Airborne 4-Frequency Radar Measurements of Precipitation and Clouds During IPHEX and RADEX

Goddard Space Flight Center has recently started flying 3 nadir-looking, X- through W-band, Doppler radars on the high-altitude NASA ER-2 aircraft. The High-altitude Wind and Rain Airborne Profiler (HIWRAP) at Ku and Ka-band is similar to the frequencies on the Global Precipitation Mission (GPM) Dual-frequency Precipitation Radar (DPR). The W-band Cloud Radar System (CRS) is similar to the CloudSat frequency, and the ER-2 X-band Radar (EXRAD) frequency is currently not flown in space but is useful for heavier precipitation. These radars have flown in the Integrated Precipitation and Hydrology Experiment (IPHEx) in the Southeast U.S. during May-June 2014, and in the Radar Definition Experiment (RADEX) off the northwest coast of the U.S. in November-December 2015. RADEX was conducted in November-December 2015 jointly with with the Olympic Mountains Experiment (OLYMPEX). Both IPHEX and OLYMPEX were sponsored by the Global Precipitation Mission (GPM) ground validation program. The ER-2 4 frequencies provide the opportunity for developing consistent cloud and precipitation retrieval algorithms as well as to expand the dynamic range (i.e., particle size) of the retrievals. There were a total of 15 (12) science flights during IPHEx (RADEX) that measured a variety of land-based and oceanic precipitation, convection, and orographic precipitation. We will present results from the IPHEX and RADEX ER-2 radars for two cases: 12 June 2014 from IPHEX with mixed stratiform and convection, and 5 December 2015 from RADEX covering a classic northwest frontal system. We will discuss the general precipitation and updraft properties of the convection from the 4 frequency measurements. We will present preliminary results from precipitation retrievals based on optimal estimation (Grecu et al. 2011).