Projects - Nitrate Measurements
Summary
| 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. |  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.
Fieldwork
March, 2011
In March, a mooring was deployed at the GAK1 location.
Photo Gallery
The mooring buoy is being lifted onto the ship's deck before departure.
The mooring's anchor must be very heavy, so is made from railroad wheels.
The Norseman at dock in Seward, AK.
The deck of a busy research vessel can be a very crowded place. Watch your step!
Water drawn from the bottles on the CTD rosette will be used to calibrate the mooring's instruments.
Left alone.
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
Preparations were made at the dock before the journey out to the mooring.
The nitrate sensor was fixed to the top of the glider.
Dora traveled down Resurrection Bay from Seward, AK to the GAK1 mooring.
They pulled up along side the mooring and checked the instruments.
The Web SLOCUM glider underwater near the mooring.
A CTD was used to collect temperature and salinity profiles and water samples.
| Support from The North Pacific Research Board is gratefully acknowledged. |  |