Wind Speed Profile Statistics from Acoustic Soundings at a Black Sea Coastal Site

Abstract

More than seven years of remote sensing data with high spatial and temporal resolution were investigated in this study. The 20-min moving averaged wind profiles form the acoustic sounding with Scintec MFAS sodar were derived every 10 min. The profiles covered from 30 to 600 m height with vertical resolution of 10 m. The wind speed probability and the Weibull distribution parameters were calculated by the maximum likelihood method at each level and then the profiles of the Weibull scale and shape parameters were analyzed. Diurnal wind speed at heights above 200 m has shown a well-expressed increase in the averaged values during the night hours, while during the day lower wind speeds were observed. The reversal height was explored from spatially and temporally homogenized diurnal wind speed data with applied quadratic functions for better interpretation of the results. In addition, analyses by type of air masses (land or sea air mass) were performed. One of the outcomes of the study was assessment of the internal boundary layer height, which was estimated to 50–80 m at the location of the sodar. The obtained information forms the basis for climatological insights on the vertical structure of the coastal boundary layer and is unique long-term data set important not only for Bulgaria but for coastal meteorology in general.

Performance Evaluation of LIDAR and SODAR Wind Profilers on the Brazilian Equatorial Margin

“…The LIDAR showed a 2% loss at all heights, while the SODAR had no losses until 170 m in height. At heights higher than this, the SODAR had small performance losses, reaching 12% at 260 m. Even considering the significant difference in latitude and hemisphere, we had considerable similarities in the performance of our SODAR compared to that of [79] (2021), mainly in the place closest to the beach (Praia in Figure 8).…”

“…[79] (2021) analyzed about 7 years of data (from 2008 to 2016) at the Ahtopol Meteorological Observatory, about 400 m away from the Black Sea (Bulgaria) at latitude 42 • 5 2.03 N. The records were taken every 10 min and filtered by a moving average of 20 min between 30 m and 600 m in height, with a 10-m resolution above 150 m. The equipment was also a SODAR Sintec MFAS with frequencies in the range of 1650-2750 Hz and multi-beam operation of nine emission and reception angles (0 • , ±9.3 • , ±15.6 • , ±22.1 • , and ±29 • ). The average efficiency data declined above 120 m (10% failure) and reached 20% failure at about 240 m, decreasing to 50% at 250 m.Even considering the significant difference in latitude and hemisphere, we had considerable similarities in the performance of our SODAR compared to that of[79] (2021), mainly in the place closest to the beach (Praia in Figure8).The average vertical profiles of the horizontal wind speed were calculated by |V| =…”