Science Quality

Science Quality Full-Resolution Data from Spray Glider Mission 12804001 (sp040-20120823T1231)

Project

Gliders in the Gulf of Mexico


Date Range

2012-08-23 to 2013-01-15


Sensors

This file contains data from the following specific instruments: Sea-Bird SBE 41CP CTD.


Summary

Spray glider data from mission 12804001, part of the Gliders in the gulf of mexico project. This is the complete science-quality dataset for the full mission, spanning from 2012-08-23 to 2013-01-15.

The overarching goal of Spray underwater glider operations in the Gulf of Mexico was to improve dynamical knowledge of oceanographic conditions in the Loop Current and associated eddies. A specific objective was to provide data to data assimilating models to establish the predictability of currents in the region.

This is a delayed-mode science-quality data product providing the highest-resolution and highest quality data for this mission. After a glider mission is complete and the glider is recovered, the full-resolution data are downloaded and quality controlled resulting in this data product. This product is typically available three to six months after a glider mission is complete.

The delayed-mode science quality full-resolution data product should be used in place of near-real-time data once this higher-quality data product is available. This is a rigorously quality controlled dataset, the results of quality control tests are included as flags. Where appropriate, in addition to the original data with quality flags, corrected variables are also provided. These are noted in the variable metadata.Users of the data must apply the quality control flag variables referenced as ancillary variables on the data variables, these flags provide necessary information for using the data.

About these measurements: A Spray glider moves slowly through the water and collects information about the water it is traveling through. It collects a series of vertical profiles from the ocean seafloor (up to 1000m deep) to the ocean surface. In typical operations to 1000 m depth, a Spray glider travels 15 miles and makes 4 profiles per day. When on the ocean surface, about every three to six hours, it sends the information it collected underwater back via satellite, and then dives back down to continue collecting data.

The Spray ocean glider carries a pumped Sea-Bird CTD to measure pressure, temperature, and salinity, a Seapoint fluorometer, and a Sea-Bird dissolved oxygen sensor. Additionally, a Nortek acoustic Doppler current profiler (ADCP) measures depth dependent water velocity. The ocean glider position is measured at the surface at the beginning and end of each dive by GPS, allowing for a dead reckoning estimation of depth averaged water velocity.

An underwater glider runs on batteries and can stay out to sea for months at a time. Spray gliders collect observations on the ascent of a dive. Sensor observations are not collected on the descent and one vertical profile of observations is collected on the ascent of each dive.


Contributors

Daniel Rudnick (PrincipalInvestigator), Instrument Development Group (processor), Guilherme Castelao (processor), Jennifer Sevadjian (resourceProvider)


References

Gopalakrishnan, G., B. D. Cornuelle, I. Hoteit, D. L. Rudnick, and W. B. Owens, 2013: State estimates and forecasts of the loop current in the Gulf of Mexico using the MITgcm and its adjoint. Journal of Geophysical Research-Oceans, 118, 3292-3314, doi: 10.1002/jgrc.20239.; Rudnick, D. L., G. Gopalakrishnan, and B. D. Cornuelle, 2015: Cyclonic eddies in the Gulf of Mexico: Observations by underwater gliders and simulations by numerical model. Journal of Physical Oceanography, 45, 313-326, doi: 10.1175/JPO-D-14-0138.1.;Todd, R. E., W. B. Owens, and D. L. Rudnick, 2016: Potential vorticity structure in the North Atlantic western boundary current from underwater glider observations. Journal of Physical Oceanography, 46, 327-348, doi: 10.1175/JPO-D-15-0112.1.


Acknowledgement

This project was funded by BP and National Science Foundation