ARM cloud radar data products: long-term record and new additions

The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program has a decades-long continuous record of zenith-pointing millimeter-wavelength cloud radar observations and corresponding value-added data products (VAPs), all publicly accessible. Observations and products are available for five highly-instrumented ARM Climate Research Facility fixed sites as well as for a growing number of shorter-term deployments of the two ARM mobile sites in climatically-important regions. The fixed sites are in the U.S. Southern Great Plains, the North Slope of Alaska, and the Tropical Western Pacific. In the past year, the ARM program has significantly upgraded its Ka-band zenith-pointing radars (KAZRs, formerly known as MilliMeter Cloud Radars, or 'MMCRs') and is installing scanning dual-wavelength cloud radars at all sites, funded through the American Recovery and Reinvestment Act of 2009. Here we describe the long-term continuous cloud radar products that are currently available. We also discuss new products in development, which will leverage ARM's recent radar acquisitions. ARM's suite of radar-based VAPs is known collectively as ARSCL (Active Remote Sensing of CLouds). ARSCL synthesizes cloud radar, micropulse lidar and ceilometer data to provide best-estimate reflectivities, Doppler velocities and spectrum widths, as well as hydrometeor masks and cloud (hydrometeor) boundaries at 10-second time intervals and approximately 45 m height intervals. The new KAZR-based ARSCL product will feature linear depolarization-based insect detection and have even finer time-height resolution. The new scanning cloud radar data will provide input for ARM's first three-dimensional ARSCL product, also described here.