THE OCEANOGRAPHY SOCIETY PACIFIC BASIN MEETING, July 1994, p.24

HOT: A time-series study of carbon cycling in the oligotrophic North Pacific

HOT Program P.I.s, staff and students

Time-series measurements at strategic sites in the world ocean are crucial for the determination of the mean state, and natural variability therein, of natural oceanic ecosystems and are thus prerequisite for studies designed to assess global environmental change. In 1988, the U.S.-Joint Global Ocean Flux Study (JGOFS) program established deep ocean time-series stations in the N. Atlantic near Bermuda (31 50'N, 64 10'W) and in the N. Pacific near Hawaii (22 45'N, 158W). On approximately monthly intervals program scientists collect core data and conduct a series of experiments that collectively contribute to the calibration and validation of existing biogeochemical models. To date, we have resolved at least three predominant scales of ecosystem variability: daily, seasonal and interannual. Each one of these requires unique physical forcing that, in certain cases, is unpredictable. Coupled with these physical changes are significant variations in ecosystem carbon production, export and recycling rates. These coupled physical-biogeochemical processes create a diverse and variable biological assemblage in a habitat previously considered by some to be uniform and monotonous.