University of Oulu

Noori, R., Bateni, S. M., Saari, M., Almazroui, M., & Torabi Haghighi, A. (2022). Strong warming rates in the surface and bottom layers of a boreal lake: Results from approximately six decades of measurements (1964–2020). Earth and Space Science, 9, e2021EA001973.

Strong warming rates in the surface and bottom layers of a boreal lake : results from approximately six decades of measurements (1964–2020)

Saved in:
Author: Noori, Roohollah1; Bateni, Sayed M.2,3; Saari, Markus1;
Organizations: 1Water, Energy and Environmental Engineering Research Unit, Faculty of Technology, University of Oulu, Oulu, Finland
2Department of Civil and Environmental Engineering, University of Hawaii at Manoa, Honolulu, HI, USA
3Water Resources Research Center, University of Hawaii at Manoa, Honolulu, HI, USA
4Centre of Excellence for Climate Change Research, Department of Meteorology, King Abdulaziz University, Jeddah, Saudi Arabia
5Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich, UK
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.1 MB)
Persistent link:
Language: English
Published: American Geophysical Union, 2022
Publish Date: 2023-01-04


High-latitude lakes are warming faster than the global average with deep implications for life on Earth. Using an approximately six-decade long in situ data set, we explored the changes in lake surface-water temperature (LST), lake deep-water temperature (LDT), lake depth-weighted mean water temperature (LDMT), and ice-free days in Lake Kallavesi, a boreal lake in central Finland, when the lake was stratified (June–August). Our results suggest that the LST is warming faster than the local air temperature (AT). As for the LST, fast warming was also observed in the LDT and LDMT, but at rates slower than those in the LST. The number of ice-free days also shows an upward trend, with a rate of about 7 days per decade during the study period. The corresponding local AT is the main driver of the LST, followed by the ice-free days and annual mean AT. Air temperature and ice-free days also mainly contribute to the changes in the LDMT. The LDT is affected more by the North Atlantic Oscillation signals in this freshwater lake. The AT in the prior months does not affect the LDT in Lake Kallavesi although the AT during the prior season, that is, spring, is the main driver of summer LDT. This highlights the local AT impact on the LDT at time scales longer than a month. The warming rates in the lake water are at a minimum in June because the lake is not yet strongly stratified in this month when compared to July and August. These findings improve our knowledge of long-term changes in the lake water temperature in a high-latitude lake, a region with severe environmental consequences due to fast changes in the AT and lake ice phenology.

see all

Series: Earth and space science
ISSN: 2333-5084
ISSN-E: 2333-5084
ISSN-L: 2333-5084
Volume: 9
Issue: 2
Article number: e2021EA001973
DOI: 10.1029/2021ea001973
Type of Publication: A1 Journal article – refereed
Field of Science: 218 Environmental engineering
1172 Environmental sciences
Funding: The study was funded by the ARCI Visit Grant programme, Profi 4, University of Oulu and Academy of Finland (no 318930).
Copyright information: © 2022 The Authors. Earth and Space Science published by Wiley Periodicals LLC on behalf of American Geophysical Union. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.