Abstract
While multiple types of remote sensing instruments have been used to investigate wind profiles associated with thunderstorms, the use of profiling Lidars (LIght Detection And Ranging) has been mostly limited to the wind energy sector. Using data from a wind energy company, this study explores the feasibility of profiling lidar data to obtain low-level (<150 m) wind profile information in and near thunderstorms. Two case studies were analyzed in which strong thunderstorms passed over the lidar while the remote sensor was operational and collecting wind speed, wind direction, and vertical velocity profiles at sub-minute resolution. Wind time histories at different levels of the wind profiles revealed that the lidar was able to collect data through the entirety of each event. The time histories also displayed a very typical thunderstorm outflow wind structure that has frequently been observed with in situ anemometry and radar remote sensing. As expected, vertical velocity data were mostly negative (indicating downdraft) during both events and exceeded – 6 m s-1 in one event. A comparison of the lidar data with in situ sonic and cup anemometers was also performed. While only 10-minute anemometer data were available, the limited comparison suggested a high degree of similarity in the mean sense, but standard deviations associated with the 10-minute lidar data were much lower than those of the anemometer data. Though this latter result was not entirely unexpected, it serves to demonstrate some of the issues that should be addressed prior to using profiling lidars in thunderstorms.
Highlights
Knowledge of the low-level wind profile in and near thunderstorms can be useful to many aspects of both atmospheric science and wind engineering
As other studies have demonstrated, the wind profiles of these events were extremely variable during the thunderstorm outflow as well as between the events themselves
A rare look at high-resolution thunderstorm vertical velocities demonstrated that while downdrafts dominated most of the outflow, there were embedded periods of near zero or even positive vertical velocity
Summary
Knowledge of the low-level wind profile in and near thunderstorms can be useful to many aspects of both atmospheric science and wind engineering. Very little information is present in the literature describing the influence of falling hydrometers on lidar-derived vertical velocities (i.e., fall-speed corrections) Such data could contribute to the understanding of thunderstorm inflow environments, low-level outflow structure and even high-resolution numerical model validation. Lidar data from a wind energy developer were acquired and analyzed These data consist of two case studies in which a high-resolution profiling lidar was operating adjacent to a tower instrumented with traditional anemometry (sonic and cup anemometers) as two thunderstorms passed over the complex. The m lidar data used in this study were examined for 180◦ offsets from the m sonic anemometer and wind vane direction data Multiple instances of this error were discovered in the 48 h of data analyzed, but only one appeared to be associated with a thunderstorm outflow on 3 July 2017. While multiple thunderstorm events were recorded throughout the lidar deployment, two events are analyzed in this study: a single-cell thunderstorm that produced a severe wind gust on 3 July 2017 and a non-severe thunderstorm cluster on 23 July 2017
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
