Numerical Studies of Meteor Crater Cold Pool Responses to Realistic Dynamical and Radiative Forcing and Comparisons with METCRAX Measurements

Northwest Research Associates, Incorporated, Seattle WA

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The Meteor Crater Experiment (METCRAX) was performed in Arizona's Meteor Crater in October 2006 because of the frequent occurrence there of stable cold pools accompanied by benign boundary layer flows. Motivations for the METCRAX studies were a better understanding of the dynamical and radiative processes influencing cold pool formation, evolution, and breakup. The small spatial scale enabled extensive instrumentation and quantification of a number of very interesting cold pool responses, including forcing by mean and variable external boundary layer flows, forcing by radiative heating and cooling, instability and mixing, and seiche responses at various periods. METCRAX data analyses and numerical studies led to a number of important insights into cold pool dynamics to date. This new research will expand on the numerical studies performed to date through applications to 1) more complex and realistic boundary layer flows, 2) realistic boundary layer stratification profiles, 3) real, rather than idealized axisymmetric, crater terrain, 4) cold pool flows that are radiatively forced, and 5) specific simulations of, and comparisons to, METCRAX observations of seiches, instability and mixing, and radiatively-forced flows. These efforts will employ a high-resolution spectral element (SE) numerical simulation code. Intellectual Merit: This additional METCRAX research will contribute a much more quantitative understanding of 1) the diversity of responses to dynamical and radiative forcing, 2) the dominant mechanisms accounting for erosion of cold pool stratification, 3) the extent to which real cold pool flows differ from idealized descriptions, and 4) whether high-resolution modeling is essential to describing such effects. Results will also be valuable in understanding cold pool dynamics in more general basins, and thus to a broader research community. Broader Impacts: A more complete understanding of cold pool dynamics, including their formation and breakup, is highly relevant outside the boundary layer research community, important to NWP, and to many cities located in basins or valleys experiencing persistent cold pool stratification that traps emissions and particulates, causes significant pollution episodes and health hazards, and may impact businesses, schools, local government, power generation, and transportation.