Investigating Wintertime Cloud Microphysical Properties and Their Relationship to Air Mass Advection at Ny-Alesund, Svalbard Using the Synergy of a Cloud Radar？Ceilometer？Microwave Radiometer

Abstract

This study investigates the relationship of cloud properties and radiative effects with air mass origin during the winter (November-February, 2016-2020) at Ny-Alesund, Svalbard, through a combination of cloud radar, ceilometer, and microwave radiometer measurements. The liquid cloud fraction (CF) was less than 2%, whereas the ice CF predominantly exceeded 10% below 6 km. The liquid water content (LWC) of mixed-phase clouds (LWCmix), which predominantly exist in the boundary layer (CFmix: 10-30%), was approximately four times higher than that of liquid clouds (LWCliq). Warm air mass advection (warm(adv)) cases were closely linked with strong southerly/southwesterly winds, whereas northerly winds brought cold and dry air masses (cold(adv)) to the study area. Elevated values of LWC and ice water content (IWC) during warm(adv) cases can be explained by the presence of mixed-phase clouds in the boundary layer and ice clouds in the middle troposphere. Consistently, the r(e) of ice particles in warm(adv) cases was approximately 5-10 mu m larger than that in cold(adv) cases at all altitudes. A high CF and cloud water content in warm(adv) cases contributed to a 33% (69 W m(-2)) increase in downward longwave (LW) fluxes compared to cloud-free conditions.