Remote sensing quantifies widespread abundance of permafrost region disturbances across the Arctic and Subarctic

I Nitze,G Grosse,B M Jones,V E Romanovsky,J Boike

doi:10.1038/s41467-018-07663-3

Abstract

Local observations indicate that climate change and shifting disturbance regimes are causing permafrost degradation. However, the occurrence and distribution of permafrost region disturbances (PRDs) remain poorly resolved across the Arctic and Subarctic. Here we quantify the abundance and distribution of three primary PRDs using time-series analysis of 30-m resolution Landsat imagery from 1999 to 2014. Our dataset spans four continental-scale transects in North America and Eurasia, covering ~10% of the permafrost region. Lake area loss (−1.45%) dominated the study domain with enhanced losses occurring at the boundary between discontinuous and continuous permafrost regions. Fires were the most extensive PRD across boreal regions (6.59%), but in tundra regions (0.63%) limited to Alaska. Retrogressive thaw slumps were abundant but highly localized (<10−5%). Our analysis synergizes the global-scale importance of PRDs. The findings highlight the need to include PRDs in next-generation land surface models to project the permafrost carbon feedback.

Highlights

The northern permafrost region (Fig. 1) varies with respect to spatial extent and characteristics of ground thermal regime, ground-ice content, climate, topography, hydrology, surface geology, and land cover[10,18,19,20]
The vast majority of permafrost areas are underrepresented in global remote sensing and modeling studies and most permafrost region disturbances (PRDs) likely remain undocumented, resulting in significant uncertainty of the current magnitude of rapid permafrost degradation processes and their role in global scale biogeochemical dynamics[7]
We analyzed 16 years of 30-m resolution earth observation data from the Landsat archive in conjunction with Pan-Arctic to global scale data products, from 1999 through 2015, to track key PRDs across four extensive latitudinal transects in Alaska, Eastern Canada, Western Siberia, and Eastern Siberia that cover more than 2.3 × 106 km[2] (~10% of the permafrost region in the Northern Hemisphere)

Summary

Introduction

The northern permafrost region (Fig. 1) varies with respect to spatial extent and characteristics of ground thermal regime, ground-ice content, climate, topography, hydrology, surface geology, and land cover[10,18,19,20]. We analyzed 16 years of 30-m resolution earth observation data from the Landsat archive in conjunction with Pan-Arctic to global scale data products, from 1999 through 2015, to track key PRDs (lake extents and their dynamics, RTS, and wildfire burn scars; Fig. 2) across four extensive latitudinal transects in Alaska, Eastern Canada, Western Siberia, and Eastern Siberia that cover more than 2.3 × 106 km[2] (~10% of the permafrost region in the Northern Hemisphere) (see Supplementary Note 1).

Results

Conclusion