Combining geostationary and polar-orbiting satellite observations for studying the effect of INP on cold clouds

Aerosol particles play a key role on Earth’s radiation budget and indirectly affect climate due to aerosol-cloud interactions (ACI), by acting as ice nucleating particles (INP) during the phase change in mixed-phased clouds. The forcing associated with the modification of cloud optical properties due to aerosol is yet insufficiently understood and represents a large uncertainty in future climate projections. Spaceborne remote sensing is a promising technique for quantifying ACI at a global scale and improving the performance of climate models.

Height-resolved measurements of aerosol optical properties from the Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite are used to estimate the vertical distributions of INP concentrations. Individually tracked clouds from geostationary observations are then matched with the aforementioned concentrations in the vicinity of those clouds. Hence, a bottom-up data set of cold clouds is formed that can be stratified according to different aerosol and cloud properties to investigate the INP effects on ice-containing clouds.