HR: 1340h
AN: A23C-0955    [Abstracts]
TI: Sensitivity of M-PACE stratocumulus to variations in aerosol properties in a mesoscale model with detailed bulk microphysics
AU: * Pinto, J O
EM: pinto@ucar.edu
AF: NCAR/RAL, 3450 Mitchell Lane, Boulder, CO 80301 United States
AU: Morrison, H C
EM: hugh@ucar.edu
AF: NCAR/MMM, 3450 Mitchell Lane, Boulder, CO 80301 United States
AB: The Fall 2004 Mixed-Phase Cloud Experiment (M-PACE) took place in the North Slope of Alaska and adjacent Arctic Ocean region to study the evolution and impact of mixed-phase clouds. Mesoscale simulations are performed using a new bulk microphysical parameterization to understand the processes that promote long-lived precipitating stratocumulus in of ice-flow. Cloud and aeorosol data observed during the field program are used to constrain the sensitivity runs which are performed to elucidate the indirect effect of aerosols on this type of cold cloud. It is found that increasing pollution (i.e., increased aerosol concentration, increased sulphur content - deactivates ice nuceli) reduces droplet size and cloud ice formation, which suppresses precipitation and increases cloud cover and water path. Throughout much of the year, these changes in cloud properties would actually serve to warm the surface thus augmenting greenhouse warming.
DE: 3311 Clouds and aerosols
DE: 3329 Mesoscale meteorology
DE: 3349 Polar meteorology
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005