HR: 1340h
AN: A23C-0965    [Abstracts]
TI: Ice Nuclei Measurements From the Mixed-Phase Arctic Cloud Experiment
AU: * Prenni, A J
EM: prenni@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Campus Delivery 1371, Fort Collins, CO 80523
AU: Harrington, J Y
EM: harring@meteo.psu.edu
AF: Pennsylvania State University, Department of Meteorology, State College, PA 16802
AU: Tjernstr”m, M
EM: michaelt@misu.su.se
AF: Stockholm University, Department of Meteorology, Stockholm, S-106 91 Sweden
AU: DeMott, P J
EM: pdemott@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Campus Delivery 1371, Fort Collins, CO 80523
AU: Avramov, A
EM: lz4ax@psu.edu
AF: Pennsylvania State University, Department of Meteorology, State College, PA 16802
AU: Long, C N
EM: chuck.long@pnl.gov
AF: Pacific Northwest National Laboratory, Atmospheric Radiation Measurement Program, Richland, WA 99352
AU: Kreidenweis, S M
EM: sonia@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Campus Delivery 1371, Fort Collins, CO 80523
AU: Olsson, P Q
EM: olsson@aeff.uaa.alaska.edu
AF: University of Alaska, Alaska Experimental Forecast Facility, Anchorage, AK 99508
AU: Verlinde, J
EM: verlinde@ems.psu.edu
AF: Pennsylvania State University, Department of Meteorology, State College, PA 16802
AU: Rogers, D C
EM: dcrogers@atd.ucar.edu
AF: NCAR, EOL/RAF, Broomfield, CO 80021
AB: Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate and regional models have generally proven unsuccessful at simulating Arctic cloudiness, particularly during the colder months. Specifically, models tend to under-predict the amount of liquid water in mixed-phase clouds. This is problematic because cloud phase can greatly impact the radiative budget. The Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted from late September through October, 2004 in the vicinity of the Department of Energy North Slope of Alaska field site, focused on characterizing low-level, Arctic stratus clouds. A major goal of the project was to determine why models tend to under-predict the amount of liquid in Arctic mixed-phase clouds. To this end, measurements of cloud and aerosol properties were made by aircraft and a suite of remote sensing devices. Ice nuclei (IN) measurements were made using a continuous flow ice thermal diffusion chamber aboard the University of North Dakota Citation II aircraft. This instrument permits processing of aerosol particles sampled through an aircraft inlet in real-time in and around cloud levels to determine IN concentrations. Using these measurements, we show that incorrect parameterizations of aerosol-cloud interactions may be partially responsible for the poor model predictions. Moreover, we show that this can lead to considerable errors in the modeled surface radiative energy budget. Results will also be compared to IN measurements collected during the Arctic spring.
DE: 0320 Cloud physics and chemistry
DE: 0321 Cloud/radiation interaction
DE: 1637 Regional climate change
DE: 3310 Clouds and cloud feedbacks
DE: 3311 Clouds and aerosols
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005