Editorial Type:
Article
Article Type:
Research Article

The 600–800-mb Minimum in Tropical Cloudiness Observed during TOGA COARE

Paquita Zuidema Program in Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado

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Print Publication:
01 Jun 1998
DOI:
https://doi.org/10.1175/1520-0469(1998)055<2220:TMMITC>2.0.CO;2
Page(s):
2220–2228
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Abstract

A minimum in cloud coverage occurring between 800 and 600 mb can be inferred from soundings taken within the tropical western Pacific warm pool. Surface observations of clouds and satellite-derived outgoing longwave radiation values suggest that the cloud minimum in the 600–800-mb layer occurs in all weather conditions. One explanation for the enhanced occurrence of clouds above (in the 400–600-mb layer) and their diminished occurrence within the 600–800-mb layer is a preferential cloud detrainment from convection into the more stable levels existing at pressures below 600 mb and above 800 mb. This mechanism is supported by the results of a buoyancy-sorting model.

Corresponding author address: Paquita Zuidema, Program in Atmospheric and Oceanic Sciences, University of Colorado, Campus Box 311, Boulder, CO 80309.

Abstract

A minimum in cloud coverage occurring between 800 and 600 mb can be inferred from soundings taken within the tropical western Pacific warm pool. Surface observations of clouds and satellite-derived outgoing longwave radiation values suggest that the cloud minimum in the 600–800-mb layer occurs in all weather conditions. One explanation for the enhanced occurrence of clouds above (in the 400–600-mb layer) and their diminished occurrence within the 600–800-mb layer is a preferential cloud detrainment from convection into the more stable levels existing at pressures below 600 mb and above 800 mb. This mechanism is supported by the results of a buoyancy-sorting model.

Corresponding author address: Paquita Zuidema, Program in Atmospheric and Oceanic Sciences, University of Colorado, Campus Box 311, Boulder, CO 80309.

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