Projects - Nitrate Measurements


In the summer of 2011 we tested a new Submersible Ultraviolet Nitrate Analyzer (SUNA) aboard Glider #159. We operated this glider near a buoy in Resurrection Bay at a location called GAK1. Nitrate measurements have historically been collected at GAK1 for many years through moored sensors as well as laboratory analysis. As the glider swam repeat transects across the moored instrument array, we collected water samples at various depths in order to compare the SUNA sensor derived Nitrate concentrations to the concentrations determined through lab analysis. At the end of the experiment, we will have a time series of water properties collected from a variety of instruments. After some post-processing we hope to develop a robust calibration curve for the SUNA instrument. This demonstration will determine the feasibility of using the SUNA sensor in open ocean conditions. The project was funded by the North Pacific Research Board.   GAKOA
The UAF oceanographic research buoy located in Resurrection Bay. In 2011, the integrated SUNA/glider swam by this mooring multiple times while scientists measured ocean properties from a ship.

Resulting Publications

Evans, W., J. Mathis, P. Winsor, H. Statscewich, and T. E. Whiteledge (2013), A Regression Modeling Approach for Studying Carbonate System Variability in the Northern Gulf of Alaska. Journal of Geophysical Research, 1, 476-489.


March, 2011

In March, a mooring was deployed at the GAK1 location.

Photo Gallery

June, 2011

In June, Hank and Peter went out to the mooring location on a chartered vessel, Dora. They used a camera to examine the instruments on the mooring for biofouling, then flew the glider with a nutrient sensor near the mooring location. A small CTD was also deployed from the ship for calibration.

Photo Gallery

Support from The North Pacific Research Board is gratefully acknowledged.