TY - JOUR
T1 - 5-cm radar echoes and their microphysical significance in Florida cumuli.
AU - Lopez, R. E.
AU - Reinking, R. F.
AU - Hallett, J.
AU - Rosenfeld, D.
PY - 1985
Y1 - 1985
N2 - Aircraft microphysical and 5-cm radar data from the second Florida Area Cumulus Experiment (FACE-2) have been interrelated to study the development of precipitation in Florida cumuli. Both sets of data demonstrate the importance of the generation of large drops not only at temperatures warmer than freezing but also at altitudes where drops become supercooled. The radar data and, to a limited extent, the microphysical data support the suggestion that a considerable number of Florida cumuli reach very substantial supercoolings, to -10oC or -20oC for example, before producing drops large enough to generate a first echo. The existence of high updraft speeds, as detected by both the aircraft platform and the radar, implies short transit times of the droplets upward through the clouds and adds credibility to these observations. The radar data further indicate that if a cloud can grow above the -10oC level before generating an echo, then it will probably grow to much greater final altitudes than one that generates a first echo at temperature levels warmer than freezing. This may result from updrafts that rise free of the load of precipitation-size drops in transit to the higher altitudes and then are enhanced owing to the release of latent heat of fusion derived from the larger amounts of supercooled liquid water transported to the higher altitudes, where a high rate of heat input from accelerated freezing is relatively more effective in maintaining convection.-Authors
AB - Aircraft microphysical and 5-cm radar data from the second Florida Area Cumulus Experiment (FACE-2) have been interrelated to study the development of precipitation in Florida cumuli. Both sets of data demonstrate the importance of the generation of large drops not only at temperatures warmer than freezing but also at altitudes where drops become supercooled. The radar data and, to a limited extent, the microphysical data support the suggestion that a considerable number of Florida cumuli reach very substantial supercoolings, to -10oC or -20oC for example, before producing drops large enough to generate a first echo. The existence of high updraft speeds, as detected by both the aircraft platform and the radar, implies short transit times of the droplets upward through the clouds and adds credibility to these observations. The radar data further indicate that if a cloud can grow above the -10oC level before generating an echo, then it will probably grow to much greater final altitudes than one that generates a first echo at temperature levels warmer than freezing. This may result from updrafts that rise free of the load of precipitation-size drops in transit to the higher altitudes and then are enhanced owing to the release of latent heat of fusion derived from the larger amounts of supercooled liquid water transported to the higher altitudes, where a high rate of heat input from accelerated freezing is relatively more effective in maintaining convection.-Authors
UR - http://www.scopus.com/inward/record.url?scp=0022167241&partnerID=8YFLogxK
U2 - 10.1029/JD090iD06p10667
DO - 10.1029/JD090iD06p10667
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AN - SCOPUS:0022167241
SN - 0148-0227
VL - 90
SP - 10667
EP - 10673
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
IS - D6
ER -