Airborne Doppler Wind Lidar Missions in the Arctic: Low Level Observations and Comparison with Models and other Observing Platforms

As part of two individual NASA funded field campaigns, NASA Langley's DAWN Airborne Doppler Wind Lidar (ADWL) was flown over and around Greenland and Iceland during three week periods in Oct-Nov 2014 and May 2015. These campaign missions were designed to study lower level atmospheric circulations in Arctic regions and to also prepare for future calibration/validation of the ESA ADM-Aeolus space-based wind lidar.

During the 2014 campaign based in Kangerlussuaq, Greenland, DAWN was flown on board the NASA Langley King Air 12-C while the NASA DC-8 was used to fly DAWN during May 2015. NASA's TWiLiTE direct detection ADWL was also flown on board the DC-8 during the May 2015 campaign while the German DLR flew their 2 micron coherent detection ADWL on board a separate Falcon Aircraft. The aircraft and lidars flew in tandem during five of the ten missions in May 2015.

In addition to the wind measurements provided by DAWN and the other lidars, the Polar WRF numerical model with an 8-10 km resolutions was run twice a day for a 48 hour forecast (including winds) during both campaigns. During the May 2015 campaign, we also launched over 80 dropsondes from the DC-8 aircraft.

The main goal of the atmospheric circulation component of the campaigns was to utilize DAWN (and the dropsondes) to measure the lower tropospheric winds and aerosols over the open oceans, land, ice sheets and transition zones of the Arctic, particularly to investigate such features as organized large eddies, stable boundary layers and Arctic low level jets. Another motivation was that, given the scarcity of observations in Arctic regions, it was hoped that these measurements would in turn be used to help in the validation of numerical model and reanalyses characterizations of airflow in the lower atmosphere.

To achieve these goals, we are investigating several important case studies over different wind regimes and different land/water/ice surfaces and will report not only on the high-resolution structure of the arctic lower atmosphere made possible by DAWN but also the inter-comparisons and validation of the different measurements and models.