Recent trends in daily temperature extremes over northeastern Spain (1960–2006)

Abstract

Abstract. Spatial and temporal characteristics of extreme temperature events in northeastern Spain have been investigated. The analysis is based on long-term, high-quality, and homogenous daily maximum and minimum temperature of 128 observatories spanning the period from 1960 to 2006. A total of 21 indices were used to assess changes in both the cold and hot tails of the daily temperature distributions. The presence of trends in temperature extremes was assessed by means of the Mann-Kendall test. However, the autocorrelation function (ACF) and a bootstrap methodology were used to account for the influence of serial correlation and cross-correlation on the trend assessment. In general, the observed changes are more prevalent in hot extremes than in cold extremes. This finding can largely be linked to the increase found in the mean maximum temperature during the last few decades. The results indicate a significant increase in the frequency and intensity of most of the hot temperature extremes. An increase in warm nights (TN90p: 3.3 days decade −1 ), warm days (TX90p: 2.7 days decade −1 ), tropical nights (TR20: 0.6 days decade −1 ) and the annual high maximum temperature (TXx: 0.27 • C decade −1 ) was detected in the 47-yr period. In contrast, most of the indices related to cold temperature extremes (e.g. cold days (TX10p), cold nights (TN10p), very cold days (TN1p), and frost days (FD0)) demonstrated a decreasing but statistically insignificant trend. Although there is no evidence of a longterm trend in cold extremes, significant interdecadal variations were noted. Almost no significant trends in temperature variability indices (e.g. diurnal temperature range (DTR) and growing season length (GSL)) are detected. Spatially, the coastal areas along the Mediterranean Sea and the Cantabrian Correspondence to: A. El Kenawy (kenawy@ipe.csic.es) Sea experienced stronger warming compared with mainland areas. Given that only few earlier studies analyzed observed changes in temperature extremes at fine spatial resolution across the Iberian Peninsula, the results of this work can improve our understanding of climatology of temperature extremes. Also, these findings can have different hydrological, ecological and agricultural implications (e.g. crop yields, energy consumption, land use planning and water resources management).

Трендови Индекса Екстремних Температура У Босни И Херцеговини ‒ Примјер Мостара

“…Позитивни/негативни трендови топлих/ хладних температурних индекса већ су утврђени бројним студијама широм региона Медитерана (Fioravanti, G. et al, 2016;Kioutsioukis, I. et al, 2010;Varfi, M. S. et al, 2009;Kostopoulou, E. & Jones, P. D., 2005;Fernández-Montes, S. & Rodrigo, F. S., 2012;Fonseca, D. et al, 2016;Kenawy, A. E. et al, 2011;Espirito Santo, F. et al, 2014). Истраживања у медитеранском и субмедитеранском дијелу југоисточне Европе, гдје се налази Босна и Херцеговина, утврдила су пораст топлих температурних индекса и смањење хладних, што указује на загријавање климатског система током друге половине 20. trends in extreme temperature indices have also been found in Europe (Klein Tank, A. M. G. & Können, G. P., 2003;Andrade, C. et al, 2012;Dankers, R. & Hiederer, R., 2008).…”

“…The upward/downward trends in warm/cold temperature indices have already been determined by numerous studies all over the Mediterranean region (Fioravanti, G. et al, 2016;Kioutsioukis, I. et al, 2010;Varfi, M. S. et al, 2009;Kostopoulou, E. & Jones, P. D., 2005;Fernández-Montes, S. & Rodrigo, F. S., 2012;Fonseca, D. et al, 2016;Kenawy, A. E. et al, 2011;Espirito Santo, F. et al, 2014). Studies in the Mediterranean and Submediterranean part of the Southeast Europe where Bosnia and Herzegovina is located have also reported an increase in warm temperature indices and a decrease in cold ones, thus indicating the warming of climate system during ТАТЈАНА ПОПОВ, СЛОБОДАН ГЊАТО И ГОРАН ТРБИЋ TATJANA POPOV, SLOBODAN GNJATO AND GORAN TRBIĆ вијека и на почетку 21. вијека (Branković, Č. et al, 2013;Zaninovic, K. & Cindric, K., 2014;Burić, D. et al, 2014;Burić, D. et al, 2015).…”

Recent trends in daily temperature extremes over southern Montenegro (1951–2010)

“…In Spain, numerous studies (Brunet et al, 2007;Rodriguez-Puebla et al, 2010) assessed trends in temperature extremes, and Brunet et al (2007) noted larger changes in high temperature extremes than in low temperature extremes over the 20th century. While analysing temperature extreme indices in northeast Spain, El Kenawy et al (2011) also observed more prevalent changes in hot extremes than in cold extremes. Toreti and Desiato (2008) analysed changes in temperature extremes over Italy and showed a cooling trend until the end of the 1970s followed by a warming trend over the last 25 yr.…”

Modernization of new irrigated lands in a scenario of increasing water scarcity: from large reservoirs to small ponds

“…The severity of droughts because of the occurrence of long periods with anomalous low precipitation is being also enhanced because of the increased potential evapotranspiration in Spain , and the decrease identified in relative humidity between 1961 and 2011 (Vicente-Serrano et al, 2014). Such trends have been accompanied by an increase in the mean maximum temperature during the last few decades, including also an increase in the frequency and magnitude of warm nights, warm days and tropical nights for the period 1960(El Kenawy et al, 2011. The consequence in the landscape of the rainfed areas of the Central Ebro basin has been a trend toward decreased vegetation cover, behaving as an early warning of landscape degradation in semi-arid Mediterranean areas (Vicente-Serrano et al, 2012;Gouveia et al, 2016;Vicente-Serrano, 2016).…”