Design of an Autonomous Polarized Raman Lidar for Arctic Observations

A dearth of high-spatial and temporal resolution measurements of atmospheric state variables directly inhibits scientific understanding of the impact of radiation and precipitation on the changing surface climate of the Greenland Ice Sheet (GIS). Specifically, more reliable and frequent measurements are needed to better constrain model predictions of the sources and sinks of the GIS. To partially address the lack of observations over the GIS, a new autonomous polarized Raman lidar system, which will measure water vapor mixing ratio, temperature, extinction, and cloud phase profiles, is under development for deployment to Summit Camp, Greenland (72° 36'N, 38° 25'W, 3250m). This high-altitude Arctic field site has co-located ancillary equipment such as a Doppler millimeter cloud radar, microwave radiometers, depolarization lidars, ceilometer, an infrared interferometer and twice-daily radiosondes which are all part of the Integrated Characterization of Energy, Clouds Atmospheric State and Precipitation at Summit (ICECAPS) project deployed as part of the Arctic Observing Network (AON). The current suite of instruments allows for a comprehensive picture of the atmospheric state above Summit but increased spatial and temporal resolution of temperature and water vapor are needed to reveal the detailed microphysical information necessary to fully understand the role of clouds over the GIS. This information is particularly relevant given the near-total surface melt event of the GIS in 2012 and the recent unprecedented loss of GS mass in the last decade. In this presentation, a system description will be provided, with emphasis the features necessary for autonomous, full diurnal operation, and how the new system will help to fill the observation gap within the already existing sensor suite.