Overview

The glider project at Stony Brook University grew out of the New York Department of Conservation's need to understand and monitor the New York Bight and its long-term health and productivity.  As a result, the School of Marine and Atmospheric Sciences at Stony Brook University developed a ten year program to measure the hydrography, chemistry and fishery biomass from seasonal cruises on the RV Seawolf and ~30 day ocean glider cruises covering the New York Bight area.  Subsequently, a collaborative program between Rutgers, Stony Brook and the University of Maine was proposed to NOAA to use the gliders that were being deployed in the Middle Atlantic Shelf and the Gulf of Maine to monitor ocean acidification in the area.  The ocean acidification monitoring makes use of a new pH sensor developed by Sea Bird Electronics, in collaboration with Grace Saba's group at Rutgers, that can be mounted on the gliders.  This new sensor has been added to the Stony Brook glider with its first cruise starting February, 2021.

The SoMAS ocean glider operation is intended to provide long term and seasonal data of the basic physical conditions in the New York Bight as part of the New York DEC's ocean monitoring effort.  The glider, SBU01, is a Webb Research Slocum G3 shallow water unit, maximum depth is 350m, equipped with the standard suite of sensors measuring temperature, conductivity, pressure, dissolved oxygen, chlorophyll fluorescence and turbidity.  The intent is to deploy the glider seasonally from south of Long Island on a cruise that includes a series of transects out to the edge of the continental shelf ending up off Sandy Hook or Little Egg Inlet, New Jersey for retrieval.  The glider propels itself through a series of dives and climbs making about 20 km per day, slower in shallow water, faster in deep water with fewer dive/climb iterations.  With the rechargeable batteries in the glider, cruise duration in MAB waters is about 32 days and ~600 km.  So far, there have been six cruises in the MAB, shown below, adding more than 13,000 vertical profiles of T, S, O2, Fl and Turbidity to the database.  In January the SeaBird CTD/pH sensor was added to the glider to provide seasonal and spatial distributions of pH to assist in monitoring the impact of CO2 absorption in the ocean.

Piloting of the glider is accomplished through a two-way Iridium satellite connection initiated by the glider when it surfaces at approximately three hour intervals.  Using Webb Research supplied software, the Slocum Fleet Mission Control or SFMC, heavily decimated realtime data are sent ashore and mission modifications can be sent to the glider.  The near realtime data that have been uploaded from the glider are currently being minimally processed by Rutgers' glider group into netcdf files for each surfacing and uploaded onto NOAA's ERDDAP server accessible via https://marine.rutgers.edu/cool/data/gliders/deployments.  

Post cruise, the complete set of glider data are offloaded from the glider's memory cards and processed using a set of routines based upon those developed by John Kerfoot (Rutgers), Robert Todd (WHOI) and Ruth Curry (BIOS).  That processing system calibrates the data, does a QA/QC check on the validity of the results and stores the data in a large Matlab file.  The Matlab files are accessible through the project server.  Matlab files are also converted to the a netcdf file format and uploaded onto NOAA's ERDDAP server (link below).  The glider data is so voluminous that using the ERDDAP server is the only practical way of making the data available to potential users. 

June, 2022, Glad to report that SBU01 has finally returned from a long sojourn at Webb for calibration and checkup.  Next deployment is scheduled for mid_July.

A new G3s Slocum glider,designated SBU02, arrived in January 2023 to back-up and compliment SBU01.  This glider has an updated computer as the older computer in SBU01 is no longer available.  Virtually all the commands used in the older version work with the new computer with some additional capabilities, in particular the ability to compress files sent over the satellite link. The new G3s glider arrived in late January equipped with a CTD/pH unit, a chlorophyll/turbidity sensor, a dissolved sensor and the DMON2 passive acoustic sensor to listen for whales of various kinds.  A portion of output from the DMON2 is telemetered ashore along with the other decimated sensor data.  The DMON2's internal computer makes preliminary identifications of whale calls which are then sent ashore to be assessed by Mark Baumgartner's group at WHOI.  Positive ID's of whales then are broadcast to a user group that includes the shipping industry in an effort to minimize ship strikes.

As of March 2023, SBU01 has also been fitted with a DMON2 and has been activated on subsequent deployments, except for October 2023 deployment.

There are two main deployment paths for the SBU gliders. For the NYDEC surveys, the main parameters include deployment out of east Long Island, NY (Shinnecock Inlet), traveling to the edge of the continental shelf, crossing the Hudson Canyon, and being recovered off the the coast of New Jersey to cover as much of the NY bight as possible. For the NYSERDA surveys, deployment is generally out of Fire Island Inlet with the focus on covering as many tracks within the offshore wind farm lease areas before being recovered off of the coast of New Jersey. For all glider deployments, the glider is generally released at a depth of ~100 ft to enable sufficient testing before starting the mission, as such the distance from shore varies accordingly.
 

Deployments

Useful Websites: