Anthropogenic aerosol effect on the regional climate in terms of urban to regional scale in Northeast Asia

Abstract:

Aerosol-cloud interactions have so complicated feedback mechanisms that it is difficult to differentiate only aerosol impacts accompanying an instability-driven forcing from various results such as changes in circulation and precipitation, etc, probably based on the simple observational frameworks. Therefore a carefully-designed target-oriented approach is needed for the understanding of aerosol effects on meteorology with regard to its radiative and physical properties. Analysis of long-term trends of aerosol and cloud optical properties derived from satellite remote sensings does not show any significant annual trends, probably their cancelling effects each other, but with a strong gradient of aerosol optical depth over the Yellow Sea in the perspective of long-term average. However urban-induced aerosols effect on cloud and precipitation is discernible in the downwind of the metropolitan area in several-hours’ time scale and within less than around 100 km spatial domain, an increasing trend of precipitation amount and frequency at the far downwind region of Seoul Metropolitan Area during 35 years, especially for light precipitation of less than 1mm per day (Eun et al., 2011). In a couple of days the much wider spread haze transported to Korea might possibly modify its radiative and cloud microphysical modification, which is difficult to draw aerosol effects only. In this regard Northeast Asia will be a good testbed for aerosol’s regional scale analysis in terms of its forcing and response regions, both of which can be separated in the specific seasons with a favorable condition.