Development of an aerosol model coupled with a climate model in the atmosphere-an application to sea-salt aerosol

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:166571

Gong, S L; Barrie, L A ^[1]; Blanchet, J P ^[2]

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1. Atmospheric Environment Service, Downview, Ontario (Canada)
2. UQAM, Montreal (Canada)

An aerosol model coupled with a climate model was developed to study the effect of aerosols on the climate. The model deals with different types and/or sizes of aerosols, each of those is represented by a prognostic continuity equation solved with other prognostic equations of a climate model. The climate model provides all the meteorological parameters, e.g. temperature, wind vector, relative humidity, cloud cover and precipitation, for the aerosol model. Physical and chemical processes of aerosols are included as a source or sink term in the continuity equation. A new method OTID (for One Time injection and Decay) was developed to use in the model to estimate the residence time of aerosols. As an initial application, this model was used with a LCM (local climate model) to simulate sea-salt aerosols in the North Sea (61.2{degrees}N x 352.5{degrees}W). Various processes of sea-salt aerosol cycle in the atmosphere, such as the generation, transport, dry and wet removals are parameterized in the model. Size distribution and wind dependency of sea-salt aerosols from the model simulation compares well with observations. It is found that total sea-salt aerosols are mainly governed by the local wind speed. A regression of the simulated results as a function of wind speed gives a slope (a) of 0.283 s m{sup -1} and background salt loading (b) 0.84 {mu}g m{sup -3}. Less dependency on wind for smaller particles is observed by both experiments and this simulation. Through OTID analysis of sea-salt aerosols, the residence time is found ranging from several hours to a week depending on the size of the particles and local meteorological conditions, The longer residence time for smaller particles explains the less dependency of sea-salt aerosols on the wind speed. Large particles have a short residence time of several hours (r = 4 - 8 {mu}m) to a day (r = 1 - 2 {mu}m) for the first two layers.

• OSTI ID: 166571
• Report Number(s): CONF-9510126--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
CLIMATE MODELS
CLIMATES
CLIMATIC CHANGE
COUPLING
ENVIRONMENTAL EFFECTS
EQUATIONS
MULTI-PARAMETER ANALYSIS
NORTH SEA
PARTICLE SIZE