Impact of seasonal diurnal variation characteristics of low-level jet on wind energy utilization in Taklimakan Desert

Abstract

With the development of the wind turbines becoming taller and taller, the height of wind turbines has entered the range of maximum wind shear influence of low-level jets. As an important wind and solar energy base in China, the Taklimakan region in Xinjiang is widely distributed with low-level jets in the east direction. In order to deepen the understanding of the low-level wind field in the Taklimakan region and clarify the potential impact of low-level jets on wind energy utilization. Using the hourly ERA5 reanalysis model level data in 2017, based on the wind profile characteristics of the Taklimakan region and the definition of low-level jets, the criterion to identify the strong and weak low-level jets is given based on the height and vertical shear of the maximum wind speed and wind speed threshold. The determination criteria for low-level jet day is defined through the coverage and duration of the low-level jets. The spatiotemporal distribution and intraseasonal variation characteristics of the low-level jets in the Taklimakan desert were analyzed. In 2017, there were 183 days that met the conditions for the criteria of low-level jets day, with the most days in summer(50 days) and the fewest days in winter(11 days). The result show that the low-level jets over the Taklimakan Desert has significant periodicity only in the diurnal scale. The diurnal variation trends of wind speed and height of strong and weak low-level jets in different seasons are basically the same, but there are differences in wind speeds. It is stronger in spring and summer than in autumn and winter.

Keywords

low-level jet / taklimakan desert / diurnal variation / wind energy utilization / multitaper power spectral density estimation