Abstract:

CTD surveys were conducted at the mouth of Mobile Bay (Main Pass) and along the ship channel out to ~15m isobath through the Fall of 2015. Typical data types depth, temperature, salinity. Surveys were conducted from September 20th to October 29th, 2015.

Suggested Citation:

Brian Dzwonkowski, Steven Dykstra, Stephan O’Brien and Grant Lockridge. 2017. CTD profiles collected during Fall survey (Sep 20 - Oct 29 2015). Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7ZP446V

Publications:

Dzwonkowski, B., Greer, A. T., Briseño-Avena, C., Krause, J. W., Soto, I. M., Hernandez, F. J., … Graham, W. M. (2017). Estuarine influence on biogeochemical properties of the Alabama shelf during the fall season. Continental Shelf Research, 140, 96–109. doi:10.1016/j.csr.2017.05.001

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. Note the day was quite windy, so we were only able to release the drifter and sample at the mouth (no offshore work). Both a LISST and CTD cast were made at station two stations later in the day (Stations: sc/DZ2 and cw/DZ5). Drifters were also released along the transect stations prior to the CTD cast survey. Data with the drifter release and LISST cast are associated with individual data submissions.

Data Parameters and Units:

Each day out has different file structure and location (listed below) 2015-09-20: CTD data at Main Pass Mobile Bay and Along ship channel (2015/09/20) DZ Buoy ddMMMMYYYYcastnumber_stationname e.g. DZ Buoy 20Sept2015026_dz6 File parameters: # name 0 = scan: Scan Count # name 1 = depSM: Depth [salt water, m], lat = 0.00 # name 2 = bat: Beam Attenuation, Chelsea/Seatech [1/m] # name 3 = density00: Density [density, kg/m^3] # name 4 = c0uS/cm: Conductivity [uS/cm] # name 5 = wetStar: Fluorescence, WET Labs WETstar [mg/m^3] # name 6 = sbeox0V: Oxygen raw, SBE 43 [V] # name 7 = sbeox0PS: Oxygen, SBE 43 [% saturation] # name 8 = sbeox0Mg/L: Oxygen, SBE 43 [mg/l] # name 9 = ph: pH # name 10 = prSM: Pressure, Strain Gauge [db] # name 11 = sal00: Salinity, Practical [PSU] # name 12 = specc: Specific Conductance [uS/cm] # name 13 = t090C: Temperature [ITS-90, deg C] # name 14 = timeS: Time, Elapsed [seconds] # name 15 = flag: 0.000e+00 Stations locations/Cast Time (CDT) in Main Pass, Mobile Bay: Main Pass, Mobile Bay (Morning) Channel far (Dz8): Actual: 30 13.432 88 01.814 Time: ~09:26 CDT Cast 00 Channel east (ce/Dz7): Planned: 30 13.5469 88 01.8825 Actual: 30 13.555 88 01.895 Time: ~09:30 CDT Cast 01 Channel EXTRA (dz_extra): Actual: 30 13.592 88 01.996 Time: ~09:33 CDT Cast 02 Channel center (cc/Dz6) Planned:30 13.631 88 02.153 Actual: 30 13.667 88 02.128 Time: 09:37 CDT Cast 03 Channel west (cw/Dz5): Planned:30 13.743 88 02.389 Actual: 30 13.782 88 02.376 Time: 09:43 CDT Cast 04 Shoal shoal (ss/Dz4): Planned:30 13.878 88 02.630 Actual: 30 13.865 88 02.653 Time: 09:47 CDT Cast 05 Shoal east (se/Dz3): Planned:30 14.142 88 03.128 Actual: 30 14.125 88 03.110 Time: 09:53 CDT Cast 06 Shoal center (sc/Dz2): Planned:30 14.342 88 03.536 Actual: 30 14.376 88 03.597 Time: 09:57 CDT Cast 07 Shoal west (sw/Dz1): Planned:30 14.613 88 04.146 Actual: 30 14.631 88 04.125 Time: 10:02 CDT Cast 08 Along ship channel survey Channel west (cw/Dz5): Actual: 30 13.749 88 02.386 Time: ~10:32 CDT Time: Cast 09 : Actual: 30 12.841 88 02.557 Time: ~10:37 CDT Cast 10 Good to 2.5 m : Actual: 30 11.959 88 02.764 Time: 10:42 CDT Cast 11 : Actual: 30 10.962 88 02.965 Time: 10:47 CDT Cast 12 REPEAT CAST : Actual: 30 10.962 88 02.965 Time: 10:49 CDT Cast 13 Good down to 5m : Actual: 30 09.968 88 03.228 Time: 10:54 CDT Cast 14 BAD : Actual: 30 07.909 88 03.653 Time: ~11:00 CDT Cast 15 BAD : Actual: 30 07.555 88 04.229 Time: 11:07 CDT Cast 16 BAD : Actual: 30 06.093 88 05.120 Time: 11:17 CDT Cast 17 BAD : Actual: 30 04.553 88 05.662 Time: 11:26 CDT Cast 18 Surface good : Actual: 30 05.652 88 04.940 Time: 11:46 CDT Cast 19 : Actual: 30 05.691 88 04.827 Time: 11:50 CDT Cast 20 Main Pass, Mobile Bay (Afternoon) Channel far (Dz8): Actual: 30 13.527 88 01.799 Time: ~13:45 CDT Cast 21 Two bad casts (Cast 22 and 23) Channel far (Dz8): Actual: 30 13.494 88 01.804 Time: ~14:03 CDT Cast 24 Channel east (ce/Dz7): Planned: 30 13.5469 88 01.8825 Actual: 30 13.546 88 01.897 Time: 14:06 CDT Cast 25 Channel center (cc/Dz6) Planned:30 13.631 88 02.153 Actual: 30 13.653 88 02.134 Time: 14:10 CDT Cast 26 Channel west (cw/Dz5): Planned:30 13.743 88 02.389 Actual: 30 13.790 88 02.376 Time: 14:14 CDT Cast 27 Shoal shoal (ss/Dz4): Planned:30 13.878 88 02.630 Actual: 30 13.912 88 02.630 Time: 14:18 NO CAST Done with Handheld YSI since so shallow. Surface: 0.25 m Temp 27.8 C degree Salinity 23.6 psu Bottom: ~1.75 m Temp 27.7 C degree Salinity 23.6 psu Shoal east (se/Dz3): Planned:30 14.142 88 03.128 Actual: 30 14.144 88 03.091 Time: 14:23 CDT Cast 28 Shoal center (sc/Dz2): Planned:30 14.342 88 03.536 Actual: 30 14.389 88 03.642 Time: 14:27 CDT Cast 29 Shoal west (sw/Dz1): Planned:30 14.613 88 04.146 Actual: 30 14.620 88 04.129 Time: 14:31 CDT Cast 30 CTD data at Main Pass Mobile Bay and Along ship channel (2015/10/09) 2015-10-09: FILENAME convention: DZdMMMYY_Mcastnumber e.g. DZ9OCT16_M000 File parameters: # name 0 = scan: Scan Count # name 1 = depSM: Depth [salt water, m], lat = 0.00 # name 2 = depSM: Depth [salt water, m], lat = 0.00 # name 3 = bat: Beam Attenuation, Chelsea/Seatech [1/m] # name 4 = density00: Density [density, kg/m^3] # name 5 = c0uS/cm: Conductivity [uS/cm] # name 6 = wetStar: Fluorescence, WET Labs WETstar [mg/m^3] # name 7 = sbeox0V: Oxygen raw, SBE 43 [V] # name 8 = sbeox0PS: Oxygen, SBE 43 [% saturation] # name 9 = sbeox0Mg/L: Oxygen, SBE 43 [mg/l] # name 10 = ph: pH # name 11 = prSM: Pressure, Strain Gauge [db] # name 12 = sal00: Salinity, Practical [PSU] # name 13 = specc: Specific Conductance [uS/cm] # name 14 = t090C: Temperature [ITS-90, deg C] # name 15 = timeS: Time, Elapsed [seconds] # name 16 = flag: 0.000e+00 Stations locations/Cast Time(CDT) in Main Pass, Mobile Bay: Main Pass, Mobile Bay Channel east (Dz8): Actual: 30 13.494 88 01.834 Time: ~11:19 CDT Cast 00 Channel east (ce/Dz7): Planned:30 13.5469 88 01.8825 Actual: 30 13.537 88 01.925 Time: ~11:22 CDT Cast 01 Channel center (cc/Dz6) Planned:30 13.631 88 02.153 Actual: 30 13.663 88 02.173 Time: 11:26 CDT Cast 02 Channel west (cw/Dz5): Planned:30 13.743 88 02.389 Actual: 30 13.762 88 02.248 Time: 11:31 CDT Cast 03 Channel west (cw/Dz5): Planned:30 13.743 88 02.389 Actual: 30 13.762 88 02.248 Time: 11:34 CDT Cast 04 REPEAT CAST Shoal shoal (ss/Dz4): Planned:30 13.878 88 02.630 Actual: 30 13.867 88 02.681 Time: 11:38 CDT Cast 05 Shoal east (se/Dz3): Planned:30 14.142 88 03.128 Actual: 30 14.124 88 03.149 Time: 11:41 CDT Cast 06 Shoal center (sc/Dz2): Planned:30 14.342 88 03.536 Actual: 30 14.354 88 03.666 Time: 11:45 CDT Cast 07 Shoal west (sw/Dz1): Planned:30 14.613 88 04.146 Actual: 30 14.590 88 04.177 Time: 11:50 CDT Cast 08 Two extra cast in Main Pass with LISST and surface and bottom water grabs (see independent data submission for LISST casts). Channel center (cc/Dz6) Planned:30 13.631 88 02.153 Actual: 30 13.660 88 02.186 Time: 13:00 CDT Cast 09 Shoal center (sc/Dz2): Planned:30 14.342 88 03.536 Actual: 30 14.088 88 03.204 Time: 13:10 CDT Cast 10 Along ship channel survey Channel west (cw/Dz5): Actual: 30 13.709 88 02.428 Time: ~14:50 CDT Time: Cast 11 : Actual: 30 12.884 88 02.557 Time: ~14:57 CDT Cast 12 : Actual: 30 12.081 88 02.764 Time: 15:06 CDT Cast 13 : Actual: 30 10.081 88 03.019 Time: 15:15 CDT Cast 14 : Actual: 30 09.948 88 03.305 Time: 15:22 CDT Cast 15 : Actual: 30 08.927 88 03.776 Time: 15:30 CDT Cast 16 2015-10-20: CTD data at Main Pass, Mobile Bay (2015/10/29) FILENAME convention: Surveyname_ddMMMYYYY_Mcastnumber_stationlocation e.g. DZ_06April2016_Mini000_cr Stations locations/Cast Time (CDT) in Main Pass, Mobile Bay: Shoal west (sw/Dz1): 30 14.613 88 04.146 Time: 10:42 CDT Shoal center (sc/Dz2):30 14.342 88 03.536 Time: 10:35 CDT Shoal east (se/Dz3):30 14.142 88 03.128 Time: 10:27 CDT Shoal shoal (ss/Dz4): 30 13.878 88 02.630 Time: 10:21 CDT Channel west (cw/Dz5) (30 13.743 88 02.389 Time: 10:16 CDT Channel center (cc/Dz6) 30 13.631 88 02.153 Time: 10:10 CDT Channel east (ce/Dz7): 30 13.5469 88 01.8825 Time: ~10:06 CDT Each CTD cast file is organized as: Column 1 = Scan Count Column 2 = Depth [salt water, m] Column 3 = Temperature [ITS-90, deg C] Column 4 = Salinity, Practical [PSU] Column 5 = sbeox0Mg/L: Oxygen, SBE 43 [mg/l] Column 6 = sbeox0PS: Oxygen, SBE 43 [% saturation] Column 7 = pH [pH] Column 8= c0uS/cm: Conductivity [uS/cm] Column 9 = flag: 0.000e+00

Methods:

CTD was allowed to soak for approximately 1 minute at shallow depth then raised to the near-surface before beginning the descent to the bottom. Bottom was determined as when the casting line went slack, at which point the CTD was raised to the surface.

Instruments:

Seabird Electronic (SBE) SBE 25 Sealogger CTD

Provenance and Historical References:

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

Individual Files: