亚马逊野火气溶胶对热带太平洋气候和ENSO的影响OA

The Amazon Rainforest,the world's largest tropical rainforest,has experienced increasingly frequent wildfires and intensified deforestation over the past two decades.Aerosols and greenhouse gases emitted by these fires not only pose serious risks to human health and ecosystems but also influence the global climate system through radiative forcing,land-atmospheric interactions,and biogeochemical processes.Using the Community Earth System Model(CESM),this study investigates the impacts of Amazon wildfire aerosols on the tropical Pa-cific climate and the El Niño-Southern Oscillation(ENSO).The results show that Amazon wildfire aerosols in-duce pronounced climatic responses in the tropics.Aerosol radiative effects generate significant cooling in the east-ern equatorial Pacific and the subtropical South Atlantic,which spreads across the tropical oceans.The enhanced cooling in the equatorial Pacific strengthens the zonal sea surface temperature gradient,intensifying easterly trade winds over the central and western equatorial Pacific.This dynamical adjustment increases sea surface height and deepens the thermocline in the western and central Pacific,thereby strengthening subsurface ocean circulation across the equatorial Pacific.Concurrently,tropical cooling suppresses precipitation in the western equatorial Pacif-ic,particularly along the southern branch of the Intertropical Convergence Zone(ITCZ).Changes in the mean state of the tropical Pacific climate further modulate ENSO characteristics,leading to a prolonged ENSO period,an increased occurrence of multi-year ENSO events,a higher frequency and intensity of extreme El Niño events,and enhanced ENSO asymmetry.The increase in multi-year events advances ENSO onset timing and results in ex-tended development phases and slower growth rates,partly attributable to strengthened nonlinear damping proces-ses.Amazon wildfire aerosols also modulate the global climate impacts of ENSO.ENSO-related precipitation a-nomalies are weakened over the tropical Pacific and Atlantic but intensified over the tropical Indian Ocean.Corre-spondingly,the Pacific-North America(PNA)and Pacific-Japan(PJ)teleconnection patterns are weakened.Fi-nally,when considered in the context of global warming,the results suggest that although aerosol emissions from Amazon wildfires may temporarily offset warming through radiative cooling,the long-term effects of vegetation loss and enhanced greenhouse gas emissions are likely to exacerbate global warming.These findings demonstrate that Amazon wildfire aerosols are not merely a byproduct of climate change but an active regulator of tropical cli-mate variability and ENSO,with important implications for future climate change projections and ENSO predic-tion.