Identifying Ice Hydrometeor Signatures Above Summit, Greenland Using a Multi-Instrument Approach

Abstract:

Ground-based microwave radiometers are commonly used to retrieve precipitable water vapor and liquid water path. These retrievals, however, may be adversely affected by ice hydrometeors, especially during ice precipitation events, which can be observed in mixed phase clouds. We establish that ice hydrometeors produce enhanced brightness temperatures in high frequency ground-based passive microwave observations. This effect is evident in several years of summer season microwave radiometer data collected at Summit Station, Greenland. Using a multi-instrument suite and coupling measurements with well-established gas and liquid absorption models, we can quantify the ice hydrometeor signature. Better knowledge of these ice effects on the passive microwave observations aids in improvement of retrieved properties, such as liquid water path, when ice is present in the column. Additionally, the use of the active cloud radar guides what regimes exhibit predominately ice precipitation. By clearly identifying the ice signature in the high frequency microwave, we establish a unique platform that can be used to assess ice habit models and particle size distributions for Arctic environments.