20Th-Century Changes of Temperature in the Mountain Regions of Central Europe

Abstract

Daily maximum and minimum temperatures from 29 low-lying and mountain stations of 7 countries in Central Europe were analyzed. The analysis of the annual variation of diurnal temperature range helps to distinguish unique climatic characteristics of high and low altitude stations. A comparison of the time series of extreme daily temperatures as well as mean temperature shows a good agreement between the low-lying stations and the mountain stations. Many of the pronounced warm and cold periods are present in all time series and are therefore representative for the whole region. A linear trend analysis of the station data for the period 1901-1990 (19 stations) and 1951-1990 (all 29 stations) shows spatial patterns of similar changes in maximum and minimum daily temperatures and diurnal temperature range. Mountain stations show only small changes of the diurnal temperature range over the 1901-1990 period, whereas the low-lying stations in the western part of the Alps show a significant decrease of diurnal temperature range, caused by strong increase of the minimum temperature. For the shorter period 1951-1990, the diurnal temperature range decreases at the western low-lying stations, mainly in spring, whereas it remains roughly constant at the mountain stations. The decrease of diurnal temperature range is stronger in the western part than in the eastern part of the Alps.

Increasing silicon concentrations in Bohemian Forest lakes

“…The increase of Si in lakes of the Alps was accompanied by an increase in base cations that was explained by an increase in the rate of weathering induced by climate warming (SommarugaWögrath et al, 1997). The present study is in an area of warming (Weber et al, 1997;Schär et al, 2004) and a negative effect of temperature on Al concentrations in the same lakes has been observed. While the solubility of BSi and weathering rate increase with temperature, the solubility of the secondary aluminosilicates decreases.…”

Changes in temperature and temperature gradients in the French Northern Alps during the last century

“…Nevertheless, the evolution of the temperatures in the Alps departs from that observed in the Northern Hemisphere starting in the 1970s. Such congruence of the temperature evolution in a mountain area with the global temperatures over the XXth century, followed by an uncoupling in the 70s and 80s has also been described in other mountainous regions (Weber et al, 1997;Beniston et al, 1997;Beniston, 2005;Bhutiyani et al, 2007). It has also been reported that, within a century timeframe, the rise in temperatures in mountainous areas is not always greater than that of the surrounding plains (Weber et al, 1997;Colombo et al, 2007;Rangwala and Miller, 2010).…”

“…Other authors have however suggested that the warming trends could be different depending on the elevation (e.g., Rebetez 2001 ;. Some studies of climate change in upland areas in other Alpine regions have shown that warming is sometimes more marked at higher altitudes (Bücher and Dessens, 1991;Weber et al, 1997). Similarly, based on data collected in Switzerland over the past 30 years, Rebetez and Reinhard, (2007) further argue that below 1100 m, the low stations display a stronger trend than the more elevated areas, whereas above this level the warming is greater at higher than at lower elevations.…”

“…Previous studies of temperature have illustrated the complex relationship between temperature and relief (Angot, 1892;Harding, 1978;Douguedroit and Saintignon, 1984;Bücher and Dessens, 1991;Beniston et al, 1994;Beniston et al, 1997;Weber et al, 1997;Diaz and Bradley, 1997;Böhm et al, 2001;Rolland, 2003;Beniston, 2006;Barry, 2008). Local factors, such as topography, can interfere with the overall interpretations made at regional scales.…”

“…For instance, valleys in close relation to one another might show very different intra-or inter-annual climate evolutions. In addition, a number of factors can come into play to modulate the temperatures measured by weather stations in mountain areas: altitude, orientation, valley shape, and location Weber et al, 1997). Altitude is nevertheless the most influential of these parameters, as montly and yearly temperatures are closely related to altitude.…”