HR: 09:28h
AN: A11G-07    [Abstracts]
TI: Analysis of the 7 Easterly Waves Observed During the NAMMA Experiment
AU: * Zawislak, J
EM: jon.zawislak@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Zipser, E
EM: ed.zipser@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Xu, W
EM: weixin.xu@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: West, G
EM: greg.west@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Wall, C
EM: christy.wall@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Olsen, B
EM: brian.v.olsen@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Li, X
EM: xuanli.li@utah.edu
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Kim, B
AF: University of Utah, Department of Meteorology 135 South 1460 East Rm 819, Salt Lake City, UT 84112, United States
AU: Douglas, M
EM: michael.douglas@noaa.gov
AF: NOAA/National Severe Storms Laboratory, 1313 Halley Circle, Norman, OK 73069, United States
AB: The 2006 NAMMA (NASA African Monsoon Multidisciplinary Analyses) Experiment was staged from the Cape Verde Islands during August and September 2006. The primary goals of the experiment were to distinguish the essential differences between developing and non-developing African easterly waves, and the effects of the Saharan Air Layer (SAL) on cloud microphysics and on the waves. The NASA DC-8 aircraft, enhanced soundings from the islands and mainland Africa, and ground-based research radars and mobile research stations produced a uniquely valuable database. During the campaign, 7 easterly waves were observed. 2 waves quickly became tropical cyclones near Africa (Debby, Helene), 2 waves did not develop, while 3 others had some role in the development of Ernesto, Florence, and Gordon that requires additional research to clarify. The focus of this study is to use the data from the NASA DC-8 and its dropsondes, serial soundings from Praia and Dakar, along with the NCEP GDAS (Global Data Assimilation System) analyses, to describe these 7 waves with a detail never before possible in this region. Careful analysis of the dropsonde data from the DC-8 often reveals significant differences from the GDAS analyses at 925 and 700 hPa, as well as humidity differences, which are quantified. LASE (Lidar Atmospheric Sensing Experiment) data on water vapor and aerosol structure is used to map the SAL from the DC-8, supplementing satellite data on clouds and aerosols. There is an important distinction between tracking the (large-scale) wave and tracking the vorticity centers within the waves. A principal finding is that there are often multiple vorticity centers within the wave, sometimes with short lifetimes, and that tropical cyclone development may depend upon their collocation with convective systems, a transient event more difficult to sample than the large-scale wave itself.
DE: 3374 Tropical meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting