The first 20 years (1978-1979 to 1998-1999) of active-layer development, Illisarvik experimental drained lake site, western Arctic coast, Canada1

2002 ◽  
Vol 39 (11) ◽  
pp. 1657-1674 ◽  
Author(s):  
J Ross Mackay ◽  
C R Burn
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Snow Depth ◽  
Weather Conditions ◽  
Active Layer Thickness ◽  
Ground Ice ◽  
Vertical Movements ◽  
Near Surface ◽  
Ground Temperatures ◽  
Lake Bottom

Active-layer thickness, snow depth, minimum soil temperatures, near-surface ground ice, soil heave, and permafrost temperatures have been measured for over 20 years following the 1978 artificial drainage of Lake Illisarvik. Measurements of active-layer thickness and other variables have been made at 25-m intervals along the major and minor axes of the oval-shaped drained-lake bed. Permafrost aggradation commenced in the lake bottom during the first winter following drainage. Before the establishment of vegetation, there was little snow cover, minimum ground temperatures were low, and the active layer was relatively thin. However, both snow depth and minimum ground temperatures have risen where vegetation has grown, the active layer has thickened, and in response, the temperature in permafrost has gradually increased. In the lake bottom, the change in snow depth associated with vegetation growth has been the dominant control on variation in active-layer thickness and not summer weather conditions, which are well correlated with thaw depths along an active-layer course established in the adjacent tundra. Changes in elevation of the surface of the lake bed have been measured with respect to some 40 bench marks anchored in permafrost, and indicate vertical movements of the surface associated with frost heave, thaw subsidence, and the growth of aggradational ice. The ground ice content of near-surface permafrost determined by drilling is in close agreement with the measured uplift of the lake bed. The rate of growth of aggradational ice has been ~0.5 cm a–1 over 20 years.

Climate warming and active layer thaw in the boreal and tundra environments of the Mackenzie Valley

2007 ◽  
Vol 44 (6) ◽  
pp. 733-743 ◽  
Author(s):  
Ming-ko Woo ◽  
Michael Mollinga ◽  
Sharon L Smith
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Climate Warming ◽  
Probability Distributions ◽  
Organic Layer ◽  
Active Layer Thickness ◽  
Near Surface ◽  
Ground Temperatures ◽  
Thaw Depth ◽  
Mineral Soils

The variability of maximum active layer thickness in boreal and tundra environments has important implications for hydrological processes, terrestrial and aquatic ecosystems, and the integrity of northern infrastructure. For most planning and management purposes, the long-term probability distribution of active layer thickness is of primary interest. A robust method is presented to calculate maximum active layer thickness, employing the Stefan equation to compute phase change of moisture in soils and using air temperature as the sole climatic forcing variable. Near-surface ground temperatures (boundary condition for the Stefan equation) were estimated based on empirical relationships established for several sites in the Mackenzie valley. Simulations were performed for typically saturated mineral soils, overlain with varying thickness of peat in boreal and tundra environments. The probability distributions of simulated maximum active layer thickness encompass the range of measured thaw depths provided by field data. The effects of climate warming under A2 and B2 scenarios for 2050 and 2100 were investigated. Under the A2 scenario in 2100, the simulated median thaw depth under a thin organic cover may increase by 0.3 m, to reach 1 m depth for a tundra site and 1.6 m depth for a boreal site. The median thaw depth in 2100 is dampened by about 50% under a 1 m thick organic layer. Without an insulating organic cover, thaw penetration can increase to reach 1.7 m at the tundra site. The simulations provide quantitative support that future thaw penetration in permafrost terrain will deepen differentially depending on location and soil.

Influence of snow on near-surface ground temperatures in upland and alluvial environments of the outer Mackenzie Delta, Northwest Territories1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada.

2012 ◽  
Vol 49 (8) ◽  
pp. 895-913 ◽  
Author(s):  
P.D. Morse ◽  
C.R. Burn ◽  
S.V. Kokelj
Keyword(s):  
Snow Cover ◽  
Active Layer ◽  
Snow Depth ◽  
Active Layer Thickness ◽  
Mackenzie Delta ◽  
Diverse Range ◽  
Near Surface ◽  
Ground Temperatures ◽  
Vegetation Height ◽  
The Difference

Relations between snow cover, active-layer thickness, and near-surface ground temperatures were determined in 2005–2009 for a diverse range of alluvial and upland settings in the outer Mackenzie Delta. Here, the snow cover developed primarily by wind redistribution, with its spatial variation controlled by topography in uplands and vegetation height in alluvial lowlands. Snow cover was the primary influence on freeze-back duration and the mean annual temperature at the top of permafrost (TTOP), with the difference in median TTOP between alluvial (–3.7 °C) and upland (–6.1 °C) settings related to the greater snow depth and soil moisture in the alluvial plain. The active layer was generally deeper in the wet alluvial lowlands, where the average duration of active-layer freeze back (101 days) was nearly double the time taken in the well-drained uplands (55 days). The surface offset (ΔTS; up to 11 °C) dominated the difference between annual mean air temperature (AMAT) and TTOP (ΔT). In alluvial terrain, ΔTS varied with snow depth, but in the uplands, ΔTS was more consistent from site to site. The small thermal offset (<2 °C) was slightly greater in alluvial terrain than in the uplands. The overall range in ΔT (2–10 °C) led to a range during the study of 7.2 °C in TTOP at the sites. The range in AMAT was 1.3 °C but up to 1.7 °C in TTOP at any one site. Permafrost was well established throughout the area except adjacent to channels where TTOP was close to 0 °C.

scholarly journals The influence of climate and hydrological variables on opposite anomaly in active-layer thickness between Eurasian and North American watersheds

2013 ◽  
Vol 7 (2) ◽  
pp. 631-645 ◽  
Author(s):  
H. Park ◽  
J. Walsh ◽  
A. N. Fedorov ◽  
A. B. Sherstiukov ◽  
Y. Iijima ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
North American ◽  
Land Surface ◽  
Snow Depth ◽  
The Arctic ◽  
Surface Model ◽  
Active Layer Thickness ◽  
Hydrological Variables ◽  
Permafrost Regions

Abstract. This study not only examined the spatiotemporal variations of active-layer thickness (ALT) in permafrost regions during 1948–2006 over the terrestrial Arctic regions experiencing climate changes, but also identified the associated drivers based on observational data and a simulation conducted by a land surface model (CHANGE). The focus on the ALT extends previous studies that have emphasized ground temperatures in permafrost regions. The Ob, Yenisey, Lena, Yukon, and Mackenzie watersheds are foci of the study. Time series of ALT in Eurasian watersheds showed generally increasing trends, while the increase in ALT in North American watersheds was not significant. However, ALT in the North American watersheds has been negatively anomalous since 1990 when the Arctic air temperature entered into a warming phase. The warming temperatures were not simply expressed to increases in ALT. Since 1990 when the warming increased, the forcing of the ALT by the higher annual thawing index (ATI) in the Mackenzie and Yukon basins has been offset by the combined effects of less insulation caused by thinner snow depth and drier soil during summer. In contrast, the increasing ATI together with thicker snow depth and higher summer soil moisture in the Lena contributed to the increase in ALT. The results imply that the soil thermal and moisture regimes formed in the pre-thaw season(s) provide memory that manifests itself during the summer. The different ALT anomalies between Eurasian and North American watersheds highlight increased importance of the variability of hydrological variables.

Permafrost and active layer research on James Ross Island: An overview

2019 ◽  
Vol 9 (1) ◽  
pp. 20-36 ◽  
Author(s):  
Filip Hrbáček ◽  
Daniel Nývlt ◽  
Kamil Láska ◽  
Michaela Kňažková ◽  
Barbora Kampová ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Layer Thickness ◽  
Active Layer ◽  
Air Temperature ◽  
Thermal Regime ◽  
Ground Temperature ◽  
Active Layer Thickness ◽  
Near Surface ◽  
James Ross Island ◽  
The Mean

This study summarizes the current state of the active layer and permafrost research on James Ross Island. The analysis of climate parameters covers the reference period 2011–2017. The mean annual air temperature at the AWS-JGM site was -6.9°C (ranged from -3.9°C to -8.2°C). The mean annual ground temperature at the depth of 5 cm was -5.5°C (ranged from -3.3°C to -6.7°C) and it also reached -5.6°C (ranged from -4.0 to -6.8°C) at the depth of 50 cm. The mean daily ground temperature at the depth of 5 cm correlated moderately up to strongly with the air temperature depending on the season of the year. Analysis of the snow effect on the ground thermal regime confirmed a low insulating effect of snow cover when snow thickness reached up to 50 cm. A thicker snow accumulation, reaching at least 70 cm, can develop around the hyaloclastite breccia boulders where a well pronounced insulation effect on the near-surface ground thermal regime was observed. The effect of lithology on the ground physical properties and the active layer thickness was also investigated. Laboratory analysis of ground thermal properties showed variation in thermal conductivity (0.3 to 0.9 W m-1 K-1). The thickest active layer (89 cm) was observed on the Berry Hill slopes site, where the lowest thawing degree days index (321 to 382°C·day) and the highest value of thermal conductivity (0.9 W m-1 K-1) was observed. The clearest influence of lithological conditions on active layer thickness was observed on the CALM-S grid. The site comprises a sandy Holocene marine terrace and muddy sand of the Whisky Bay Formation. Surveying using a manual probe, ground penetrating radar, and an electromagnetic conductivity meter clearly showed the effect of the lithological boundary on local variability of the active layer thickness.

scholarly journals Characteristics of air and ground temperatures and the reconstruction of active layer thickness on the Rink Plateau, James Ross Island, Antarctic Peninsula

2006 ◽  
Vol 68 (4) ◽  
pp. 287-298
Author(s):  
Junko MORI ◽  
Toshio SONE ◽  
Jorge A. STRELIN ◽  
Cesar A. TORIELLI ◽  
Kotaro FUKUI
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Antarctic Peninsula ◽  
Active Layer Thickness ◽  
Ground Temperatures ◽  
James Ross Island

Contrasting thermal responses of permafrost to winter warming events under different snow regimes in the subarctic

2021 ◽  
Author(s):  
Didac Pascual Descarrega ◽  
Margareta Johansson
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Snow Depth ◽  
Thermal Response ◽  
Winter Precipitation ◽  
The Arctic ◽  
Active Layer Thickness ◽  
Thermal Dynamics ◽  
Winter Warming

&lt;p&gt;Winter warming events (WWE) in the Swedish subarctic are abrupt and short-lasting (hours-to-days) events of positive air temperature that occur during wintertime, sometimes accompanied by rainfall (rain on snow; ROS). These events cause changes in snow properties, which affect the below-ground thermal regime that, in turn, controls a suite of ecosystem processes ranging from microbial activity to permafrost and vegetation dynamics. For instance, winter melting can cause ground warming due to the shortening of the snow cover season, or ground cooling as the reduced snow depth and the formation of refrozen layers of high thermal conductivity at the base of the snowpack facilitate the release of soil heat. Apart from these interacting processes, the overall impacts of WWE on ground temperatures may also depend on the timing of the events and the preceding snowpack characteristics. The frequency and intensity of these events in the Arctic, including the Swedish subarctic, has increased remarkably during the recent decades, and is expected to increase even further during the 21st Century. In addition, snow depth (not necessarily snow duration) is projected to increase in many parts of the Arctic, including the Swedish subarctic. In 2005, a manipulation experiment was set up on a lowland permafrost mire in the Swedish subarctic, to simulate projected future increases in winter precipitation. In this study, we analyse this 15-year record of ground temperature, active layer thickness, and meteorological variables, to evaluate the short- (days to weeks) and long-term (up to 1 year) impacts of WWE on the thermal dynamics of lowland permafrost, and provide new insights into the influence of the timing of WWE and the underlying snowpack conditions on the thermal response of permafrost. On the short-term, the thermal responses to WWE are faster and stronger in areas with a shallow snowpack (5-10 cm), although these responses are more persistent in areas with a thicker snowpack (&gt;25 cm), especially after ROS events. On the long term, permafrost in areas with a thicker snowpack exhibit a more durable warming response to WWE that results in thicker active layers at the end of the season. On the contrary, we do not observe a correlation between WWE and end of season active layer thickness in areas with a shallow snowpack.&amp;#160;&lt;/p&gt;

scholarly journals Permafrost thaw and ground settlement considering long-term climate impact in northern Alaska

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Zhaohui Joey Yang ◽  
Kannon C. Lee ◽  
Haibo Liu
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Air Temperature ◽  
Climate Model ◽  
Ground Surface ◽  
Active Layer Thickness ◽  
Near Surface ◽  
Surface Conditions ◽  
Ice Content ◽  
Northern Alaska

AbstractAlaska’s North Slope is predicted to experience twice the warming expected globally. When summers are longer and winters are shortened, ground surface conditions in the Arctic are expected to change considerably. This is significant for Arctic Alaska, a region that supports surface infrastructure such as energy extraction and transport assets (pipelines), buildings, roadways, and bridges. Climatic change at the ground surface has been shown to impact soil layers beneath through the harmonic fluctuation of the active layer, and warmer air temperature can result in progressive permafrost thaw, leading to a deeper active layer. This study attempts to assess climate change based on the climate model data from the fifth phase of the Coupled Model Intercomparison Project and its impact on a permafrost environment in Northern Alaska. The predicted air temperature data are analyzed to evaluate how the freezing and thawing indices will change due to climate warming. A thermal model was developed that incorporated a ground surface condition defined by either undisturbed intact tundra or a gravel fill surface and applied climate model predicted air temperatures. Results indicate similar fluctuation in active layer thickness and values that fall within the range of minimum and maximum readings for the last quarter-century. It is found that the active layer thickness increases, with the amount depending on climate model predictions and ground surface conditions. These variations in active layer thickness are then analyzed by considering the near-surface frozen soil ice content. Analysis of results indicates that thaw strain is most significant in the near-surface layers, indicating that settlement would be concurrent with annual thaw penetration. Moreover, ice content is a major factor in the settlement prediction. This assessment methodology, after improvement, and the results can help enhance the resilience of the existing and future new infrastructure in a changing Arctic environment.

scholarly journals Mapping the Main Characteristics of Permafrost on the Basis of a Permafrost-Landscape Map of Yakutia Using GIS

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 462
Author(s):  
Alyona A. Shestakova ◽  
Alexander N. Fedorov ◽  
Yaroslav I. Torgovkin ◽  
Pavel Y. Konstantinov ◽  
Nikolay F. Vasyliev ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Climatic Conditions ◽  
Active Layer Thickness ◽  
Distribution Maps ◽  
Ground Temperatures ◽  
Cryogenic Process ◽  
The Republic ◽  
Ice Content ◽  
Landscape Map

The purpose of this article was to compile four separate digital thematic maps of temperature and ice content of permafrost, the active layer thickness, and cryogenic processes in Yakutia as a basis for assessing changes to modern climate changes and anthropogenic disturbances. In this work, materials on permafrost were used, serving as the basis for compiling a permafrost landscape map of the Republic of Sakha (Yakutia). The maps were compiled using ArcGIS software, which supports attribute table mapping. The ground temperature and active layer thickness maps reflected landscape zonality and regional differences. Peculiarities of genetic types of Quaternary deposits and climatic conditions reflected the ice content of surface sediments and cryogenic process distribution maps. One of the most common is ground temperatures from −2.1 to −4.0 °C, which were found to occupy about 37.4% of the territory of Yakutia. More than half of the region was found to be occupied by permafrost landscapes with a limited thickness of the active layer up to 1.1 m. Ice-rich permafrost (more than 0.4 in ice content) was found to be typical for about 40% of the territory. Thermokarst is the most hazardous process that occurs in half of Yakutia.

scholarly journals A multisite dataset of near-surface soil temperature, active-layer thickness, and soil and vegetation conditions measured in northwestern Canada, 2016-2017

2021 ◽  
Author(s):  
Y Zhang ◽  
R Touzi ◽  
W Feng ◽  
G Hong ◽  
T C Lantz ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Land Use Planning ◽  
Surface Soil ◽  
Active Layer Thickness ◽  
Data Set ◽  
Near Surface ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Boreal Landscape

Quantifying and understanding spatial variation in permafrost conditions at the landscape-scale is important for land use planning and assessing the impacts of permafrost thaw. This report documents detailed field data observed at 110 sites in two areas in northwestern Canada from 2016 to 2017. One area is a northern boreal landscape near Inuvik and the other is a tundra landscape near Tuktoyaktuk. The observations include near-surface soil temperatures (Tnss) at 107 sites, and active-layer thickness, soil and vegetation conditions at 110 sites. The data set includes the original Tnss records, the calculated daily, monthly, and annual averages of Tnss, soil and vegetation conditions at these sites, and photographs taken in the field. This data set will be useful for understanding the spatial heterogeneity of permafrost and validating modelling and mapping products.

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