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Characteristics of Deep Tropical and Subtropical Convection from Nadir-Viewing High-Altitude Airborne Doppler RadarThis paper presents observations of deep convection characteristics in the tropics and subtropics that have been classified into four categories: tropical cyclone, oceanic, land, and sea breeze. Vertical velocities in the convection were derived from Doppler radar measurements collected during several NASA field experiments from the nadir-viewing high-altitude ER-2 Doppler radar (EDOP). Emphasis is placed on the vertical structure of the convection from the surface to cloud top (sometimes reaching 18-km altitude). This unique look at convection is not possible from other approaches such as ground-based or lower-altitude airborne scanning radars. The vertical motions from the radar measurements are derived using new relationships between radar reflectivity and hydrometeor fall speed. Various convective properties, such as the peak updraft and downdraft velocities and their corresponding altitude, heights of reflectivity levels, and widths of reflectivity cores, are estimated. The most significant findings are the following: 1) strong updrafts that mostly exceed 15 m/s, with a few exceeding 30 m/s, are found in all the deep convection cases, whether over land or ocean; 2) peak updrafts were almost always above the 10-km level and, in the case of tropical cyclones, were closer to the 12-km level; and 3) land-based and sea-breeze convection had higher reflectivities and wider convective cores than oceanic and tropical cyclone convection. In addition, the high-resolution EDOP data were used to examine the connection between reflectivity and vertical velocity, for which only weak linear relationships were found. The results are discussed in terms of dynamical and microphysical implications for numerical models and future remote sensors.
Document ID
20120009530
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Heymsfield, Gerald M.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Tian, Lin
(Maryland Univ. Baltimore County Baltimore, MD, United States)
Heymsfield, Andrew J.
(National Center for Atmospheric Research Boulder, CO, United States)
Li, Lihua
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Guimond, Stephen
(Florida State Univ. Tallahassee, FL, United States)
Date Acquired
August 25, 2013
Publication Date
February 1, 2010
Publication Information
Publication: Journal of the Atmsopheric Sciences
Volume: 67
Issue: 2
Subject Category
Meteorology And Climatology
Report/Patent Number
GSFC.JA.6219.2012
Distribution Limits
Public
Copyright
Other

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