NSSL scientist studies C-Band polarization radar in France
The C-Band radar in France
Through a strategic partnership, scientists can now share and compare results across the Atlantic to jointly evaluate the feasibility of polarization at C-Band. The project is called PANTHERE, and the trans-Atlantic link is CIMMS scientist J.J. Gourley, who was offered a post-doc by MeteoFrance to lend his expertise to the program.
PANTHERE (Programme ARAMIS Nouvelle Technologie Hydromet Extension et REnouvellement - translated to "new program for the extension and renewal of new hydrometeorological technology") aims to extend and upgrade the French weather radar network. Meteo-France purchased a C-band dual-polarization radar from Gematronik and recently installed it approximately 20 km to the west of Paris in the town of Trappes. C-band radars use a shorter wavelength (5cm) than the WSR-88D radars (10cm) and are less expensive.
A major component of PANTHERE is to evaluate the improvements to quantitative precipitation estimation and hydrometeor particle identification afforded by dual-polarization radar. This part of the project is being designed very similarly to the Joint POLarization Experiment (JPOLE) conducted at NSSL. J.J. contributed to the early JPOLE proposal, he is familiar with the experimental design, and more importantly, he collaborates directly with JPOLE scientists to gain insight.
One challenge J.J. is addressing in his research is the drawback of using a 5-cm wavelength radar in heavy precipitation. The beam becomes absorbed by the precipitation, causing a "rain shadow," or wedge of relatively low reflectivity at ranges beyond which intense convection was sampled. In addition, he is assessing the quality, precision, and calibration of raw, polarimetric variables. Ultimately, he'll develop algorithms that incorporate all the information from polarimetric radar to identify different types of precipitation.
This temporary assignment offers benefits to both Meteo-France and NSSL. In exchange for NSSL's expertise, NSSL's radar group can use the information from France in their current project to determine the quality of polarization diverse measurements at C-band through a working relationship with the private sector and other countries.
