Future Trajectory of Arctic System Evolution
7
Citation
104
Reference
10
Related Paper
Citation Trend
Keywords:
Water cycle
Describes use of air temperatures to determine permafrost presence for engineering purposes. Annual mean temperature and thawing index (a yearly summation of daily mean temperature over 32 F) in 61 localities of northern Canada were compared with reported permafrost occurrences. The latter are divided into four categories: free of permafrost; discontinuous permafrost; continuous permafrost in forest, and in tundra. Correlations were found in all but twelve of the localities; the latter are considered individually and in some, permafrost was uncertain.
Cite
Citations (7)
Abstract 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.
Active layer
Cite
Citations (42)
유역의 수문반응은 기후-토양-식생의 복합적인 프로세스에 의해서 결정된다. 증발산량은 기후-토양-식생을 연결하는 매우 중요한 수문순환성분으로서, 유역에서의 수문순환을 정확하게 이해하기 위해서 연 증발산량에 관한 연구가 매우 중요한 의미를 가지게 된다. 본 연구에서는 강수량, 잠재 증발산량과 식생의 영향을 고려하는 산림율을 적용하여 우리나라에 적합한 연 증발산량 산정모형을 제시하였다. 제안된 모형이 높은 수준으로 연 증발산량을 모의하고 있지는 않으나 이전에 제시된 경험식 보다 좀 더 정확한 연 증발산량을 산정하였다. 이에 본 연구는 기후-토양-식생의 역학분석의 연구 방향을 제시해줄 수 있을 것으로 판단된다. The hydrologic response of watershed determined by complex process about climate-soil-vegetation. Evapotranspiration is very important component of hydrological cycle to connect climate, soil and vegetation. The research of annual evapotranspiration the watershed is primary topic for understanding hydrological cycle in watershed. A suitable model for South Korea which relates annual evapotranspiration to precipitation, potential evapotranspiration, and ratio of forest considering vegetation effect, is proposed in this study. Result of the proposed model is not high quality about estimating evapotranspiration but it is better than previous model which relates annual evapotranspiration. This study is able to suggest research direction about dynamic analysis of climate-soil-vegetation.
Water cycle
Hydrological modelling
Cite
Citations (4)
Water cycle
Irrigation scheduling
Cite
Citations (15)
Abstract Climate‐driven thawing of Arctic permafrost renders its vast carbon reserves susceptible to microbial degradation, serving as a potentially potent positive feedback hidden within the climate system. While seemingly intuitive, the relationship between thermally driven permafrost losses and organic carbon (OC) export remains largely unexplored in natural settings. Filling this knowledge gap, we present down‐core bulk and compound‐specific radiocarbon records of permafrost change from a sediment core taken within the Alaskan Colville River delta spanning the last c . 2,700 years. Fingerprinted by significantly older radiocarbon ages of bulk OC and long‐chain fatty acids, these data expose a thermally driven increase in permafrost OC export and/or deepening of mobilizable permafrost layers over the last c . 160 years after the Little Ice Age. Comparison of OC content and radiocarbon data between recent and Roman warming episodes likely implies that the rate of warming, alongside the prevailing boundary conditions, may dictate the ultimate fate of the Arctic's permafrost inventory. Our findings highlight the importance of leveraging geological records as archives of Arctic permafrost mobilization dynamics with temperature change.
Carbon fibers
Cite
Citations (6)
Water cycle
Potential evaporation
Global Change
Cite
Citations (2,079)
Table (database)
Cite
Citations (68)
Table (database)
Settlement (finance)
Cite
Citations (32)
Using continuous data obtained from 17 monitoring sites, the permafrost temperature profiles and the depths of zero annual amplitude (DZAA) on the Qinghai-Tibet Plateau are examined. Permafrost thermal trumpet curves are generally narrow and the DZAAs are generally shallow in warm permafrost regions, especially at sites where the permafrost temperature is close to 0 °C. The observed DZAAs in warm permafrost regions are indeed generally less than 7.0 m and for three sites less than 4.0 m. In low-temperature permafrost areas, the situation is reversed: the thermal trumpet curves are generally wide and the DZAAs are generally deep. Theoretical and numerical analyses clearly show there is a causal relationship between permafrost warming and the decrease of the DZAA. Latent heat effects are buffering the increase of permafrost temperature and result in narrow thermal trumpet curves and shallow DZAAs. Based on observations and numerical analyses, this research suggests that most of the permafrost on the Qinghai-Tibet Plateau is undergoing internal thaw and the latent heat effects have important implications on the permafrost thermal regime. The temperature-dependent adjustments in permafrost will promote both the downward and upward degradation of permafrost as a result of climate warming.
Cite
Citations (27)