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Introduction |
What does it mean to use MODIS retrievals consistently? |
Estimating Aerosol Radiative Effect |
Results
Results
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Seasonal values of aerosol optical thickness (left)
and aerosol radiative effect at the top of the atmosphere (right) from the Terra satellite.
The four numbers in each latitude-longitude section represents a seasonal mean for that
section from all available monthly data.
. The seasons in each box are Northern winter (upper left), Northern Spring (upper right), Northern Summer (lower left) and Northern Fall (lower right)
Radiative effect values of the bottom panel are fluxes in units of W m-2.
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The results include estimates of monthly mean direct aerosol radiative effect over the oceans, globally and in 13 regional sections, for both the Terra and Aqua satellites.
The figure shows seasonal values in each of the regions. The largest aerosol radiative effect occurs in the northern Indian ocean in the summertime when desert dust is transported from the Arabian peninsula. The northern hemisphere, in general, experiences much stronger aerosol effect than the southern hemisphere, even in the Fall when southern biomass burning increases the effect somewhat. The least aerosol effect occurs in the southern tropical Pacific, where there are few nearby sources of aerosol.
Global values of total clear-sky aerosol shortwave radiative effect over the oceans in cloud free conditions are found to be -4.7 ± 0.3 Wm-2 to -5.2 ± 0.3 Wm-2 . The global values of aerosol optical thickness and radiative effect are remarkably consistent from season to season and year to year. These numbers closely resemble other observationally-based estimates of the same quantity. Individual regions show greater variability, spatially, seasonally and annually.
In summary, the MODIS analysis of the aerosol effect on the radiative fluxes adds a new measurement perspective to a climate change problem dominated so far by models.
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Introduction |
What does it mean to use MODIS retrievals consistently? |
Estimating Aerosol Radiative Effect |
Results
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