New Insights into Convective Updraft Kinematics and Microphysics Provided by the ARM SGP X-SAPR Network

Description

It is hypothesized, and generally supported by simulations, that deep convective updraft thermals evolve on timescales of ~5-10 minutes, with a corresponding spatial scale of ~1 km, albeit with some variability suspected across storm morphologies. Observations at these scales, however, are rare, or nonexistent, with the bulk of previous rapid-scan research radar capabilities dedicated to low-level tornado observations. Such high spatial and temporal resolution observations are necessary to address gaps in our understanding of deep convection microphysics, and improve microphysics parameterization schemes. The Department of Energy's network of three X-band scanning polarimetric radars at the Oklahoma Southern Great Plains site are capable of targeted scanning that addresses these needs, and this past summer was run in a limited-sector mode with approximately 90-second intervals between sector volumes. Preliminary data supports the hypothesis of a short thermal timescale (~5 minutes), with multiple successive thermals present in a single isolated storm cell. Analysis of the temporal and spatial scales for isolated convective storms and mesoscale convective systems bears important implications for convective parameterizations and other model development efforts.