Published in:
Earth System Science Data, 14 (2022) 2, Seite 865-884
Language:
English
DOI:
10.5194/essd-14-865-2022
ISSN:
1866-3516
Origination:
Footnote:
Description:
Abstract. Monitoring the thermal state of permafrost (TSP) isimportant in many environmental science and engineering applications.However, such data are generally unavailable, mainly due to the lack ofground observations and the uncertainty of traditional physical models. Thisstudy produces novel permafrost datasets for the Northern Hemisphere (NH),including predictions of the mean annual ground temperature (MAGT) at thedepth of zero annual amplitude (DZAA) (approximately 3 to 25 m) and activelayer thickness (ALT) with 1 km resolution for the period of 2000–2016, aswell as estimates of the probability of permafrost occurrence and permafrostzonation based on hydrothermal conditions. These datasets integrateunprecedentedly large amounts of field data (1002 boreholes for MAGT and452 sites for ALT) and multisource geospatial data, especially remotesensing data, using statistical learning modeling with an ensemblestrategy. Thus, the resulting data are more accurate than those of previouscircumpolar maps (bias = 0.02±0.16 ∘C and RMSE = 1.32±0.13 ∘C for MAGT; bias = 2.71±16.46 cm andRMSE = 86.93±19.61 cm for ALT). The datasets suggest that the arealextent of permafrost (MAGT ≤0 ∘C) in the NH, excludingglaciers and lakes, is approximately 14.77 (13.60–18.97) × 106 km2 and that the areal extent of permafrost regions (permafrostprobability >0) is approximately 19.82×106 km2. The areal fractions of humid, semiarid/subhumid, and arid permafrost regions are 51.56 %, 45.07 %, and 3.37 %, respectively. Theareal fractions of cold (≤-3.0 ∘C), cool (−3.0 ∘Cto −1.5 ∘C), and warm (>-1.5 ∘C)permafrost regions are 37.80 %, 14.30 %, and 47.90 %, respectively.These new datasets based on the most comprehensive field data to datecontribute to an updated understanding of the thermal state and zonation ofpermafrost in the NH. The datasets are potentially useful for variousfields, such as climatology, hydrology, ecology, agriculture, public health,and engineering planning. All of the datasets are published through theNational Tibetan Plateau Data Center (TPDC), and the link is https://doi.org/10.11888/Geocry.tpdc.271190 (Ran et al.,2021a).