Global distribution of photosynthetically active radiation as observed from satellites

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Journal of Climate; (United States)

DOI:https://doi.org/10.1175/1520-0442(1992)005<0056:GDOPAR>2.0.CO;2· OSTI ID:6721347

Pinker, R T; Laszlo, I ^[1]

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1. Univ. of Maryland, College Park (United States)

Concern about possible effects of a steady increase in CO[sub 2] on the earth's climate, and the fact that current estimates of sources and sinks of CO[sub 2] do not balance, generated interest to improve knowledge of rates at which carbon is cycled between the oceans, land, and atmosphere. The net primary productivity (NPP) - namely, the rate at which inorganic carbon is transformed into organic matter - is strongly controlled by the availability and intensity of photosynthetically active radiation (PAR); the distribution of photoactive pigments; the efficiency with which the light is absorbed; and the efficiency of its conversion into organic matter. In this study the feasibility to derive one of the above parameters is demonstrated - namely, PAR on a global scale. In the past, information on PAR was obtained from local ground measurements in the 0.4-0.7-[mu]m spectral interval. In the absence of such measurements, PAR was estimated from measured total solar irradiance, using empirical conversion factors.' It is demonstrated that this important biogeophysical parameter can now be derived from satellite observations. The inference model is implemented with global satellite data that are available from the International Satellite Cloud Climatology Project (ISCCP) to produce for the first time global fields of PAR and corresponding conversion factors.' 54 refs., 7 figs.

• OSTI ID: 6721347
• Journal Information: Journal of Climate; (United States), Vol. 5:1; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
SOLAR RADIATION
DISTRIBUTION
GLOBAL ASPECTS
ORGANIC MATTER
PHOTOSYNTHESIS
PRODUCTIVITY
SATELLITES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
MATTER
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
RADIATIONS
STELLAR RADIATION
SYNTHESIS
540110*