Dagens bild 7 februari 2019
Frans Josefs Land
Kalla och ensliga öar vilka tillhör Ryssland. Årsmedeltemperatur är -18 grader.
Endast militärer från Ryssland bor här.
From the end of the nineteenth century, air temperature increased more sharply in the Arctic that elsewhere on Earth (e.g. Budyko 1974; Przybylak 2000, 2007, 2016; Alekseev 2003; Overland et al. 2004; IPCC 2013). For example, Svalbard (land data) in the period 1865–1920 was markedly colder than nowadays (1981–2010) by about 3 °C (Przybylak et al. 2016). In approximately the last 140 years, there have been two periods of significant temperature increases in the Arctic. The first began in around 1918–1920 and lasted until 1938 and has been called the ‘1930s warming’ (Bengtsson et al. 2004). Other works have referred to this period as the ‘Early Twentieth Century Warming’ (ETCW, Brönnimann 2009) or the ‘Early Twentieth Century Arctic Warming’ (ETCAW, Wegmann et al. 2017, 2018). Our results confirm the observations for the last expedition from the historical study period in 1930/1931. These years covered the warmest part of the ETCW (Table 3, Fig. 4). In turn, the second increased warming of the Arctic began around 1980 (Johannessen et al. 2004) or according to Przybylak (2007) in about the mid-1990s. Changes in overall atmospheric circulation have long been believed to have been the cause of the ETCW (e.g. Scherhag 1937). As the modern climate warming (since 1975) has progressed in a largely similar manner to the progression of the ETCW (Wood and Overland 2010; Semenov and Latif 2012), there has been renewed interest in the insufficiently well-explained causes of the ETCW using the latest research methods, including, primarily, climate models. An analysis of the literature shows that the cause of such a significant warming in the present period is still not clear
Summarising the key results of the analyses conducted in the study, it can be concluded that on FJL:
Air temperature in 1899–1914 during three expeditions was 1.8–4.6 °C lower than the modern period in winter (Oct–Apr). However, during the 1930/31 expedition it was 4.6 °C warmer than the years 1981–2010. Our results relate to what has been called the ‘1930s warming’, referred to by various authors in the literature as the ETCW or the ETCAW.
Wind speeds in three expeditions (1903/1904, 1913/1914 and 1930/1931) were 0.6–2.2 m s−1 higher than at present. Decidedly weaker winds than at present (by 2.1 m s−1) were recorded during the 1899–1900 expedition.
WCT values in the 1903/1904 and 1913/1914 expedition years were lower (by 6.4 and 2.0 °C, respectively) than at present. In the winter (Oct–Apr) of the 1899–1900 and 1930/31 expeditions, the threat to human health was less than at present (by 1.3 and 4.0 °C, respectively).
Uppgifter hämtade från:
10 jan 2019