Time lapse imagery of the ice-on event at Darfáljávri (Lake Tarfala), Kebnekaise mountains, northern Sweden, autumn 2024
Nina Kirchner, Johanna Dahlkvist, Jamie Barnett, Daniella Lillieroth Charalambous
This dataset contains images of Darfáljávri taken every 2 hours (irrespective of day- or nighttime) during the period from 24 September, 2024 to 31 October, 2024. During this period, the surface of Darfáljávri transitions from being ice-free to ice-covered, an event referred to as "ice-on".
The dataset can be used to observe the ice-on event and to assign a date to it. Knowledge of lake ice phenology, i.e. seasonal formation and loss of the lacustrine ice cover, is of importance since the timing of ice-on impacts lake processes such as stratification and vertical mixing.
The pictures were acquired using a camera positioned on the mountain flank along Darfáljávri’s north-eastern shore, at 1220 m above sea level. In total, there are 443 images. The later the season, the more pictures are dark because of the approaching of the polar night.
LacustrineLake IceDarfáljávriLake TarfalaTarfalaLake iceLake ice phenologyIce-on
Download dataScientific highlights
This dataset allows to assign a precise date to the ice-on event at Darfáljávri in autumn 2024. Defining ice-on as the first occasion after the ice-free summer season on which the lake becomes completely ice-covered and remains so for the rest of the winter, it was attained on 09 October, 2024.
Some notable events in the time-lapse imagery of the establishing lake ice cover include:
Pre-ice-on
- 26 September: Pronounced ripples on lake surface (picture 24).
- 07 October: First occasion of clearly identifiable thin ice layer formation on central lake surface (picture 153).
Ice-on
- 09 October: First occasion of clearly identifiable ice cover across the entire lake surface (picture 177).
- 11 October: Patterning of snow cover on frozen lake surface (picture 204).
- 18 October: Ice surface appears wet (picture 285). Coincides with positive air temperatures since 17 October after previous prevailing negative temperatures.
- 22 – 24 October: Camera lense apparently partly frozen (pictures 331, 340).
- 31 October: Snow accumulating and thickening over entire frozen lake surface (picture 443).
Picture numbers in the scientific highlights correspond to picture numbers in the dataset. Note that the camera produces black-white images under certain light conditions, such as during dusk and dawn and under some low-visibility weather conditions.
Name
Version
Citation
References
Kirchner N, Weckström J, Jansen J, Schenk F, Barnett J, Granebeck A, Leppäranta M, Korhola A (2024) Water temperature, mixing, and ice phenology in the arctic–alpine Lake Darfáljávri (Lake Tarfala), northern Sweden. Arctic, Antarctic, and Alpine Research 56. https://doi.org/10.1080/15230430.2023.2287704
Data description
The dataset consists of image files (JPG) of Darfáljávri, with the date and time (Swedish daylight saving time, UTC+2) included in each photo. Image file names are numbered in chronological order.
The pictures were acquired using a camera positioned on the mountain flank along Darfáljávri’s north-eastern shore, at ~67.9° N, 18.6° E, at 1220 m above sea level.
The data were collected using a Hunter Orion Trail Camera 4G. The camera elevation is 1.8 m above ground. Each JPG file has a size of ~2.3 MB. The total size of the dataset is ~1.05 GB
During a few short periods, fog, snow and/or rain obscures the view of the lake. Also, due to shorter periods of daylight during autumn, the number of dark images between dusk and dawn successively increases.
Project
The data were collected as part of a project within the Arctic Avenue Spearhead Research project between Stockholm University and the University of Helsinki, Finland, running between 2019 and 2022. Data is collected solely by Tarfala Research Station since 2023. The support of our co-workers on the Arctic Avenue activity Lake thermal and mixing dynamics under changing climate (J. Weckström, K. Weckström, A. Korhola, and F. Schenk) is gratefully acknowledged.
Publisher
Bolin Centre Database
License
First name
Nina
Last name or organisation
Kirchner
Email address
Address
Tarfala Research Station and Department of Physical Geography; Stockholm University
Postal code
SE-106 91
City
Stockholm
Country
Sweden
GCMD science keyword
Earth science
GCMD location
Continent > Europe > Northern Europe > Scandinavia > Sweden
Dataset language
English
Begin date
2024-09-24
End date
2024-10-31