HARGLO-3: Wind Intercomparisons During IHOP It has been our intention to take take advantage of Earth-Science field experiments to enable low-cost wind lidar intercomparisons and that opportunity presented itself when GLOW and HARLIE were funded to participate in the International H2O Project (IHOP), which held a large, multi-investigator field campaign to characterize in great detail the atmospheric moisture field and moist processes like convection and precipitation. Geary Schwemmer, Bruce Gentry NASA/GSFC Tom Wilkerson USU

International H2O Project (IHOP 2002) Research Objectives: Quantitative Precipitation Forecast Convective Initiation Boundary layer processes Instrumentation 7 May to 16 June 2002 Southern Great Plains The IHOP field campaign objectives were mainly focused on determining the impact of a well characterized moisture field on quantitative forecasts of convection, precipitation, and boundary layer dynamics. In addition, there were many investigators with new instruments involved that sought to evaluate their performance under field conditions and compare their results with other instruments making similar or complementary data. HARGLO-3 is an effort to perform such an evaluation on as many wind instruments as were involved and making coincident measurements with the HARLIE and GLOW lidars, which were deployed adjacent to many other instruments at a site in the Oklahoma panhandle which became know as the Homestead Site because of its location around an abandoned homestead, one of the few uncultivated acres for miles around. This site was selected for its proximity to a large ground-based S-Band polarimetric radar (S-Pol).

IHOP Homestead Site Wind Instruments GLOW Collected over 210hrs of data. HARLIE operated 24/7 SKYCAM cloud-tracked winds S-POL Doppler Radar surface anemometer, GPS sondes (1-4 /day) Sodar, MAPR, Umass FM-CW Radar Transients: MIPS, DOW, X-POL, ELDORA, HRDL, WCR, Dropsondes MAPR is ELDORA is an X-Band Radar WCR is Wyoming Cloud Radar (mm band) (Bart Geertz, PI) MIPS is Mobile Integrated Profiling System- MIPS (U. of Alabama - Huntsville): Knupp is IHOP PI. Among other things it contains: 5-beam 915 MHz profiler: 20 m vertical resolution 3-beam sodar: 20 m vertical resolution every 20 s up to 200-600 m FM-CW S-Band Radar (University of Massachusetts): This profiling radar would provide information on boundary-layer structure and waves propagating overhead. Available. Vertical resolution: 2.5 m

HARGLO-3 Objectives Statistical Comparisons of various wind measurements Develop hybrid data products combining surface data with aerosol and molecular lidar data Determine validity “windows” in time and space for various instruments We will continue in a similar fashion to HARGLO-2, performing statistical intercomparisons between the various wind measurements in HARGLO-3. We also want to devote some time and attention on how best to combine aerosol and molecular wind lidar data into a hybrid data set. Help determine what types of other measurements would best serve a networked wind measurement system for experiments similar to IHOP. Using all of the measurements in HARGLO-3, develop a climatology of SGP winds during IHOP. Using these statistics, develop time and space “data validity windows” for the various instruments.

Time-line of Homestead Wind Measurements: 43 days, 16 wind instruments In addition to the 9 wind instruments at or near the Homestead site, we have identified several transients, either mobile ground-based or airborne instruments that at one time or another were making measurements in the vicinity of the Homestead site. We have put together a time-line of all the wind measurements at Homestead to help identify the data coincidences and narrow down our data analysis tasks. Because of the large number of instruments and the extended period of operations, this should be a significant wind intercomparison study. We will be tackling this large task immediately after wrapping up the HARGLO-2 analysis, which is in the final stages now.

HARLIE IHOP Data Products Wind Profiles Backscatter Profiles Boundary Layer Heights Cloud Fraction vs Height & Time

HARGLO – 4+ Increase & extend ground-based instruments Focus on relating airborne to ground-based measurements and verifying sampling strategies Help develop a validation plan for spaceborne Doppler wind lidars For our next effort we wish to involve two or more airborne Doppler lidar measurements in conjunction with ground-based Doppler lidars, not only to compare measurements, but to verify sampling strategies as we move from small spatial scales sampled on short time scales to larger spatial scales sampled less frequently. Along with modeling efforts performed by others, this will help to establish a strategy for validating the first generation spaceborne Doppler lidar wind profiler.