Long term precipitation trends and variability within the Mediterranean region

Abstract

Abstract. In this study, the trends and variability of annual precipitation totals and annual rain days over land within the Mediterranean region are analyzed. Long term groundbased observations concerning, on one hand, monthly precipitation totals and rain days from 40 meteorological stations within the Mediterranean region were obtained from the Hellenic National Meteorological Service and the World Climate Data and Monitoring Programme (WCDMP) of the World Meteorological Organization. On the other hand, high spatial resolution (0.5 • × 0.5 • ) gridded monthly data CRU TS 3.1 were acquired from the Climatic Research Unit, University of East Anglia, for the period 1901-2009. The two datasets were compared by means of trends and variability, while the influence of the North Atlantic Oscillation (NAO) in the Mediterranean precipitation was examined. In the process, the climatic changes in the precipitation regime between the period 1961-1990 (reference period) and the period 2071-2100 (future climate) were presented using climate model simulations (RACMO2.1/KNMI). The future climate projections were based on SRES A1B.The findings of the analysis showed that statistically significant (95 % confidence level) negative trends of the annual precipitation totals exist in the majority of Mediterranean regions during the period 1901-2009, with an exception of northern Africa, southern Italy and western Iberian peninsula, where slight positive trends (not statistically significant at 95 % CL) appear. Concerning the annual number of rain days, a pronounced decrease of 20 %, statistically significant (95 % confidence level), appears in representative meteorological stations of east Mediterranean, while the trends are insignificant for west and central Mediterranean. Additionally, NAO index was found to be anticorrelated with the Correspondence to: P. T. Nastos (nastos@geol.uoa.gr) precipitation totals and the number of rain days mainly in Spain, southern France, Italy and Greece. These correlations are higher within the rain season (October-March) than the entire year. Based on the results of regional climate model RACMO2.1/KNMI, precipitation is very likely to decrease almost 20 % in the period 2071-2100 compared to 1961-1990

Documenting the complex relationship between self-efficacy, resiliency, and workplace empowerment: a case study of humanitarian workers in Palestine

“…Recent climatological and geological research warns of increased risk of agricultural drought, earthquake, and water scarcity in the eastern Mediterranean and southwestern Asia in the near future (Al-Dabbeek and El-Kelani 2008;Al-Dabbeek 2010;Donat et al 2014;Giorgi and Lionello, 2008;Philandras et al 2011;Givati and Rosenfeld 2013;Lelieveld et al 2012;Salehyan 2008). Combined with Israeli limitations made on capacity for maintenance or repair to public utility systems (for example, waste disposal, sewage treatment, and access to electricity), lack of comprehensive resource database construction and maintenance, and irregular training, these predictions of risk imply greater stress on local humanitarian workers in Palestine to service communities in need (Abd Rabou 2011; Alhindi and Al-Louh 2013;Al-Khatib et al 2007;Barakat and Davis 1997;Erekat et al 2013;Taha et al 2014).…”

Evolution des pluies extrêmes dans le bassin du Chéliff (Algérie) au cours des 40 dernières années 1971–2010

“…La baisse du nombre de jours pluvieux s'explique par une réduction significative des évè-nements pluvieux de faible intensité. Philandras et al (2011) ont analysé la tendance des pluies journalières de 40 stations de la Méditerranée et ont trouvé une réduction significative de 20 % du nombre de jours de pluie à l'Est de la Méditerra- née alors que la tendance est non significative au Centre et à l'Ouest du bassin méditerranéen.…”

Spatio-temporal patterns of meteorological droughts in the Balearic Islands (Spain)

“…There is a generalized agreement within the scientific community on the warming conditions predominant in most of the Mediterranean basin during last decades, where a general increase on average temperatures has been recorded (Repapis et al, 2004;Brunetti et al, 2006;Alpert et al, 2008;Camuffo et al, 2010;Homar et al, 2010). Nevertheless, past evolution and future projections for precipitation are more variable than those of temperature, and present a very high spatiotemporal variability (Sumner et al, 2003;Alpert et al, 2008;Philandras et al, 2011;Quintana-Seguí et al, 2011), which may create more complex drought patterns. In this sense, many studies have addressed meteorological drought patterns analysis within the western Mediterranean region using in-situ observations (Lana et al, 2001;Bonaccorso et al, 2003;VicenteSerrano et al, 2004;Di Lena et al, 2014) and, although they showed predominant drying conditions since the decade of 1970, in most cases they did not found significant trends in the evolution of drought indices.…”