Publications

Export 2 results:
Sort by: Author Title Type [ Year  (Desc)]
2011
McFarquhar, GM, Ghan S, Verlinde J, Korolev A, Strapp JW, Schmid B, Tomlinson JM, Wolde M, Brooks SD, Cziczo D, Dubey MK, Fan JW, Flynn C, Gultepe I, Hubbe J, Gilles MK, Laskin A, Lawson P, Leaitch WR, Liu P, Liu XH, Lubin D, Mazzoleni C, Macdonald AM, Moffet RC, Morrison H, Ovchinnikov M, Shupe MD, Turner DD, Xie SC, Zelenyuk A, Bae K, Freer M, Glen A.  2011.  Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds. Bulletin of the American Meteorological Society. 92:183-+.   10.1175/2010bams2935.1   AbstractWebsite

INDIRECT AND SEMI-DIRECT AEROSOL CAMPAIGN (ISDAC): THE IMPACT OF ARCTIC AEROSOLS ON CLOUDS A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's primary aim was to examine the effects of aerosols, including those generated by Asian wildfires, on clouds that contain both liquid and ice. ISDAC utilized the Atmospheric Radiation Measurement Pro-gram's permanent observational facilities at Barrow and specially deployed instruments measuring aerosol, ice fog, precipitation, and radiation. The National Research Council of Canada Convair-580 flew 27 sorties and collected data using an unprecedented 41 state-of-the-art cloud and aerosol instruments for more than 100 h on 12 different days. Aerosol compositions, including fresh and processed sea salt, biomass-burning particles, organics, and sulfates mixed with organics, varied between flights. Observations in a dense arctic haze on 19 April and above, within, and below the single-layer stratocumulus on 8 and 26 April are enabling a process-oriented understanding of how aerosols affect arctic clouds. Inhomogeneities in reflectivity, a close coupling of upward and downward Doppler motion, and a nearly constant ice profile in the single-layer stratocumulus suggests that vertical mixing is responsible for its longevity. observed during ISDAC. Data acquired in cirrus on flights between Barrow and Fairbanks, Alaska, are improving the understanding of the performance of cloud probes in ice. Ultimately, ISDAC data will improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and determine the extent to which surface measurements can provide retrievals of aerosols, clouds, precipitation, and radiative heating.

2007
Lubin, D, Vogelmann AM.  2007.  Expected magnitude of the aerosol shortwave indirect effect in springtime Arctic liquid water clouds. Geophysical Research Letters. 34   10.1029/2006gl028750   AbstractWebsite

Radiative transfer simulations are used to assess the expected magnitude of the diurnally-averaged shortwave aerosol first indirect effect in Arctic liquid water clouds, in the context of recently discovered longwave surface heating of order 3 to 8 W m(-2) by this same aerosol effect detected at the Barrow, Alaska, ARM Site. We find that during March and April, shortwave surface cooling by the first indirect effect is comparable in magnitude to the longwave surface heating. During May and June, the shortwave surface cooling exceeds the longwave heating. Due to multiple reflection of photons between the snow or sea ice surface and cloud base, the shortwave first indirect effect may be easier to detect in surface radiation measurements than from space.