Ground-based measurement technologies: Observation of the tropospheric aerosol by using a Mie Lidar. Observation at the arid region in China

Abstract

Intensive observations of the tropospheric aerosols were made at Shapotou, Ningxia province, China in the period from March to May 2001. Preliminary analysis of the data shows the following features. 1) A dense atmospheric dust layer always existed in the lowermost troposphere whose top was 2 to 3 km above the ground surface. It is considered that the layer corresponded to the local mixing layer. 2) Distinct dust layers sometimes appeared at height around 4 or 5 km. It is considered that these layers were on the way of long-range transport. 3) In May, there was a case in which tops of the local dust layer reached up to height around 5 km. In such a condition, injection of the dust into free atmosphere might have occurred easily. 4) Generally, aerosol optical depth was small in the early morning, and large in the period of afternoon to the evening. However, maximum optical depth was observed in the midnight in several eases.