Cloud characteristics over central Amazonia during GTE/ABLE 2B derived from multispectral visible and infrared spin scan radiometer atmospheric sounder observations

Multispectral GOES/Visible and Infrared Spin Scan Radiometer Atmospheric Sounder (VAS) observations in the carbon dioxide absorption band at 15 μm have been used to calculate diurnal cloud statistics over central Amazonia region for 4 days during the Global Tropospheric Experiment/Amazon Boundary Layer Experiment (GTE/ABLE IIB). The CO2 technique calculates both cloud top pressure and effective emissivity from radiative transfer principles. Transmissive clouds that are partially transparent to terrestrial radiation have been reliably separated from opaque clouds in the statistics of cloud cover. A high incidence of transmissive clouds (about 47%) was found on the average. Diurnal characteristics of cloud cover over Amazonia have been linked to convective activity over this region. On days with afternoon convection, an increase in low-altitude opaque clouds was followed by a subsequent increase in high-altitude transmissive clouds.

[1]  R. J. Reed,et al.  The Diurnal Variation of Deep Convection and Inferred Precipitation in the Central Tropical Pacific During January–February 1979 , 1985 .

[2]  An Estimate of the Daily Variation of Cloudiness Over the GATE A/B Area , 1976 .

[3]  L. Jenne,et al.  Global distribution of total cloud cover and cloud type amounts over land , 1986 .

[4]  Patrick Minnis,et al.  Diurnal variability of regional cloud and clear-sky radiative parameters derived from GOES data. Part II : November 1978 cloud distributions. , 1984 .

[5]  W. Menzel,et al.  Two years of cloud cover statistics using VAS. [Visible infrared spin scan radiometer Atmospheric Sounder] , 1989 .

[6]  William L. Smith,et al.  Improved Cloud Motion Wind Vector and Altitude Assignment Using VAS. , 1983 .

[7]  William L. Smith,et al.  Comparison of Satellite-Deduced Cloud Heights with Indications from Radiosonde and Ground-Based Laser Measurements , 1978 .

[8]  A. Gruber,et al.  Diurnal variation of outgoing longwave radiation , 1988 .

[9]  Moustafa T. Chahine,et al.  Remote Sounding of Cloudy Atmospheres. I. The Single Cloud Layer , 1974 .

[10]  Patrick Minnis,et al.  Diurnal Variability of Regional Cloud and Clear-Sky Radiative Parameters Derived from GOES Data. Part I: Analysis Method , 1984 .

[11]  Phillip A. Arkin,et al.  Spatial and Annual Variations in the Diurnal Cycle of Large-Scale Tropical Convective Cloudiness and Precipitation , 1987 .

[12]  D. Hartmann,et al.  Diurnal variation of outgoing longwave radiation in the tropics , 1986 .

[13]  William L. Smith,et al.  NIMBUS-5 sounder data processing system, part I : measurement characteristics and data reduction procedures , 1974 .

[14]  John M. Wallace,et al.  Satellite-Inferred Morning-to-Evening Cloudiness Changes , 1980 .