Streletskiy, Dmitry A; CALM; GTN-P; Wieczorek, Mareike; Heim, Birgit; Bartsch, Annett (2025): GTN-P CALM: 35 years of Active Layer Thickness (ALT) across latitudinal and elevational gradients in the Northern Hemisphere [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.972777
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Published: 2025-09-09 • DOI registered: 2025-10-10
Abstract:
The Global Terrestrial Network for Permafrost (GTN‐P) established by the International Permafrost Association (IPA) and WMO under the GCOS and GTOS networks is the primary international global program for monitoring the permafrost Essential Climate Variables (ECVs). Active Layer Thickness (ALT) is formulated as one important ECV by WMO and GCOS. The presented data collection is based on ALT data collected and managed by the Circumpolar Active Layer Monitoring Network-CALM under GTN‐P / IPA. The CALM observational network observes the long-term response of the active layer and near-surface permafrost to climate change over multi-decadal time scales in the Northern and the Southern hemisphere. The CALM activities and data are hosted on the CALM website (http://www.gwu.edu/~calm) and updated regularly. The data collection presented here contains 263 ALT time series located in the Northern Hemisphere and spans 35 years (1990-2024) of annual (discontinuous) ALT. The ALT time-series cover the Arctic and mountain permafrost in the Swiss Alps and Asia, latitudinal and elevation gradients, making these records unique and providing an important snapshot of the state of permafrost across these complex landscapes. The data provided here has been assembled from the original data sources and optimized by the validation team in the ESA Permafrost_cci project for the validation of the Permafrost_cci ALT time series maps.
Related to:
Nelson, Frederick E; Shiklomanov, Nikolay I; Nyland, Kelsey E (2021): Cool, CALM, collected: the Circumpolar Active Layer Monitoring program and network. Polar Geography, 44(3), 155-166, https://doi.org/10.1080/1088937X.2021.1988001
Westermann, Sebastian; Barboux, Chloé; Bartsch, Annett; Delaloye, Reynald; Grosse, Guido; Heim, Birgit; Hugelius, Gustaf; Irrgang, Anna Maria; Kääb, Andreas Max; Matthes, Heidrun; Nitze, Ingmar; Pellet, Cécile; Seifert, Frank Martin; Strozzi, Tazio; Wegmüller, Urs; Wieczorek, Mareike; Wiesmann, Andreas (2024): ESA Permafrost Climate Change Initiative (Permafrost_cci): Permafrost active layer thickness for the Northern Hemisphere, v4.0 [dataset]. NERC EDS Centre For Environmental Data Analysis, https://doi.org/10.5285/D34330CE3F604E368C06D76DE1987CE5
Project(s):
CCI Permafrost (ESA_CCI_Permafrost_CCN2)
Coverage:
Median Latitude: 62.748101 * Median Longitude: 146.994497 * South-bound Latitude: 31.816670 * West-bound Longitude: 7.273075 * North-bound Latitude: 81.400720 * East-bound Longitude: -20.552800
Date/Time Start: 1990-01-01T00:00:00 * Date/Time End: 2024-01-01T00:00:00
Minimum Elevation: -1.0 m * Maximum Elevation: 4788.0 m
Event(s):
CALM_C1 (C1, Alexandria Fiord) * Latitude: 78.883330 * Longitude: -75.916670 * Elevation: 0.0 m * Location: Canada * Method/Device: Sampling permafrost (PERM) * Comment: PI: Greg Henry, Method: Spatially-oriented mechanical probing at 100 m Grid or Transect
CALM_C3A (C3 A, North Head) * Latitude: 69.719720 * Longitude: -134.461900 * Elevation: 12.0 m * Location: Canada * Method/Device: Sampling permafrost (PERM) * Comment: PI: Caroline Duchesne, Sharon Smith, Method: Thaw tube measurements
CALM_C3B (C3 B, North Head) * Latitude: 69.719720 * Longitude: -134.461900 * Elevation: 12.0 m * Location: Canada * Method/Device: Sampling permafrost (PERM) * Comment: PI: Caroline Duchesne, Sharon Smith, Method: Spatially-oriented mechanical probing at 100 m Grid or Transect
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | Wieczorek, Mareike | |||
| 2 | Site | Site | Wieczorek, Mareike | Site Code | ||
| 3 | Name | Name | Wieczorek, Mareike | Site Name | ||
| 4 | Identification | ID | Wieczorek, Mareike | GTN-P ID | ||
| 5 | Country | Country | Wieczorek, Mareike | |||
| 6 | Area/locality | Area | Wieczorek, Mareike | |||
| 7 | Latitude of event | Latitude | Wieczorek, Mareike | |||
| 8 | Longitude of event | Longitude | Wieczorek, Mareike | |||
| 9 | DATE/TIME | Date/Time | Wieczorek, Mareike | Geocode | ||
| 10 | Active layer depth | ALD | cm | Wieczorek, Mareike | Active layer thickness (ALT); maximum thaw depth at the end of the summer | |
| 11 | Sample comment | Sample comment | Wieczorek, Mareike | Comment on data, extracted from CALM website | ||
| 12 | Comment | Comment | Wieczorek, Mareike | ESA CCI Permafrost validation comment |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
22587 data points
Download Data
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