The moisture origin of dew: Insights from three sites with contrasting climatic conditions

Dew is one of the important moisture sources in many arid and semiarid regions. The knowledge origin dew under various climatic conditions still lacking. Isotopic variations can preserve information about formation mechanisms. Therefore, isotopic compositions precipitation (δ2H, δ18O, δ17O, d-excess, lc-excess 17O-excess) were investigated at three sites with different (i.e., Gobabeb extremely dry climate, Nice Mediterranean climate Indianapolis humid continental climate). results showed that there types Gobabeb: advective dew, groundwater-derived shallow soil water-derived accounting for 27.3%, 45.4% 27.3% events, respectively. ultimate other two from South Atlantic Ocean a mixture Indian Oceans, included ocean-derived North local evapotranspiration replenishment, local-derived mainly Europe Sea, 39.1% 60.9% All likely dew. Based on origins, future trends speculated global warming. frequencies climates are uncertain due to concurrent increases atmospheric water vapour temperature. would decrease decreasing increasing drought, uncertain. This study provides practical method distinguish sources, such useful prediction change.