Convective Meteorology (Mesoscale Dynamics)

Sensitivity of simulated urban-atmosphere interactions in Oklahoma City to urban parameterization

Larissa Reames

School of Meteorology

06 May 2016, 3:00 PM

National Weather Center, Room 5600
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK

Earth's population is increasingly concentrated in urban areas, with nearly two-thirds of the world's population expected to live in urban areas by 2050 according to the U.N It is also known that urban areas can have a significant effect on precipitation pattern and thunderstorm lightning intensity. Thus as the amount of people within cities grows, it is becoming more important to understand, and to be able to correctly predict, the interactions between urban environments and the atmosphere. Using the WRF-ARW at 500-m grid spacing, model-simulated urban-atmosphere interactions in Oklahoma City were investigated. One simulation with no urban area (CTRL) was produced to serve as a comparison point for the other urban simulations. To compare against CTRL, one run using a modified version of the Noah land surface model to parameterize the urban surface (LSM) was performed. In addition, two simulations using the more complex single-layer urban canopy model parameterization, each with different urban fraction values, were run. All three urban simulations produced a stronger heat island at night than during the day, as expected. In LSM, this heat island extended further throughout the CBL, resulting in a deeper CBL depth. In addition, while LSM daytime wind speeds are slower in the urban area, as predicted by observations, SLUCM1 and SLUCM2 near-surface wind speeds are higher in the urban area than rural areas.

Convective Meteorology (Mesoscale Dynamics) Seminar Series website