Abstract:

On the inner shelf of Alabama coast, a CTD survey was conducted using Seabird SBE 25 Sealogger CTD on 2016-04-03. The survey, conducted aboard the R/V E.O. Wilson, measured depth, conductivity, temperature, salinity, oxygen, pH, beam attenuation, beam transmission, and density.

Suggested Citation:

Brian Dzwonkowski, Steven Dykstra, Stephan O'Brien, and Grant Lockridge. 2017. CTD profiles, Main Pass, Mobile Bay, Alabama, April 3, 2016. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7D50KCT

Purpose:

The objective of this ongoing research is to identify the influence of fluvial water and its suspended particulate matter on coastal regions including the ecosystem and its susceptibility to oil. This particular study aims to understand the nature of buoyant freshwater plumes in shallow micro-tidal environments. Hydrographic surveys were conducted with a CTD.

Data Parameters and Units:

FILENAME convention: CTDname_dMMMYYY_surveycastnumber_stationlocation e.g. Mini_3APR2016_DZ020_M03 Stations locations/Cast Time(CDT) on the Alabama Shelf: Each CTD cast file is organized as: Column 1 = Depth [salt water, m] Column 2= Conductivity [uS/cm] Column 3 = Temperature [ITS-90, deg C] Column 4 = Salinity, Practical [PSU] Column 5= Oxygen, SBE 43 [mg/l] Column 6 = Oxygen, SBE 43 [% saturation] Column 7= ph: pH Column 8 = Scan Count Column 9 = Beam Attenuation, Chelsea/Seatech [1/m] Column 10 = Beam Transmission, Chelsea/Seatech [%] Column 10 = Density [sigma-t, Kg/m^3]

Methods:

CTD was allowed to soak for approximately 1 minute at shallow depth than raised to the near-surface before beginning the descent to the bottom. Bottom was determine when casting line went slack, at which point the CTD was raised to the surface. M03: 30 12.058 -88 07.369 Time: 15:40 CDT M02: 30 10.950 -88 04.675 Time: 16:23 CDT M01: 30 10.479 -88 01.157 Time: 16:42 CDT JC04: 30 07.800 -88 1.716 Time: 17:00 CDT JC2: 30 07.800 -88 05.766 Time: 17:20 CDT M04: 30 07.780 -88 07.491 Time: 17:40 CDT M05: 30 03.086 -88 07.365 Time: 18:10 CDT AL07: 30 07.518 -88 04.300 Time: 18:40 CDT AL04: 30 10.980 -88 02.982 Time: 18:55 CDT (Estimated Time) Stations locations/Cast Time(CDT) at Main Pass, Mobile Bay: Shoal west (sw): 30 14.6174 -88 04.1607 Time: 19:55 CDT Shoal center (sc): 30 14.3670 -88 03.6461 Time: 20:09 CDT Shoal east (se): 30 14.1383 -88 03.1365 Time: 20:19 CDT Channel west (cw): (30 13.7800 -88 02.3971 Time: 20:37 CDT Channel center (cc): 30 13.6678 -88 02.1323 Time: 20:47 CDT Channel east (ce): 30 13.5469 -88 01.8825 Time: ~21:00 CDT (estimated time)

Instruments:

SeaBird SBE 25 Sealogger CTD, SeaBird SBE43, Chelsea/Seatech transmissometer

Error Analysis:

See Seabird Electronics technical reports

Provenance and Historical References:

These stations are regularly repeated station during the CONCORDE consortium field surveys.

Individual Files: