M. Makarova (SPbUSt. Petersburg St. U.) – Measurements using a Bruker IFS 125HR (resolution up to 0.002 cm-1) began in 2009. The observation site is located in a suburb of greater St. Petersburg. Retrieval algorithms: SFIT4 (V.0.9.4.4), PROFFIT 9.6. Ancillary atmospheric observations include those made using a UV/Vis. spectrometer, a microwave radiometer, and an aerosol lidar (ceilometer). Measurements affiliated with the Aerosol Robotic Network (AERONET) are also conducted.