PhD Proposal: Edward Strobach

TITLE: Investigations of Marine Boundary Layer Winds Using a Doppler LIDAR   ABSTRACT: Low-level winds have different characteristics offshore compared to onshore due to air-sea and land-sea interactions. It was recently discovered that low-level winds frequently decrease with height in parts of the Mid-Atlantic, contradicting traditional viewpoints of the vertical wind structure. As a result, research determining the processes that cause decreased winds must be conducted in order to understand the possible impact they may have on the marine boundary layer structure, changes in meteorological conditions, and wind farm power performance. Most of what is understood about how low-level winds change, temporally and spatially, has been limited to onshore studies due to the lack of offshore profile observations. Recently however, researchers have begun to explore the possibility of utilizing remote sensing instruments—particularly Doppler LIDARs (Light Detection and Ranging)—for long-term studies on offshore platforms such as buoys and research vessels. The main objective of this research is to determine whether Doppler LIDARs are suitable instruments for measuring vertical profiles of wind and turbulence near the surface under different meteorological conditions, given that a Doppler LIDAR is mounted on a platform susceptible to wave motion. This research proposes the creation of a motion compensation algorithm tailored to a Doppler LIDAR instrument, which assesses the accuracy of collected measurements under a variety of platform motions and wind conditions dependent on sea state and meteorology. This will be made possible by implementing a forward model that makes use of simulated winds adapted to a Doppler LIDAR system, while incorporating both LIDAR parameters and platform motion from campaigns into a simulation. Results from the forward model will be used in conjunction with wind shear and Line of Sight variance to determine measurement uncertainty through time-height correlations. In addition to the forward model-observational analyses, tower data collected from a fixed platform during the UMES (University of Maryland Eastern Shore) campaign will be compared to compensated results from the moving Doppler LIDAR, which will in turn, be compared to results from the forward model.