Recent trends in wind speed across Saudi Arabia, 1978–2013: a break in the stilling. (29th January 2018)

• Record Type: Journal Article
• Authors: Azorin‐Molina, Cesar; Rehman, Shafiqur; Guijarro, Jose A.; McVicar, Tim R.; Minola, Lorenzo; Chen, Deliang; Vicente‐Serrano, Sergio M.
• Is Part Of: International journal of climatology. Volume 38(2018)Supplement 1
• Page Start: e966
• Page End: e984
• Publication Date: 2018-01-29
• Subjects: wind speed -- trends -- stilling break -- teleconnection indices -- Saudi Arabia; Climatology -- Periodicals; Climat -- Périodiques; Climatologie -- Périodiques; 551.605
• DOI: 10.1002/joc.5423
• Languages: English
• ISSNs: 0899-8418

Abstract

ABSTRACT: We analyse recent trends and variability of observed near‐surface wind speed from 19 stations across Saudi Arabia (SA) for 1978–2013. The raw wind speed data set was subject to a robust homogenization protocol, and the stations were then classified under three categories: (1) coast, (2) inland and (3) mountain stations. The results reveal a statistically significant ( p < 0.05) reduction of wind speed of −0.058 m s −1 dec −1 at annual scale across SA, with decreases in winter (−0.100 m s −1 dec −1 ) and spring (−0.066 m s −1 dec −1 ) also detected, being non‐significant in summer and autumn. The coast, inland and mountain series showed similar magnitude and significance of the declining trends across all SA series, except for summer when a decoupled variability and opposite trends of wind speed between the coast and inland series (significant declines: −0.101 m s −1 dec −1 and −0.065 m s −1 dec −1, respectively) and the high‐elevation mountain series (significant increase: +0.041 m s −1 dec −1 ) were observed. Even though wind speed declines dominated across much of the country throughout the year, only a small number of stations showed statistically significant negative trends in summer and autumn. Most interestingly, a break in the stilling was observed in the last 12‐year (2002–2013) period (+0.057 m s −1 dec −1 ; not significant) compared to the significant slowdown detected in the previous 24‐year (1978–2001) period (−0.089 m s −1 dec −1 ). This break in the slowdown of winds, even followed by a non‐significant recovery trend, occurred in all seasons (and months) except for some winter months. Atmospheric circulation plays a key role in explaining the variability of winds, with the North Atlantic Oscillation positively affecting the annual wind speed, the Southern Oscillation displaying a significant negative relationship with winds in winter, spring and autumn, and the Eastern Atlantic negatively modulating winds in summer. Abstract : Wind speed declined significantly across Saudi Arabia for 1978–2013. A recent break in the stilling has been detected for 2002–2013. Atmospheric circulation modes partly explain the variability of surface winds.