Quasi-coincident observations of polar stratospheric clouds by ground-based lidar and CALIOP at Concordia (Dome C, Antarctica) from 2014 to 2018

Polar stratospheric clouds (PSCs) have been observedfrom 2014 to 2018 from the lidar observatory at theAntarctic Concordia station (Dome C), included as a primarystation in the NDACC (Network for Detection of AtmosphericClimate Change). Many of these measurementshave been performed in coincidence with overpasses of thesatellite-borne CALIOP (Cloud Aerosol Lidar with OrthogonalPolarization) lidar, in order to perform a comparison interms of PSC detection and composition classification. Goodagreement has been obtained, despite intrinsic differences inobservation geometry and data sampling. This study reports,to our knowledge, the most extensive comparison of PSC observationsby ground-based and satellite-borne lidars.The PSCs observed by the ground-based lidar andCALIOP form a complementary and congruent dataset andallow us to study the seasonal and interannual variations inPSC occurrences at Dome C. Moreover, a strong correlationwith the formation temperature of NAT (nitric acid trihydrate),TNAT, calculated from local temperature, pressure,and H2O and HNO3 concentrations is shown. PSCs appearat Dome C at the beginning of June up to 26 km and start todisappear in the second half of August, when the local temperaturesstart to rise above TNAT. Rare PSC observations inSeptember coincide with colder air masses below 18 km.