In mid-December 2010, a new Ka-band ARM zenith radar (KAZR) began a two-week pre-operational test alongside the ARM millimeter wavelength cloud radar (MMCR) at the Southern Great Plains site. This ushers in a new era for the fixed-position cloud data previously acquired by the MMCR. The MMCR will be retired at all of ARM’s permanent research sites in favor of the new KAZR, which is expected to provide significantly improved sensitivity.
Since it began operating in 1996, the MMCR set the standard for providing data about cloud boundaries, vertical velocity, and reflectivity. Through the American Recovery and Reinvestment Act of 2009, ARM was provided the opportunity to significantly update the radar’s technology. As a result, the KAZR is essentially a new radar. Sourced by a different manufacturer, it uses only two of the same components—the antenna and transmitter—as the previous model. Although the user community must familiarize itself with a new instrument name, the ingested data format is as similar as possible to the historical MMCR ingest. Additionally, the change should be transparent for researchers who use data from the MMCR through the widely used Active Remotely Sensed Cloud Locations, or ARSCL, value-added product.