smadar egert

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, ...

On September 7th 2015, an unprecedented dust storm approached the East Mediterranean (EM) basin. The storm origin was in the Iran, Iraq, Syria and the Turkey border. The Israeli meteorological service considered the storm as exceptional due to its extent of over 6 days, occurrence time in early September and concentrations reaching values 100 times the normal. Previous studies examined the formation and evolution of the dust storm synoptic scale and explained why aerosol models often failed to simulate it. This study concentrates on spatial and vertical meso-scale dust spreading over Israel based on several remote sensing instruments including eight micro light detection and ranging (LIDAR) ceilometers. The ceilometers high resolution attenuated backscatter profiles (every 10 m and 15 s) reveal the downward motion of elevated dust plume as it penetrated Israel, ground coverage and gradual dispersion. The additional data of spectral radiometers and ground particulate ma...

Both hardware and software methods are used to extend LIDAR detection capability in terms of range resolution and concentration threshold. Non overlapping targets are used at different ranges along the LIDAR line of sight (LOS) to replace the dependence on low aerosol backscattering. Methods of signal processing are used in concentration calculations. Presented experimental data demonstrate the method capability.

A standoff detection of atmospheric tracer dispersion in a military installation, using active and passive remote sensors, was demonstrated in a field test. System performance was evaluated at various atmospheric conditions, different forms of tracer release and different rates of release. Source locations as well as sensors positions were varied between test. A network of point detectors was used as