U.S. Joint Global Ocean Flux Study (U.S. JGOFS)

Research

The U.S. JGOFS program has consisted of six cooperating, complementary activity elements – time-series measurements at Hawaii and Bermuda, process studies, global surveys, synthesis and modeling efforts and data management. U.S. JGOFS is the U.S. national program of JGOFS, an international program sponsored by the Scientific Committee on Oceanic Research (SCOR) and the International Geosphere-Biosphere Programme (IGBP). U.S JGOFS is also an element of the U.S. Global Change Research program. The early history and broad framework of the U.S. JGOFS program has been described in a Science Plan (Long-Range Plan, U.S. JGOFS, 1990). The Plan includes a full description of the five JGOFS program elements. A brief summary follows.

Time-series: Starting in 1988, JGOFS initiated two time-series measurement programs at Hawaii and Bermuda time series stations (HOT and BATS, respectively). The objective of the time-series effort is to provide well-sampled seasonal resolution of biogeochemical variability at a limited number of ocean observatories, provide support and background measurements for process-oriented research, as well as test and validate observations for biogeochemical models. The HOT and BATS records now span a period greater than 10 years with well over 100 successful cruises at each site and permanent moorings in place to assess ocean variability in the oligotrophic ocean.

Process Studies: The objective of the process studies component has been to target key process links in our current models of the oceanic biogeochemical system and enhance our causal understanding of the processes. The goal of process-oriented studies is to provide a mechanistic understanding of ocean processes in sufficient detail to predict and stimulate biogeochemical fluxes at representative sites in the ocean. The four major U.S. JGOFS Process Studies were:

North Atlantic Bloom Experiment (NABE)
April through July 1989

Equatorial Pacific Process Study (EqPac)
February through April and August through December 1992

Arabian Sea Process Study
October 1994 through January 1996

Antarctic Environment and Southern Ocean Process Study (AESOPS)
August 1996 to March 1998

CO₂ Survey: The rationale for the large-scale survey component of JGOFS is to provide a composite, basin to global scale, biogeochemical view of the ocean. The large-scale survey of basin-to-global oceanic CO₂ parameters conducted as part of the WOCE Hydrographic Program cruises is a major component of the JGOFS survey program element.

Satellite Observations of Ocean Color: Satellites can provide a large-scale view of the ocean. In particular, the ocean color sensor Sea-viewing Wide Field Sensor (SeaWiFS) is of interest to JGOFS due to its ability to measure surface chlorophyll distribution.

Synthesis and Modeling: The main objective of the Synthesis and Modeling Project (SMP) is to synthesize knowledge gained from the U.S. JGOFS and related studies into models that reflect our current understanding of the ocean carbon cycle and its associated uncertainties. In particular, the processes that control carbon partitioning among ocean reservoirs, and the implications on ocean/atmosphere carbon exchange, are emphasized.

Data Management: The Data Management Office (DMO) was developed to meet the data management needs of U.S. JGOFS. The DMO manages a data system which provides access to U.S. JGOFS data sets comprised of information generated from the program's five complementary activity elements.