DOI: 10.1175/JCLI-D-14-00286.1
Scopus记录号: 2-s2.0-84907841747
论文题名: Multidecadal variations in the relationship between the NAO and winter precipitation in the Hindu Kush-Karakoram
作者: Filippi L. ; Palazzi E. ; Von Hardenberg J. ; Provenzale A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 20 起始页码: 7890
结束页码: 7902
语种: 英语
Scopus关键词: Multidecadal variations
; Winter precipitation
; decadal variation
; evaporation
; jet stream
; moisture transfer
; North Atlantic Oscillation
; precipitation (climatology)
; precipitation intensity
; secular variation
; westerly
; wind velocity
; winter
; Arabian Sea
; Arabian Sea
; Himalayas
; Indian Ocean
; Persian Gulf
英文摘要: Winter precipitation over the Hindu Kush-Karakoram (HKK) range in the western Himalayas is generated by westerly perturbations whose dynamics is affected by the North Atlantic Oscillation (NAO). Larger precipitation is typically recorded during the positive NAO phase. In this work, the relationship between the NAOand winter precipitation in theHKKis explored further, using an ensemble of precipitation datasets and the 40-yr ECMWF Re-Analysis (ERA-40) and Twentieth Century Reanalysis (20CR) data. The mechanisms underlying this relationship are discussed, with a focus on the secular variations that occurred in the last century. The NAO exerts its control on HKK precipitation by altering the intensity of westerly winds in the region of the Middle East jet stream (MEJS). Results indicate that evaporation from the Persian Gulf, the northern Arabian Sea, and the Red Sea plays an important role. During positive NAO phases, westerlies are strengthened and enhanced evaporation occurs from these basins owing to higher surface wind speed. The extra moisture combines with stronger westerlies and results in enhanced moisture transport toward the HKK. Precipitation datasets covering the twentieth century show an alternation of periods of strong and weaker influence of theNAOon precipitation in the HKK. It is found that these variations are associated with changes in the spatial pattern of the NAO: the relative position of the two centers of action of the NAO determines to what extent it can modulate the MEJS, affecting precipitation in the HKK. © 2014 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51052
Appears in Collections: 气候变化事实与影响
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作者单位: Institute of the Atmospheric Sciences and Climate ISAC-CNR, Dipartimento di Ingegneria Meccanica e Aerospaziale, Politecnico di Torino, Torino, Italy; Institute of the Atmospheric Sciences and Climate, ISAC-CNR, Torino, Italy
Recommended Citation:
Filippi L.,Palazzi E.,Von Hardenberg J.,et al. Multidecadal variations in the relationship between the NAO and winter precipitation in the Hindu Kush-Karakoram[J]. Journal of Climate,2014-01-01,27(20)