Technical Note: One year of Raman-lidar measurements in Gual Pahari EUCAARI site close to New Delhi in India – Seasonal characteristics of the aerosol vertical structure

摘要

One year of multi-wavelength (3 backscatter + 2 extinction + 1depolarization) Raman lidar measurements at Gual Pahari, close to New Delhi,were analysed. The data was split into four seasons: spring (March–May),summer (June–August), autumn (September–November) and winter (December–February). The verticalprofiles of backscatter, extinction, and lidar ratio and their variabilityduring each season are presented. The measurements revealed that, onaverage, the aerosol layer was at its highest in spring (5.5 km). In summer,the vertically averaged (between 1–3 km) backscatter and extinctioncoefficients had the highest averages (3.3 Mm sr and 142 Mmat 532 nm, respectively). Aerosol concentrations were slightlyhigher in summer compared to other seasons, and particles were larger insize. The autumn showed the highest lidar ratio and high extinction-relatedÅngström exponents (AE), indicating the presence of smallerprobably absorbing particles. The winter had the lowest backscatter andextinction coefficients, but AE was the highest, suggesting still alarge amount of small particles.