The dry and hot American Southwest under the present and future climates

The American Southwest is undergoing alarming climate crises, suffering from the on-going mega drought, frequent flash flooding, heat waves, and wildfires that cause air pollution. The climate crises are mainly associated with hydroclimatic processes and particularly water fluxes across the different components of the climate system. This study serves to discuss where the author stand in terms of scientific understanding of hydroclimatic systems in this region and their physical drivers (e.g., the North American Summer monsoon and Pacific North American teleconnections). This work highlights the relative contributions of precipitation and temperature to droughts through the lens of theories and modeling tools. More importantly, it is crucial to characterize the relative roles of internal variability and external forcing in shaping the hydroclimatic system in the southwestern United States. Future pathways are also described including high-resolution global modeling system, advancing understanding relative roles of precipitation and temperature in modulating hydroclimate system, further understanding the role of external forcing, as well as the partnership between scientists and other stakeholders.