Permafrost active layer

Dobiński, Wojciech

doi:10.1016/j.earscirev.2020.103301

Cited by 44 publications

(28 citation statements)

References 95 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The correctness of the hypothetical model presented here is evidenced by all known thermal profiles of permafrost, in which it is clearly visible that their intersection with the 0 °C axis always has a sharp angle and a more asymptotic character at the permafrost base than at the permafrost table (Dobiński 2020a). It is also documented by empirical research (Elvebakk 2010;Szewczyk and Nawrocki 2011).…”

Section: Permafrost Degradation From Belowsupporting

confidence: 66%

Permafrost Base Degradation: Characteristics and Unknown Thread With Specific Example From Hornsund, Svalbard

Dobiński

Kasprzak

2022

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

Permafrost degradation is one of the most pressing issues in the modern cryosphere related to climate change. Most attention is paid to the degradation of the top of the active permafrost associated with contemporary climate. This is the most popular issue because in the subsurface part of it there is usually the greatest accumulation of ground ice in direct relation to the changes taking place. The melting of ground ice is the cause of the greatest changes related to subsidence and other mass-wasting processes. The degradation of the subsurface permafrost layer is also responsible for the increased emission of CO2 and methane. However, this is not a fully comprehensive look at the issue of permafrost degradation, because depending on its thickness, changes in its thermal properties may occur more or less intensively throughout its entire profile, also reaching the base of permafrost. These changes can degrade permafrost throughout its profile. The article presents the basic principles of permafrost degradation in its overall approach. Both the melting of the ground ice and the thermal degradation of permafrost, as manifested in an increase in its temperature in part or all of the permafrost profile, are discussed. However, special attention is paid to the degradation characteristics from the permafrost base. In the case of moderately thick and warm permafrost in the zone of its sporadic and discontinuous occurrence, this type of degradation may particularly contribute to its disappearance, and surficial consequences of such degradation may be more serious than we expect on the basis of available research and data now. A special case of such degradation is the permafrost located in the coastal zone in the vicinity of the Hornsund Spitsbergen, where a multidirectional thermal impact is noted, also causing similar degradation of permafrost: from the top, side and bottom. Especially the degradation of permafrost from the permafrost base upwards is an entirely new issue in considering the evolution of permafrost due to climate change. Due to the difficulties in its detection, this process may contribute to the threats that are difficult to estimate in the areas of discontinuous and sporadic permafrost.

show abstract

Section: Permafrost Degradation From Belowsupporting

confidence: 66%

Permafrost Base Degradation: Characteristics and Unknown Thread With Specific Example From Hornsund, Svalbard

Dobiński

Kasprzak

2022

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The ALT is especially vulnerable to regional climate, vegetation, snow cover, and thermal properties of the soil (Dobiński, 2020; Park et al., 2013; Peng et al., 2017; Shur et al., 2005). To better understand the impacts of these factors on the ALT variation, we examined the relationship between the ALT and the air temperature, precipitation, snow depth, and NDVI.…”

Section: Discussionmentioning

confidence: 99%

“…Historical data have revealed that the ALT in the North American and Russian Arctic regions, Europe, and Central Asia has exhibited substantial interannual variability since the 1980s (Brown et al., 2000; Harris et al., 2003; Nelson et al., 2004; Zhao et al., 2010). In addition, the hydrothermal characteristics of the active layer have also shown extreme seasonal variability, which will ultimately affect the hydrological processes and eco‐environmental stability of the permafrost environment (Connon et al., 2018; Dobiński, 2020; Park et al., 2013; Yuan et al., 2020).…”

Section: Introductionmentioning

confidence: 99%

Active Layer Thickness Variation on the Qinghai‐Tibetan Plateau: Historical and Projected Trends

2021

JGR Atmospheres

View full text Add to dashboard Cite

As the buffer layer between the atmosphere and permafrost, the active layer is vulnerable to climate change. The variation in the active layer thickness (ALT) has important effects on surface energy balance, ecosystem, hydrological cycle, vegetation cover, and engineering construction in permafrost regions. The goal of this study is to discuss the active layer variation under different shared socioeconomic pathways (SSPs) for specific warming levels and to reveal the potential interactions between the ALT and the associated driving factors in typical hydrological basins. We revised the Stefan solution using the edaphic factor and the thawing index calculated by multimodel data from the Coupled Model Intercomparison Project Phase 6 to estimate the variation in the ALT. During 2015 to 2100, the ALT will increase by 14 cm (SSP1‐2.6), 43 cm (SSP2‐4.5), and 1.44 m (SSP5‐8.5), with average increase rates of 2.5 cm/decade, 5.8 cm/decade, and 17.5 cm/decade, respectively. The rates of increase of the ALT in the Hexi basin, Inner basin, Mekong basin, Yangtze basin, and Yellow basin are 12.6 cm/decade, 6.7 cm/decade, 5.2 cm/decade, 8.0 cm/decade, and 5 cm/decade, respectively. These results illustrate that air temperature is the primary determinant of ALT variation and normalized difference vegetation index (NDVI) and snow depth may influence the ALT change. The most significant correlations are between the ALT and NDVI in the Yangtze basin. In different seasons, the spring snow depth has the greatest impact on the ALT in the Hexi basin.

show abstract

“…These differences may be due to the way ALT Crocus was calculated using ISBA soil layers. This trend may also be related with the very high spatial variability of ALT values (coefficient of variation of CALM data of Standard Deviation/ mean 35%), as ground thermal regime strongly varies across regions and sites (Shiklomanov et al, 2012;Park et al, 2013;Dobinski, 2020) and according to soil composition. The depth of the active layer can range from half a meter in warmer, ice-rich environments to a few meters in bedrock and the coldest permafrost regions.…”

Section: Active Layer Thickness Trendmentioning

confidence: 99%

Improved Simulation of Arctic Circumpolar Land Area Snow Properties and Soil Temperatures

et al. 2021

View full text Add to dashboard Cite

The impact of high latitude climate warming on Arctic snow cover and its insulating properties has key implications for the surface and soil energy balance. Few studies have investigated specific trends in Arctic snowpack properties because there is a lack of long-term in situ observations and current detailed snow models fail to represent the main traits of Arctic snowpacks. This results in high uncertainty in modeling snow feedbacks on ground thermal regime due to induced changes in snow insulation. To better simulate Arctic snow structure and snow thermal properties, we implemented new parameterizations of several snow physical processes—including the effect of Arctic low vegetation and wind on snowpack—in the Crocus detailed snowpack model. Significant improvements compared to standard Crocus snow simulations and ERA-Interim (ERAi) reanalysis snow outputs were observed for a large set of in-situ snow data over Siberia and North America. Arctic Crocus simulations produced improved Arctic snow density profiles over the initial Crocus version, leading to a soil surface temperature bias of −0.5 K with RMSE of 2.5 K. We performed Crocus simulations over the past 39 years (1979–2018) for circumpolar taiga (open forest) and pan-Arctic areas at a resolution of 0.5°, driven by ERAi meteorological data. Snowpack properties over that period feature significant increase in spring snow bulk density (mainly in May and June), a downward trend in snow cover duration and an upward trend in wet snow (mainly in spring and fall). The pan-Arctic maximum snow water equivalent shows a decrease of −0.33 cm dec−1. With the ERAi air temperature trend of +0.84 K dec−1 featuring Arctic winter warming, these snow property changes have led to an upward trend in soil surface temperature (Tss) at a rate of +0.41 K dec−1 in winter. We show that the implemented snowpack property changes increased the Tss trend by 36% compared to the standard simulation. Winter induced changes in Tss led to a significant increase of 16% (+4 cm dec−1) in the estimated active layer thickness (ALT) over the past 39 years. An increase in ALT could have a significant impact on permafrost evolution, Arctic erosion and hydrology.

show abstract

Permafrost active layer

Cited by 44 publications

References 95 publications

Permafrost Base Degradation: Characteristics and Unknown Thread With Specific Example From Hornsund, Svalbard

Permafrost Base Degradation: Characteristics and Unknown Thread With Specific Example From Hornsund, Svalbard

Active Layer Thickness Variation on the Qinghai‐Tibetan Plateau: Historical and Projected Trends

Improved Simulation of Arctic Circumpolar Land Area Snow Properties and Soil Temperatures

Contact Info

Product

Resources

About