Influence of Topography and the Underlying Surface of the Bohai Sea on Wind and Gust Forecasts

Abstract

Wind is defined as the movement of air parcels in a particular direction. The wind speed detected by meteorological instruments increases or decreases suddenly as a result of the different amounts of kinetic energy carried by each air parcel. Peak wind gusts, defined as the maximum based on running mean wind speeds in a short sampling period, are a sudden increase in wind speed caused by air parcels with high kinetic energies (Huschke, 1959). Gusts are closely related to physical parameters such as the mean wind speed, the boundary layer turbulence, the roughness of the underlying surface and the atmospheric stability (Cheng et al., 2012;Letson et al., 2018;Vickery & Skerlj, 2005). Gust records are also affected by instrument characteristics and sample intervals (Holmes & Ginger, 2012).The World Meteorological Organization (WMO) (2018), has specified the mean wind speed as the average wind speed over 10 min and the gust wind speed as the maximum of 3-s running mean wind speed (WMO, Harper

Comparison of Spring Wind Gusts in the Eastern Part of the Tibetan Plateau and along the Coast: The Role of Turbulence

“…Turbulence may arise from complex topography and may contribute to the strong local characteristics of the wind gusts [11][12][13]. Harper et al [14] reported that the various bottom surface properties of the ocean and land lead to distinct turbulence and wind gusts under diverse substrates (e.g., inland, off-land, off-sea and offshore), indicating that wind gusts have significant sea-land differences.…”

“…Harper et al [14] reported that the various bottom surface properties of the ocean and land lead to distinct turbulence and wind gusts under diverse substrates (e.g., inland, off-land, off-sea and offshore), indicating that wind gusts have significant sea-land differences. Similarly, Wang et al [13] classified the Bohai Sea and its coastal areas into four regions based on topography and analyzed every region's peak gust climatology through observations. They found that a rough bottom surface stimulated stronger turbulence and increased the peak gust and gust factor.…”