ACCESS NUMBER: 30854 

STUDY TITLE: Observation of the Atmospheric Boundary Layer in the Western and 

Central Gulf of Mexico 

REPORT TITLE: Observation of the Atmospheric Boundary Layer in the Western and 

Central Gulf of Mexico 

CONTRACT NUMBER(S): 1434-01-97-CT-30854 

SPONSORING OCS REGION: Gulf of Mexico 

APPLICABLE PLANNING AREA(S): Western and Central Gulf of Mexico 

FISCAL YEAR(S) OF PROJECT FUNDING: 1998,1999,2000,2001,2002 

COMPLETION DATE OF REPORT: April 2002 

COST(S): FY 1998: $619,198; FY 1999: $161,075; FY 2000: $150,623; FY 2001: 

$156,105; FY 2002: $165,244 

PROJECT MANAGER: G.Zeigler 

AFFILIATION: Vaisala Inc. 

ADDRESS: 5600 Airport Boulevard, Boulder, Colorado 80301 

PRINCIPAL INVESTIGATOR: T. Dye 

KEY WORDS: Western Gulf; Central Gulf; atmospheric boundary layer; marine 

boundary layer; radar profiler; radio acoustic sounding system; meteorological 

measurements; upper air meteorological data; surface meteorological data; platform 

measurement sites; GOES satellite data transmission. 

BACKGROUND: For the Gulf of Mexico, data sets poorly represent how temperature, 

winds, and mixing height vary vertically over the atmospheric boundary layer and free 

troposphere. Empirical constants and relationships are used to approximate vertical 

variations in temperature, winds, and other boundary layer properties. However, direct 

observations more accurately describe vertical variations. The MMS has an interest in 

collecting field observations of the vertical structure of the marine boundary layer 

because such observations would reduce uncertainties in environmental assessments. 

OBJECTIVE: To obtain field observations describing the vertical structure of the 

marine boundary layer over the Western and Central Gulf of Mexico for ongoing and 

future applications. 

DESCRIPTION: Field observations of upper air wind and temperature, surface wind, 

surface temperature, surface relative humidity, surface pressure, and sea surface 
ACCESS NUMBER: 30854 

temperature were collected at two offshore platform sites for a continuous 40-month 

period. 

Site selection criteria included a shallow water location to collect data that will help 

measure how the marine boundary layer is affected by the land/sea breeze mechanism, 

and a deep water location to collect data that will help measure how the marine 

boundary layer is affected by interaction between advecting air masses and colder 

waters in the Gulf of Mexico. 

Using these criteria, Vermillion 22D was selected as the shallow water data collection 

site and South Marsh Island 161A was selected as the deep water data collection site. 

SIGNIFICANT CONCLUSIONS: The data base collected provides the type of direct 

atmospheric measurements needed to help better define the vertical structure of the 

marine boundary layer in order to reduce uncertainties in environmental assessments. 

STUDY RESULTS: Meteorological measurement equipment was installed, operated, 

maintained and audited at the two sites during the data collection period, and was 

removed following completion. This included a 915 MHz pulsed-Doppler radar profiler 

at each site to collect upper air wind and virtual temperature data, and a suite of 

standard in-situ sensors to collect surface (platform level) wind, temperature, relative 

humidity, pressure, and sea surface temperature data. 

Data were retrieved from both sites each hour by transmission to a collection and 

processing facility through the NOAA GOES satellite communications system. All 

retrieved data were quality checked upon receipt and were made available to NOAA in 

near real-time. Validation and reporting of collected data was accomplished each 

month, and a complete data base of all measurements recorded during the continuous 

40-month observation period was compiled at the end of the data collection program. 

The overall data capture rate achieved for the 40-month measurement period was 

89.3%, which was slightly below the project goal of 90% due to practical time-delay 

limitations in accessing the meteorological and communications equipment at the 

remote sites when corrective maintenance was needed, such as to reset the equipment 

after power interrupts. The achieved data capture rate did not vary significantly by data 

type or site. 

The data collection project was conducted according to its planned schedule except for 

an initial delay awaiting site RF transmission licenses, was completed within its planned 

budget, and was conducted with no personnel or equipment accidents. 

STUDY PRODUCTS: 2002. Observation of the Atmospheric Boundary Layer in the 

Western and Central Gulf of Mexico. A final performance report by Vaisala 

Meteorological Systems Inc. and Sonoma Technology, Inc. for the U.S. Department of 

the Interior, Minerals Management Service, Gulf of Mexico Region, OCS, New Orleans, 

LA. Contract No. 1434-01-97-CT-30854. 125 pp. 
ACCESS NUMBER: 30854 

Location of Selected Monitoring Sites