Impact of Cloud-Borne Aerosol Representation on Aerosol Direct and Indirect Effects

Journal Article · Thu Sep 21 04:00:00 EDT 2006 · Atmospheric Chemistry and Physics, 6:4163-4174

DOI:https://doi.org/10.5194/acp-6-4163-2006· OSTI ID:883684

Ghan, Steven J; Easter, Richard C

Aerosol particles attached to cloud droplets are much more likely to be removed from the atmosphere and are much less efficient at scattering sunlight than if unattached. Models used to estimate direct and indirect effects of aerosols employ a variety of representations of such cloud-borne particles. Here we use a global aerosol model with a relatively complete treatment of cloud-borne particles to estimate the sensitivity of simulated aerosol, cloud and radiation fields to various approximations to the representation of cloud-borne particles. We find that neglecting transport of cloud-borne particles introduces little error, but that diagnosing cloud-borne particles produces global mean biases of 20% and local errors of up to 40% for many variables of interest. A treatment that predicts the total mass concentration of cloud-borne particles for each mode yields smaller errors and runs 20% faster than the complete treatment.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 883684
• Report Number(s): PNNL-SA-49093; 8599; KP1201010
• Journal Information: Atmospheric Chemistry and Physics, 6:4163-4174, Journal Name: Atmospheric Chemistry and Physics, 6:4163-4174 Journal Issue: 12 Vol. 6; ISSN 1680-7324
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
99 GENERAL AND MISCELLANEOUS
AEROSOLS
ATMOSPHERIC CHEMISTRY
CLOUDS
DROPLETS
Environmental Molecular Sciences Laboratory
MATHEMATICAL MODELS