Arctic Cloud and Aerosol Remote Sensing Research at Arctic Facility for Atmospheric Remote Sensing (AFARS)

University Of Alaska Fairbanks Campus, Fairbanks AK

Investigators

Abstract

Arctic clouds have a significant impact on local and global climate and weather through modulating the radiation balance at high latitudes but are yet not very well understood. Aerosol transport to this region probably has a large influence on cloud formation and microphysical properties because of the region's meteorological isolation, lack of local aerosol sources, and the pristine air quality conditions encountered for much of the year. Climate change promises to be particularly evident in polar regions, and Arctic clouds may be particularly susceptible to the effects of global warming, thus providing the potential for additional climatic feedbacks. Our knowledge of atmospheric conditions must be improved as recognized by the upcoming International Polar Year research effort. A comprehensive remote sensing measurement program from the University of Alaska Fairbanks Arctic Facility for Atmospheric Remote Sensing (AFARS, at 64.86 deg N and 147.84 deg W) will be conducted to lessen our uncertainties about Arctic cloud and aerosol properties, and particularly to examine aerosol indirect effects on clouds. AFARS has three polarization lidars operating at 0.532, 0.694, 1.06 and 1.574 micrometers, a 0.607 micrometer nitrogen Raman channel, a polarimetric Doppler W-band (3.2-mm) radar, and a suite of ultraviolet, visible, and infrared radiometers. As in previous midlatitude studies, AFARs observations will be coordinated with observations by Earth Observing System A-train satellites during overpasses. The specific goals are to use multiple remote sensors, both ground- and space-based, to characterize the macrophysical and microphysical properties of mid- and high-level clouds in our region and to compare them to their midlatitude counterparts; study aerosol intrusions into the normally clean Arctic environment protected by the barrier of Polar Fronts, and at the same time improve aerosol characterization through combined multi-wavelength depolarization, Stokes parameterization, and Raman lidar methods; more intensively study recent findings that aerosols, such as transported Asian dust, volcanic dust, and forest fire smoke, are indirectly affecting clouds; and test the ability of satellite methods to characterize the clouds and aerosols we observe. The intellectual merit of this program is that it matches a unique ensemble of university-based remote sensing instruments with satellite data in a largely unstudied part of the globe, offering the chance for fundamental new discoveries. The broader impacts arise through student and postdoctoral scientist involvement. New scientists will be trained in the remote sensing arena. Even more broadly, the research addresses processes and impacts of climate change in the Arctic.