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The Dryline on 22 May 2002 during IHOP_2002: Convective-Scale Measurements at the Profiling SiteA detailed analysis of the structure of a double dryline observed over the Oklahoma panhandle during the first International H2O Project (IHOP_2002) convective initiation (CI) mission on 22 May 2002 is presented. A unique and unprecedented set of high temporal and spatial resolution measurements of water vapor mixing ratio, wind, and boundary layer structure parameters were acquired using the National Aeronautics and Space Administration (NASA) scanning Raman lidar (SRL), the Goddard Lidar Observatory for Winds (GLOW), and the Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE), respectively. These measurements are combined with the vertical velocity measurements derived from the National Center for Atmospheric Research (NCAR) Multiple Antenna Profiler Radar (MAPR) and radar structure function from the high-resolution University of Massachusetts frequency-modulated continuous-wave (FMCW) radar to reveal the evolution and structure of the late afternoon double-dryline boundary layer. The eastern dryline advanced and then retreated over the Homestead profiling site in the Oklahoma panhandle, providing conditions ripe for a detailed observation of the small-scale variability within the boundary layer and the dryline. In situ aircraft data, dropsonde and radiosonde data, along with NCAR S-band dual-polarization Doppler radar (S-Pol) measurements, are also used to provide the larger-scale picture of the double-dryline environment. Moisture and temperature jumps of about 3 g kg(sup -1) and 1 -2 K, respectively, were observed across the eastern radar fine line (dryline), more than the moisture jumps (1-2 g kg(sup -1)) observed across the western radar fine line (secondary dryline). Most updraft plumes observed were located on the moist side of the eastern dryline with vertical velocities exceeding 3 m s(sup -1) and variable horizontal widths of 2-5 km, although some were as wide as 7-8 km. These updrafts were up to 1.5 g kg(sup -1) moister than the surrounding environment. Although models suggested deep convection over the Oklahoma panhandle and several cloud lines were observed near the dryline, the dryline itself did not initiate any storms over the intensive observation region (IOR). Possible reasons for this lack of convection are discussed. Strong capping inversion and moisture detrainment between the lifting condensation level and the level of free convection related to an overriding drier air, together with the relatively small near-surface moisture values (less than 10 g kg(sup -1)), were detrimental to CI in this case.
Document ID
20070031191
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Demoz, Belay
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Flamant, Cyrille
Weckwerth, Tammy
(National Center for Atmospheric Research Boulder, CO, United States)
Whiteman, David
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Evans, Keith
(Maryland Univ. Baltimore County Baltimore, MD, United States)
Fabry, Frederic
(McGill Univ. Montreal, Quebec, Canada)
DiGirolamo, Paolo
(Universita degli Studi della Basilicata Potenza, Italy)
Miller, David
(Science Systems and Applications, Inc. Lanham, MD, United States)
Geerts, Bart
(Wyoming Univ. Laramie, WY, United States)
Brown, William
(Wyoming Univ. Laramie, WY, United States)
Schwemmer, Geary
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Gentry, Bruce
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Feltz, Wayne
(Wisconsin Univ. Madison, WI, United States)
Wang, Zhien
(Maryland Univ. Baltimore County Baltimore, MD, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2006
Publication Information
Publication: Monthly Weather Review
Volume: 134
Issue: 1
Subject Category
Meteorology And Climatology
Report/Patent Number
MWR3054
Distribution Limits
Public
Copyright
Other

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