HR: 1330h
AN: A22A-1057    [PDF]
TI: Formation of Anvil Ice Particles in a Deep Cumulus Updraft of CRYSTAL-FACE Simulated with an Explicit Microphysics Model - The Influence of Various Nucleation Processes
AU: * Phillips, V T
EM: vtp@gfdl.noaa.gov
AF: Princeton University/Geophysical Fluid Dynamics Laboratory (GFDL), P.O. Box 308, Princeton, NJ 08540 United States
AU: Sherwood, S
EM: Steven.Sherwood@yale.edu
AF: Geology Dept, Yale University, P.O. Box 208109, New Haven, CT 06520 United States
AU: Bansemer, A
EM: bansemer@ucar.edu
AF: NCAR/MMM, 3450 Mitchell Lane, PO Box 3000, Boulder, CO 80307-3 United States
AU: Conant, W C
EM: wconant@caltech.edu
AF: Department of Environmental Sciences and Engineering,ÿ California Institute of Technology, 210-41 Caltech, 1200 E California Blvd, Pasadena, CA 91125 United States
AU: Heymsfield, A
EM: heyms1@ncar.ucar.edu
AF: NCAR/MMM, 3450 Mitchell Lane, PO Box 3000, Boulder, CO 80307-3 United States
AU: Heymsfield, G
EM: heymsfield@agnes.gsfc.nasa.gov
AF: Goddard Space Flight Center, NASA, Greenbelt,, MD 20771 United States
AU: Poellot, M
EM: poellot@aero.und.edu
AF: Dept. of Atmospheric Sciences, University of North Dakota (UND), P.O. Box 9006, Grand Forks, ND 58202-9006 United States
AU: Vanreken, T
EM: vanreken@caltech.edu
AF: Department of Environmental Sciences and Engineering,ÿ California Institute of Technology, 210-41 Caltech, 1200 E California Blvd, Pasadena, CA 91125 United States
AB: Simulations of a cumulonimbus cloud observed by the Citation aircraft in the Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE) with an advanced version of the Explicit Microphysics Model (EMM) are presented here. Observations of the concentration of cloud condensation nuclei (CCN) by the Twin Otter aircraft in the planetary boundary layer are utilized to provide inputs to the model, together with measurements by the ER-2 and Citation aircraft. The interconnected mechanisms of secondary droplet nucleation and the warm rain process both combine to regulate the supercooled droplet concentration in the mixed phase region of the updraft, which determines the anvil ice concentration aloft. Perturbations in the turbulence enhancement coefficients for coalescence and in the CCN concentration are found to alter the properties of the anvil updraft because of their effects on the warm rain process. Homogeneous aerosol freezing can occasionally occur if the anvil ice concentration in parcels becomes very low.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting