Abstract:

At the mouth of Mobile Bay (Main pass), a CTD survey was conducted using Seabird SBE 25 Sealogger CTD on 2016-04-09. It measured depth (m), conductivity (uS/cm), temperature(ITS-90, deg C), salinity (PSU), and density (sigma-t).

Suggested Citation:

Brian Dzwonkowski, Grant Lockridge, and Steven Dykstra. 2017. CTD profile data, Mobile Bay main pass, 2016-04-09. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7154FF5

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: surveyname_DiscoveryDay_ddMonthYYYY_timeofday_CTDnamecastnumber_stationlocation e.g.; DZ_DiscoveryDay_09April2016_Morning_Mini002_se Each CTD cast file is organized as: Column 0 = scan: Scan Count Column 1 = depSM: Depth [salt water, m], lat = 0.00 Column 2 = bat: Beam Attenuation, Chelsea/Seatech [1/m] Column 3 = density00: Density [density, kg/m^3] Column 4 = c0uS/cm: Conductivity [uS/cm] Column 5 = sbeox0V: Oxygen raw, SBE 43 [V] Column 6 = sbeox0PS: Oxygen, SBE 43 [% saturation] Column 7 = sbeox0Mg/L: Oxygen, SBE 43 [mg/l] Column 8 = ph: pH Column 9 = prSM: Pressure, Strain Gauge [db] Column 10 = sal00: Salinity, Practical [PSU] Column 11 = specc: Specific Conductance [uS/cm] Column 12 = t090C: Temperature [ITS-90, deg C] Column 13 = timeS: Time, Elapsed [seconds] Column 14 = flag: 0.000e+00 Stations locations/Cast Time(CDT) in Main Pass, Mobile Bay: Shoal west (sw): 30 14.617 -88 04.161 Time: 08:30 CDT Shoal center (sc): 30 14.367 -88 03.646 Time: 08:35 CDT Shoal east (se): 30 14.138 -88 03.1365 Time: 8:44 CDT Shoal Shallow (ss): 30 13.8965 88 02.6461 Time: 8:49 CDT Channel west (cw) 30 13.780 -88 02.397 Time: 8:54 CDT Channel center (cc): 30 13.668 -88 02.132 Time: 8:58 CDT Channel east (ce): 30 13.547 -88 01.883 Time: 09:09 CDT Channel far (cf): 30 13.4824 88 01.7444 Time: 09:14 CDT NOTE: very strong FRONT observed between CE and CF

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 determined when casting line went slack. After which point the CTD was raised to the surface.

Instruments:

Sea-Bird SBE25 Sealogger CTD

Individual Files: