Application of Doppler Wind Lidar Observations to Improve Scientific Understanding and Forecasting of Extreme Weather Events

For nearly 30 years, the atmospheric research community has been aware that pulsed laser-based Doppler wind lidars (DWL) promised new insights to the evolution of severe weather such as tropical cyclones, tornadic storms and mesoscale convective complexes. Although there have been a few airborne pulsed DWL field campaigns in this period, advances in the lidar technology and investment in its utility for atmospheric studies is now accelerating, being targeted at not only basic research but also operational meteorology and a future space-based mission. Recent (2008) experiments in the western Pacific involved two airborne pulsed DWL systems in a focused investigation of typhoon genesis and intensification. Results from that effort are now going into the design of an ambitious program of hurricane research using airborne lidars on such platforms as NOAA’s P3, NASA’s DC8 and Global Hawk and the Navy’s P3 and Twin Otter. If all goes as planned, within the next 5 years there will be more than 1000 flight hours of pulsed DWL equipped aircraft collecting data that has the potential to transform the way in which we monitor and predict the lifecycles of severe storms.

NASA Langley Research Center has a long history of developing 2-micron laser transmitter for wind sensing. With support from NASA Laser Risk Reduction Program (LRRP) and Instrument Incubator Program (IIP), NASA Langley Research Center has developed a state-of-the-art compact lidar transceiver for a pulsed coherent Doppler lidar system for wind measurement.

Recently, LaRC 2-micron coherent Doppler wind lidar system was selected to contribute to the NASA Science Mission Directorate (SMD) Earth Science Division (ESD) hurricane field experiment in 2010 titled Genesis and Rapid Intensification Processes (GRIP). The Doppler lidar system will measure vertical profiles of horizontal vector winds from the DC-8 aircraft using an existing 2-micron, pulsed, coherent detection, Doppler wind lidar system that is ready for DC-8 integration. The measurements will typically extend from the DC-8 to the earth’s surface. They will be highly accurate in both wind magnitude and direction. Displays of the data will be provided in real time on the DC-8. The pulsed Doppler wind lidar is much more powerful than past Doppler lidars. The operating range, accuracy, range resolution, and time resolution will be unprecedented. We expect the data to play a key role, combined with the other sensors, in improving understanding and predictive algorithms for hurricane strength and track.