HR: 16:00h
AN: A12F-01    [PDF]
TI: Ground Based Remote Sensing of the First Aerosol Indirect Effect: An Update
AU: * Previdi, M
EM: mprevidi@envsci.rutgers.edu
AF: Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901 United States
AU: Feingold, G
EM: Graham.Feingold@noaa.gov
AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Veron, D E
EM: veron@envsci.rutgers.edu
AF: Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901 United States
AU: Eberhard, W L
EM: Wynn.Eberhard@noaa.gov
AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AB: The first aerosol indirect effect can be defined as an increase in the shortwave albedo of clouds due to higher concentrations of atmospheric aerosol, whereby the aerosol acts as cloud condensation nuclei to produce increased cloud droplet concentrations and smaller, more reflective droplets. The current work is one step toward achieving a more complete understanding of the indirect effect, which will consequently allow for a better determination of how changes in cloud induced by aerosol may affect the radiation budget and thus the climate. We utilize a series of continuous ground-based measurements from the Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) program to investigate the indirect effect. Days that exhibit ice-free, single layered, nonprecipitating clouds are analyzed, with the indirect effect quantified as the relative change in cloud droplet effective radius for a relative change in aerosol extinction (under conditions of equivalent cloud liquid water path). Several cases from the first six years of our analysis (1998-2003) are described here, and probable reasons for the differences in the cloud response to aerosol among the cases are discussed.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting