Doppler Aerosol WiNd (DAWN) Lidar from CPEX 2017: Convective Process Studies and Comparisons with Other Wind Measurement Sensors and Numerical Models

In May-June 2017, NASA conducted the airborne 2017 Convective Processes in the Tropics Experiment (CPEX) which featured the Doppler Aerosol WiNd (DAWN) lidar along with dropsondes and other remote sensing instruments aboard a NASA DC-8 aircraft to study convective processes and circulations in the tropics. Sixteen NASA DC-8 missions were flown into the Gulf of Mexico (GoM), Caribbean Sea, and the Atlantic Ocean where a comprehensive set of observations (particularly winds from DAWN and the dropsondes) were taken near isolated, scattered, and organized deep convection during all phases of the convective life cycle.

As will be shown, DAWN can provide high resolution (4 -12 km in the horizontal and 35 – 150 m in the vertical) wind measurements from the surface to 8-10 km in undisturbed as well as convective conditions. Comparison with other wind measurements such as those from dropsondes, cloud motion vectors and ocean buoys will be presented.

During the CPEX missions, the NASA DC-8 flew a series of “boxes” with ~100 Km sides over the GoM and Caribbean Sea during varying degrees of convection. Mass divergence budgets computed through the vertical column of these boxes under the different convective states will be presented and discussed. We will also provide comparisons between the DAWN observations and budgets and those computed from WRF model forecasts provided by the University of Utah. In addition, the DAWN measurements are also being assimilated into the WRF model and their impact on forecast of Tropical Cindy will be illustrated.