CTD (conductivity-temperature-depth) data collected on Stellwagen Bank on U.S. Geological Survey field activity 2015-062-FA, aboard the R/V Auk, Oct. 21 and 22 and Nov. 3 and 4 2015

These data were collected with a Sea-Bird CTD (conductivity, temperature, depth) instrument - a SBE 19plus SeaCAT Profiler CTD (discontinued in 2008). This instrument was deployed on the USGS SEABed Observation and Sampling System (SEABOSS). The SEABOSS is an instrument developed by the USGS to collect samples and video and photographic images of the seabed to aid in the interpretation of seabed sonar imagery. The CTD is mounted horizontally on the SEABOSS frame and its maximum depth is approximately 1 meter above the seabed. The specifications for the CTD instrument are as follows:

SBE19plus, serial number 01906617 manufactured by Sea-Bird Electronics, Inc.

Firmware version: 2.2c
Firmware date: 7 December 2009
Manufactured date: 29 July 2010
Software version: 2.3.0

Internal sensors:

main temperature, serial number 01906617
main conductivity, serial number 01906617
main pressure, type, strain, serial number 3161799

External sensors from WET Labs:

ECO-FLNTURT CHL, serial number FLNTURT-1798; WET Labs fluorometer, ECO-AFL/FL
ECO-FLNTURT TURB, serial number FLNTURT-1798; WET Labs turbidity meter, ECO-NTU

Configuration:

Instrument battery operated; not connected to a conducting cable
Profile mode: sampling rate 4 per second, averaged to provide each data point
CTD deployed on the USGS SEABed Observation and Sampling System (SEABOSS)

Data archive:

Upcast data, collected from the seabed to ~1 meter below the sea surface

Sensor specifications:

Temperature (degrees C):

measurement range -5 to +35 degrees C; initial accuracy +-0.005; resolution 0.0001;

Conductivity (S/m):

measurement range 0 to 9 S/m; initial accuracy +- 0.0005; resolution varies: 0.00005 (most oceanic water; resolves 0.4 ppm in salinity); 0.00007 (high salinity water; resolves 0.4 ppm in salinity); 0.00001 (fresh water; resolves 0.1 ppm in salinity)

Strain gauge pressure:

measurement range 0 to full scale range: 20/100/350/600/1000/2000/3500/7000; initial accuracy +- 0.1% of full scale range; resolution 0.002% of full scale range.

Turbidity sensor:

wavelength 700 nm; sensitivity 0.01 NTU, rant 0-25 NTU

Flourescence sensor:

Chlorophyll-a 470 nm EX/695 nm EM; sensitivity 0.2 micro-g/l; range 0-125 micro-g/l Chl

The Sea-Bird instrument is mounted on the SEABOSS system. The downcast and drift data are omitted from the dataset because the data are unreliable. The downcast data are not reliable near the surface; the drift data are not reliable due to the up and down motion of the SEABOSS. The upcast data are collected along a controlled ascent from the seabed to the surface. At the end of the day (or the cruise), the CTD data are downloaded via a laptop using the Sea-Bird software. The upcast portion of the data are manually extracted from the dataset based on the deepest (usually) depth and progressive shallower depths. The upcast locations are at the end of the video drift. The latitude and longitude of the end of the video drift is available from 2015-062-FA_station_data_summary dataset, available from the Larger Work citation. The station summary data are available in XLSX, CSV, and shapefile formats.

Added keywords section with USGS persistent identifier as theme keyword.