Seminar

Abstract

The structure and dynamics of the atmospheric boundary layer (ABL), especially at nighttime, are poorly understood because of a variety of sampling issues, but are very important for many practical applications including Air Quality, Aviation, Climate, Wind Energy, and for improving numerical weather prediction (NWP) model forecasts. Research lidars, designed and developed at the Earth System Research Laboratory (ERSL) of the National Oceanic and Atmospheric Administration (NOAA), have been highly effective in the study of dynamic processes in the atmospheric boundary layer (ABL) providing precise, quantitative data on wind flow properties both inland and offshore. Most of these studies included measurements of wind and turbulence profiles at high spatial and temporal resolution from surface up to several hundred meters aloft. The fine resolution measurements are critical for the rapidly expanding wind-energy industry that requires accurate assessment of wind resources and turbulence structure of the boundary layer at the heights of turbine rotors. The presentation highlights results obtained from the NOAA High Resolution Doppler lidar (HRDL) studies of atmospheric processes that may impact the operational reliability and lifetime of wind turbines and their components, as well as resource assessment, forecasting, and the uncertainty in generated wind power.

Examples of the HRDL measurements during inland field programs in the Great Plains and offshore field programs in the Gulf of Maine will be shown, illustrating wind characteristics e important for the wind energy industry. These examples include low-level jet properties as well as time series and distributions of quantities such as wind speed, direction, and shear through the blade layer. HRDL was also used to obtain simultaneous measurements of vertical and horizontal wind flow features both upwind and downwind of a multi-megawatt wind turbine. Accounting for wakes is an important issue in the optimization of siting turbines in the wind farm, operational strategies to reduce wake effects, and improved design of wind turbines. Overall, the success in the wind energy industry depends on accurate estimation of wind resources and reduced uncertainty in power production. High-resolution lidar data, providing better understanding and modeling of BL processes, also benefit other applications.