A study of low level jet characteristics using a sodar-RASS profiling system

摘要

The development and characteristics of low level jets (LLJs) over the western site of a knife edge mountain in the Greater Athens area, Greece, is presented. The data were collected for a five-month period, with a commercial sodar-RASS profiling system that was placed at the foot of Mount Hymettus (1026 m) which is located on the north-south axis of the eastern side of the city of Athens. The LLJ cases were classified into three main categories according to the possible forcing mechanism. The classification was based on the background flow, the diurnal course of solar radiation and cloudiness and the atmospheric stability. In order to reveal the mechanism that is responsible for the LLJ occurrences, the non-Coriolis forcing at LLJ heights has been calculated. A simple arithmetic model was applied and the results were compared with experimental findings.