Remote Sensing of Microphysical Processes during OLYMPEX

The OLYMPEX field experiment provided numerous opportunities to sample precipitation in a variety of meteorological regimes from airborne “satellite simulator” instruments in the vicinity of the Olympic Peninsula. Airborne radar measurements from X, Ku, Ka, and W bands (with Doppler) and passive microwave measurements in several bands between 10 and 200 GHz complemented ground-based S-, C-band, and K-band radars, numerous gauge/disdrometer sites, and airborne microphysics probes from the University of North Dakota Citation aircraft. These measurements can be used to improve satellite precipitation algorithms and, when coupled with state-of-the-art particle scattering and radiative transfer models, can be used to better identify microphysical processes such as growth of frozen hydrometeors by vapor deposition, riming, aggregation, and seeder-feeder mechanisms which can be influenced by and feed back to complex orographically-enhanced dynamics. Better representation of these physical processes in mesoscale models can then lead to better predictions of precipitation in this area, another OLYMPEX goal.

This study will present examples from several OLYPMEX cases of these various processes, identified using airborne in-situ data and ground instrumentation, and their active (radar) and passive microwave signatures. The Atmospheric Radar Transfer Simulator (ARTS), a fully polarized, three-dimensional radiative transfer framework, will be used to demonstrate the capability of various active/passive instrument combinations to identify these processes.