DOI: 10.1007/s00382-015-2718-7
Scopus记录号: 2-s2.0-84966269087
论文题名: Impact of euro‑Atlantic blocking patterns in iberia precipitation using a novel high resolution dataset
作者: Sousa P.M. ; Barriopedro D. ; Trigo R.M. ; Ramos A.M. ; Nieto R. ; Gimeno L. ; Turkman K.F. ; Liberato M.L.R.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 46, 期: 7 起始页码: 2573
结束页码: 2591
语种: 英语
英文关键词: Atmospheric blocking
; Cyclones
; Extremes
; Iberian Peninsula
; Precipitation
英文摘要: In this work we reassess the impacts of blocking patterns on precipitation regimes in the Iberian Peninsula, distinguishing between north Atlantic and European blocking. For this we take full advantage of the recently developed high-resolution datasets for the Iberian countries. Precipitation anomalies during blocking events obtained with this dataset allow a much finer regional characterization of the impacts in both average and extreme daily precipitation, particularly when compared to widely used low-resolution reanalysis datasets. Blocked patterns induce a negative-positive dipole of precipitation anomalies from northwest to southeast Iberia. Increases are widespread during Atlantic blocks and pronounced in southern and eastern areas of Iberia, while during European blocks they are more spatially restricted, with increases above 50 % in coastal Mediterranean areas, which represents a considerable fraction of the annual precipitation. Blocking impacts in precipitation are nearly opposite to those found during strong zonal flow situations, but there are also some asymmetries in the precipitation responses. A significant increase in cyclones and cut-off lows frequency southwards of blocking structures is related to precipitation excesses over southern and eastern areas, where dynamical factors and local processes play a crucial role. On the contrary, precipitation deficits in northwest Iberia during blocking episodes are better explained by a reduction in north Atlantic frontal activity and simultaneous decreases in large-scale moisture advection towards northern Iberia. We show that these anomalies during blocking result from changes in precipitation amount rather than from increases in rainy days, pointing to more extreme rainfall regimes, particularly in southeastern Iberia. Finally, an Extreme Value Analysis was performed, fitting Generalized Pareto Distributions to precipitation extremes. Results show that the different extreme precipitation regimes of northwest and Mediterranean regions are partially determined by opposite anomalies of the zonal flow. Thus, heavy precipitation events in Mediterranean areas are usually short-lived and frequently associated with blocking conditions, while in northwest Iberia the total accumulations during rainfall episodes are more important for triggering extreme events and they are mainly related to strong westerly flows. © Springer-Verlag Berlin Heidelberg 2015. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53773
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; Departamento de Física de la Tierra II, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain; Instituto de Geociencias (IGEO), CSIC-UCM, Madrid, Spain; EPhysLab (Environmental Physics Laboratory), Universidad de Vigo, Ourense, Spain; Centro de Estatística e Aplicações, Universidade de Lisboa, University of Lisbon, Lisbon, Portugal; Escola de Ciências e Tecnologia, Universidade de Trás-os-Montes e Alto Douro, UTAD, Vila Real, Portugal
Recommended Citation:
Sousa P.M.,Barriopedro D.,Trigo R.M.,et al. Impact of euro‑Atlantic blocking patterns in iberia precipitation using a novel high resolution dataset[J]. Climate Dynamics,2016-01-01,46(7)