Recent recovery of surface wind speed in northwest China

Abstract

Previous studies have reported that much of the surface wind speed (SWS) over the mid-latitudes of the northern hemisphere has declined. However, very few studies have investigated the relatively recent phenomenon of wind recovery. Based on 68 wind data series, this paper examines changes in wind speed in northwest China between 1969 and 2015. In 1992, following a decade of sharply decreasing at a rate of 0.036 m s −1 a −1 (p < .05), the SWS began to significant increase at a rate of 0.004 m s −1 a −1 . The specific reasons for this increase are as follows: (a) The decrease in SWS during the pre-1992 slowdown period is the result of declining wind speeds in spring and summer, whereas increases in wind speed during the post-1992 recovery period are caused by increased wind in winter. (b) The number of days featuring strongly varying wind speeds has changed. Specifically, the number of days above 2 m s −1 all show a significant decreasing trend from 1969 to 1992, whereas the number of days of 1-3 m s −1 shows a significant upward trend from 1993 to 2015. (c) Stations located between 1,000 and 1,500 m.a.s.l. (meter above sea level) are more sensitive to climate change than those at other altitudes, which shows the biggest decline (increase) trend during wind speed slowdown (recovery) period. These stations could potentially act as climatic indicators to predict future wind speed changes. SWS in northwest China have been affected by changes both in large-scale atmospheric circulation and in regional warming. Surface pressure gradient variations between high-and low-latitude regions may be important contributors to wind speed changes under asymmetric warming. However, urbanization is only moderately responsible for trend changes in SWS. K E Y W O R D S climate change, northwest China, surface wind speed, wind recovery 1 | INTRODUCTION Surface wind speed (SWS) links the land surface with the lower atmosphere and partially governs the transfer of energy, water and momentum between the two (Azorin-Molina et al., 2014). Therefore, understanding the evolution of long-term SWS is of great relevance in evaluating coastal erosion (Viles and Goudie, 2003), wind energy (Pryor et al., 2006), pollutant dispersion (Pineda-Martinez et al., 2011), surface energy balance, and hydrological cycle (Roderick et al., 2007). Roderick et al. (2007) first proposed the concept of "wind stilling" to explain the observed decrease in pan-evaporation in Australia. McVicar et al. (2012) furtherperformed a meta-analysis of 148 regions. Their studies show that declines in SWS are geographically wide-spread, with declines in both hemispheres in the tropics and mid-latitudes, and increases at high-latitudes (i.e.,~>70 latitude). Meanwhile, based on observational evidence at two mountainous regions, McVicar et al. (2010) reported that nearsurface wind speeds were declining more rapidly at higher elevations than those at lower ones. It is worth mentioning that over the past 30-50 years in mid-latitude regions, the SWS declined from −0.004 m s −1 a −1 to...

Variability of Daily Maximum Wind Speed across China, 1975–2016: An Examination of Likely Causes

“…Our analyses of the relationship of the observed DMWS anomalies with three teleconnection indices with synoptic features concord with previous studies on mean wind speed (Gong and Ho 2003;Lin et al 2013;Y. Li et al 2018).…”

“…Despite the fact that no previous China DMWS study applied a homogenization method (Table 1), similar spatial patterns were found herein when compared to those regional studies (Wang et al 2015;Dong et al 2018). Moreover, significant (p , 0.05) changepoints were also detected in our DMWS series, which might be associated with the decadal variability of large-scale atmospheric circulation as previous studies stated (e.g., Azorin-Molina et al 2018b;Y. Li et al 2018).…”

“…The rapid warming in high and middle latitudes of the Eurasian continent observed in the last few decades (IPCC 2013) could weaken the meridional temperature gradient (Guo et al 2011;Lin et al 2013). This will modify large-scale pressure gradient through thermal adaption (Lin et al 2013;Y. Li et al 2018), which consequently affects DMWS dynamics.…”

“…Following previous studies where the relationships between daily mean wind speed variability and teleconnection indices were investigated in China (e.g., L. Y. Li et al 2018), three atmospheric circulation modes were chosen to assess for the first time the influence of large-scale atmospheric circulation changes on observed DMWS variability.…”

Stilling and Recovery of the Surface Wind Speed Based on Observation, Reanalysis, and Geostrophic Wind Theory over China from 1960 to 2017

“…This conclusion has been verified in many other studies (Achberger et al 2006;Dumitrescu et al 2014;Earl et al 2013;McVicar et al 2008;Minola et al 2016;Vautard et al 2010). Recent studies have found SWS recovery phenomena since the last decade over Saudi Arabia (Azorin-Molina et al 2018a), South Korea (Kim and Paik 2015), and China (Li et al 2018;Lin et al 2013). More details about global wind speed change in recent years can be found in the overviews of Wu et al (2018a) and Hartfield et al (2018).…”