Articles | Volume 9, issue 9
Research article
07 Sep 2016
Research article |  | 07 Sep 2016

Ceilometer evaluation of the eastern Mediterranean summer boundary layer height – first study of two Israeli sites

Leenes Uzan, Smadar Egert, and Pinhas Alpert

Abstract. Active remote-sensing instruments, such as ceilometers, have been shown to be potentially useful for the investigation of the behavior of the atmospheric mixing layer height (MLH). For the first time ever, high-resolution measurements of backscatter intensity, taken from two CL31 ceilometers situated inland and onshore of Israel, have enabled evaluation of the mean diurnal cycle of the MLH in the eastern Mediterranean region. Although the Israeli summer synoptic conditions are considered to be quite stable, results for the summer season (July–August 2014) showed the inland MLH to be about 200 m higher than the MLH at the onshore site, situated only 7.5 km away. The prevailing influence of the sea breeze front (SBF), as it progresses inland, is presented by the ceilometer plots. Complementing results were found between the radiosonde profiles and the adjacent ceilometer at the inland site of Beit Dagan. In contrast to the expected regularity of clear skies during the Israeli summer, the ceilometers revealed significant cloud cover throughout the day, with higher presence onshore. Assessment of cloud thickness in further research would serve to improve the evaluation of the MLH evolution.

Short summary
Compared to other regions, the eastern Mediterranean is rich in aerosol content and dust storms but poor in atmospheric measurements. This research is a first attempt in Israel to estimate the diurnal mixed layer height (MLH) based on CL31 ceilometers using the wavelet covariance transform (WCT) method. Simultaneous measurements, onshore and inland, showed a significant difference of 200 m of the MLH between the two sites, only 7.5 km apart, which complies well with radiosonde profiles.