Little Influence of Asian Anthropogenic Aerosols on Summer Temperature in Central East Asia Since 1960

Abstract

Recent summer surface air temperature (SAT) variations over Central East Asia (CEA) have been influenced by greenhouse gas and aerosol forcing since 1960. But how CEA SAT responds to contrasting changes in Asian, and European and North American aerosol sources remains unclear. By analyzing observations and model simulations, here we show that aerosol-forced summer SAT changes over CEA since 1960 come mostly from the effects of aerosols outside Asia, with relatively small influences from Asian aerosols. Unlike Europe, where direct and indirect aerosol effects on surface solar radiation drive the SAT long-term trend and decadal variations, over CEA atmospheric circulation response to aerosols outside Asia plays an important role. Aerosol-forced anomalous low-level low pressure in mid-latitude Eurasia may influence the SAT anomalies downstream over mid-latitude Asia, including a warm anomaly around CEA. The results suggest that caution is needed in attributing SAT changes around CEA to anthropogenic aerosols from Asia.