DOI: 10.1002/2015GL065819
论文题名: The importance of rare, high-wind events for dust uplift in northern Africa
作者: Cowie S.M. ; Marsham J.H. ; Knippertz P.
刊名: Geophysical Research Letters
ISSN: 0094-8571
EISSN: 1944-8302
出版年: 2015
卷: 42, 期: 19 起始页码: 8208
结束页码: 8215
语种: 英语
英文关键词: dust emission
; ERA-Interim
; interannual variability
; northern Africa
; surface observations
; thresholds
Scopus关键词: Dust
; Probability density function
; Dust emission
; Era interims
; Interannual variability
; northern Africa
; Surface observation
; thresholds
; Wind
; annual variation
; dust
; emission inventory
; frequency analysis
; probability density function
; threshold
; wind forcing
; wind velocity
; North Africa
英文摘要: Dust uplift is a nonlinear thresholded function of wind speed and therefore particularly sensitive to the long tails of observed wind speed probability density functions. This suggests that a few rare high-wind events can contribute substantially to annual dust emission. Here we quantify the relative roles of different wind speeds to dust-generating winds using surface synoptic observations of dust emission and wind from northern Africa. The results show that winds between 2 and 5 m s-1 above the threshold cause the most emission. Of the dust-generating winds, 25% is produced by very rare events occurring only at 0.1 to 1.4% of the time, depending on the region. Dust-producing winds are underestimated in ERA-I, since it misses the long tail found in observations. ERA-I overpredicts (underpredicts) the frequency of emission strength winds in the southern (northern) regions. These problems cannot be solved by simple tunings. Finally, we show that rare events make the largest contribution to interannual variability in dust-generating winds and that ERA severely underestimates this interannual variability. Key Points Winds between 2 and 5 m/s above emission thresholds dominate emission Events occurring at 0.1 to 1.4% of the time cause 25% of dust-generating winds Tuning cannot correct ERA-I, which does not capture interannual variability © 2015. The Authors. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946963013&doi=10.1002%2f2015GL065819&partnerID=40&md5=4769e23d9c85118f79453db79c2f9bb1
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8187
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Institute for Climate and Atmospheric Science, School of Earth and Environment, University of Leeds, Leeds, United Kingdom
Recommended Citation:
Cowie S.M.,Marsham J.H.,Knippertz P.. The importance of rare, high-wind events for dust uplift in northern Africa[J]. Geophysical Research Letters,2015-01-01,42(19).