Cooperative Institute for Mesoscale Meteorological Studies

RESEARCH

 

NOAA Strategic Goal 3: Serve Society’s Need for Weather and Water Information

Basic Convective and Mesoscale Research

Other Agency – Numerical Modeling Study of the Time-Dependent Behavior of Convection

Doswell (primary – CIMMS at OU), Weber, Loftus, Baranowski, DuFran

Funding Agency: NSF

Objectives
Determine how environmental factors, notably the forcing that initiates deep convection and the environmental wind and thermodynamic profiles, control the time-dependent behavior of deep convective storms.

Accomplishments
This project is nearing completion - it involves the use of a 3-D cloud model ARPI3 (similar to the ARPS model), developed by Dr. Daniel Weber of CAPS. The aim has been to determine how environmental factors, notably the forcing that initiates deep convection and the environmental wind and thermodynamic profiles, control the time-dependent behavior of deep convective storms. Simulation study results can be viewed at: http://www.caps.ou.edu/~dweber/bubbles.html. Three Masters Theses were produced from this work. 192 model runs have been completed and diagnosis of the results has shown that the occurrence of sustained multicell convection is quite sensitive to the initial CAPE and less so on the shear. A measure of the behavior of the convection – the extent to which the multicell updrafts are more plume-like or bubble-like – has been developed. The frequency of new updraft regeneration also depends on the CAPE and shear, with a strong sensitivity to the CAPE. In fall 2007, we plan to submit a renewal proposal to continue this work, to include more simulations over a wider range of environmental conditions, to fill in more of the multidimensional parameter space.

This project is ongoing.

Publications
Baranowski, B.C., C. A. Doswell, D.B. Weber, and A.M. Loftus, 2006: The sensitivity of numerically simulated multicell convection to grid spacing and computational missing coefficients. 23rd Conf. Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc., CD-ROM.

Loftus, A.M, C.A. Doswell III, D.B. Weber, and B.C. Baranowski, 2006: Parameterized mesoscale forcing mechanisms for initiating numerically-simulated isolated multicellular convection. 23rd Conf. Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc., CD-ROM.