A1 Journal article (refereed)
Variability and drivers of winter near-surface temperatures over boreal and tundra landscapes (2024)

Tyystjärvi, V., Niittynen, P., Kemppinen, J., Luoto, M., Rissanen, T., & Aalto, J. (2024). Variability and drivers of winter near-surface temperatures over boreal and tundra landscapes. Cryosphere, 18, 403-423. https://doi.org/10.5194/tc-18-403-2024

JYU authors or editors

Publication details

All authors or editors: Tyystjärvi, Vilna; Niittynen, Pekka; Kemppinen, Julia; Luoto, Miska; Rissanen, Tuuli; Aalto, Juha

Journal or series: Cryosphere

ISSN: 1994-0416

eISSN: 1994-0424

Publication year: 2024

Publication date: 29/01/2024

Volume: 18

Pages range: 403-423

Publisher: Copernicus GmbH

Publication country: Germany

Publication language: English

DOI: https://doi.org/10.5194/tc-18-403-2024

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/93278

Abstract

Winter near-surface air temperatures have important implications for ecosystem functioning such as vegetation dynamics and carbon cycling. In cold environments, the persistence of seasonal snow cover can exert a strong control on the near-surface temperatures. However, the lack of in situ measurements of both snow cover duration and surface temperatures over high latitudes has made it difficult to estimate the spatio-temporal variability in this relationship. Here, we quantified the fine-scale variability in winter near-surface air temperatures (+2 cm) and snow cover duration (calculated from temperature time series) using a total of 441 microclimate loggers in seven study areas across boreal and tundra landscapes in Finland during 2019–2021. We further examined the drivers behind this variation using a structural equation model and the extent to which near-surface air temperatures are buffered from free-air temperatures during winter. Our results show that while average winter near-surface temperatures stay close to 0 ∘C across the study domain, there are large differences in their fine-scale variability among the study areas. Areas with large topographical variation, as well as areas with shallow snowpacks, showed the greatest variation in near-surface temperatures and in snow cover duration. In the tundra, for example, differences in minimum near-surface temperatures between study sites were close to 30 ∘C and topography was shown to be an important driver of this variability. In contrast, flat topography and long snow cover duration led to little spatial variation, as well as long periods of decoupling between near-surface and air temperatures. Quantifying and understanding the landscape-wide variation in winter microclimates improves our ability to predict the local effects of climate change in the rapidly warming boreal and tundra regions.

Keywords: temperature; snow cover; climate changes; weather phenomena

Contributing organizations

Related projects

Ministry reporting: Yes

VIRTA submission year: 2024

Preliminary JUFO rating: 3