Abstract:

The oceanographic community routinely collects time-series data of hydrographic properties and water current velocity of the marine environment. Such data are essential for establishing baseline characteristics of marine and estuarine ecosystems. These data are from a small coastal ocean observing system 25 kilometers southwest of the mouth of Mobile Bay, Alabama (30.0902°N, 88.2116°W), that the Dauphin Island Sea Lab (DISL) has been operating. The overarching goal of the research was to identify and determine the kinematic and dynamic transport processes that govern the distribution, dispersion, dilution, and fate of oil-derived substances in Alabama's coastal waters. As such, the project examined the flow field characteristics on the Alabama shelf from the Eulerian perspective. The data were collected between 2015-07-28 and 2015-12-09. The instruments were deployed on 2015-07-28 replaced on 2015-10-14. The dataset contains temperature data (five thermistors and two moored CTDs) and velocity data (upward looking ADCP).

Suggested Citation:

Brian Dzwonkowski, Mimi Tzeng, and Grant Lockridge. 2017. Fisheries Oceanography in Coastal Alabama (FOCAL) Mooring Data (Fall 2015). Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N73F4MQ6

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

Soto, I. M., Cambazoglu, M. K., Boyette, A. D., Broussard, K., Sheehan, D., Howden, S. D., … Cressman, K. (2018). Advection of Karenia brevis blooms from the Florida Panhandle towards Mississippi coastal waters. Harmful Algae, 72, 46–64. doi:10.1016/j.hal.2017.12.008

Purpose:

The objective of this ongoing research is to monitor the physical structure of the coastal ocean. This data is a subset of the regularly maintained FOCAL mooring. The site is the longest running time series of water column data in the Mississippi Bight and is an important asset for assessing long-term changes in the physical state of the region. Hydrographic and current velocity data from this site have been used in multiple physical and interdisciplinary studies of circulation, hydrography, and the biophysical interactions associated with the inner shelf of the northern Gulf of Mexico. The DISL mooring is located at 30°05.410'N, 88°12.694'W, 25 km southwest of Mobile Bay, Alabama, in 20 m of water.

Data Parameters and Units:

Each CTD file is organized as temperature, ITS-90 [deg C]; conductivity [S/m]; pressure [db]; salinity, PSS-78 [PSU]; sound velocity, chen millero [m/s]; time [Julian days]; flag: [0]. Each thermistor file is organized as temperature [degrees C]; date; time. Each ADCP file is organized as n [sample number]; bin; y [year]; m [month]; d [day]; h [hour]; min [minute]; t_day [Julian day]; tdep [total dep]; dep [bin depth]; u [cm/s] (east(+)/west(-), horizontal velocity); v [cm/s] (north(+)/south(-)horizontal velocity); spd [speed, cm/s]; dir [direction, degrees]; ECMP [Data Flag] Interpolated (if interpolated). NO COMPASS correction was done on the ADCP - direction is from the instrument compass. The raw RDI ADCP files require RDI software to convert to human readable files. WinADCP [Teledyne, 2015] can export data from the raw file (*.000) directly to a MATLAB file without requiring additional reformatting steps.

Methods:

The thermistors sample once per minute.The ADCP does a 5-minute burst sample (5 minute average) every 20 minutes.The CTD samples once per minutes.

Instruments:

The instruments used are SBE 39 Thermister, SBE 37 CTD, and an RDI 600 kHz ADCP Workhorse Sentinel (upward looking on the bottom).

Individual Files: