NCAR's S-Pol radar proves fieldworthy
"Measuring heavy rains accurately is important for anticipating flash floods," explains NCAR scientist Jim Wilson (Atmospheric Technology Division), who heads the S-Pol precipitation experiment. "Hail can fool the WSR-88D into 'thinking' it's raining harder than it actually is, thereby introducing uncertainty into the issuance of flash flood warnings." In fact, the Buffalo Creek storm did produce a flash flood that washed away a road and left two people dead.
|NCAR's dual-polarimetric radar, S-Pol. (Photo by Carlye Calvin)|
To quantify the advantages of dual over single polarization, NCAR is planning a series of experiments over the next few years in various seasons and locations around the United States. Anticipating promising results from the current refinement of the now-15-year-old technology, scientists at the National Severe Storms Laboratory (NSSL) are already working on how to add it to the existing WSR-88D network, which was installed around the country in the early 1990s. Colorado State University and NSSL use dual-polarimetric radar data and are collaborating with NCAR on the S-Pol tests. CSU will deploy the S-Pol in early 1997 northeast of Denver.
S-Pol is NCAR's second dual-polarization radar. Its predecessor, CP-2, was expensive to set up because it required the construction of a concrete pad at each new site. By contrast, S-Pol can be placed on a base of four seatainers--the same ones it's shipped in--for assembly at any stable, accessible site in the world. The 28-foot aluminum dish can withstand winds up to 50 miles an hour and can be covered with a radome in more severe weather. An improved antenna provides more accurate measurements than CP-2 did, and a new data processor uses modern digital technology.
For information on deploying the radar, contact Jeff Keeler, ATD Remote Sensing Facility (303-497-2031 or firstname.lastname@example.org).