EOL scientist Tammy Weckwerth (r) looks over S-Pol data with SOARS Protoge Theresa Aguilar from Texas Tech University during the Refractivity Experiment For H2O Research And Collaborative operational Technology Transfer (REFRACTT). Not only can the research gleaned from REFRACTT data improve precipitation forecasts by enhancing the observed field of water vapor, the experiment was an excellent opportunity for students in atmospheric science to gain hands-on experience with observational datasets.
Priority 2: Building Capacity for Coping with Weather and Climate Hazards
Refractivity Experiment For H2O Research And Collaborative operational Technology Transfer (REFRACTT)
Background
The REFRACTT experiment was conducted from 5 June through 11 August 2006 in northeastern Colorado in an effort to test a new observing strategy of tracking atmospheric moisture just above Earth's surface to help forecasters pin down the locations where storms might rage a few minutes to a few hours later. Up to now, the sparse network of surface weather stations has limited forecasters' ability to map fields of moisture and predict exactly where heavy rains might develop. One of the scientific objectives of REFRACTT was to assess potential improvements these measurements may have in numerical model forecasts of quantitative precipitation. The ultimate, long-term goal is to implement radar refractivity measurements on the national network of operational radars. More information on REFRACCT is available here.
Progress
NCAR scientists were part of a multi-agency team of researchers who collected and analyzed very high resolution measurements of water vapor variability and transport in the convective boundary layer. Preliminary processing of the entire data set is nearing completion, and the data is being reviewed for consistency and errors. The Ka band system, which operated with S-Pol for about three weeks of the 12-week experiment, is still under development, and thus special care is required for analysis of that data.
Plans
Researchers will create a final data set using determined corrections, and. and then undertake a special study to look at Zdr calibration and Zdr stability. A full on-line report will be prepared, along with metadata sub-sets to allow future scientists to select periods of data for analysis. Rsearchers expect that the final data set will consist of over two TeraBytes of polarimetric radar data and several thousand summary images of those data. Other efforts will focus on re-engineering the tools required to produce quality-assured fields of radar refractive index.
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