New Lidar Remote Sensing Capabilities at the Atmospheric Radiation Measurement Climate Research Facilities (Invited)

In 2009 the US Department of Energy’s Atmospheric Radiation Measurement Climate Research Facility (ACRF) was awarded funds through the American Recovery and Reinvestment Act (ARRA) for instrument acquisitions and upgrades. A significant portion of that award is being used to acquire new advanced lidar systems for all of the ACRF sites. Efforts are currently underway to develop the following systems: 1) one Raman lidar for installation at the Tropical West Pacific (TWP) site in Darwin, Australia; 2) two High Spectral Resolution Lidars (HSRL) for deployment at the North Slope of Alaska (NSA) site in Barrow, and with the second mobile facility (AMF2); 3) three coherent Doppler lidars for deployment at the Southern Great Plains (SGP) site in Oklahoma, TWP-Darwin, and with the first mobile facility (AMF1). Additionally, the following systems are being upgraded: 1) laser ceilometers at SGP, TWP, NSA, and mobile facilities; 2) Micropulse Lidars (MPL) at SGP, TWP, NSA, and mobile facilities; 3) the existing Raman lidar at SGP. The new Raman lidar at TWP-Darwin will provide time and height resolved measurements of water vapor mixing ratio, temperature, aerosol extinction, backscatter, and depolarization. The design of this system will closely follow that of the existing Raman lidar at SGP. The SGP Raman system has been operational for well over 10 years and is well proven. Over the years a number of upgrades have been incorporated that have greatly improved performance of the system. Examples include simultaneous photon counting and analog detection electronics, the addition of two rotational Raman channels for temperature profiling, and continuous active boresight alignment. The new system at Darwin will incorporate these features as well. The HSRL systems will improve cloud and aerosol remote sensing at NSA and AMF2 by enabling a direct measurement of extinction. Extinction profiles at these sites are currently being generated as PI data products from MPL data. The HSRL measurement technique obviates the need to assume a constant (or prescribed) backscatter-to-extinction ratio, as is currently the case when using MPL data. The Doppler lidars will help fill a long standing measurement gap within ACRF. These systems will operate in a vertically staring mode to acquire long-term measurements of clear-air vertical velocities in the lower troposphere. These data will be used to investigate statistics of updrafts and downdrafts, and the vertical transport of aerosols. This presentation will discuss the expected performance characteristics of the new ACRF lidar systems and the impact that the new systems are expected to have on the science.