THE RELATIONSHIP BETWEEN CLOUD DROPLET AND AEROSOL NUMBER CONCENTRATIONS FOR CLIMATE MODELS
✍ Scribed by GULTEPE, I; ISAAC, G A
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 413 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0899-8418
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✦ Synopsis
Aerosols have an effect on cloud droplet size and concentration, and thus affect the radiative properties of clouds. The purpose of this study is to develop parameterized equations between droplet number concentration (Nd) and total aerosol number concentration (N,) for use in numerical weather prediction models and global climate models. In situ observations of droplet and aerosol number concentrations collected during four field projects are used. Variables Nd and N, for stratus and stratocumulus clouds are averaged over 10-km lengths to represent scales close to those used in these models. The Nd value is added to the interstitial aerosol number concentration (Ni) to obtain in cloud N,. The relationships generated are compared with current parameterizations. The results suggest that parameterized equations obtained from three field projects, representing clouds formed over land, are similar. The fourth one, representing clouds over ocean, is found similar to the other three for lower concentration of N,, but different for higher values of N,. The value of Nd in clouds generally increases with N,. This suggests that the relationship between Nd and N, may be universal. However, local variability can be very important.
W.Y WORDS: maritime and continental clouds over North America; microphysical parameterization and statistical analysis; aircraft observations; aerosol and droplet concentrations; radiative fluxes.