Search

A ground-based backscatter Lidar, operating at 355nm was setup at the roof top of School of Physics, Universiti Sains Malaysia to study the aerosol content around Penang Island. During the operation of the Lidar, it had successfully obtained information on two haze events that struck Penang Island, which occurred during the month of July 2013 and March 2014, respectively. It was found that these two haze events showed different characteristics, such as the numbers and thickness of the aerosol layers. Multiple layers of aerosol were found in haze event during March 2014 and the aerosol layers were very thick. In contrast, only a single layer of aerosol was found in the haze event during July 2013 and the aerosol layer was relatively thin. Columnar aerosol optical depth (AOD) of these two haze events also showed some differences. Columnar AOD for the haze event occurred in July 2013 varied between 1.00±0.11 to 1.82±0.01, while columnar AOD for haze event occurred during March 2014 varied between 0.47±0.15 to 3.03±0.05. Finally, by combining HYSPLIT backtrajectories and MODIS satellite data, the possible origin of the haze aerosol was determined. It was found that the haze aerosol is either produced inside Malaysia or by neighboring countries which was later brought to Penang by monsoon wind. [ABSTRACT FROM AUTHOR]

Haze is a phenomenon which occurs when there is a great amount of tiny particulates suspended in the atmosphere. During the period of March 2014, a long period of haze event occurred in Penang, Malaysia. The haze condition was measured and monitored using a ground-based Lidar system. By using the measurements obtained, we evaluated the performance of the ECMWF MACC-II model. Lidar measurements showed that there was a thick aerosol layer confined in the planetary boundary layer (PBL) with extinction coefficients exceeding values of 0.3 km-1. The model however has underestimated the atmospheric conditions in Penang. Backward trajectories analysis was performed to identify aerosols sources and transport. It is speculated that the aerosols came from the North-East direction which was influenced by the North-East monsoon wind and some originated from the central eastern coast of Sumatra along the Straits of Malacca. [ABSTRACT FROM AUTHOR]