Moisture intrusion into the arctic stratosphere linked to ozone depletion events

Abstract:

The investigation of cloud formation mechanisms in the UTLS (Upper-Troposphere/Lower-Stratosphere) is a core activity of the CSA SACIA (Signatures of Aerosol-Cloud Interaction over the Arctic) project. In previous communications, we reported on possible atmospheric circulation mechanisms by which water vapor, the cardinal driver of cloud formation, was lifted to the tropopause and even into the stratosphere. The latter case was associated with the formation of Polar Stratospheric Cloud (PSC) and attendant ozone depletion (PSCs being initiators of chemical ozone depletion reactions). The link between the air mass / moisture transport and cloud formation is critical: the wind and particle remote sensing measurements provided by the Aeolus satellite is an important tool in understanding this link. In addition, PSC particle size retrieval using combined Calipso/CloudSat profiles was attempted in order to identify the PSC nucleation zones. The Suomi NPP temperature and humidity profiles, provided by the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) served to contextualize the Calipso/CloudSat findings. The link between ozone loss, moisture dynamics and cloud formation was also analyzed using the ground-based CANDAC (Canadian Network for the Detection of Atmospheric Change) Rayleigh-Mie-Raman LiDAR (CRL) and ECCC radiosonde profiles acquired at Eureka, Nunavut, Canada.