The Remote Response in the Northern Pacific Climate During Winter to Deforestation in the Maritime Continent

The Maritime Continent (MC) has experienced significant anthropogenic land use changes, mainly deforestation, which has led to local surface warming and marked convergence in the lower troposphere and divergence in the upper. The remote consequences of this deforestation remain unclear and present considerable uncertainties. In this study, we employ a fully coupled climate model and a linear baroclinic model to explore the effects of altered land-atmosphere interactions due to MC deforestation on high-latitude climates. Our series of idealized experiments demonstrates that MC deforestation can induce upper-level diabatic heating. This generates a barotropic Rossby wave that moves poleward, drawing energy from the subtropical jet across the Central to Eastern Pacific regions via eddy-mean flow interactions. Such interactions amplify the Aleutian Low, promoting the northward transport of warm air, leading to notable warming anomalies. This influx of warmth contributes to sea ice melt, initiating a positive ice-albedo feedback. A lapse-rate feedback is also observed in adjacent high-latitude land areas, amplifying terrestrial warming. These reinforcing feedbacks, combined with the direct temperature transport enabled by the strengthened Aleutian Low, cumulatively result in pronounced high-latitude warming originally due to the tropical land use changes.