Ushering in the first operational precipitation radar on the U.S. Arctic Coast, engineers completed acceptance testing for the new X-band scanning ARM precipitation radar (X-SAPR) on June 21 at its location atop the Barrow Arctic Research Center in Alaska. Data from the radar are transmitted through a wireless connection to the ARM site data system. With the radar up and running, signal returns on June 24 provided an indication of the radar’s coverage over the North Slope, reaching distances of 200-250 kilometers to the north of Barrow over the Arctic Ocean.

The “X-band” refers to the 9.5-gigahertz frequency at which the radar operates. Different frequencies detect different types (sizes) of cloud particles and also determine how far the radar can detect those particles. The X-band radar is sensitive to precipitating particles, and in the snow and light rain common in Barrow, it can “see” these precipitating system to great ranges. This dual-polarization Doppler radar provides details about precipitation that allow scientists to more accurately estimate rainfall, classify precipitation types (rain, sleet, snow) and map wind fields.

“The radar will provide the first routine observations of the structure and evolution of precipitating cloud systems over the climatologically sensitive Arctic Ocean,” said Dr. Hans Verlinde, professor of meteorology at the Pennsylvania State University and ARM’s site scientist for the North Slope of Alaska. “Along with the precipitation estimates, these observations will allow scientists to come to a better understanding of Arctic clouds and how these may be represented in climate models.”

The new radar is the latest in a series of enhancements to ARM’s North Slope of Alaska site through approximately $10 million in funding from the American Recovery and Reinvestment Act. To view more photos of new instruments and progress at the site, visit the image collection via Flickr.