Coordinated in-situ and remote sensing precipitation measurements at the Kessler Farm Field Laboratory in Central Oklahoma

Understanding the microphysics of precipitation and the atmosphere in which it forms and evolves is important for scientists to accurately estimate rainfall rates and improve parameterizations in models that predict the weather. Therefore, the University of Oklahoma (OU) in collaboration with NOAA's National Severe Storms Laboratory (NSSL) is building up a suite of instrumentation to measure the properties of precipitation at the Kessler Farm Field Laboratory (KFFL) located in Central Oklahoma. Measurements from this site build upon other precipitation studies being conducted within the Norman meteorological community. In particular, data collected at KFFL are being used in conjunction with the two S-band weather radars operated in Norman. One is a polarimetric radar system (KOUN) and the other is a phased array radar (NWRT). These two radars are located only 30 km from KFFL. In the presentation we give an overview of this new facility, provide a description of the various instruments and their measuring capabilities, and show examples of recently collected data. In particular, we will focus on how these complementary measurements are being used to study precipitation and precipitation microphysics.

Instrumentation recently installed at KFFL for precipitation studies include a UHF boundary layer radar (BLR), a two-dimensional video disdrometer (2DVD), and a network of tipping-bucket rain gauges (PicoNet). In addition to these instruments from OU, KFFL is host to one of the Boundary Facilities of the DOE Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP) Site. It is equipped with an Atmospheric Emitted Radiance Interferometer (AERI), balloon sounding system, microwave radiometer, temperature, humidity, winds, and pressure sensors, and a Vaisala Ceilometer. Also located at KFFL is a 404-MHz wind profiler operated as part of the NOAA Profiler Network and one of the Oklahoma Mesonet stations. The Oklahoma Mesonet is a collection of environmental monitoring stations operated by OU and the Oklahoma State University (OSU). The locations of these instruments at KFFL are shown in the accompanying figure. Each of the red enumerated dots represents a node in the PicoNet. The KOUN and NWRT radars are not shown. With this collection of instruments it is possible to classify the type of precipitation present above the site (rain, snow, sleet, graupel, hail, etc.), the dynamic state of the atmosphere through which the precipitation is falling, the development and evolution with height of the precipitation particles, and the characteristics (size distribution, particle shape, fall speed) and spatial distribution of the precipitation once it reaches the ground.