Temperature Regimes of the Active Layer and Seasonally Frozen Ground under a Forest‐Steppe Mosaic, Mongolia

Dashtseren, Avirmed; Ishikawa, Mamoru; Iijima, Yoshihiro; Yamkhin, Jambaljav

doi:10.1002/ppp.1824

Cited by 38 publications

(56 citation statements)

References 38 publications

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“…Forest cover effectively blocks incoming shortwave radiation and produces organic‐rich soils, both of which keep the ground cool and allow permafrost to persist . This process is the typical formation pathway for ecosystem‐driven permafrost and is clearly seen at the forest sites of Terelj‐N (thermal offset = −1.5°C) and Udleg (−0.1°C) in the Hentii Range (Figure , Table S1).…”

Section: Resultsmentioning

confidence: 95%

Thermal states, responsiveness and degradation of marginal permafrost in Mongolia

Mamoru

Jamvaljav

Dashtseren

et al. 2018

Permafrost & Periglacial

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Ground thermal conditions in marginal permafrost in Mongolia were assessed using ground temperatures measured year‐round at 69 borehole sites. Permafrost is continuous in northern Mongolia and exists as sporadic/isolated patches in the south. Ground temperatures are strongly controlled by local environmental factors, such as topographic depressions that concentrate cold air during winter, ice‐rich strata that prevent penetration of sensible heat, and tree cover that reduces incident solar radiation. Permafrost temperatures are typically between −1 and 0°C; colder permafrost (< −2°C) occurs in the northern extent of continuous permafrost and at high elevations in the sporadic/isolated permafrost zones. Relict permafrost, which is thermally disconnected from seasonal air temperature fluctuations, is present near the latitudinal and elevational limits of perennially frozen ground. Cold and thermally responsive permafrost is dominant in the continuous and discontinuous zones, while warm and thermally unresponsive permafrost is dominant in the sporadic and isolated zones. Overall, the climate‐driven permafrost in the colder regions is stable, while the ecosystem‐driven permafrost in the warmer regions is degrading.

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Section: Resultsmentioning

confidence: 95%

Thermal states, responsiveness and degradation of marginal permafrost in Mongolia

Mamoru

Jamvaljav

Dashtseren

et al. 2018

Permafrost & Periglacial

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“…Potential exists in using more comprehensive metrics including the normalized difference in air and ground temperatures [60] and changes in volumetric water content [61]. The possibility for the derivation of these metrics is increasing as Mongolia continues to develop their borehole and climate monitoring networks [62,63].…”

Section: Assumptions and Limitationsmentioning

confidence: 99%

Role of Surface Melt and Icing Events in Livestock Mortality across Mongolia’s Semi-Arid Landscape

et al. 2019

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Livestock production is a socioeconomic linchpin in Mongolia and is affected by large-scale livestock die-offs. Colloquially known as dzuds, these die-offs are driven by anomalous climatic events, including extreme cold temperatures, extended snow cover duration (SCD) and drought. As average temperatures across Mongolia have increased at roughly twice the global rate, we hypothesized that increasing cold season surface melt including soil freeze/thaw (FT), snowmelt, and icing events associated with regional warming have become increasingly important drivers of dzud events as they can reduce pasture productivity and inhibit access to grazing. Here, we use daily brightness temperature (T b ) observations to identify anomalous surface melt and icing events across Mongolia from 2003-2016 and their contribution to dzuds relative to other climatic drivers, including winter temperatures, SCD, and drought. We find a positive relationship between surface melt and icing events and livestock mortality during the fall in southern Mongolia and during the spring in the central and western regions. Further, anomalous seasonal surface melt and icing events explain 17-34% of the total variance in annual livestock mortality, with cold temperatures as the leading contributor of dzuds (20-37%). Summer drought showed the greatest explanatory power (43%) but overall had less statistically significant relationships relative to winter temperatures. Our results indicate that surface melt and icing events will become an increasingly important driver of dzuds as annual temperatures and livestock populations are projected to increase in Mongolia.

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“…Permafrost studies for the Mongolian Altai are rare [17][18][19]. The distribution of permafrost in Mongolia is only mosaic-like owing to the fact that the country is located at the southern boundary of the Siberian permafrost.…”

Section: Introductionmentioning

confidence: 99%

“…Permafrost predominantly occurs in the Altai, Khangai, Khentii and Khuvsgul mountains and their surroundings. Generally, the thickness of the active layer and seasonally frozen ground show large spatial variations depending on microclimatic conditions, driven by topography, thermal soil properties, and vegetation cover on local scales [17][18][19][20][21]. Permafrost in the Khangai, Khentii and Khuvsgul mountains usually occur under forested regions [18,21,22], while in the Altai Mountains it occurs under alpine grassland.…”

Section: Introductionmentioning

confidence: 99%

Glaciers, Permafrost and Lake Levels at the Tsengel Khairkhan Massif, Mongolian Altai, During the Late Pleistocene and Holocene

et al. 2017

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Understanding paleo—and recent environmental changes and the dynamics of individual drivers of water availability is essential for water resources management in the Mongolian Altai. Here, we follow a holistic approach to uncover changes in glaciers, permafrost, lake levels and climate at the Tsengel Khairkhan massif. Our general approach to describe glacier and lake level changes is to combine traditional geomorphological field mapping with bathymetric measurements, satellite imagery interpretation, and GIS analyses. We also analysed climate data from two nearby stations, and measured permafrost temperature conditions at five boreholes located at different elevations. We identified four glacial moraine systems (M4-M1) and attribute them to the period from the penultimate glaciation (MIS 4/5) until the Little Ice Age (MIS 1). During the Local Last Glacial Maximum (LLGM; MIS 2), a glacier reached down into the western Kharganat Valley and blocked it, resulting in the formation of the endorheic Khar Lake basin. Subsequently, the lake was fed mainly by precipitation and permafrost meltwater. In recent years, glaciers have been in strong recession, yet Khar Lake levels have remained relatively stable, which is in contrast to mainly decreasing lake levels in other regions throughout Mongolia. While temperatures in the Altai are increasing (leading to increasing evaporation), precipitation in higher elevations has increased, which—in addition to increased glacier and permafrost melting—would counteract the increasing aridity effects. A systematic and holistic monitoring of glaciers, permafrost, lake levels and climate in the Mongolian Altai is necessary, and results from (sub-)disciplines need to be correlated

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Temperature Regimes of the Active Layer and Seasonally Frozen Ground under a Forest‐Steppe Mosaic, Mongolia

Cited by 38 publications

References 38 publications

Thermal states, responsiveness and degradation of marginal permafrost in Mongolia

Thermal states, responsiveness and degradation of marginal permafrost in Mongolia

Role of Surface Melt and Icing Events in Livestock Mortality across Mongolia’s Semi-Arid Landscape

Glaciers, Permafrost and Lake Levels at the Tsengel Khairkhan Massif, Mongolian Altai, During the Late Pleistocene and Holocene

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