HR: 11:20h
AN: A32B-05 [Abstracts]
TI: 2D optical array probe analysis of precipitating cumulonimbus clouds during EPIC 2001
AU: * Baumgardner, D
EM: darrel@servidor.unam.mx
AF: Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico
City, 04510, Mexico
AU: Raga, G B
EM: raga@servidor.unam.mx
AF: Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico
City, 04510, Mexico
AB:
During the 2001 East Pacific Investigation of Climate (EPIC) experiment, numerous measurements were made of
the size distributions of raindrops in convective clouds that were developing over a region of the Mexican inter-
tropical convergence zone (ITCZ). These measurements were made with optical array probes (PMS 2D-C and
2D-P) mounted on the National Science Foundation Hercules C-130, operated by the National Center for
Atmospheric Research. In addition to capturing shadow images of individual drops between 25 μm and
6400 μm, these instruments also record the distance between each drop via a measurement of arrival times
in the spectrometers lasers. The separation distance, along with the drop size, provides detailed information
about the microstructure of precipitation.
The 2D probe measurements have been analyzed as a function of altitude above cloud base, horizontal distance
from cloud edges, cloud droplet size distributions (2-50 μm) and vertical wind velocities. The objective of the
analysis is to evaluate the spatial distribution of precipitation events with respect to the microphysical and
dynamical processes that are related to the development and evolution of rain in tropical convective clouds. In
addition, the reflectivity is calculated from the size distributions and evaluated to assess how inhomogeneities in
the precipitation might be observed by meteorological radars.
DE: 0320 Cloud physics and chemistry
DE: 3311 Clouds and aerosols
DE: 3354 Precipitation (1854)
DE: 3394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly