Aerosol optical depth over the mountainous region in central Asia (Issyk‐Kul Lake, Kyrgyzstan)

Aerosol optical depth measurements over Issyk‐Kul Lake acquired with the handheld sun photometer Microtops II are analyzed. Aerosol found over the mountainous region at the elevation of 1650 m above sea level resembles mostly clean background conditions. The yearly aerosol optical depth at a wavelength 500 nm ∼0.10 ± 0.03 is in agreement with the multi‐year means from the background sites of the Aerosol Robotic Network (AERONET). Over a period of 4 years optical depth showed a seasonal pattern, with a maximum observed during summer. A link has been made between new and previously acquired data in order to provide a reliable trend for the region.