Intensification of hot Eurasian summers by climate change and land–atmosphere interactions

• Published in: Scientific reports Vol. 9; no. 1; pp. 10866 - 8
• Main Authors: Sato, Tomonori, Nakamura, Tetsu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.07.2019; Nature Publishing Group
• Subjects: 704/106/125; 704/106/242; 704/106/35/823; 704/106/694/674; Air temperature; Atmosphere; Climate change; Climate effects; General circulation models; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Snow; Soil moisture; Spatial distribution; Temperature; Temperature effects
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-47291-5

Persistent abnormal hot weather can cause considerable damage to human society and natural environments. In northern Eurasia, the recent change in summer surface air temperature exhibits a heterogeneous pattern with accelerated warming around the Eastern European Plain and Central Siberia, forming a wave train-like structure. However, the key factors that determine the magnitude and spatial distribution of this summer temperature trend remain unclear. Here, a huge ensemble of general circulation model (GCM) simulations show that the recent summer temperature trend has been intensified by two factors: steady warming induced by external forcing and inhomogeneous warming induced by internal atmosphere–land interactions that amplify quasi-stationary waves. The latter is sensitive to both snow cover and soil moisture anomalies in the spring, suggesting the potential of land surface monitoring for better seasonal prediction of summer temperatures. Dramatic changes in the circumpolar environment, characterised by Eurasian snow variation and Arctic Ocean warming, collectively affect summertime climate via memory effects of the land surface.