I. Ungureanu, S. Stefan, D. Nicolae, Investigation of the cloud cover and planetary boundary layer (PBL)  characteristics using ceilometer CL-31, Romanian Reports in Physics, 62/2 (2010) 396-404.

Title: Investigation of the cloud cover and planetary boundary layer (PBL) characteristics using ceilometer CL-31

Abstract: The aim of the present paper is to present applications of the ceilometer measurements for the study of the cloudiness, cloud types and the characteristics of the Planetary Boundary Layer (PBL).The PBL is the layer where earth’s surface interacts with the large scale atmospheric flow. The ceilometer CL-31 is a mini-lidar used in remote sensing measurements, especially for the cloud bases. The data used for this study were obtained as results of the measurements performed in Magurele (44.35 N, 26.03 E) for a long winter (November 2008-March 2009). The CL-VIEW and Lab-View programs were used for data processing to obtain the images and vertical backscatter profiles. The images allow to determine the cloud types, the presence of the aerosol layers, precipitation and the fog. The results of the images and vertical profiles analysis have shown the most cases of stratus clouds in this period. The appearance of altocumulus or cirrus clouds is connected to the air masses advection. The special cases with precipitation or aerosol intrusions were discussed in connection with meteorological parameters, using HYSPLIT4 model and synoptic situations. The large cloudiness and precipitation periods were confirmed by meteorological data. This emphasizes the applicability of the ceilometer’s data in characterizing of the PBL.

Key words: ceilometer, clouds, aerosols, PBL