Changes in the Duration of European Wet and Dry Spells during the Last 60 Years

Abstract

Daily rain gauge data over Europe for the period from 1950 to 2009 were used to analyze changes in the duration of wet and dry spells. The duration of wet spells exhibits a statistically significant growth over northern Europe and central European Russia, which is especially pronounced in winter when the mean duration of wet periods increased by 15%–20%. In summer wet spells become shorter over Scandinavia and northern Russia. The duration of dry spells decreases over Scandinavia and southern Europe in both winter and summer. For the discrimination between the roles of a changing number of wet days and of a regrouping of wet and dry days for the duration of the period, the authors suggest a fractional truncated geometric distribution. The changing numbers of wet days cannot explain the long-term variability in the duration of wet and dry periods. The observed changes are mainly due to the regrouping of wet and dry days. The tendencies in duration of wet and dry spells have been analyzed for a number of European areas. Over the Netherlands both wet and dry periods are extended in length during the cold and the warm season. A simultaneous shortening of wet and dry periods is found in southern Scandinavia in summer. Over France and central southern Europe during both winter and summer and over the Scandinavian Atlantic coast in summer, opposite tendencies in the duration of wet and dry spells were identified. Potential mechanisms that might be responsible for the changing durations of wet and dry periods and further perspectives are discussed.

Characteristics of consecutive dry days variations in China

“…CDD means the maximum number of consecutive days with precipitation less than a certain threshold which varies (Frich et al 2002;Nastos and Zerefos 2009;Zolina et al 2013). Considering the vast regional climate differences in China, we adopt the low threshold of 0.1 mm/day for better regional comparisons rather than 1 mm/day.…”

Current Climatic Variability of Extreme Precipitation in Russia

“…Однако их анализ также важен для понимания механиз-мов, приводящих к возникновению сильных осадков. Наконец, третья груп-па характеристик и, соответственно, третий подход, предполагает анализ продолжительности и интенсивности периодов с непрерывными осадками (Zolina et al, 2010(Zolina et al, , 2013. Эта характеристика существенно отличается от первых двух.…”

“…Нами был развит метод, позволяющий рассчитать вклад различ-ных долей суммарного количества дней с осадками в сезонные или месячные суммы осадков в предположении аппроксимации распределения всей вы-борки Гамма-распределением (Zolina et al, 2009(Zolina et al, , 2013. Гамма-распределе-ние относится к семейству экспоненциальных распределений, определенных в положительной области.…”

Partial duration series distributions of the European dry spell lengths for the second half of the twentieth century

“…In the last decades, numerous analyses related to dry spell lengths, DSL, have been applied in different regions, as the Iberian Peninsula (Martín-Vide and Gómez 1999 ;Vicente-Serrano 2003;Serra et al 2006 ;Lana et al 2006a, b , 2008a, b , Sánchez et al 2011, Greece (Anagnostopoulou et al 2003 ;Nastos and Zerefos 2009 ), Croatia (Cindrić et al 2010 ), Eastern Mediterranean (Kutiel 1985 ;Kostopoulou and Jones 2005 ), Italy (Brunetti et al 2002 ), Switzerland (Schmidli and Frei 2005 ), France (Galloy et al 1982 ;Douguédroit 1987 ), Belgium (Berger and Goossens 1983 ), Norway (Perzyna e.Proofing http://eproofing.springer.com/journals/printpage.php?token=XH5Or7J6x... 1994 ), Brazil (Carvalho et al 2013 ), Iran (Sarhadi and Heydarizadeh 2014 ), Argentina (Llano and Penalba 2011 ), USA (Groisman and Knight 2008 ), China (Gong et al 2005 ;She et al 2013 ), Europe (Heinrich and Gobiet 2011 ;Serra et al 2013Serra et al , 2014Zolina et al 2013 ) and West Africa (Sivakumar 1992 ), among others.…”