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Title: Characteristics of small tropical cumulus clouds and their impact on the environment

Abstract

This study uses a number of data sets (Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator data, space shuttle photography, Radiation Measurement System data, aircraft data, and shipboard soundings) to investigate the characteristics of small tropical cumulus clouds and their impact on their environment. The goal is to uncover useful information with application to radiative transfer simulation and satellite remote sensing. In fields of small cumulus clouds, size distributions are found to decrease in number with increasing diameter according to a double power law relation, often with a clear break diameter. Fractal dimensions corresponding to the horizontal area and perimeter of the clouds are greater for the larger clouds than for the smaller clouds, with the same break diameter as the size distributions, meaning that the larger clouds have more ragged perimeters. These two results suggest a characteristic horizontal length scale dividing larger and smaller boundary layer cumuli. Spatial distributions show a clear tendency toward clustering. Smaller cumuli appear to grow upward more quickly with increasing horizontal size than do larger cumuli. Albedo is found to increase with greater cloud fraction and higher solar zenith angle. Even sparse fields of small cumulus cause significant shortwave forcing at the ocean surface. Simulationmore » suggests that small cumulus may introduce significant errors into sea surface temperature retrievals and that such clouds can be difficult to remove with operational cloud-filtering schemes. Clouds smaller than about 1 km in diameter are not seen to precipitate. {copyright} 1998 American Geophysical Union« less

Authors:
;  [1]
  1. Program in Atmospheric and Oceanic Sciences, University of Colorado at Boulder (United States)
Publication Date:
OSTI Identifier:
328557
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research
Additional Journal Information:
Journal Volume: 103; Journal Issue: D22; Other Information: PBD: Nov 1998
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; SOLAR RADIATION; INSOLATION; CLOUDS; CLOUD COVER; CLIMATES; TROPICAL REGIONS; ENVIRONMENTAL EFFECTS; ALBEDO; DISTRIBUTION FUNCTIONS; FRACTALS; ASPECT RATIO; MORPHOLOGY; DIMENSIONS; ATMOSPHERIC PRECIPITATIONS; REMOTE SENSING; TEMPERATURE MONITORING

Citation Formats

Benner, T C, and Curry, J A. Characteristics of small tropical cumulus clouds and their impact on the environment. United States: N. p., 1998. Web. doi:10.1029/98JD02579.
Benner, T C, & Curry, J A. Characteristics of small tropical cumulus clouds and their impact on the environment. United States. https://doi.org/10.1029/98JD02579
Benner, T C, and Curry, J A. 1998. "Characteristics of small tropical cumulus clouds and their impact on the environment". United States. https://doi.org/10.1029/98JD02579.
@article{osti_328557,
title = {Characteristics of small tropical cumulus clouds and their impact on the environment},
author = {Benner, T C and Curry, J A},
abstractNote = {This study uses a number of data sets (Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator data, space shuttle photography, Radiation Measurement System data, aircraft data, and shipboard soundings) to investigate the characteristics of small tropical cumulus clouds and their impact on their environment. The goal is to uncover useful information with application to radiative transfer simulation and satellite remote sensing. In fields of small cumulus clouds, size distributions are found to decrease in number with increasing diameter according to a double power law relation, often with a clear break diameter. Fractal dimensions corresponding to the horizontal area and perimeter of the clouds are greater for the larger clouds than for the smaller clouds, with the same break diameter as the size distributions, meaning that the larger clouds have more ragged perimeters. These two results suggest a characteristic horizontal length scale dividing larger and smaller boundary layer cumuli. Spatial distributions show a clear tendency toward clustering. Smaller cumuli appear to grow upward more quickly with increasing horizontal size than do larger cumuli. Albedo is found to increase with greater cloud fraction and higher solar zenith angle. Even sparse fields of small cumulus cause significant shortwave forcing at the ocean surface. Simulation suggests that small cumulus may introduce significant errors into sea surface temperature retrievals and that such clouds can be difficult to remove with operational cloud-filtering schemes. Clouds smaller than about 1 km in diameter are not seen to precipitate. {copyright} 1998 American Geophysical Union},
doi = {10.1029/98JD02579},
url = {https://www.osti.gov/biblio/328557}, journal = {Journal of Geophysical Research},
number = D22,
volume = 103,
place = {United States},
year = {Sun Nov 01 00:00:00 EST 1998},
month = {Sun Nov 01 00:00:00 EST 1998}
}