Absorption of solar radiation by clouds: observations versus models
Science (New York, N.Y.)
|January 27, 1995
Summary
Scientists observed anomalous solar radiation absorption by clouds, finding clouds absorb significantly more solar energy than models predict. This unexplained phenomenon impacts the Earth's energy budget and requires further investigation.
Area of Science:
- Atmospheric science
- Climate science
- Radiative transfer
Background:
- Clouds have historically shown unexplained anomalous absorption of solar radiation.
- Existing theoretical models do not fully account for observed solar absorption by clouds.
- Tropospheric aerosols have been suggested as a cause, but their variability contrasts with observed absorption patterns.
Purpose of the Study:
- To investigate the discrepancy between observed and modeled solar absorption by clouds.
- To quantify the anomalous solar absorption by clouds using collocated measurements.
- To assess the consistency of cloud absorption across different seasons and locations.
Main Methods:
- Utilized collocated satellite and surface measurements of solar radiation.
- Collected data from five geographically diverse locations.
- Analyzed solar radiation data to determine atmospheric absorption by clouds.
Main Results:
- Observed significant solar absorption by clouds, exceeding model predictions.
- Quantified an additional 25 watts per square meter of global-mean absorption by the cloudy atmosphere.
- Found cloud absorption to be remarkably invariant with respect to season and location, unlike aerosol effects.
Conclusions:
- Enhanced cloud absorption of solar radiation is a significant factor in the Earth's energy budget.
- The physical cause of this anomalous absorption remains unknown.
- This finding necessitates a revision of current atmospheric energy budget models.
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