Realistic simulations of atmospheric gravity waves over the continental U.S. using precipitation radar data

Abstract

AbstractConvectively forced gravity waves can affect the dynamics of the upper troposphere and middle atmosphere on local to global scales. Simulating these waves requires cloud‐resolving models, which are computationally expensive and therefore limited to case studies. Furthermore, full‐physics models cannot accurately reproduce the locations, timing, and intensity of individual convective rain cells, limiting the validation of simulated waves. Here, we present a new modeling approach that retains the spatial scope of larger‐scale models but permits direct validation of the modeled waves with individual cases of observed waves. Full‐physics cloud‐resolving model simulations are used to develop an algorithm for converting instantaneous radar precipitation rates over the U.S. into a high‐resolution latent heating/cooling field. This heating field is used to force an idealized dry version of the WRF model. Wave patterns and amplitudes observed in individual satellite overpasses are reproduced with remarkable quantitative agreement. The relative simplicity of the new model permits longer simulations with much larger and deeper domains needed to simulate wave horizontal/vertical propagation. Eliminating the complicating factors of cloud physics and radiation this approach provides a link between conceptual and full‐physics models and is suitable for studying wave‐driven far‐field circulation patterns.