Impact of an acceleration of ice sheet melting on monsoon systems

Abstract. The study of past climates has demonstrated the occurrence Heinrich events during which major ice discharges occurred at polar sheet, leading to significant additional sea level rise. strongly influenced oceanic circulation and global climate. However, standard climate change scenarios (Representative Concentration Pathways or RCPs) do not consider such potential rapid sheet collapse; RCPs only dynamic evolution greenhouse gas emissions. We carried out water-hosing simulations using Institute Pierre Simon Laplace Climate Model (IPSL-CM5A) simulate a melting Greenland Antarctic sheets, equivalent +1 +3 m rise (SLR). Freshwater inputs were added RCP8.5 emission scenario over 21st century. contribution SLR from sheets differentiated impacts. freshwater input in is diluted by circumpolar current, its impact moderate. Conversely, North Atlantic slows down Meridional Overturning Circulation. This slowdown leads changes winds, inter-hemispheric temperature pressure gradients, resulting southward shift tropical rain belt eastern Pacific region. American African monsoons are affected south. Changes monsoon occur later, while South start earlier. drier boreal summer, southern intensifies austral summer. Simulated for Asian Australian monsoons.