All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 93 15 4
PDF Downloads 13 9 5

A Preliminary Assessment of the Importance of Coalescence in Convective Clouds of the Eastern Transvaal

Graeme K. MatherCansas International Corporation (Pty) Ltd., Nelspruit 1200, Republic of South Africa

Search for other papers by Graeme K. Mather in
Current site
Google Scholar
PubMed
Close
,
Brian J. MorrisonCansas International Corporation (Pty) Ltd., Nelspruit 1200, Republic of South Africa

Search for other papers by Brian J. Morrison in
Current site
Google Scholar
PubMed
Close
, and
Griffith M. Morgan Jr.Simpson Weather Associates, Charlottesville, VA 22903

Search for other papers by Griffith M. Morgan Jr. in
Current site
Google Scholar
PubMed
Close
Full access

Abstract

For the past three years, a Learjet has been making microphysical measurements in new cloud development on the flanks of multicellular storms in the eastern Transvaal area of South Africa. Data from an imaging probe and a forward scattering spectrometer have been averaged for each storm for all first cloud penetrations between −8° and −12°C. Clear images of drops of diameters greater than 300 μm are found in 40% of the 42 storms measured.

Most of the observed drops are associated with the more “maritime” droplet spectra. Also, the appearance of coalescence around −10°C appears to be related to cloud base temperatures and buoyancies, rather than changes in air masses, suggesting that cloud thermodynamics may play a dominant role in determining cloud microphysics in the Nelspruit area.

Abstract

For the past three years, a Learjet has been making microphysical measurements in new cloud development on the flanks of multicellular storms in the eastern Transvaal area of South Africa. Data from an imaging probe and a forward scattering spectrometer have been averaged for each storm for all first cloud penetrations between −8° and −12°C. Clear images of drops of diameters greater than 300 μm are found in 40% of the 42 storms measured.

Most of the observed drops are associated with the more “maritime” droplet spectra. Also, the appearance of coalescence around −10°C appears to be related to cloud base temperatures and buoyancies, rather than changes in air masses, suggesting that cloud thermodynamics may play a dominant role in determining cloud microphysics in the Nelspruit area.

Save