Observations of orographic precipitation - analyzing incoming air properties

For the purpose of answering the question: “What causes the duration of rain showers?” the investigator has studied data of incoming air, upstream of a small island at the west coast of Norway. Data from a rain gauge network and a dual GPS instrument have been used. Result from a 1-km model simulation is also included in presentation.

The analysis of the incoming water flux and rain gauge time serie show a clear correlation between pulses in the mositure flux measured by the dual GPS instrument and rain showers over the island. However, the amplitude of the moisture flux is primarily explained by waves with synoptic temporal scale (2-3 days).