Changes in Soil Water Storage under Global Warming in CMIP5 models

Abstract:

Changes in global hydrological cycle play an important role in the Earth’s climate system. In this study, we use simulations from CMIP5 (Coupled Model Intercomparison Project Phase 5) model archives to estimate changes in seasonal cycle of terrestrial soil water under global warming (with the RCP8.5 scenario). Our preliminary results show that future global warming is leading to declines in snow fall and snow amount in most models and a lack of snow melt during spring and summer results in less recharge of soil moisture, which makes soil water less during the dry season over most of the middle and high latitudes of the Northern Hemisphere. In addition, decreases in the soil ice also play an important role in modifying the seasonal variations of soil water via affecting the infiltration and runoff rates, which might cause the soil dry out faster. The increase in annual cycle of the global soil water under global warming found in this study has important implications for water management and water security under climate changes due to an increase in the water distribution heterogeneity.