AUV-BAsed Investigation of the Role of Nutrient Variability in the Predictive Modeling of Physical Processes in the Littoral Ocean.

摘要

Progress was made in the design of instruments to perform high-sensitivity measurements of ammonium, nitrate, and nitrite in the upper ocean and in data analysis from field expeditions with those instruments; The Long-Term Goal is to use tiny nutrient changes as descriptors of geophysical fields in the upper ocean. Expedition data showed the importance of wind. Low wind stress led to large ammonium peaks. As wind stress increased, ammonium peaks weakened and then disappeared. Thus the features of ammonium peaks are descriptors of wind effects on the condition of the surface ocean. The Masserini/Fanning lab nutrient sensor was adapted for a Bluefin-type AUV and then modified further into a robust lightweight pulsed xenon fluorescence nutrient analyzer that is cheap and can work on smaller boats. The importance of this new analyzer will be its ability to make possible the large number of surveys necessary to follow the occurrence and fate of ammonium peaks. Finally, initial evaluations of the ISUS ultraviolet-based nitrate sensor indicated that it can function in our coastal waters but has problems and is not very sensitive.