You are invited to attend an EOL Seminar presented
by Jeffrey Stith from EOL - RAF on Tuesday, February 22 at 2:00
p.m. at Foothills Laboratory, Building 2, Room 1022.
Refreshements will be served
The results from several recent studies of the microphysical and
kinematic structure of updrafts and downdrafts in convective storms in
the Amazon and at Kwajalein, Marshall Islands, will be presented. The
studies are based on in situ airborne measurements of the cloud
particles and updraft speed. These will be compared with similar
measurements made from convective storms during two field projects in
North Dakota. Remarkably similar particle types and concentrations
were found in the two tropical locations when updrafts at similar
temperatures were examined. Examination of the updraft structures in
these clouds reveals that they are also quite similar. The tropical
clouds contained chain aggregate ice particles, which may be due to
electrical forces in the clouds, and high concentrations of small
quasi-spherical ice particles at relatively warm temperatures. Most
liquid water was confined to the mid to lower levels of the tropical
clouds and decreased at midlevels, although small amounts of liquid
water were found at much colder temperatures. In contrast, liquid
water from the North Dakota storms increased at cloud midlevels.
Midlevel tropical updrafts almost always contain precipitation, while
some updrafts at midlevels in the North Dakota clouds were free of
precipitation. The highest concentrations of cloud droplets in the
North Dakota clouds were observed at cloud midlevels, not near the
cloud base, suggesting the formation of new droplets well above the
cloud base.
For more information, contact Renee Ray at ext. 2050, rray@ucar.edu.
Wed, Feb 16, 2005 to Tue, Feb 22, 2005
