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Abstract The recent summer surface air temperature (SAT) changes over densely populated Eurasia exhibit a non‐uniform pattern with amplified warming over Europe and East Asia (EA) but weak warming over Central Asia (CA), forming a wave train‐like structure. However, the key factors that determine this non‐uniform warming pattern remain unclear. By analyzing observations and model simulations, here, we show that more than half of the SAT multidecadal variations from 1950 to 2014 over Europe‐west Asia and EA may have resulted from external forcing, rather than from internal variability in the Atlantic as previously thought. In contrast, the recent SAT over CA is influenced mainly by internal variations in the Atlantic and Pacific oceans. Large ensemble model simulations suggest that the forced SAT multidecadal variations over Eurasia are mainly caused by changes in greenhouse gases and aerosols. Our findings provide strong evidence for major impacts of external forcing on multidecadal climate variations over Eurasia.
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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.
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- PAR ID:
- 10381076
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 49
- Issue:
- 7
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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