A tipping point in the contribution of extratropical cyclones to Antarctic surface mass balance

Extratropical cyclone (EC) is a main source of precipitation at midlatitudes, but its contribution to the Antarctic surface mass balance (SMB) still remains uncertain. Based on five global climate model simulations, we propose that it probably exists a tipping point of the SMB during the evolution of the Antarctic Ice Sheet (AIS), and EC greatly contributes to the tipping point. Before the tipping point, decreasing elevation of the AIS and warming sea surface temperature promote southward movement of ECs, leading to increased precipitation and inhibiting the AIS melting. However, EC becomes a negative contribution to SMB due to increased AIS surface temperature, runoff and rainfall. This study highlights that EC contributes to the tipping point of the AIS evolution.