HR: 08:15h
AN: A11B-02    [PDF]
TI: Small, Highly Reflective Ice Crystals in CRYSTAL-FACE Anvil Cirrus
AU: * Garrett, T J
EM: tgarrett@met.utah.edu
AF: Meteorology Department University of Utah, 135 S 1460 E, Salt Lake City, UT 84112 United States
AU: Gerber, H
EM: hgerber6@comcast.net
AF: Gerber Scientific Inc, 1643 Bentana Way, Reston, VA 20190 United States
AU: Baumgardner, D G
EM: darrel@ucar.edu
AF: Universidad Nacional Automoma de Mexico, Ciudad Universitaria, Mexico City, DMF 04150 Mexico
AU: Twohy, C H
EM: twohy@coas.oregonstate.edu
AF: Oregon State University, College of Oceanography and Atmospheric Sciences, Corvallis, OR 97331 United States
AU: Weinstock, E M
EM: elliot@huarp.harvard.edu
AF: Harvard University, 12 Oxford St, Cambridge, MA 02138 United States
AB: Aircraft measurements, obtained during CRYSTAL-FACE using new instruments, indicate that ice crystals within cirrus anvils have smaller sizes and are more reflective than is assumed in most \textbf{}current climate models. Cloud mass, scattering cross section and number concentration were highly correlated within any given temperature range. Consequently, values of effective radius $r_{e}$ were primarily a function of temperature, increasingly exponentially from approximately 5 $\mu m$ at -75 $\textdegree$C to 30 $\mu m$ at freezing. Values of the asymmetry parameter $g$ were 0.75$\pm0.01$ between freezing and -55 $\textdegree$C. For a given model prediction of cloud mass, these results suggest low-latitude cirrus anvils should have greatly higher values of cloud albedo and emissivity than is usually assumed in climate model representations of these clouds.
UR: http://www.met.utah.edu/tgarrett/Publications/Icescattering/GRL2003.pdf
DE: 0320 Cloud physics and chemistry
DE: 0360 Transmission and scattering of radiation
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting