41EIPT Polarimetric Radar Data Assimilation With a Parameterized Radar Operator Using MPAS-JEDI

A parameterized polarimetric radar operator (P-PRO) has been developed for assimilating polarimetric radar observations such as ZDR and KDP in addition to reflectivity (ZHH). P-PRO consists of both the nonlinear forward operator and its tangent linear and adjoint and is incorporated into MPAS-JEDI, a new-generation data assimilation (DA) system for the model for prediction across scales - atmosphere (MPAS-A) based upon the Joint Effort for Data assimilation Integration (JEDI) framework. P-PRO allows to simulate and assimilate dual-pol radar observables from S-band and C-band radars and is potentially expandable to radars operating in other frequencies (e.g., X-band). MPAS-JEDI with P-PRO can analyze mixing ratios of precipitating hydrometeors for a single-moment microphysics scheme or both mixing ratios and number concentrations for a double-moment microphysics scheme, using either variational-based DA techniques or ensemble Kalman filter-based DA techniques. Dual-pol radar DA experiments are conducted for two afternoon thunderstorm cases over Taiwan in June 2022 (PRECIP campaign period) with Taiwan’s local dual-pol radar network using MPAS-JEDI’s hybrid-3DEnVar and LETKF DA techniques. Preliminary results of assimilating ZDR and/or KDP on top of ZHH indicate encouraging analysis and forecast improvements when verifying against rainfall observations and independent NCAR S-Pol radar data. The NCAR team is working to expand the capability for assisting pre-campaign planning and post-campaign analysis with NSF NCAR’s future Airborne Phased Array Radar (APAR), which is under active development.