surfaces, when present, specified 

in Table 3 .2 .2 . Some of these surfaces are associated with specific water masses brought 

into the Gulf by the Loop Current. The CTD operator had discretion to trip unused 

bottles to fill gaps in bottle spacing or to sample in interesting features in temperature, 

salinity, fluorescence, or percent transmission profiles. Extra bottles, when available, 

were taken at 20-m and 50-m depths for flow cytometry sampling. Generally, in water 

depths of 100 m or more, all 12 bottles were tripped regardless of availability of surfaces . 

Discrete water samples were taken for nutrients (phosphate, silicate, nitrate, nitrite, 

ammonium, and urea) and dissolved oxygen at all stations and for PM, POC/PON, and 

phytoplankton pigments at approximately 60 stations on each cruise. The PM/POC/PON 

and pigment samples usually were taken from the same stations to facilitate integration 

and interpretation of data. For salinity, samples were measured at bottles from the 

inshore-most and offshore-most stations, from leaking bottles, and for stations with 

unplanned bottle trips. Salinity also was measured from surface bucket samples taken at 

each station located in regions under possible influence of river water. 

Water samples were drawn and processed as soon as the CTD-Rosette system was 

brought on board. Analyses of dissolved oxygen, nutrients, and salinity were performed 

at sea. Samples for PM, POC/PON, and phytoplankton pigments were filtered at sea, and 

the filters returned for final processing onshore. Methods and analysis specifications are 

provided in previous NEGOM-COH annual reports (Jochens and Nowlin, 1998, 1999) . 

Table 3.2 .2 Bottle tripping locations. 

Trip Location Comments 

Top 

Chlorophyll maximum 

Bottom 

Available 6g surfaces : 

24.6 

25.4 

25.9 

26.2 

26.5 

26.8 

27.0 

27.15 or 27 .10 

27.45 

Other bottles if available 

generally about 3-m depth 

as indicated by downcast fluorescence maximum 

generally 1 to 5 m above sea floor 

salinity maximum in Subtropical Underwater 

oxygen maximum in 18°C Sargasso Sea Water 

oxygen minimum in Tropical Atlantic Central Water 

salinity minimum in Antarctic Intermediate Water 

interesting features in downcast profiles or for spacing 
42 

PON measurements were made on all NEGOM-COH cruises. Although not required by 

the contract, PON data are included in the master bottle data sets for each cruise. 

Methods of sample collection and analysis for the POC/PON filters are described in 

Jochens and Nowlin (1998, 1999) . POC/PON filter samples for N6 through N9 were 

analyzed at the Virginia Institute of Marine Science . 

3.2 .3 Acoustic Doppler Current Profiler Measurements 

ADCP measurements were made along track on cruises N6, N7, N8, and N9. Data were 

collected using a 150-kHz broadband ADCP (S/N 1183) for N6 through N8 . A 150-kHz 

narrowband ADCP (S/N 355) was used on cruise N7 along lines 10 and 11 and on cruise 

N9. Also, an experimental Ocean Surveyor 38 kHz (OS-38) ADCP (S/N 8) was operated 

simultaneously with the 150 kHz ADCPs on N7, N8, and N9 . All three ADCP 

instruments were manufactured by RD Instruments (RDI) of San Diego, CA. The OS-38 

was on loan to the NEGOM-COH program by RDI for the purposes of side-by-side 

comparison with the 150 kHz instruments, beta-testing of data acquisition software, and 

instrument development . Figure 3 .2.1 shows locations with data from the 150 kHz 

instruments, giving the general cruise tracks for collection of ADCP data. Dates of data 

collection and quantity of raw ADCP and navigation data are summarized in Table 3 .2.3 . 

Accurate ship position data are crucial for useful shipboard ADCP data. Differential 

global positioning system (DGPS) position fixes were used when available . ADCP data 

processing, recording, and instrument control were done using the DOS-based RDI 

TRANSECT program during cruises N6, N8, and N9. The Windows-based RDI 

VMDAS program was the data acquisition software used on N7 . Details on instrument 

specifications, mounting on the vessel, data processing, and associated navigation data 

are provided in Jochens and Nowlin (1998). 

A Sperry gyrocompass was used to provide ship heading to the ADCP during cruise N6. 

The gyrocompass historically has provided a source of error when determining current 

velocity because of lag and directional sticking, thus leading to directional biases that 

have to be systematically corrected. Therefore, an AshTech ADU2 3DF positioning 

antenna array (S/N AD00251), installed on the RN Gyre and capable of more accurate 

ship heading by utilizing DGPS fixes, was configured to provide ship heading directly to 

Table 3 .2 .3 . Dates and quantity of 150 kHz ADCP data. 

Cruise ADCP Start ADCP Stop Acquisition Quantity of OS-38 

(UTC) (UTC) Program Data 

(Mbyte) 

N6 15 August 1999 

19:33 

N7 13 November 1999 

03:30 

N8 15 April 2000 

14 :57 

N9 29 July 2000 

02:56 

28 August 1999 

04:42 

24 November 1999 

23:55 

25 April 2000 

12 :56 

08 August 2000 

11 :41 

TRANSECT 401 no 

VMDAS 1007 yes 

TRANSECT 620 yes 

TRANSECT 586 yes 
31 °N 

-~ 

I 'N 

ississippi 

a a 

Florida 

eorgia 

i ssissippi 

a 

Fl orida 

eorgia 

30°N ~ / 30°N 

29°N a f / ~ y 

28°N I 28°N 

Cruise N6 Cruise N7 

27°N ~b3 S i 27oN 

r 

`~ 

90°W 89°W 88°W 87°W 86°W 85W 84°W 83°W 82°W 90°W 89°W 88°W 87°W 86°W 85 ~' vk ' 84°W 83°W 82°W 

31 °N 

-~ 

I 'N 

ississippi 

a 

Florida 

eorgia 

i ssissippi 

a s a 

Flo 

eorgia 

rida 

30°N ~ / 30°N \ 

29°N 

1 

- /' 29~N 

.~ 

~.1 \1 V 

28°N 28°N S 

Cruise N8 - - ! v Cruise N9 

27°N 

r N 

~'~, 

0 

27 ° N 

' 

0 

90°W 89°W 88°W 87°W 86°W 85 Jv 84°W 83°W 82°W 90°W 89°W 88°W 87°W 86°W 85,N 84°W 83°W 82°W 

Figure 3 .2 .1 . Locations of ADCP data for cruises N6, N7, N8, and N9. 

w 
44 

the ADCP during cruises N7, N8, and N9 . For N6, ship heading determined using the 

AshTech was saved in a separate file for post-cruise integration into the ADCP 

processing . The AshTech heading allows processing and QA/QC of data collected while 

on-station, accelerating/decelerating, and turning; these data were discarded on past 

cruises due to the unreliability of the gyro heading during these times. 

The configurations recorded for the ADCP during each cruise are shown in Table 3 .2.4. 

Configurations are basically identical for each cruise, except that bin sizes for the OS-38 

are 40 m. This enhances continuity among the different cruises and simplifies analysis 

and interpretation . The number of velocity pings per ensemble was changed from 2 to 1 

on N7 and subsequent cruises to enhance the ensemble processing procedures. 

3 .2 .4 XBT Measurements 

Expendable bathythermograph (XBT) profiles were obtained using Sippican, Inc ., T7 and 

T 10 probes . T 10s operate to 200 m and were used at stations in water depths of 200 m or 

shallower. T7s operate to depths of 760 m and were used at other stations . The probe 

type for each XBT deployment which produced usable data, as well as the drop locations, 

are given in Tables 3 .1 .3 (N6), 3 .1 .6 (N7), 3 .1 .9 (N8), and 3.1 .12 (N9) . XBT deployment 

locations are shown in Figures 3 .1 .1 (N6), 3.1 .2 (N7), 3 .1 .3 (N8), and 3 .1 .4 (N9) . On N6, 

there were 89 successful XBTs out of 99 launches. On N7, there were 103 XBT launches 

of which 84 produced data. On N8, 81 XBTs were released, 78 returned good data. On 

N9, there were 75 successful XBTs out of 76 launches. Methods for deployment were 

detailed in Jochens and Nowlin (1998). 

Table 3 .2 .4 . ADCP configuration summary. 

Parameter Cruise 

N6 N7 N8 N9 

Instrument type 

Frequency (kHz) 

Transducer pattern 

Depth cell length (m) 

Number of depth cells 

Segment time (minutes) 

Time between pings (sec) 

Velocity pings per ensemble 

First bin depth (m) 

Transmit pulse length (m) 

Blank after transmit (m) 

Navigation type 

Data recorded 

broadband broadband broadband narrowband 

153.6 153.6 153.6 153 .6 

convex convex convex concave 

4 4 4 4 

90 90 90 60 

5 5 5 5 

1 1 1 1 

2 1 1 1 

14 14 14 14 

4 4 4 4 

4 4 4 4 

DGPS DGPS DGPS DGPS 

raw, raw, raw, raw, 

navigation, navigation, navigation, navigation, 

averaged averaged averaged averaged 
45 

3.2 .5 Underway Measurements 

Near-surface (-3 m) temperature, conductivity, and fluorescence were logged every 2 

minutes throughout cruises N6 through N9 using the Serial ASCII Interface Loop (SAIL) 

system on the R/V Gyre . These measurements continued and extended similar data 

logging during cruises N 1 through NS in the first and second field years . The 

fluorescence was calibrated to chlorophyll concentration by correlation with chlorophyll 

samples obtained from the flow through stream. The underway measurements are 

supplemental to the contractually required data discussed in Sections 3 .2.1 through 3.2.4. 

However, these underway data are useful in fixing the location of river plumes and other 

confluence and frontal regimes . Details on sensors, logging procedures, calibration 

procedures, and QA/QC of underway measurements were given in the first annual report 

(Jochens and Nowlin, 1998) . During the third year, data usually were logged from port 

of departure to port of return. 

Raw data from each cruise generally are better than 95% complete along the cruise track . 

Locations of 2-minute data are shown in Figure 3 .2 .2 . Breaks in the SAIL data logging 

are seen as gaps in the tracks in the figure. The causes of the longer hiatus periods were 

lock-up of computer systems and/or pump problems resulting in no flow to the main lab 

or sensors . Other down time during the four cruises was approximately 2 to 4 minutes 

per day when the SAIL data computer was backed up. Locations of discrete samples that 

were filtered and analyzed for chlorophyll for calibration of the flow-through fluorometer 

data are given in Figure 3.2 .3 . 

3 .3 Summary, of Field Data Collected 

A summary of the data collected and scientific participation on the three cruises 

conducted in this reporting period is given in Table 3 .3 .1 . Samples taken at test or 

supplementary stations are not included in this tabulation . In addition, visiting 

researchers on each cruise collected complementary data for use in their individual 

research programs . Information relative to these complementary programs is given in 

Table 3 .3 .2 and described in section 3.1 . 

3 .4 Summary of Collateral Data Assembl 

To provide comparative information, historical data and physical oceanographic and 

ancillary data collected concurrently with the NEGOM-COH field program have been 

assembled. Historical data sets include hydrography and current measurements . These 

were summarized in Jochens and Nowlin (1998). Concurrent data sets were identified 

and assembled, including sea surface height anomaly (SSHA) from satellite altimeter, sea 

surface temperature from satellite Advanced Very High Resolution Radiometer 

(AVHRR) sensors, and ocean color from the SeaWiFS satellite . Ancillary data were 

acquired, including river discharge, surface wind speed and direction, air temperature, 

surface barometric pressure, frontal passages, and sea level . Using the surface 

meteorological observations and objective analysis, surface wind and wind stress fields 

were produced at one-hour intervals using objective analysis (see Figure 5 .1 .1 in Jochens 

and Nowlin, 1999, for an example). Table 3.4 .1 shows the major concurrent and 

ancillary data sets assembled . 
31°N 3 I 'N 

i 

a s 

ssissippi Florida 

eorgta a 

ississippi Flo rida 

orgia 

30°N 30°N 

29°N ,w 29°N ~-- 

28°N I r 28°N 

c 

Cruise N6 Cruise N7 ~ Y 

° 

r N ~o ~ ; 

27oN 

i 

gb g i i ~ '<' 27 N ~ 

90°W 89°W 88°W 87°W 86°W 85 h 84°W 83°W 82°W 90°W 89°W 88°W 87°W 86°W 85 Jv 84°W 83°W 82°W 

31 °N 31 °N 

i 

a 

ssissippi Florida 

eorgia a a a 

ississippi Flo rida 

eorgia 

30°N ~ 30°N 

v 

29°N 29°N 

28°N 

\,/ 

V 

?H°N 

V 

Cruise N8 ~-r N `~~ Cruise N9 

27°N 

q~ 

`3, g ~ 0 ~ ~' 27°N ~ 0 

90°W 89°W 88°W 87°W 86°W 85 J~ 84°W 83°W 82°W 90°W 89°W 88°W 87°W 86°W 85 v4 84°W 83°W 82°W 

Figure 3 .2 .2 . Locations of near-surface, flow-through temperature, salinity, and fluorescence data logged every 

2 minutes on cruises N6, N7, N8, and N9 . 
31°N 

30°N 

29°N 

28°N 

27°N 

ssissippi 

.. 

31°N 

90°W 89°W 88°W 87°W 86°W 85~J- 84°W 83°W 82°W ~ 90°W 89°W 88°W 87°W 86°W 854 84°W 83°W 82°W 

31°N 31°N 

30°N r'Cj 

~. :n ., ::s.: ~ 

30°N 'v 

~ ~ . 

29°N 29'N 

o . ~ " 

. .' 

28°N 

" - " 

28°N . .

. . . ~ ~ . 

Cruise N8; n=99 (99 used) 0 

Cruise N9; n=101 (100 used) 

0 

27oN 2 7 ° N 

90°W 89°W 88°W 87°W 86°W 85 W 84°W 83°W 82°W 90°W 89°W 88°W 87°W 86°W 85 dv 84°W 83°W 82°W 

Figure 3 .2 .3 . Locations of discrete samples filtered for calibration at sea of near-surface, flow-through fluorometer 

~1 data on cruises N6, N7, N8, and N9. Stars denote outlier points not used in the calibration. 
48 

Table 3 .3 .1 . Summary of data collection and scientific participation on NEGOM-COH 

cruises. Cruise duration and track length represent port-to-port values ; the cross-shelf 

track is approximately 2742 km. Numbers from test supplemental stations are excluded. 

Description N6 N7 N8 N9 

August November April August 

1999 1999 2000 2000 

Cruise duration (days) 13 13 12 11 

Cruise track (km) 3743a 3659b 2825 31954 

Total hydrographic stations 100 99 102 99 

CTD stations 98 98 101 98 

Nutrient stations 98 98 101 98 

Oxygen stations 98 98 101 98 

Salinity stations 23 22 27 24 

Pigment stations 60 59 60 60 

Particulate matter stations 60 52 59 60 

Particulate organic carbon stations 61 52 60 60 

XBT drops (successful/total) 89/99 84/103 78/81 75/76 

Nutrient samples 913 899 960 913 

Oxygen samples 913 901 937 913 

Salinity samples 175 176 195 188 

Pigment samples 175 170 163 158 

Particulate matter samples 180 156 174 180 

Particulate organic carbon samples 126 100 118 106 

Surface bucket salinity samples 58 81 68 95 

Surface chlorophyll samples 101 99 99 101 

Underway surface temperature and 2 min 2 min 2 min 2 min 

conductivity logging 

Underway surface fluorescence 2 min 2 min 2 min 2 min 

logging 

Total scientific party 23 18 24 23 

NEGOM-COH scientists 13 14 13 15 

Guest investigators on board 6 3 7 5 

Students 10 7 12 11 

Complementary studies 7 5 10 4 

a Galveston, TX, to Panama City, FL 

b Gulfport, MS, to St. Petersburg, FL; excludes ADCP run 

St. Petersburg, FL, to Pascagoula, MS 

d Pascagoula, MS, to Panama City, FL 
49 

Table 3 .3 .2 Complementary programs on NEGOM-COH hydrography surveys. 

Description N6 N7 N8 N9 

Drifter launches 30 

Flow cytometry sampling yes yes yes 

Bio-optical stations -2 per day -2 per day -2 per day -2 per day 

Safire system sampling yes yes yes yes 

Shipek-type grab cores 40 

Gravity box cores 4/2 32 

Piston cores 4 

38 kHz ADCP testing yes yes yes 

Altimeter-in situ data observers 1 

Red tide observer 1 

Phytoplankton sampling yes 

Salinity water samples for teaching 6 

Otter or benthic trawls 3 4 

Secchi depth readings yes 

NASA bio-optical over-flights yes 

Table 3 .4 .1 . Gulf of Mexico collateral data assembled in support of NEGOM-COH. 

Data Type Dates Major Sources 

Sea surface height anomaly fields 

(blended TOPEX/Poseidon and 

ERS-2 satellite altimeter product) 

Sea surface temperature fields 

(satellite AVHRR) 

Sea surface ocean color fields 

(SeaWiFS) 

November 1997-August 2000; 

Daily 

November 1997-August 2000; 

7-day composites 

Composites for periods of 9 

NEGOM cruises 

Dr. Robert L. Leben, Colorado 

Center for Astrodynamics 

Research, University of Colorado 

Johns-Hopkins University, 

Applied Physics Laboratory 

Dr. Frank Muller-Karger, 

University of South Florida 

River discharge : Mississippi and 

rivers discharging into the 

northeast Gulf 

Meteorological : wind speed and 

direction, barometric pressure, air 

and sea surface temperature, 

relative humidity, dew point 

Currents : current meter and 

moored ADCP 

1998 and 1999 water years ; 

available data for 2000 

November 1997-August 2000 

March 1997 through March 1999 

Sea level various 

U.S . Geological Survey 

National Data Buoy Center, 

various airports 

Science Applications 

International Corp., NEGOM 

DeSoto Canyon Eddy Intrusion 

Study 

Conrad Blutcher Institute; NOAA 

National Ocean Service 

51 

4 DATA QUALITY ASSURANCE AND CONTROL 

A summary of the results of data processing and quality assurance/quality control 

(QA/QC) processing for cruises NS through N8 and preliminary results for cruise N9 are 

discussed in this section. The data processing and QA/QC methods for each type of data, 

together with results of QA/QC processing for November 1997 through June 1998, were 

presented in the first annual report (Jochens and Nowlin, 1998) . Changes to those 

methods and a summary of the results of QA/QC processing for July 1998 through June 

1999 were given in the second annual report (Jochens and Nowlin, 1999). 

4.1 Continuous Profile Data 

The composite plots of CTD temperature versus salinity for cruises NS (spring 1999), N6 

(summer 1999), N7 (fall 1999), N8 (spring 2000), and N9 (summer 2000 ; preliminary 

data) show good quality results for the continuous sensors (Figures 4.1 .1 through 4 .1 .5) . 

Note the seasonal differences for temperatures higher than 18°C and the lack of scatter 

and the tight fit below 18°C. 

4 .2 Discrete Measurements 

4 .2 .1 Nutrients, Oxvgen, and Salinit 

Nitrate versus phosphate concentrations for cruises NS - N7 (1999) and N8 - N9 (2000) 

are shown in Figures 4.2.1 and 4.2.2, respectively . The Redfield ratio of 16 :1 for N:P is 

indicated by the line. Note that nitrate values are generally high relative to this ratio. 

The data pairs near phosphate of 1 .45 gM and nitrate of 13 gM are from station 

N6COREOOC (station A on cruise N6), located west of the Mississippi River Delta at a 

depth of 32 .4 m in a hypoxic region . Several nutrient data points are still under 

investigation, but many of the unusual points are from areas directly influenced by river 

discharge. Extremely high values of nitrate (»33 gM) and other nutrients occurred in 

association with river discharge on cruise N5; such data are not shown. 

On cruise N8, duplicate nutrient samples were taken at stations 32, 33, and 95 . One set 

was analyzed at sea, the duplicate was frozen and analyzed at a later time. The frozen 

samples from station 95 were bad, so the results were discarded. Comparisons of frozen 

and fresh sample analyses for the other two stations are shown in Figures 4.2 .3 and 4.2 .4 . 

The composite plot of bottle salinity versus CTD salinity for cruises NS through N9 is 

shown in Figure 4.2 .5 . The overall agreement is good, as shown by the r2 values of 0 .94 

or better for each cruise . Differences occurred mainly in regions with significant vertical 

gradients of salinity over the depth difference between the bottle sample and the deeper 

CTD sample, suggesting the same waters were not sampled. These were mainly at nearshore, shallow, river-influenced stations . Several points are still under investigation . 

Dissolved oxygen concentration versus sigma-theta for cruises NS - N7 (1999) and N8 -

N9 (2000) are shown in Figures 4.2 .6 and 4.2 .7, respectively . The dissolved oxygen 

concentrations behaved as expected, with more variability in the less dense upper water 

than in the denser deep water. Note the oxygen minimum at about 6e = 27.15 or 27.10 

kg~m 3; this is associated with the Tropical Atlantic Central water mass. Note further the 

group of data at ae - 25 kg m-3 and dissolved oxygen <1 .4 mL~L-I ; these are in the 

hypoxic zone west of the Mississippi River Delta on N6 (N6COREOOC) . 
52 

33 

31 

29 

27 

25 

23 

.. 

V 21 

a 

19 

a. 

F" 17 

.Y 

C 

0 15 

a 

13 

11 

9 

5 

U 

e 

E 

F 

ro 

C 

d 

0 G. 

3 

20 

8 10 12 14 16 18 20 

Salinity 

I I I i I . i I . I' I I 't L' 1 

22 24 26 28 30 32 34 36 38 

Salinity 

Figure 4.1 .1 . Composite potential temperature-salinity diagram for stations from 

cruise NS (May 1999). Inset shows points with salinity 

less than 20. 
53 

33 

31 

29 

27 

25 

23 

.. 

0 21 

19 

a. 

F" 17 

c 

0 15 

a 

13 

11 

9 

7 

5 

33 

U 

e- 30 

27 

E 

F 24 

c 

c 21 

a 

- IA 

3 I.~ 

20 

8 10 12 14 16 18 20 

a Salinity 

LL ~ I . I I~ - I ~ ' I ~I I ~ 1 ' I~ I 'I I . I . F 

22 24 26 28 30 32 34 36 38 

Salinity 

Figure 4.1 .2 . Composite potential temperature-salinity diagram for stations from cruise 

N6 (August 1999) . Inset shows points with salinity less than 20. 
54 

33 

31 

29 

27 

25 

23 

., 

U 21 

19 

a. 

17 

c 

0 15 

a 

13 

11 

9 

7 

5 

33 

! U 

°- 30 

27 

E 

E 24 

a 

- 0 21 

G. 

- 18 

3 I~ 

20 

8 10 12 14 16 18 20 

Salinity 

- 

I I I . I I~ ; I . 1 ! I i l ~ I P I LL I -- 'I III Y' . 

22 24 26 28 30 32 34 36 38 

Salinity 

Figure 4.1 .3 . Composite potential temperature-salinity diagram for stations from cruise 

N7 (November 1999). Inset shows points with salinity less than 20. 
55 

33 

31 

29 

27 

25 

23 

., 

V 21 

19 

a 

E 

F" 17 

o 15 

13 

11 

9 

7 

5 

33 

U 

~- 30 

27 

E 

F z4 

c 

0 21 

a 

IR 

3 

20 

8 10 12 14 16 18 20 -

Salinity 

22 24 26 28 30 32 34 36 38 

Salinity 

Figure 4.1 .4 . Composite potential temperature-salinity diagram for stations from cruise 

N8 (April 2000) . Inset shows points with salinity less than 20. 
56 

33 

31 

29 

27 

25 

23 

,. 

a 21 

a 

19 

a 

F" 17 

c 

0 15 

a 

13 

11 

9 

7 

5 

33 

v 

v 30 

27 

E 

F 24 

c 

0 21 

a 

18 

3 

20 

8 10 12 14 16 18 20 ' / 

Salinity 

22 24 26 28 30 32 34 36 38 

Salinity 

Figure 4 .1 .5 . Composite potential temperature-salinity diagram, using preliminary 

data, for stations from cruise N9 (July/August 2000). Inset shows points 

with salinity less than 20. 
57 

33 

30 

27 

24 

21 

18 

is 

12 

9 

6 

3 

O 

""41 "

. 

~ 1. .; . 

"5 . 

" ~. 

_ I~r 

Hypoxic zone _ 

west of Delta 

on N6 _ 

!'w~ ~r ~' 

0.0 0.5 1 .0 1 .5 2.0 

Phosphate (l-tM) 

Figure 4.2 .1 . Phosphate versus nitrate for 1999 cruises NS (spring), N6 (summer), 

and N7 (fall) . The line represents the Redfield ratio of N:P (16 :1). 
58 

33 

30 

27 

24 

21 

10 

N 

is 

12 

9 

6 

3 

. .~; . 

a:jV,' . 

. ~.:: 

' :~.° . 

. 

.% 

_ ~~,::~ . 

. ~~.x.: 

. . 

o 1 !14 

0 9 

0.0 0.5 1 .0 1 .5 2.0 

Phosphate (AM) 

Figure 4.2 .2 . Phosphate versus nitrate for 2000 cruises N8 (spring) and N9 

(summer). The line represents the Redfield ratio of N:P (16:1). 

N9 data are preliminary . 
59 

2.0 . . . . . . .

. Phosphate 28 . I Silicate 

r 

099 

2 

r = 0 8 24, 

r 

r, = 1 .000 

1 .5 20- 

16- 

1 .0 

/ 

° 12 

Z 

~ 

0 . 5 

4 

0.0 0 

0.0 0.5 1 .0 1 .5 2.0 0 4 8 1216202428 

Fresh Fresh 

321 

' 

Nitrate 025 Nitrite 

28 . r2 = 1 .000 0

.20 r2 = 0.997 

24 

0 15 

16- 0 

. 

w 12 w 0.10 

8 0 05 

4 

. 

0 0.00 

0 4 8 12 16 20 24 28 32 0.00 0.05 0.10 0.15 0.20 0.25 

Fresh Fresh 

020 0.40 

Urea 

0.15 0.30 r2 = 0.033 

0 0.10 0 0.20 

w rS. 

0 .05 . , Ammonium r 0 .10 - " 

2 = 0.011 

0.00 0.00 

0.00 0.05 0.10 0.15 0.20 0 .00 0.10 0.20 0 .30 0.40 

Fresh Fresh 

Figure 4.2 .3 . Frozen versus fresh nutrient concentrations (AM) from station 32 on 

NEGOM cruise N8 (April 2000). There are 12 pairs each. 
60 

Phosphate 28 Silicate 

rz = 0.999 24 r2 = 1 .000 1 .5 20- 

U 0 16 

1 .0 

w w 12 

0.5 

4 

0.0 0 

0.0 0.5 1 .0 1 .5 2 .0 0 4 8 12 16202428 

Fresh Fresh 

32 ~ Nitrate ~~25 

rz = 1 .000 0 2098 

24 

. 

0.15 

0 16 0 

: 

12 w 0.10 

8 0.05 

4 

0 0.00 

0 4 8 121620242832 0.00 0.05 0 .10 0.15 0.20 0.25 

Fresh Fresh 

0 .20 0.40 

Urea 

0 .15 0.30 r2 = 0.128 

c 

0 0 .10 0 0.20 

w w 

0 05 Ammonium . 0 10 00 

r2 = 0 .000 

. 

~ 

0.00 "" 0.00 

0.00 0.05 0.10 0.15 0.20 0.00 0.10 0.20 0.30 0.40 

Fresh Fresh 

Figure 4.2 .4 . Frozen versus fresh nutrient concentrations (bcM) from station 33 on 

NEGOM cruise N8 (April 2000). There are 12 pairs each. 
61 

37 

Cruise : NS N6 N7 N8 N9 36 

r2 : 0.945 0.991 0.995 0.982 0.978 

35 no. pairs: 350 189 184 205 199 

34 

33 

32 - 

31 

' 

30 

. 

29 - . ' . 

.~ 28 

Q 27 - 

H 

U 26 - 

25 - 

24 

23 

22 

21 

20 - 

19 

18 

1 8 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 

Bottle Salinity 

Figure 4.2 .5 . Ensemble upcast CTD salinity versus bottle salinity for cruises NS 

through N9. Outliers generally are from stations with strong stratification 

caused by the influence of river discharge. N9 data are preliminary. 
62 

10 

11 

12 

13 

14 ' 

15 ' . 

16 

M 17 

18 

19 

20 - 

an 

v~ 21 . ' ' . 

:: . : . 

22 - 

23 

" .s 

;60. 

24 

. : , . ' ~ . 

25 

26 - 

27 

28 

1 2 3 4 5 6 7 8 9 

Dissolved oxygen (mL'L-') 

Figure 4.2 .6 . Dissolved oxygen versus upcast sigma-theta for 1999 cruises 

NS (spring), N6 (summer), and N7 (fall) . 
63 

11 

12 - 

13 

14 

15 - 

16 - 

17 

00 18 

19 - 

C1 20 - 

. ' . ~ . 

v~ 21 ~ `'' , . 

22 Y:y~` 

23 

24 

25 

26 - " w rY ~' 

27 - 

28 1 

1 2 3 4 5 6 7 8 9 

Dissolved oxygen (mL ' L-') 

Figure 4.2 .7 . Dissolved oxygen versus upcast sigma-theta for 2000 cruises 

N8 (spring) and N9 (summer). N9 data are preliminary . 
64 

4.2 .2 Particulates 

Examination of N2 PM data revealed a systematic error in the processing of blanks by 

one shift on the cruise . The 11 suspect blanks were deleted from the data set and PM 

concentrations were re-determined with the remaining 19 blanks. This correction ensures 

a more accurate estimate of PM from beam c derived from transmissometer data. Three 

bottles each were tripped at depths of -1 .5 mpand 54.6 m at station 35 on cruise N6 and 

analyzed for POC and PON. Results are shown in Table 4.2.1 . 

Table 4.2 .1 . POC and PON from two depths at station 35 on NEGOM cruise N6. 

Pressure 

(db) 

Depth 

(m) 

POC 

(gg~L-') 

PON 

(~tg" L-) 

Transmissometer 

(V) 

2 .571 1 .6 32.20 4.36 4.414 

2 .630 1 .6 39.60 5 .89 4.421 

2 .479 1 .5 36.57 5 .54 4.422 

56.017 54.6 32.96 6.60 4.377 

55 .967 54.6 22.45 5 .65 4.379 

55 .953 54.6 32.96 6.95 4.380 

For the NEGOM cruises, ratios of POC to PON usually ranged from about 4 to 8 . For 

cruise N5, however, the ratios were unusually large, going from 2 to 14. The variability 

of the POC and PON concentrations for different depths were not out of the ordinary . 

The filter processing and analysis procedures used for NS were the same as for all other 

cruises, and no analytical or processing errors were found. 

4 .2 .3 Pigments 

Because of availability of new detector equipment and an authentic standard to verify its 

presence, antheraxanthin was added to pigments measured by HPLC for cruises N6 

through N9. HPLC analysis methods were described in Jochens and Nowlin (1998) . 

4.3 Acoustic Doppler Current Profiler Measurements 

QA/QC processing of ADCP data was described in detail in Section 4 of Jochens and 

Nowlin (1998, 1999). A brief summary is given here, together with processing 

modifications and results for cruises NS through N9. 

ADCP and DGPS navigation data are recorded using one of two data acquisition 

programs, TRANSECT or VMDAS. TRANSECT records binary ADCP data, converts 

the data to engineering units, averages the data into five-minute or other user-defined 

segments, and converts the averaged data into ASCII format . The averaged data then are 

merged with the navigation data supplied by either the ship gyroscope or the AshTech 

DGPS antenna array . Standard processing was performed on TRANSECT-recorded data 

and was used on N5, N6, N8, and N9 . VMDAS is an MS-Windows based program that 
65 

allows for more advanced averaging, merging, and visualization schemes than available 

with TRANSECT. As with TRANSECT, VMDAS records binary ADCP data and 

converts the data to engineering units. Ensemble processing was used on VMDASrecorded data and merged ensembles, consisting of 4-6 seconds of data, with the 

navigation data from the AshTech antenna to produce current velocities. The velocities 

then are averaged to produce the five-minute data, which are output in ASCII format . 

Ensemble processing was used on N7. It also could be used on the raw TRANSECT 

data, but this was not done on the other NEGOM data. 

4.3 .1 Standard ADCP Processing 

Current velocity is estimated by subtracting ship speed from the 5-minute averaged 

ADCP transducer velocities. Poor estimates of ship velocity will seriously degrade data 

quality . Therefore, good, reliable DGPS data are crucial for a quality shipboard ADCP 

data set . Ship velocity estimated by the ADCP bottom-tracking mode is used when good 

bottom track fixes are available, usually in water depths of less than 300 m. Calculated 

DGPS ship velocity is used when the ship is in deeper water. The subset of data with 

both bottom-track and navigation velocities is used to perform a directional calibration of 

the ADCP after the procedure of Joyce (1989). Complex regression statistics for bottomtrack versus DGPS navigation velocities and average DGPS ship speed for cruises N6 

through N9 are summarized in Table 4 .3 .1 . These show the regression angle and 

modulus fall within typical values of mean alignment error (1-2 degrees) and sensitivity 

error (1 .00 to 1 .04) for the R/V Gyre. After navigation data are merged with ADCP data, 

current data are inspected for additional problems and bad data segments are removed or 

flagged . Results of this step are summarized in Table 4.3.2. In standard processing, data 

collected while the ship is on-station, accelerating, decelerating, or turning sharply are 

discarded. These data are eliminated because ship velocity in these situations is not 

constant during the five-minute average and, therefore, when a constant velocity is 

assumed and removed, the resulting current velocity can have significantly large error. 

4.3 .2 Ensemble Processing Procedure 

Ensemble processing begins with the raw ensemble data, which typically consist of 1-2 

velocity pings and 1-2 bottom-track pings. Each ping is 2 seconds; the time for each 

Table 4.3 .1 . Complex regression statistics for GPS velocity versus bottom-track velocity 

from 150 kHz ADCP data on cruises NS through N9. 

Description N5 N6 N7 N8 N9 

Stations for misalignment 1897 NA 1918 1615 2121 

angle 

Sample size used 958 NA 1651 3380 10090 

Clockwise regression angle -1 .485678° -0 .4627° 2.246100° - 1 .9792186° -1 .361789° 

(a) 

Regression modulus (b,-q) 1 .002232 1 .00278 1 .013704 0.9853648 1 .010795 

Coherence parameter (p ) 0.9190487 0.98127 0.9674937 0.9853648 0.9998852 

Averap GPS ship speed 443.44 NA 467.49 443 .16 449.61 

(cm-s- ) 

NA = Not Available 
66 

Table 4.3 .2 . Results of evaluation of 150 kHz ADCP data for external factors on cruises 

NS through N9 and number of data segments rejected. 

Description N5 N6 N7 N8 N9 

Total number of segments 3696 NA 96512 3040 2917 

Segments rejected for no navigation data 28 NA 415 85 53 

Segments rejected for insufficient beams 12 NA 4174 0 20 

Segments rejected for bottom-track depth too shallow 270 NA 2448 235 85 

Segments rejected for slow ship speed (< 100 cm~s-1 ) 468 NA 0 873 627 

Segments rejected for fast ship speed (> 650 cm-s- ~) 0 NA 0 0 0 

Segments rejected for % of good pings in first bin < 30 0 NA 481 0 3 

Preliminary number of usable segments 2918 NA 88994 1847 2129 

Segments rejected for bad navigation data 281 NA 0 0 0 

Segments rejected for outliers 0 NA 0 0 157 

Final number of usable segments 2637 NA 88994 1847 1972 

NA = Not Available 

ensemble is, therefore, typically 8 seconds. Aside from the duration of the data used (8 

seconds versus five minute averages), ensemble processing is similar to standard 

processing. The input data are merged with the navigation data by removing an accurate 

estimate for the ship velocity, and the current velocity is estimated. The ensemble 

processing procedure also uses bottom-track and DGPS velocities to estimate the Joyce 

parameters described in Section 4.3 .1 . The current velocity data set then is averaged into 

five minute bins for processing with the final standard processing routines. 

The advantage of ensemble processing is that it allows estimation of current velocities for 

those periods when the ship is drifting on station, turning, accelerating, or decelerating . 

Additionally, on occasion one or more ensembles in a segment had bad or unrealistic 

values that resulted in the removal of an entire 5-minute average segment. By quality 

controlling and discarding bad ensembles prior to averaging into five-minute bins, the 

data quality is substantially increased. 

The success of the ensemble processing depends on reliable, accurate ship position and 

heading data at intervals of at most one second. This level of accuracy is impossible to 

achieve by the ship's Sperry gyrocompass . It is achievable with the AshTech ADU2 3DF 

positioning array, which collects high-precision pitch, roll, and heading information. 

Pitch and roll information also can be incorporated directly into the ADCP data stream, 

but this was not done for N7. Jochens and Nowlin (1999) includes additional specific 

aspects of the ensemble processing . 

4.3 .3 Results of OA/OC for NS throueh N9 

Cruise N5 : The 150 kHz broadband instrument was returned to the manufacturer in 

December 1998 for complete refurbishment, repair, and upgrade of firmware. Prior to 

N5, it was installed on the RN Gyre . Replacement transducer heads, however, were 

substituted in place of original heads, which had not been completely refurbished prior to 

the cruise . On-shore calibrations and diagnostics showed all transducers were functioning 

properly and within instruments tolerances . Diagnostics performed after installation 

aboard ship and while at sea also were passed . However, it was discovered early in the 

cruise that there was an unusually low percentage of "good" beam scans. While checking 
67 

backscatter intensities, it was further discovered that two of the four transducer heads 

were giving incoming signal intensities above normal. The problem persisted for a day 

or two, so the instrument was removed from it's housing and all transducer heads, leads, 

and connections were thoroughly cleaned . The strong signals remained. 

A call to RDI while at sea led RDI engineers to believe that the stronger signal intensities 

were degrading the overall data quality. They believed the low percentage good values 

were due to the use of a data quality component of the TRANSECT software called the 

fish algorithm. The fish algorithm compensates for unusually strong signal intensities by 

assuming that strong backscatter is caused by the instrument passing over a school of 

fish . The algorithm then excludes these strong signals when determining current 

velocity . This is ordinarily not a problem because typically schools of fish only affect 

one beam at a time and three beams are left to produce the three-beam solution necessary 

for current velocity estimation . However, because two beams were affected, the 

instrument could not produce the three-beam solution and, therefore, produced a bad data 

indicator which led to the low percentage good values . 

The RDI engineers believed that by turning off the fish algorithm, the data quality could 

be improved because the algorithm could no longer exclude any beams and both strong 

and weak transducer beams could be used to produce the three-beam solution for current 

velocity. The drawback was that when the transducer actually passed over a school of 

fish, the algorithm would not be on to compensate for it . Accordingly, the instrument 

was set to mode WM1, which turns off the fish-finder mode. We later learned, however, 

that the normal mode of operation for the ADCP is mode WM4, which is the mode 

recommended for moving platforms, and that mode WMl is recommended only for use 

with stationary platforms. 

Because the broadband penetration depth was nominally 120-130 m, RDI also suggested 

switching the broadband instrument into narrowband mode (WB1). This provided deeper 

penetration to 200 m, but increased the noise associated with a single ensemble . 

However, it was decided that the increased noise was less important than the added 

benefit of the deeper penetration. The switch to narrowband mode was made at the same 

time the fish algorithm was turned off. This occurred inshore of Line 11 . 

After cruise N7, it was determined that setting the instrument to narrowband mode 

(WB 1) and turning off the fish-finder algorithm (WM1) were incompatible when the 

instrument was in water depths greater than 100 m. Therefore, data recorded during NS 

after the inshore station at Line 11 and that are in water depths deeper than 100 m are 

considered suspect . Data are retained in the data set, with a warning included in the 

metadata. Heading information was given by the ship gyroscope and standard processing 

was used. 

Cruise N6: The 150 kHz broadband instrument was refitted with the original, refurbished 

transducer heads for the N6 cruise . The instrument settings were set to the default values 

used during cruises N2 and N3, using the broadband mode and with the fish-finder mode 

on. The ADCP data recorded during N6 did not have any significant problems, and the 

data quality is good. Heading information was given by the ship gyroscope and standard 

processing was used. 

Cruise N7: VMDAS was used to record and process the 150 kHz ADCP data while at 

sea on cruise N7 . Unfortunately, the instrument settings included the WM1 and WB1 

modes of operation . This again put the instrument in an incompatible mode similar to the 
68 

NS cruise . During N7, this configuration was used for the entire cruise . Therefore, all 

data in water depths greater than 100 m are considered suspect. Data are retained in the 

data set; metadata warnings are given in the data file . VMDAS was determined not to 

play a roll in the corruption of these data. AshTech heading information was 

incorporated directly into the instrument during data acquisition and ensemble processing 

was used. 

Cruise N8 : Due to the problems encountered during N7, TRANSECT was used as the 

data acquisition software and standard processing was performed. This also preserved 

continuity with prior cruises that used the TRANSECT program for data acquisition. The 

150 kHz instrument was configured to incorporate pitch and roll information, as well as 

heading, from the AshTech array into each ensemble. Including pitch and roll 

information improves data quality by reducing the error associated with each velocity 

estimate. It was determined during processing that the recorded ship velocity for each 

five-minute segment was in error. New ship velocities were than calculated from the 

DGPS fixes and substituted in each segment. 

Cruise N9: The broadband 150 kHz ADCP was damaged prior to cruise N9; it was 

replaced with the narrowband 150 kHz ADCP. TRANSECT was used as the data 

acquisition software, and standard processing was performed . Navigation data from the 

AshTech antenna array was incorporated directly into the ADCP data stream . The 

problem associated with DGPS velocity errors that was encountered during N8 was fixed 

by correcting the input data stream to the ADCP. All ADCP navigation and instrument 

systems worked properly during this cruise. The data are thought to be of high quality . 

38 kHz Data: Standard processing was performed on the 38 kHz Ocean Surveyor ADCP 

for cruises N6, N8, and N9 ; ensemble processing was used for N7. For cruises N6, N8, 

and N9, the 38 kHz data sets compared well with those of the 150 kHz for velocities in 

similar water depths and locations. The first bin for the 38 kHz was centered at 40 m. 

Each bin was 20 m. Thus, the 38 kHz provided data for water depths greater than 

approximately 50 m. Over deep water, data were collected to 550 m while steaming 

and up to 1000 m while on station. 

4.4 XBT Measurements 

The QA/QC procedures for XBT measurements were detailed in Jochens and Nowlin 

(1999) . The corrections for top and bottom cutoffs, outlier removal, and similar QA/QC 

actions for cruises NS through N9 are recorded in the metadata of the file header. 

Additionally, for cruise N7, one XBT profile (N7L09S21X) originally thought to be 

good, was determined to be bad and consequently was removed from the data set. 

4.5 Underway Measurements 

Chlorophyll was computed using fluorescence obtained from the Turner Design model 10 

flow-through fluorometer. The computed values generally agreed with the extracted 

chlorophyll to ±0.1 [ig~L-' or better in low chlorophyll, bio-optical Type II environments 

and to ± 0.5 ~tg~L-' or better in high chlorophyll, bio-optical Type I environments on each 

of cruises N6 through N9. Figures 4.5 .1, 4 .5 .2, 4.5 .3, and 4.5 .4 summarize these 

calibration data for the summer and fall 1999 and the spring and summer 2000 cruises . 

Fluorescence-chlorophyll data that exceeded 3 standard deviations from the mean were 

excluded from the determination of the calibration curves . These outlier data are shown 

as triangles on the figures. 
69 

0.7 T-. , . 

(a) Type II (low chlorophyll) water 

. . 

0.6 - 

.-, 

0.5 

. . 

- 

" " . . 

0.4 

r 

U 

0.3 

U 

~ . 

0.2 

" ~ Ch1= 0 0029283*flc - 0.342 

0.1 

. 

~ " 

% 

n=53 ;r2=0.843 

0.0 

100 150 200 250 300 350 400 

SAIL pick-up (millivolts) 

10.0 ., . . . ., . . . ., . . .,, . . 

9.0 (b) Type I (high chlorophyll) water 

8 .0 

7.0 - 

6.0 

U 5.0 

-d 

4.0 

~. 3.0 -- 

2 . 0 - % Chl = 0.005384*flc - 1 .14 

1 .0 n = 46 ; r2 = 0 .696 

0.0 

., 

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 

SAIL pick-up (millivolts) 

Figure 4 .5 .1 . Flow-through fluorometer calibration for cruise N6 (August 1999). 

Triangles denote outliers not used in the correlation. 
70 

0.5 ,- , 

(a) Type II (low chlorophyll) water 

0.4 - 

...~ 

. . 

. . 

°° 0.3 - 

U 

. 

.. 

.b 

:r 0 2 

. . . . 

~. .. ~ ~ . . 

. 

U cC 

~. r .. + 

K 

0 .1 ~~ 

Chi = 0 .002429*flc - 0.25 

n = 77; rz = 0.828 

0.0 

150 175 200 225 250 275 300 

SAIL pick-up (millivolts) 

3 .0 

(b) Type I (high chlorophyll) water 

2.5 

2.0 

on 

1 .5 U 

'C o 

U 

sue

. 1 . 0 

K 

0.5 " ~ Chl ~ 0.0054*flc - 1 .22 

n=18 ;r2=0.945 

0 . 0 

250 300 350 400 450 500 550 600 650 700 750 800 

SAM pick-up (millivolts) 

Figure 4.5 .2 . Flow-through fluorometer calibration for cruise N7 (November 1999). 

Triangles denote outliers not used in the correlation. 
71 

0.6 ,- . . ., ,, ,, ,,  

(a) Type II (low chlorophyll) water 

0.5 

0.4 

00 

0.3 U 

U 

t`~. 0. 

. . . 

Chl = 0.0027878*flc - 0.29 

0.1 n = 89; r2 = 0.866 

.. . 

0.0 - 

100 120 140 160 180 200 220 240 260 280 300 

SAIL pick-up (millivolts) 

3A ~.-~- . ., . . 

(b) Type I (high chlorophyll) water 

2 .5 

2.0 - bn 

1 .5 U - 

b a 

U 

`d 1 . 

0.5 Chl = 0 .0032758*flc - 0.23 

n=10;r2=0.953 

0.0 ~ . . I . . I . . I . . . I . . . I . . I - 

300 400 500 600 700 800 900 1000 

SAIL pick-up (millivolts) 

Figure 4.5 .3 . Flow-through fluorometer calibration for cruise N8 (April 2000). 
72 

2 .0 

1 .7 

1 .4 

1 .1 

U 

0.9 

0.6 

0.3 

0.0 

. . . , 

(a) Type II (low chlorophyll) water 

" Chl 0.0031218*flc - 0.43 

2 

r 

97; r 0.913 

100 275 450 625 

SAIL pick-up (millivolts) 

5 .0 

(b) Type I (high chlorophyll) water 

4.0 

a 

3 .0 

U 

b 

ILI 2.0 

U cC 

1 .0 

0 

0 

Chl = 0.022997*flc - 15.61 

n=03 ;r2 =0.993 

800 I 

0.0 L 

750 800 850 900 

SAIL pick-up (millivolts) 

950 

Figure 4.5 .4 . Flow-through fluorometer calibration for cruise N9 (July/August 2000). 

Triangles denote outliers not used in the correlation. 
73 

5 LITERATURE CITED 

Jochens, A. E., and W. D. Nowlin, Jr . 1998. Northeastern Gulf of Mexico Chemical 

Oceanography and Hydrography Study between the Mississippi Delta and Tampa 

Bay, Annual Report: Year 1 . OCS Study MMS 98-0060. U. S. Department of the 

Interior, Minerals Management Service, Gulf of Mexico OCS Region, New 

Orleans, LA. 126 pp. 

Jochens, A. E., and W. D. Nowlin, Jr. 1999. Northeastern Gulf of Mexico Chemical 

Oceanography and Hydrography Study between the Mississippi Delta and Tampa 

Bay, Annual Report: Year 2. OCS Study MMS 99-0054 . U. S. Department of the 

Interior, Minerals Management Service, Gulf of Mexico OCS Region, New 

Orleans, LA. 123 pp . 

Joyce, T. M. 1989. On in-situ 'calibration' of shipboard ADCPs. J. Atm. Ocn. Tech., 6, 

169-172. 

PSN, NT OFTy~'y The Department of the Interior Mission 

oW 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; preserving the 

_ ~ environmental and cultural values of our national parks and historical places; and providing for the 

~4ACH 3 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 

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 

(OCS), collect revenue from the Federal OCS and onshore Federal and Indian lands, and distribute 

P those revenues. 

'~ ~ANAGLI~~ by 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 .