Abstract:

This dataset contains a vertical profile of images of marine snow collected in the Orca Basin (Gulf of Mexico, 27˚00.287’ N, 91˚17.560' W) during the R/V Endeavor EN586 on 2016-08-11. A CTD profile accompanies the imagery. The profile gives a complete depth distribution of marine snow from the sea surface, through the pycnocline, to within 10 m of the seafloor. Images were collected by a Nikon D7000 digital camera every seven seconds.

Suggested Citation:

Arne Diercks. 2020. Vertical Profile of Snow Cam Images and CTD profile collected aboard R/V Endeavor cruise EN586 in the Orca Basin, Gulf of Mexico on 2016-08-11. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-cvqx-4j58

Purpose:

The documentation of the vertical distribution of marine aggregates in the Orca Basin within the Gulf of Mexico. The Orca Basin is an intriguing location at which to study marine snow due to its unique geological and hydrographic setting: the deepest ~200 m of the basin is filled with anoxic, hypersaline brine.

Data Parameters and Units:

Time (Julian Days, [decimal days, UTC]), elapsed time [hours], elapsed time [minutes], elapsed time [seconds], depth ([salt water, lat = 28.00, [m]), descent rate [m/s], beam attenuation (WET Labs C-Star [1/m]), beam transmission (WET Labs C-Star [%]), fluorescence (WET Labs CDOM [mg/m^3]), turbidity (WET Labs ECO [NTU]), turbidity (WET Labs ECO, 2 [NTU],) potential temperature (ITS-90, [deg C]), salinity (Practical [PSU]), temperature (ITS-90 [deg C]), Voltage 0, Voltage 1, Voltage 2, Voltage 3, Voltage 4, Voltage 5, flag. Correction note: The cruise information in the file "GRIIDC_Cruise_Data_EN586-SnowCam.xlsx" contains a typo in the dates, and should be 2016-07-23 to 2016-08-15.

Methods:

The timestamp (local, Central Time) embedded in the EXIF data of the individual images may be correlated with the CTD data (UTC). The CTD data are presented in three formats: SnowCamCast#7.cnv reports every 0.25 seconds; SnowCamCast#7_01262018_7secDOWN.cnv reports every seven seconds; SnowCamCast#7_01262018_1mDOWN.cnv reports at 1m intervals. Camera settings: f5.6, 1/60s, ISO100.

Instruments:

SBE19plus' CTD, Nikon D7000 digital camera, Nikkor AF-S DX 35mm f1.8G lens.

Individual Files: