Research Strategies for the U.S. Global Change Research Program (1990) / Chapter Skim
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7 Biogeochemical Dynamics in the Ocean
7 Biogeochemical Dynamics in the Ocean
Pages 200-214
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From page 200... ...
The objective of the effort was to develop the capability to predict the effect of projected climatic change on the ocean's physical, chemical, and biogeochemical processes, especially as they feed back to climate via the release or absorption of radiatively important gases such as carbon dioxide and organic sulfur species. This chapter identifies the current efforts to meet that challenge, both with existing programs and with recommendations for new efforts.
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From page 201... ...
Yet another example can be taken from the effect of ozone depletion on antarctic organisms. The potential increased levels of ultraviolet radiation could affect the phytoplankton that constitute the base of the food web in aquatic ecosystems by reducing the amount of primary production and altering community structure.
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From page 202... ...
The capability for global measurement of ocean color by satellite-borne instn~ments and the subsequent inference of biological productivity have provided new impetus to these studies. Also developed were in situ techniques for direct measurement of the vertical transport of biogenic material in the water column by sediment traps as well as high-precision methods for the detection of trace species in very small amounts.
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From page 204... ...
The ocean is also an important source for several chemicals in the atmosphere, including sulfur species, certain low molecular hydrocarbons, and some halogenated species. It is important that the JGOFS program work closely with atmospheric chemistry programs so that fluxes from the atmosphere are measured and the mechanisms for transfer understood.
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From page 205... ...
A close working relationship is now developing between JGOFS and IGAC, and plans are being made for a formal relationship between these two programs, which would be particularly appropriate since they are both part of the IGBP. Oceanic Ecosystem Response to Climatic Change Global oceanic fluxes of carbon and other materials are mediated through the complex interactions of the growth, reproduction, and mortality dynamics of oceanic communities and their constituent populations.
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From page 206... ...
Tropical Ocean-Atmosphere Interactions Considerable progress has been made in the past 2 or 3 years in actually predicting change in the study of E1 Nino, the periodic anomalous warming (and cooling) that occurs in the tropical Pacific Ocean accompanied by global atmospheric changes.
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From page 207... ...
. WOCE has as central observational elements a global observing network of precision satellite measurements of the surface winds and currents, direct current measurements, and precise measurement of temperature, salinity, and chemistry.
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From page 208... ...
WOCE will be augmented by the NOAA Atlantic Climate Change program, which will study air-sea interaction in the North Atlantic Ocean. The Atlantic Climate Change program will provide valuable information on the environmental context for biological studies (NOAA, 1990~.
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From page 209... ...
The subsequent increased levels of ultraviolet radiation could affect the phytoplankton that constitute the base of the food web in aquatic ecosystems. Studies have shown that increased levels of ultraviolet exposure result in reduced primary production and an altered community structure.
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From page 210... ...
A prerequisite for an efficient monitoring scheme that covers the broad spectrum of physical and biogeochemical processes is to have models of the way these processes work. Models of the physical processes and of primary production processes are being developed through TOGA, WOCE, and JGOFS.
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From page 211... ...
The data from this system have been valuable in helping TOGA scientists develop an operational ocean model for E1 Nino predictions. The international framework is in place, through the International Global Ocean Station System (IGOSS)
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From page 212... ...
Satellite measurements are essential to monitoring: for the first part of the 1990s the various research missions that have been described above will provide the necessary information. But for the late 1990s and beyond, for true monitoring of global change, instruments of EOS need to be in place to monitor ocean color, wind stress, and ocean currents, as well as ocean temperature and rainfall.
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From page 213... ...
It is important that the JGOFS program continue to work closely with the relevant atmospheric chemistry programs, in particular IGAC, so that fluxes between the atmosphere and the ocean are understood and the boundary conditions are established. Increased cooperation and coordination between JGOFS and IGAC are encouraged and should be strengthened.
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From page 214... ...
Program: A Core Project of the International Geosphere-Biosphere Program. IAMAP Commission on Atmospheric Chemistry and Global Pollution.
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