Interannual variations of the thermal regime of the active layer and near-surface permafrost in northern Alaska

1995 ◽  
Vol 6 (4) ◽  
pp. 313-335 ◽  
Author(s):  
V. E. Romanovsky ◽  
T. E. Osterkamp
Keyword(s):  
Active Layer ◽  
Thermal Regime ◽  
Interannual Variations ◽  
Near Surface ◽  
Northern Alaska

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 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 Comparison of model-produced active layer fields: Results for northern Alaska

2007 ◽  
Vol 112 (F2) ◽  
Author(s):  
Nikolay I. Shiklomanov ◽  
Oleg A. Anisimov ◽  
Tingjun Zhang ◽  
Sergey Marchenko ◽  
Frederick E. Nelson ◽  
...  
Keyword(s):  
Active Layer ◽  
Northern Alaska

scholarly journals Geophysical imaging of permafrost in the SW Svalbard – the result of two high arctic expeditions to Spitsbergen

2020 ◽  
Author(s):  
Mariusz Majdanski ◽  
Artur Marciniak ◽  
Bartosz Owoc ◽  
Wojciech Dobiński ◽  
Tomasz Wawrzyniak ◽  
...  
Keyword(s):  
Surface Waves ◽  
Active Layer ◽  
High Arctic ◽  
The Arctic ◽  
Seismic Profiles ◽  
Frozen Ground ◽  
Near Surface ◽  
Seismic Processing ◽  
Reflection Seismic ◽  
Sea Coast

<p>The Arctic regions are the place of the fastest observed climate change. One of the indicators of such evolution are changes occurring in the glaciers and the subsurface in the permafrost. The active layer of the permafrost as the shallowest one is well measured by multiple geophysical techniques and in-situ measurements.</p><p>Two high arctic expeditions have been organized to use seismic methods to recognize the shape of the permafrost in two seasons: with the unfrozen ground (October 2017) and frozen ground (April 2018). Two seismic profiles have been designed to visualize the shape of permafrost between the sea coast and the slope of the mountain, and at the front of a retreating glacier. For measurements, a stand-alone seismic stations has been used with accelerated weight drop with in-house modifications and timing system. Seismic profiles were acquired in a time-lapse manner and were supported with GPR and ERT measurements, and continuous temperature monitoring in shallow boreholes.</p><p>Joint interpretation of seismic and auxiliary data using Multichannel analysis of surface waves, First arrival travel-time tomography and Reflection imaging show clear seasonal changes affecting the active layer where P-wave velocities are changing from 3500 to 5200 m/s. This confirms the laboratory measurements showing doubling the seismic velocity of water-filled high-porosity rocks when frozen. The same laboratory study shows significant (>10%) increase of velocity in frozen low porosity rocks, that should be easily visible in seismic.</p><p>In the reflection seismic processing, the most critical part was a detailed front mute to eliminate refracted arrivals spoiling wide-angle near-surface reflections. Those long offset refractions were however used to estimate near-surface velocities further used in reflection processing. In the reflection seismic image, a horizontal reflection was traced at the depth of 120 m at the sea coast deepening to the depth of 300 m near the mountain.</p><p>Additionally, an optimal set of seismic parameters has been established, clearly showing a significantly higher signal to noise ratio in case of frozen ground conditions even with the snow cover. Moreover, logistics in the frozen conditions are much easier and a lack of surface waves recorded in the snow buried geophones makes the seismic processing simpler.</p><p>Acknowledgements               </p><p>This research was funded by the National Science Centre, Poland (NCN) Grant UMO-2015/21/B/ST10/02509.</p>

scholarly journals Unearthing the Boreal Soil Resistome Associated with Permafrost Thaw

2020 ◽  
Author(s):  
Tracie J. Haan ◽  
Devin M. Drown
Keyword(s):  
Antibiotic Resistance ◽  
Active Layer ◽  
Resistance Genes ◽  
Soil Bacteria ◽  
Bacterial Community Composition ◽  
Ecological Niches ◽  
Whole Genome ◽  
Near Surface ◽  
Permafrost Thaw ◽  
Insight Into

ABSTRACTUnderstanding the distribution and mobility of antibiotic resistance genes (ARGs) in soil bacteria from diverse ecological niches is critical in assessing their impacts on the global spread of antibiotic resistance. In permafrost associated soils, climate and human driven forces augment near-surface thaw altering the overlying active layer. Physiochemical changes shift bacterial community composition and metabolic functioning, however, it is unknown if permafrost thaw will affect ARGs comprising the boreal soil resistome. To assess how thaw shifts the resistome, we performed susceptibility testing and whole genome sequencing on soil isolates from a disturbance-induced thaw gradient in Interior Alaska. We found resistance was widespread in the Alaskan isolates, with 87% of the 90 isolates resistant to at least one of the five antibiotics. We also observed positive trends in both the proportion of resistant isolates and the abundance of ARGs with permafrost thaw. However, the number of ARGs per genome and types of genes present were shown to cluster more strongly by bacterial taxa rather than thaw emphasizing the evolutionary origins of resistance and the role vertical gene transfer has in shaping the predominantly chromosomally encoded ARGs. The observed higher proportion of plasmid-borne and distinct ARGs in our isolates compared to RefSoil+ suggests local conditions affect the composition of the resistome along with selection for ARG mobility. Overall taxonomy and geography shape the resistome, suggesting that as microbial communities shift in response to permafrost thaw so will the ARGs in the boreal active layer.IMPORTANCEAs antibiotic resistance continues to emerge and rapidly spread in clinical settings, it is imperative to generate studies that build insight into the ecology of environmental resistance genes that pose a threat to human health. This study provides insight into the occurrence of diverse ARGs found in Alaskan soil bacteria which is suggestive of the potential to compromise health. The observed differences in ARG abundance with increasing permafrost thaw suggest the role of soil disturbance in driving the distribution of resistant determinants and the predominant taxa that shape the resistome. Moreover, the high-quality whole genome assemblies generated in this study are an extensive resource for microbial researchers interested in permafrost thaw and will provide a steppingstone for future research into ARG mobility and transmission risks.

scholarly journals Active layer thermal regime in two climatically contrasted sites of the Antarctic Peninsula region

2016 ◽  
Vol 42 (2) ◽  
pp. 457 ◽  
Author(s):  
F. Hrbáček ◽  
M. Oliva ◽  
K. Laska ◽  
J. Ruiz-Fernández ◽  
M. A. De Pablo ◽  
...  
Keyword(s):  
Active Layer ◽  
Antarctic Peninsula ◽  
Thermal Regime ◽  
Active Layer Thickness ◽  
Mean Annual Temperature ◽  
Climate Trends ◽  
Ground Temperatures ◽  
Air Temperatures ◽  
Discontinuous Permafrost ◽  
The Antarctic

Permafrost controls geomorphic processes in ice-free areas of the Antarctic Peninsula (AP) region. Future climate trends will promote significant changes of the active layer regime and permafrost distribution, and therefore a better characterization of present-day state is needed. With this purpose, this research focuses on Ulu Peninsula (James Ross Island) and Byers Peninsula (Livingston Island), located in the area of continuous and discontinuous permafrost in the eastern and western sides of the AP, respectively. Air and ground temperatures in as low as 80 cm below surface of the ground were monitored between January and December 2014. There is a high correlation between air temperatures on both sites (r=0.74). The mean annual temperature in Ulu Peninsula was -7.9 ºC, while in Byers Peninsula was -2.6 ºC. The lower air temperatures in Ulu Peninsula are also reflected in ground temperatures, which were between 4.9 (5 cm) and 5.9 ºC (75/80 cm) lower. The maximum active layer thickness observed during the study period was 52 cm in Ulu Peninsula and 85 cm in Byers Peninsula. Besides climate, soil characteristics, topography and snow cover are the main factors controlling the ground thermal regime in both areas.

scholarly journals Dynamical Downscaling Data for Studying Climatic Impacts on Hydrology, Permafrost, and Ecosystems in Arctic Alaska

2016 ◽  
Author(s):  
Lei Cai ◽  
Vladimir A. Alexeev ◽  
Christopher D. Arp ◽  
Benjamin M. Jones ◽  
Anna Liljedahl ◽  
...  
Keyword(s):  
Observational Data ◽  
Dynamical Downscaling ◽  
Dew Point ◽  
Climatic Variables ◽  
The Arctic ◽  
Linear Scaling ◽  
Permafrost Degradation ◽  
Near Surface ◽  
Temperature Bias ◽  
Northern Alaska

Abstract. Climatic changes are most pronounced in northern high latitude regions. Yet, there is a paucity of observational data, both spatially and temporally, such that regional-scale dynamics are not fully captured, limiting our ability to make reliable projections. In this study, a group of dynamical downscaling products were created for the period 1950 to 2100 to better understand climate change and its impacts on hydrology, permafrost, and ecosystems at a resolution suitable for northern Alaska. An ERA-interim reanalysis dataset and the Community Earth System Model (CESM) served as the forcing mechanisms in this dynamical downscaling framework, and the Weather Research & Forecast (WRF) model, embedded with an optimization for the Arctic (Polar WRF), served as the Regional Climate Model (RCM). This downscaled output consists of multiple climatic variables (precipitation, temperature, wind speed, dew point temperature, and surface air pressure) for a 10 km grid spacing at three-hour intervals. The modeling products were evaluated and calibrated using a bias-correction approach. The ERA-interim forced WRF (ERA-WRF) produced reasonable climatic variables as a result, yielding a more closely correlated temperature field than precipitation field when long-term monthly climatology was compared with its forcing and observational data. A linear scaling method then further corrected the bias, based on ERA-interim monthly climatology, and bias-corrected ERA-WRF fields were applied as a reference for calibration of both the historical and the projected CESM forced WRF (CESM-WRF) products. Biases, such as, a cold temperature bias during summer and a warm temperature bias during winter as well as a wet bias for annual precipitation that CESM holds over northern Alaska persisted in CESM-WRF runs. The linear scaling of CESM-WRF eventually produced high-resolution downscaling products for the Alaskan North Slope for hydrological and ecological research, together with the calibrated ERA-WRF run, and its capability extends far beyond that. Other climatic research has been proposed, including exploration of historical and projected climatic extreme events and their possible connections to low-frequency sea-atmospheric oscillations, as well as near-surface permafrost degradation and ice regime shifts of lakes. These dynamically downscaled, bias corrected climatic datasets provide improved spatial and temporal resolution data necessary for ongoing modeling efforts in northern Alaska focused on reconstructing and projecting hydrologic changes, ecosystem processes and responses, and permafrost thermal regimes. The dynamical downscaling methods presented in this study can also be used to create more suitable model input datasets for other sub-regions of the Arctic. Supplementary data are available at https://doi.org/10.1594/PANGAEA.863625.

SPECTRAL SIGNATURE OF COUPLED FLOW IN THE REFREEZING ACTIVE LAYER, NORTHERN ALASKA

1992 ◽  
Vol 13 (3) ◽  
pp. 273-284 ◽  
Author(s):  
Samuel I. Outcalt ◽  
Kenneth M. Hinkel ◽  
Frederick E. Nelson
Keyword(s):  
Active Layer ◽  
Spectral Signature ◽  
Coupled Flow ◽  
Northern Alaska

Thermal regime of soil active layer at the Bolshevik Island (Archipelago Severnaya Zemlya) during 2016 – 2020 years

2021 ◽  
Author(s):  
Alexander Makshtas ◽  
Petr Bogorodski ◽  
Ilya Jozhikov
Keyword(s):  
Heat Flux ◽  
Spatial Variability ◽  
Active Layer ◽  
Thermal Regime ◽  
Soil Layer ◽  
Underlying Surface ◽  
Wave Radiation ◽  
Heat Flux Sensor ◽  
Research Station ◽  
Contact Method

<p>Investigations of active soil layer on the Research station “Ice Base Cape Baranova’’ had been started in February 2016 after installation on the meteorological site sensors of Finnish Meteorological Institute: thermochain with IKES PT00 temperature sensors at depths of 20, 40, 60, 80 and 100 cm, soil heat flux sensor HFP, and two ThetaProbe type ML3 soil moisture sensors. Based on the results of measurements annual cycle of soil temperature changes was revealed with amplitudes 10 - 15 ° C less than the amplitudes of surface air layer temperature (Ta) and especially the temperature of the soil upper surface (Tsrad), in great degree determined by short-wave radiation heating and long-wave radiation cooling. Approximation by linear fittings shows average rates of increase Ta - 0.4°C/year, Тsrad - 0.3°C/year, and temperatures of active soil layer - 0.2°C/year.</p><p>The data on thermal regime of active soil layer and characteristics of energy exchange in atmospheric surface layer make it possible to draw the conclusion about the reason for the abnormally warm state of the upper meter soil layer in summer 2020, despite in March during the whole period under study active soil layer was the warmest in 2017. Comparison in temperatures of the underlying surface and characteristics of surface heat balance during period under study showed that in 2020 the temperature of the soil surface at the end of May for a short time reached the temperature of snow melting. It is happened 25 days earlier than in 2017 as well as other years and led to radical decrease in surface albedo, sharp increase of heat flux to the underlying surface, and increased duration of active soil layer heating.</p><p>Additionally, permafrost thawing studies using a manual contact method were carried out on the special site, organized according to CALM standards. These studies showed significant variety of soil active layer thicknesses in the relatively small area (~0.12 km<sup>2</sup>), which indicates significant spatial variability of microrelief, structure and thermophysical properties of soil, as well as vegetation, typical for Arctic desert. Calculations carried out with version of the well-known thermodynamic Leibenzon model for various parameterizations of vegetation and soil properties partly described peculiarities of spatial variability of observed thawing depths.</p>

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