@article{fdi:010072415,
  title = {{M}odelling extreme dry spells in the {M}editerranean region in connection with atmospheric circulation},
  author = {{T}ramblay, {Y}ves and {H}ertig, {E}.},
  editor = {},
  language = {{ENG}},
  abstract = {{L}ong droughts periods can affect the {M}editerranean region during the winter season, when most of annual precipitation occurs, and consequently have strong impacts on agriculture, groundwater levels and water resources. {T}he goal of this study is to model annual maximum dry spells lengths ({AMDSL}) that occur during the extended winter season ({O}ctober to {A}pril). {T}he spatial patterns of extreme dry spells and their relationships with large-scale atmospheric circulation were first investigated. {T}hen, {AMDSL} were modelled using {G}eneralized {E}xtreme {V}alue ({GEV}) distributions incorporating climatic covariates, to evaluate the dependences of extreme dry spells to synoptic patterns using an analogue approach. {T}he data from a network of 160 rain gauges having daily precipitation measurements between 1960 and 2009 are considered together with the {ERA}-20{C} reanalysis of the 20th century to provide atmospheric variables (geopotential heights, humidity, winds). {A} regional classification of both the occurrence and the duration of {AMDSL} helped to distinguish three spatially contiguous regions in which the regional distributions were found homogeneous. {F}rom composite analysis, significant positive anomalies in geopotential height ({Z}500) and negative anomalies in zonal wind ({U}850) and relative and specific humidity ({S}850, {R}850) were found to be associated with {AMDSL} in the three regions and provided the reference to build analogue days. {F}inally, non-stationary {GEV} models have been compared, in which the location and scale parameters are related to different atmospheric indices. {R}esults indicates, at the whole {M}editerranean scale, that positives anomalies of the {N}orth {A}tlantic {O}scillation index and to a lesser extent the {M}editerranean {O}scillation index are linked to longer extreme dry spells in the majority of stations. {F}or the three regions identified, the frequency of {U}850 negative anomalies over {N}orth {A}frica is significantly associated with the magnitude of {AMDSL}. {AMDL} are also associated with the frequency of 5850 negative anomalies for the southeastern region, and with positive {Z}500 anomalies for the {W}estern and {N}orth-eastern {M}editerranean regions.},
  keywords = {{E}xtreme ; {D}ry spells ; {GEV} ; {M}editerranean ; {ERA}-20{C} ; {MEDITERRANEE} ; {ZONE} {MEDITERRANEENNE}},
  booktitle = {},
  journal = {{A}tmospheric {R}esearch},
  volume = {202},
  numero = {},
  pages = {40--48},
  ISSN = {0169-8095},
  year = {2018},
  DOI = {10.1016/j.atmosres.2017.11.015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072415},
}