Patterns of the isotopic composition of precipitation in time and space: data from the Israeli storm water collection program

The data from a precipitation sampling program in Israel show the synoptic scale history of the air masses to be the predominant factor which controls the isotopic data. Within a single storm, the passage of a front is always associated with values most depleted in the heavy isotopes. Local factors and especially the enrichment of the heavy isotopic species resulting from partial evaporation of rain in low lying stations, are superimposed on these large-scale effects.