Heat waves in lowland Germany and their circulation-related conditions

Abstract

The research study aimed at assessing multiannual variability of heat wave occurrence in the lowland part of Germany between 1966 and 2015 and determining the role of atmospheric circulation in their occurrence. The analysis was conducted with the use of two independent datasets, that is, the dataset of Germany's National Meteorological Service, Deutscher Wetterdienst, and American meteorological reanalysis database of the National Centre for Environmental Prediction/National Centre for Atmospheric Research. This article defines a hot day as a day with maximum temperature of [30°C, and a heat wave as a sequence of at least three such days. The observed warming translated into an increase in a number of hot days and, consequently, an increase in the frequency of heat wave occurrence. In the analysed 50-year period, the smallest number of heat waves was observed between 1976 and 1985, and the largest number between 2006 and 2015 in the lowland part of Germany. The occurrence of heat waves in lowland Germany was related to anticyclonic circulation.

Occurrence of strong and very strong heat stress in Poland and its circulation conditions

“…The data were obtained from the collections of the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis (Kalnay et al 1996) available in the archives of NOAA ESRL PSD (Earth System Research Laboratory Physical Science Division). The selection of the level of 300 hPa was made based on previously published study results, evidencing that the greatest anomalies of geopotential heights are recorded in the upper troposphere (Chen et al 2017;Tomczyk 2018). Moreover, the level is commonly used in synoptics (WMO 2010).…”

Thermal Conditions in the City of Poznań (Poland) during Selected Heat Waves

“…In turn, three heat waves occurred in the city area, but they were not recorded in the Poznań-Ławica station. These were the waves of 2008 (30 May-3 June), 2009 (29 June-4 July) and 2011 (3)(4)(5)(6)(7)(8). Across the city, the longest heat wave was recorded in August 2015.…”

“…The consequence of the aforementioned changes is the increasingly frequent occurrence of hot days and heat waves [2][3][4][5][6]. The waves of 2003, 2006, 2010 and 2015 are to be highlighted amongst the recent extreme heat waves of Poland and Europe.…”

Thermal conditions in the summer season on the Polish coast of the Baltic Sea in 1966-2015

“…These authors adopted a definition of characteristic days based on relative thresholds (the basis was the 95th percentile of T max ), and not on absolute values as in this article, which resulted in showing different rates of change. The increase in the number of warm and hot days has been demonstrated in numerous studies concerning the area of Poland (Ustrnul et al, 2010;Tomczyk, 2014;Owczarek and Filipiak, 2016;Sulikowska et al, 2016;Bartoszek and Krzyżewska, 2017), as well as other European regions (Avotniece et al, 2010;Kundzewicz and Huang, 2010;Kažys et al, 2011;Tomczyk and Bednorz, 2016;Tomczyk and Sulikowska, 2017). The increasing occurrence of warm and hot days has been also translated into the more frequent occurrence of heat waves.…”

“…According to Krzyżewska (2010), extreme weather phenomena cause not only a decrease in profits from tourism, but also pose a threat to human life and health. This has been particularly important in the last decades, in which an increase in the frequency of hot days and heat waves is observed (Sulikowska et al, 2016;Tomczyk and Bendorz, 2016;Tomczyk and Sulikowska, 2017), which results in a significant increase in the number of deaths caused by biometeorological conditions affecting human body systems (Kuchcik, 2001;Paldy and Bobvos, 2009;Bobvos et al, 2015;Revich et al, 2015). The progressive climate warming will also have a positive impact by extending the summer tourist season mitigating the seasonality phenomenon and, consequently, also the environmental nuisance (Koźmiński and Michalska, 2016a).…”