Active layer thickness variations on the Qinghai–Tibet Plateau under the scenarios of climate change

Abstract. Active layer thickness (ALT) is an important index to reflect the stability of permafrost. The retrieval of ALT based on Interferometric Synthetic Aperture Radar (InSAR) technology has been investigated recently in permafrost research. However, most of such studies are carried out in a limited extend and relatively short temporal coverage. The combination of temporal-spatial multi-layer soil moisture data and multi-temporal InSAR is a promising approach for the large-scale characterization of ALT. In this study, we employed Small Baseline Subset Interferometry (SBAS-InSAR) technology to obtain the seasonal surface deformation from radar images of Envisat and Sentinel-1 in a permafrost region of Qinghai-Tibet Plateau (QTP). We attempt to verify and calibrate the temporal-spatial multi-layer soil moisture product in combination with the in-situ data. Based on the land subsidence data and the temporal-spatial multi-layer soil moisture data, we further improve method to retrieve the ALT information. This paper describes the progress so far and point out the future work.

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Active layer thickness calculation over the Qinghai–Tibet Plateau

Cold Regions Science and Technology ◽

10.1016/j.coldregions.2009.01.005 ◽

2009 ◽

Vol 57 (1) ◽

pp. 23-28 ◽

Cited By ~ 48

Author(s):

Qiangqiang Pang ◽

Guodong Cheng ◽

Shuxun Li ◽

Wengang Zhang

Keyword(s):

Layer Thickness ◽

Active Layer ◽

Tibet Plateau ◽

Active Layer Thickness ◽

Qinghai Tibet Plateau

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Changes in active-layer thickness and near-surface permafrost between 2002 and 2012 in alpine ecosystems, Qinghai–Xizang (Tibet) Plateau, China

Global and Planetary Change ◽

10.1016/j.gloplacha.2014.09.002 ◽

2015 ◽

Vol 124 ◽

pp. 149-155 ◽

Cited By ~ 111

Author(s):

Qingbai Wu ◽

Yandong Hou ◽

Hanbo Yun ◽

Yongzhi Liu

Keyword(s):

Layer Thickness ◽

Active Layer ◽

Tibet Plateau ◽

Active Layer Thickness ◽

Alpine Ecosystems ◽

Near Surface

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Permafrost Degradation within Eastern Chukotka CALM Sites in the 21st Century Based on CMIP5 Climate Models

Geosciences ◽

10.3390/geosciences9050232 ◽

2019 ◽

Vol 9 (5) ◽

pp. 232 ◽

Cited By ~ 4

Author(s):

Alexey Maslakov ◽

Natalia Shabanova ◽

Dmitry Zamolodchikov ◽

Vasili Volobuev ◽

Gleb Kraev

Keyword(s):

Climate Change ◽

Layer Thickness ◽

Active Layer ◽

21St Century ◽

Climate Models ◽

Climate Scenario ◽

Active Layer Thickness ◽

Climate Change Scenarios ◽

Permafrost Degradation ◽

Degradation Rates

Permafrost degradation caused by contemporary climate change significantly affects arctic regions. Active layer thickening combined with the thaw subsidence of ice-rich sediments leads to irreversible transformation of permafrost conditions and activation of exogenous processes, such as active layer detachment, thermokarst and thermal erosion. Climatic and permafrost models combined with a field monitoring dataset enable the provision of predicted estimations of the active layer and permafrost characteristics. In this paper, we present the projections of active layer thickness and thaw subsidence values for two Circumpolar Active Layer Monitoring (CALM) sites of Eastern Chukotka coastal plains. The calculated parameters were used for estimation of permafrost degradation rates in this region for the 21st century under various IPCC climate change scenarios. According to the studies, by the end of the century, the active layer will be 6–13% thicker than current values under the RCP (Representative Concentration Pathway) 2.6 climate scenario and 43–87% under RCP 8.5. This process will be accompanied by thaw subsidence with the rates of 0.4–3.7 cm∙a−1. Summarized surface level lowering will have reached up to 5 times more than current active layer thickness. Total permafrost table lowering by the end of the century will be from 150 to 310 cm; however, it will not lead to non-merging permafrost formation.

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Modelling and mapping climate change impacts on permafrost at high spatial resolution for an Arctic region with complex terrain

The Cryosphere ◽

10.5194/tc-7-1121-2013 ◽

2013 ◽

Vol 7 (4) ◽

pp. 1121-1137 ◽

Cited By ~ 32

Author(s):

Y. Zhang ◽

X. Wang ◽

R. Fraser ◽

I. Olthof ◽

W. Chen ◽

...

Keyword(s):

Climate Change ◽

Layer Thickness ◽

Spatial Resolution ◽

Active Layer ◽

Complex Terrain ◽

Climate Change Impacts ◽

Arctic Region ◽

Slope Aspect ◽

Active Layer Thickness ◽

Topographic Effects

Abstract. Most spatial modelling of climate change impacts on permafrost has been conducted at half-degree latitude/longitude or coarser spatial resolution. At such coarse resolution, topographic effects on insolation cannot be considered accurately and the results are not suitable for land-use planning and ecological assessment. Here we mapped climate change impacts on permafrost from 1968 to 2100 at 10 m resolution using a process-based model for Ivvavik National Park, an Arctic region with complex terrain in northern Yukon, Canada. Soil and drainage conditions were defined based on ecosystem types, which were mapped using SPOT imagery. Leaf area indices were mapped using Landsat imagery and the ecosystem map. Climate distribution was estimated based on elevation and station observations, and the effects of topography on insolation were calculated based on slope, aspect and viewshed. To reduce computation time, we clustered climate distribution and topographic effects on insolation into discrete types. The modelled active-layer thickness and permafrost distribution were comparable with field observations and other studies. The map portrayed large variations in active-layer thickness, with ecosystem types being the most important controlling variable, followed by climate, including topographic effects on insolation. The results show deepening in active-layer thickness and progressive degradation of permafrost, although permafrost will persist in most of the park during the 21st century. This study also shows that ground conditions and climate scenarios are the major sources of uncertainty for high-resolution permafrost mapping.

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High Spatial Resolution Modeling of Climate Change Impacts on Permafrost Thermal Conditions for the Beiluhe Basin, Qinghai-Tibet Plateau

Remote Sensing ◽

10.3390/rs11111294 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1294 ◽

Cited By ~ 6

Author(s):

Jing Luo ◽

Guoan Yin ◽

Fujun Niu ◽

Zhanju Lin ◽

Minghao Liu

Keyword(s):

Climate Change ◽

Climate Change Impacts ◽

Tibet Plateau ◽

Ecosystem Change ◽

Active Layer Thickness ◽

Climate Projections ◽

Permafrost Degradation ◽

Thermal Dynamics ◽

Discontinuous Permafrost ◽

Qinghai Tibet Plateau

Permafrost is degrading on the Qinghai-Tibet Plateau (QTP) due to climate change. Permafrost degradation can result in ecosystem changes and damage to infrastructure. However, we lack baseline data related to permafrost thermal dynamics at a local scale. Here, we model climate change impacts on permafrost from 1986 to 2075 at a high resolution using a numerical model for the Beiluhe basin, which includes representative permafrost environments of the QTP. Ground surface temperatures are derived from air temperature using an n-factor vs Normalized Differential Vegetation Index (NDVI) relationship. Soil properties are defined by field measurements and ecosystem types. The climate projections are based on long-term observations. The modelled ground temperature (MAGT) and active-layer thickness (ALT) are close to in situ observations. The results show a discontinuous permafrost distribution (61.4%) in the Beiluhe basin at present. For the past 30 years, the permafrost area has decreased rapidly, by a total of 26%. The mean ALT has increased by 0.46 m. For the next 60 years, 8.5–35% of the permafrost area is likely to degrade under different trends of climate warming. The ALT will probably increase by 0.38–0.86 m. The results of this study are useful for developing a deeper understanding of ecosystem change, permafrost development, and infrastructure development on the QTP.

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Simulated response of the active layer thickness of permafrost to climate change

Atmospheric and Oceanic Science Letters ◽

10.1016/j.aosl.2020.100007 ◽

2020 ◽

pp. 100007

Author(s):

Ruichao Li ◽

Jinbo Xie ◽

Zhenghui Xie ◽

Junqiang Gao ◽

Binghao Jia ◽

...

Keyword(s):

Climate Change ◽

Layer Thickness ◽

Active Layer ◽

Active Layer Thickness

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Status, Changes and Impacts of Permafrost on Qinghai-Tibet Plateau

10.5194/egusphere-egu2020-6246 ◽

2020 ◽

Author(s):

Lin Zhao ◽

Guojie Hu ◽

Defu Zou ◽

Ren Li ◽

Yu Sheng ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Active Layer ◽

Climate Warming ◽

Global Climate ◽

Tibet Plateau ◽

Active Layer Thickness ◽

Permafrost Region ◽

Permafrost Degradation ◽

Qinghai Tibet Plateau

Due to the climate warming, permafrost on the Qinghai-Tibet Plateau (QTP) was degradating in the past decades. Since its impacts on East Asian monsoon, and even on the global climate system, it is fundamental to reveal permafrost status, changes and its physical processes. Based on previous research results and new observation data, this paper reviews the characteristics of the status of permafrost on the QTP, including the active layer thickness (ALT), the spatial distribution of permafrost, permafrost temperature and thickness, as well as the ground ice and soil carbon storage in permafrost region.The results showed that the permafrost and seasonally frozen ground area (excluding glaciers and lakes) is 1.06 million square kilometters and 1.45 million square kilometters on the QTP. The permafrost thickness varies greatly among topography, with the maximum value in mountainous areas, which could be deeper than 200 m, while the minimum value in the flat areas and mountain valleys, which could be less than 60 m. The mean value of active layer thickness is about 2.3 m. Soil temperature at 0~10 cm, 10~40 cm, 40~100 cm, 100~200 cm increased at a rate of 0.439, 0.449, 0.396, and 0.259&#176;C/10a, respectively, from 1980 to 2015. The increasing rate of the soil temperature at the bottom of active layer was 0.486 oC/10a from 2004 to 2018.The volume of ground ice contained in permafrost on QTP is estimated up to 1.27&#215;104 km3 (liquid water equivalent). The soil organic carbon staored in the upper 2 m of soils within the permafrost region is about 17 Pg. Most of the research results showed that the permafrost ecosystem is still a carbon sink at the present, but it might be shifted to a carbon source due to the loss of soil organic carbon along with permafrost degradation.Overall, the plateau permafrost has undergone remarkable degradation during past decades, which are clearly proven by the increasing ALTs and ground temperature. Most of the permafrost on the QTP belongs to the unstable permafrost, meaning that permafrost over TPQ is very sensitive to climate warming. The permafrost interacts closely with water, soil, greenhouse gases emission and biosphere. Therefore, the permafrost degradation greatly affects the regional hydrology, ecology and even the global climate system.

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