HR: 17:30h
AN: B34A-06    [Abstracts]
TI: The Effects of Urban Land-Surface Processes on Thunderstorm Characteristics in the Indianapolis Urban Region
AU: Pyle, P
EM: pcpyle@ncsu.edu
AF: North Carolina State University, Attn: Patrick Pyle Department of Marine, Earth and Atmopsheric Sciences 2800 Faucette Drive, Rm. 1125 Jordan Hall North Carolina State University, Raleigh, NC 27695
AU: * Niyogi, D
EM: dniyogi@purdue.edu
AF: Purdue University / Indiana State Climate Office, # 201, Life Science Plant and Soils Laboratory # 915 W. State Street # Purdue University, West Lafayette, IN 47907-2054
AU: Arya, P
EM: spary@ncsu.edu
AF: North Carolina State University, Attn: S. Pal Arya Department of Marine, Earth and Atmopsheric Sciences 2800 Faucette Drive, Rm. 1125 Jordan Hall North Carolina State University Raleigh, North Carolina 27695-8208, Raleigh, NC 27695-8208
AU: Wolfe, B
EM: mwolfe@purdue.edu
AF: Purdue University / Indiana State Climate Office, # 201, Life Science Plant and Soils Laboratory # 915 W. State Street # Purdue University, West Lafayette, IN 47907-2054
AU: Shepherd, M
EM: marshall.shepherd@nasa.gov
AF: NASA, Attn: Marshall Shepherd Public Inquiries Business Center NASA Headquarters Suite 1M32, Washington, DC 20546-0001
AB: An urban storm climatology was examined for the time period of 2000-05 for the Indianapolis, IN (IND) urban area. The hypothesis of this study is urban regions alter the intensity and composition/structure of approaching thunderstorms due to the heterogeneity of the surface characteristics. The analysis was focused on the summer months of May through August. Over fifty thunderstorm cases that produced severe weather reports in and/or near the Indianapolis, Marion County area, were examined. Rural storms were also investigated during this time period on identical days of the urban storm reports. Storm characteristics were examined in the four rural counties of Miami (North), Jackson (South), Wayne (East), and Vigo (West) that lie in an approximate seventy-five mile radius of Indianapolis. Statistical analysis using a Chi-square statistical test supports the hypothesis of the study that urban regions alter the composition of the thunderstorms more than the rural areas. A more detailed table was created to classify the events under various synoptic situations of a cold front, pre-frontal warm sector, stationary front, upper level shortwave or vorticity max and direction of propagation. Further analysis will be performed to study if a link exists between synoptic conditions and storm composition change. Select cases will be further investigated in the synoptic conditions as well as land use sensitivity tests within the Mesoscale Model 5 (MM5). A case that will be tested first is an event on 13 June 2005. This event was a single cell thunderstorm that formed due to daytime heating and moderate shear of near 30kts ahead of an approaching cold front. As the cell moved northeastward across the downtown Indianapolis urban region, it split and intensified in base reflectivity and Vertically Integrated Liquid (VIL) producing nearly one inch of rainfall (Doppler estimated) on the northeast (downwind) region of the Indianapolis urban region. Sensitivity tests will include simulating a control run with the urban region and investigating the effects of removing, increasing, and decreasing the 'sprawl' of the urban region. Urbanization effects will also be simulated by ingesting early 20th century land use data into the model. Storm characteristics as well as pre-storm environmental land-surface parameters will be studied to further understand the validity of the hypothesis.
DE: 3314 Convective processes
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
SC: Biogeosciences [B]
MN: Fall Meeting 2005