Comparison of cloud forcing derived from the Earth Radiation Budget Experiment with that simulated by the NCAR (National Center for Atmospheric Research) Community Climate Model

Journal Article · Fri Jul 20 04:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JD095iD08p11679· OSTI ID:5398740

Kiehl, J T ^[1]; Ramanathan, V ^[2]

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1. National Center for Atmospheric Research, Boulder, CO (USA)
2. Univ. of Chicago, IL (USA)

A comprehensive comparison of top atmosphere radiative quantities from the Earth Radiation Budget Experiment (ERBE) with the same quantities from the latest version of the National Center for Atmospheric Research Community Climate Model (CCM) is presented. Comparison between ERBE clear-sky longwave fluxes and CCM1 indicates larger outgoing flux in the model than measured by ERBE. This overestimation is ascribed to the prevalent dryness of the model. Comparison of clear sky albedo indicates good agreement over oceans and land. Total outgoing longwave flux also reflects the moisture deficiency of the model, but differences due to an underprediction of effective high cloud are also apparent. The clear-sky and total fluxes are combined to form the cloud radiative forcing from the ERBE data and the CCM. Comparison of shortwave cloud radiative forcing indicates deficiencies in the model where marine stratus clouds are absent. Large longwave cloud forcing over the tropical deep convective regions in Indonesia and South America are present in the model but are underestimated compared with the ERBE results. Three regions, located over Indonesia, the equatorial Pacific, and the North Atlantic, are considered in detail. For the Indonesian region where deep convection is present, the authors consider the statistical correlation between the longwave cloud forcing and the shortwave cloud forcing from the ERBE data and CCM. Results indicate a near cancellation between the SWCF and LWCF for these regions, whereas the model predicts a net cooling. Another major area of discrepancy is over the North Atlantic and Pacific oceans where ERBE shows that clouds significantly reduce the solar heating of the oceans. While the model simulates this cooling, the magnitude is underpredicted by more than a factor of 2.

• OSTI ID: 5398740
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:D8; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
ASIA
ATLANTIC OCEAN
CLIMATE MODELS
CLOUDS
COMPARATIVE EVALUATIONS
COOLING
DEVELOPING COUNTRIES
EARTH ATMOSPHERE
EVALUATION
INDONESIA
ISLANDS
LATIN AMERICA
MATHEMATICAL MODELS
MOISTURE
PACIFIC OCEAN
PERFORMANCE
RADIATIONS
RESOURCE ASSESSMENT
SEAS
SOLAR RADIATION
SOUTH AMERICA
STELLAR RADIATION
STRATOSPHERE
SURFACE WATERS
VARIATIONS
WAVELENGTHS