| Abstract:
In this research four spring widespread frosts were studied in the west of Iran. In this research spring widespread frost is a day when absolute minimum temperature of te April occurred in that day for all of the selected stations.
To study the synoptic conditions of the formation of these frosts, daily weather maps of the surface of the earth, level of weather 400hpa, and absolute minimum temperature of 13 stations in the west of Iran were studied in zero hour
.
Results showed that all of the frosts were cold advection in origin and frost days are synchronous with location of a low pressure system of air on the Caspian Sea.
|