10:45 AM - 12:15 PM
[ACG47-P04] Simulation of typhoon observation by airborne polarimetric radar (3)
Keywords:Aircraft observation, Typhoon observation, Polarimetric radar
We conducted simulations of airborne radar observation of typhoons in JpGU2021 and JpGU2022 using numerical simulation data to simulate dual-polarization radar observations and showed the feasibility of the observations, but also showed that there are issues in securing observation coverage in a limited observation time. In this report, to further refine the simulation, we added an estimate of attenuation due to precipitation and calculated the total attenuation on the ground surface, which is useful for estimating the attenuation-corrected radar reflection intensity factor (Z). Furthermore, a retrieval algorithm for the internal physics of typhoons was studied based on the observed data. In particular, for retrieval of the wind speed field, we also studied the reproduction of the wind speed field in the scanning plane using radar scanning data. This is an application of the Velocity Azimuth Display (VAD) method of ground-based radar for estimating horizontal wind speed to airborne radar scanning in the cross-track direction, which is expected to also retrieve characteristics of vertical motion within the scanning domain. Since there are currently not many surface scattering measurements using polarimetric radar, we will examine the extent to which the surface values of Zdr and KDP (obtained from range derivative of φDP) can be used for retrieval. The former is usually corrected for Zdr attenuation using KDP, but can be evaluated using the total attenuation estimated from the sea-surface scattering cross section; KDP is estimated using the range derivative of observed φDP, but the large variation of φDP due to the backscattering phase shift is a problem. The estimation of KDP is expected to be improved by using φDP of sea-surface scattering as a constraint.