9301368 Karl This project provides a deep-water, open ocean hydrostation as the oligotrophic ocean benchmark for observing and interpreting physical and biogeochemical oceanic variability. Repeat field measurements of a suite of core parameters are made on approximately monthly intervals, as well as compilation of the data and distribution to the scientific community. The current project includes ongoing improvements to the measurements being made such as the addition of a continuous hydroprofiling, extension of selected HOTS cruises, continuation of the sediment trap mooring and added measurements of low-level ammonium determinations, and bacterial production measurements using a new techniuque. Related grants awarded simultaneously with this one include Bidigare (OCE- 9315311) for pigment measurements, and Winn (OCE 9315312) for inorganic CO2. Continued work on HOTS will contribute to understanding of the role of the oligotrophic ocean in the global carbon cycle and to resolving the time scale of variations in processes important to that cycle.
