Ground-Based Millimeter- and Submillimiter Wave Observations of the Arctic Atmosphere

Ground-based millimeter(mm)- and submillimeter (submm)-wave observations were collected during the Arctic winter by a new 25-channel scanning radiometer. Theoretical analysis and observations are shown to demonstrate the enhanced sensitivity of mm- and submm-wave radiometers with respect to conventional instruments, such microwave radiometers and global positioning system, to small changes in water vapor and liquid at low contents. A quantitative analysis of mm- and submm-wavelength sensitivity was carried out, yielding factors from 1.5 to 69 (3 to 4) for integrated water vapor (liquid water) content when compared to 20-30 GHz radiometers. A weighting function analysis illustrates the capability to retrieve atmospheric temperature, humidity, and liquid path from ground-based scanning radiometer (GSR) observations in the extreme conditions of the Arctic winter. Finally, we show preliminary results for the retrievals, and we discuss the path of the future research