Observations of the width of cloud droplet spectra in stratocumulus

AMS Citation:
Pawloska, H., W. W. Grabowski, and J. -L. Brenguier, 2006: Observations of the width of cloud droplet spectra in stratocumulus. Geophysical Research Letters, 33, L19810, doi:10.1029/2006GL026841.
Date:2006-10-07
Resource Type:article
Title:Observations of the width of cloud droplet spectra in stratocumulus
Abstract: This paper discusses in-situ aircraft observations of cloud microphysics in eight cases of marine stratocumulus investigated during the Second Aerosol Characterization Experiment (ACE2) in the eastern subtropical Atlantic. The emphasis is on the spectral width of cloud droplet spectra, an important parameter affecting radiative properties of clouds and the development of drizzle and rain. For a given flight (i.e., for given characteristics of the cloud condensation nuclei, CCN), local droplet concentration varies considerably. The standard deviation of the cloud droplet spectra, σ, is typically in the range of 1 to 2 μm. It does not vary systematically between maritime and polluted clouds, and shows a surprisingly small difference between near-adiabatic and diluted cloud samples. The relative dispersion d, the ratio between σ and the mean radius inline equation is between 0.1 and 0.4. In agreement with previous studies, larger values are typically associated with polluted clouds, mostly because such clouds have smaller droplets. For all flights, d either decreases with height or does not change significantly. Based on these observations, a simple parameterization of the relative dispersion d is proposed.
Subject(s):Cloud physics and chemistry, Clouds and aerosols, Regional modeling
Peer Review:Refereed
Copyright Information:Copyright 2006 American Geophysical Union.
OpenSky citable URL: ark:/85065/d7639q1k
Publisher's Version: 10.1029/2006GL026841
Author(s):
  • H. Pawloska
  • Wojciech Grabowski - NCAR/UCAR
  • J.-L. Brenguier
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