Assimilation of Insar-Derived PWV Maps Exhibit Potential for Atmosphere Convective Storm Characterization

Abstract

In this work, we study the problem of assimilating high resolution Precipitable Water Vapor (PWV) maps using the Weather Research and Forecast 3D Variational Data assimilation system (WRF-3DVar). The PWV maps are obtained using the Sentinel-1 Synthetic Aperture Radar (SAR) images and the SAR interferometry (InSAR) technique. The influence of the high resolution PWV data on the initial condition of WRF and during the next 12 hours is studied. We demonstrate that the assimilation of InSAR PWV maps increases both the water vapor concentration and temperature over areas affected by extreme weather events so correctly generating localized convection cells. The PWV forecast, after the assimilation of InSAR maps, are compared with the PWV estimates provided by a dense GNSS network. The precipitation pattern and amount are compared to meteorological radar measurements. The case study of the extreme weather event that affected the city of Adra, Spain, on 6th September 2015, is used to demonstrate how the assimilation of high resolution PWV maps.