Detection of long range transport of aerosols with elevated layers over high altitude station in the central Himalayas: A case study on 22 and 24 March 2012 at ARIES, Nainital

An advanced version of Boundary Layer LiDAR system, termed as LiDAR for atmospheric measurement and probing (LAMP) has been operational, at Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, a high altitude station, in central Himalayas, since October 2011. The site is at an altitude, which is well above the planetary boundary layer particularly during the night when observations are taken and thus, lies in the free troposphere. Also, there are no anthropogenic sources of aerosols nearby. However, from March to June, due to strong convection, the aerosols get transported to higher altitudes, up to 2 km or more, from the nearby urban and distant regions as well. Here, a case study of each long range transport and convectively driven elevated aerosol layers, observed with LAMP on 22 and 24 March 2012, has been presented. The lowest aerosol layer observed on 24 and 28 March 2012 in vertical aerosol backscatter profile is attributed to the transport from adjoining regions via boundary layer evolution and associated mixing.