Contributors: Mark Ivey, Bernie Zak, Jeff Zirzow, Sandia National Labs

1. To DEWLine USGS Facilities 40M Met tower Tip Tower Present Weather Sensor Skydeck RASS deck Great White User Facility NOAA Instruments & Facilities Legend: ARM = yellow Others = blue Summer Barrow User Facility Since 1998, the ACRF North Slope of Alaska (NSA) site, with instrumented facilities near the towns of Barrow and Atqasuk, has provided data about cloud and radiative processes at high latitudes. Campaign-scale atmospheric measurements in the Arctic for research activities funded by the DOE ARM Program began nearly a year earlier during the Surface Heat Budget of the Arctic (SHEBA) Experiment. Cloud and aerosol measurements in the Arctic are important because climate models suggest the Arctic is particularly sensitive to climate change. Near-surface warming across the Arctic has been approximately twice the global average since the late 1960s. Ice and snow extent in higher latitudes have an important contribution to climate trends through the ice-albedo feedback. The magnitude of this feedback remains uncertain because it is strongly coupled to Arctic cloud processes and ocean heat transport, both poorly understood. Perennial sea ice in the Arctic declined by more than 20% since the mid-1970s, raising concerns that a threshold in the ice-albedo feedback may have been crossed. The record decline in sea-ice extent and increased melting of the Greenland ice sheet in 2007 provide further support for that conclusion. By improving our understanding of cloud processes and radiative transfer in the Arctic atmosphere, data from ACRF can help address one of the major sources of uncertainties in climate models, thereby reducing uncertainty in climate predictions. Barrow The U.S. Department of Energy's Atmospheric Radiation Measurement Climate Research Facilities on the North Slope of Alaska Barrow Field Site Total Precipitation Sensor Barrow ACRF Barrow Arctic Research Center (BARC), Owned by UIC Corporation, Managed by Barrow Arctic Science Consortium Barrow User Facility & Great White Entrance in Winter Joshua Ivanoff Operator, Part time, Barrow New Members of the NSA Team Near the NSA Duplex in Barrow Martin Stuefer Rapid Response Manager, University of Alaska, Fairbanks Jessie Cherry Co Mentor for T PS, University of Alaska, Fairbanks Robin Mongoyak Operator, Part time, Barrow Valerie Sparks Administrative Assistant, NSA Program Office, Sandia, Albuquerque Atqasuk Inside Instrument Shelter Outside, Skyrad Upcoming IOP Spring 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,for the United States Department of Energy’s National Nuclear Security Administrationunder contract DE-AC04-94AL85000. Contributors: Mark Ivey, Bernie Zak, Jeff Zirzow, Sandia National Labs Martin Stuefer, Jessica Cherry, University of Alaska Fairbanks Hans Verlinde, Scott Richardson, Penn State University