University of Oulu

Rasmus, S., Kivinen, S., Irannezhad, M. (2018) Basal ice formation in snow cover in Northern Finland between 1948 and 2016. Environmental Research Letters, 13 (11), 114009. doi:10.1088/1748-9326/aae541

Basal ice formation in snow cover in Northern Finland between 1948 and 2016

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Author: Rasmus, Sirpa1,2; Kivinen, Sonja3; Irannezhad, Masoud4,5
Organizations: 1Arctic Centre, University of Lapland
2Department of Biological and Environmental Science, University of Jyväskylä
3Department of Geographical and Historical Studies, University of Eastern Finland
4School of Environmental Science and Engineering, Southern University of Science and Technology (SUSTech)
5Water Resources and Environmental Engineering Research Group, University of Oulu
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.1 MB)
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Language: English
Published: IOP Publishing, 2018
Publish Date: 2018-12-28


Basal ice formation in the terrestrial snow cover is a common phenomenon in northern circumpolar areas, one having significant impacts on ecosystems, vegetation, animals and human activities. There is limited knowledge on the spatial and temporal occurrence of basal ice formation because of the sparse observation network and challenges involved in detecting formation events. We present a unique dataset on the annual extent of ice formation events in northern Finland between 1948 and 2016 based on reindeer herders’ descriptions of the cold season in their management reports. In extreme years, basal ice can form over wide geographical extents. In approximately half of the herding districts studied, it occurred more frequently in the period 1983–2016 than in the period 1948–1982. Furthermore, five out of seven of the most extensive basal ice formation events (90th percentile) occurred between 1991 and 2016. The most commonly reported processes related to ice formation were thaw or rain-on-snow events followed by freezing of the snow cover. Years with extensive basal ice formation were often characterized by above-average October–December air temperatures, air temperature variations around 0 °C and relatively high precipitation. However, basal ice did not occur during all warm and wet early winters, and formation events were generally weakly linked to the large-scale atmospheric teleconnections. Another risk factor for reindeer grazing associated with warm and rainy early winters is the growth of mycotoxin-producing molds below the snow. Approximately 24% of all reported mold formation events co-occurred with basal ice formation. The prevalence and frequency of basal ice formation events can be assessed based on our results. Our work contributes to understanding long-term fluctuations and changes in snow and ice conditions and the impacts of this variability in circumpolar areas.

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Series: Environmental research letters
ISSN: 1748-9326
ISSN-E: 1748-9326
ISSN-L: 1748-9326
Volume: 13
Issue: 11
Article number: 114009
DOI: 10.1088/1748-9326/aae541
Type of Publication: A1 Journal article – refereed
Field of Science: 1172 Environmental sciences
Funding: Sirpa Rasmus' work has been funded through the project 'Changing operational environment of Finnish reindeer herding' by the Finnish Cultural Foundation and NCoE ReiGN by NordForsk.
Dataset Reference: Supplementary data:
Copyright information: © 2018 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.