• The Korean Journal of Quaternary Research
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• v.33 no.1_2
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• pp.1-23
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• 2021

In response to the increase in atmospheric carbon dioxide and greenhouse gases, the global mean temperature is rising rapidly. In particular, the warming of the Arctic is two to three times faster than the rest. Associated with the rapid Arctic warming, the sea ice shows decreasing trends in all seasons. The faster Arctic warming is due to ice-albedo feedback by the presence of snow and ice in polar regions, which have higher reflectivity than the ocean, the bare land, or vegetation, higher long-wave heat loss to space than lower latitudes by lower surface temperature in the Arctic than lower latitudes, different stability of atmosphere between the Arctic and lower latitudes, where low stability leads to larger heat losses to atmosphere from surface by larger latent heat fluxes than the Arctic, where high stability, especially in winter, prohibits losing heat to atmosphere, increase in clouds and water vapor in the Arctic atmosphere that subsequently act as green house gases, and finally due to the increase in sensible heat fluxes from low latitudes to the Arctic via lower troposphere. In contrast to the rapid Arctic warming, in midlatitudes, especially in eastern Asia and eastern North America, cold air outbreaks occur more frequently and last longer in recent decades. Two pathways have been suggested to link the Arctic warming to cold air outbreaks over midlatitudes. The first is through troposphere in synoptic-scales by enhancing the Siberian high via a development of Rossby wave trains initiated from the Arctic, especially the Barents-Kara Seas. The second is via stratosphere by activating planetary waves to stratosphere and beyond, that leads to warming in the Arctic stratosphere and increase in geopotential height that subsequently weakens the polar vortex and results in cold air outbreaks in midlatitudes for several months. There exists lags between the Arctic warming and cold events in midlatitudes. Thus, understanding chain reactions from the Arctic warming to midlatitude cooling could help improve a predictability of seasonal winter weather in midlatitudes. This study reviews the results on the Arctic warming and its connection to midlatitudes and examines the trends in surface temperature and the Arctic sea ice.

• Atmosphere
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• v.28 no.4
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• pp.393-402
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• 2018

This study investigated future changes in the Arctic permafrost features and related biogeochemical alterations under global warming. The Community Land Model (CLM) with biogeochemistry (BGC) was run for the period 2005 to 2099 with projected future climate based on the Special Report on Emissions Scenarios (SRES) A2 scenario. Under global warming, over the Arctic land except for the permafrost region, the rise in soil temperature led to an increase in soil liquid and decrease in soil ice. Also, the Arctic ground obtained carbon dioxide from the atmosphere due to the increase in photosynthesis of vegetation. On the other hand, over the permafrost region, the microbial respiration was increased due to thawing permafrost, resulting in increased carbon dioxide emissions. Methane emissions associated with total water storage have increased over most of Arctic land, especially in the permafrost region. Methane releases were predicted to be greatly increased especially near the rivers and lakes associated with an increased chance of flooding. In conclusion, at the end of $21^{st}$ century, except for permafrost region, the Arctic ground is projected to be the sink of carbon dioxide, and only permafrost region the source of carbon dioxide. This study suggests that thawing permafrost can further to accelerate global warming significantly.

• Ocean and Polar Research
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• v.32 no.1
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• pp.85-95
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• 2010

There is increasing consensus that global warming is seriously affecting the Arctic region. Sea Ice decreases and sea level rise have led to environmental change in Arctic Ecosystems, while also making the Arctic sea route more accessible to humans. There are complicated international governance dynamics in play, in addition to commercial and scientific interests in the Arctic region. This provides a unique opportunity for Korea to lead the future direction of Arctic policy in response to the global issues such as climate change and economic or scientific interests. Korea acquired Ad-hoc Observer status of the Arctic Council(AC) in 2008, which is the only pan-Arctic intergovernmental organization. It consists of six working groups: ACAP, AMAP, CAFF, PAME, EPPR, SDWG that implement research, survey, and monitoring. AC's Observer country has the opportunity to participate in a diverse range of activities such technical and expertise support, research and monitoring, financial support and conference organization. In order for Korea to expand its activities in the Arctic region, we suggest the following approach: First, Korea should become more actively engaged with the Arctic Council and its activities; Second, Korea should construct organized collaborative networks of national experts to respond to Arctic issues; Third, Korea should develop collaborations with Arctic states; Finally, Korea should intensify its research on international relations and international laws related to the Arctic region.

• Maritime Security
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• v.2 no.1
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• pp.151-184
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• 2021

Global warming due to climate change is one of the biggest challenges in the 21st century. Global warming is not only a disaster that threatens the global ecosystem but also an opportunity to reduce logistics costs and develop mineral resources by commercializing Arctic routes. The Arctic paradox, in which ecological and environmental threats and new economic opportunities coexist, is expected to have a profound impact on the global environment. As the glaciers disappear, routes through the Arctic Ocean without passing through the Suez and Panama Canals emerged as the 'third route.' This can reduce the distance of existing routes by 30%. Global warming has also brought about changes in the geopolitical paradigm. As Arctic ice begins to melt, the Arctic is no longer a 'constant' but is emerging as the largest geopolitical 'variable' in the 21st century. Accordingly, the Arctic, which was recognized as a 'space of peace and cooperation' in the post-Cold War era, is now facing a new strategic environment in which military and security aspects are emphasized. After the Cold War, the Arctic used to be a place for cooperation centered on environmental protection, but it is once again changing into a stage of competition and confrontation between superpowers, heralding 'Cold War 2.0.' The purpose of this study is to evaluate the strategic value of the Arctic Ocean from geopolitical and geoeconomic perspectives and derive strategic implications by analyzing the dynamics of the New Cold War taking place in the Arctic region.

• Ocean and Polar Research
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• v.32 no.4
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• pp.379-386
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• 2010

This study examines changes in the Arctic sea ice associated with global warming by analyzing the climate coupled general circulation models (CGCMs) provided in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. We selected nine models for better performance under 20th century climate conditions based on two different criteria, and then estimated the changes in sea ice extent under global warming conditions. Under projected 21st century climate conditions, all models, with the exception of the GISS-AOM model, project a reduction in sea ice extent in all seasons. The mean reduction in summer (-63%) is almost four times larger than that in winter (-16%), resulting an enhancement of seasonal variations in sea ice extent. The difference between the models, however, becomes larger under the 21st century climate conditions than under 20th century conditions, thus limiting the reliability of sea-ice projections derived from the current CGCMs.

• Atmosphere
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• v.24 no.2
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• pp.131-140
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• 2014

The "Barents Oscillation (BO)", first designated by Paul Skeie (2000), is an anomalous recurring atmospheric circulation pattern of high relevance for the climate of the Nordic Seas and Siberia, which is defined as the second Emperical Orthogonal Function (EOF) of monthly winter sea level pressure (SLP) anomalies, where the leading EOF is the Arctic Oscillation (AO). BO, however, did not attracted much interest. In recent two decades, variability of BO tends to increase. In this study, we analyzed the spatio-temporal structures of Atmospheric internal modes such as Arctic Oscillation (AO) and Barents Oscillation (BO) and examined how these are related with Arctic warming in recent decade. We identified various aspects of BO, not dealt in Skeie (2000), such as upper-level circulation and surface characteristics for extended period including recent decade and examined link with other surface variables such as sea-ice and sea surface temperature. From the results, it was shown that the BO showed more regionally confined spatial pattern compared to AO and has intensified during recent decade. The regional dipolelar structure centered at Barents sea and Siberia was revealed in both sea-level pressure and 500 hPa geopotential height. Also, BO showed a stronger link (correlation) with sea-ice and sea surface temperature especially over Barents-Kara seas suggesting it is playing an important role for recent Arctic amplification. BO also showed high correlation with Ural Blocking Index (UBI), which measures seasonal activity of Ural blocking. Since Ural blocking is known as a major component of Eurasian winter monsoon and can be linked to extreme weathers, we suggest deeper understanding of BO can provide a missing link between recent Arctic amplification and increase in extreme weathers in midlatitude in recent decades.

• Journal of the Korean earth science society
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• v.40 no.4
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• pp.329-339
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• 2019

Arctic warming is a global issue. The sea ice in the Arctic plays a crucial role in the climate system. We thought that a recent abnormality in many countries in the northern hemisphere could be related to the effects of shrinking sea ice in the Arctic. Many research groups monitor sea ice in the Arctic for climate research. Satellite remote sensing is an integral part of Arctic sea ice research due to the Arctic's large size, making it difficult to observe with general research equipment, and its extreme environment that is difficult for humans to access. Along with monitoring recent weather changes, Korea scientists are conducting polar remote sensing using a Korean satellite series to actively cope with environmental changes in the Arctic. The Korean satellite series is known as KOMPSAT (Korea Multi-Purpose Satellite, Korean name is Arirang) series, and it carries optical and imaging radar. Since the organization of the Satellite Remote Sensing and Cryosphere Information Center in Korea in 2016, Korean research on and monitoring of Arctic sea ice has accelerated rapidly. Moreover, a community of researchers studying Arctic sea ice by satellite remote sensing increased in Korea. In this article, we review advances in Korea's remote sensing research for the polar cryosphere over the last several years. In addition to satellite remote sensing, interdisciplinary studies are needed to resolve the current limitations on research on climate change.

• The Korean Journal of Ecology
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• v.21 no.4
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• pp.383-387
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• 1998

the geoecology of the alpine and subalpine belts of the Korean Peninsula, its component plant group, its environmental history, and climatic amplitudes of the arctic-alpine and alpine plants has reviewed and discussed. The present-day alpine and subalpine landscapes are likely to have been formed during the post-glacial warming phase. The disjunctive distribution of many alpine and subalpine plants, however, suggests a former continuous distribution of these both locally and on a broader, and the subsequent breakdown of a former continuous range into fragments as the climate ameliorated during the post-glacial warming phase. The presences of numerous arctic-alpine and alpine plants on the alpine and subalpine belts of the Korean Peninsula, are mainly their relative degree of sensitivity to high summer temperatures. The continued survivals of alpine species and landscape in Korea is in danger if global warming associated the greenhouse effect takes place.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.2
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• pp.86-94
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• 2023

Climate change is more rapid in the Arctic than elsewhere in the world, and increased precipitation and warming are expected cause changes in biogeochemical processes due to altered microbial communities and activities. It is crucial to investigate microbial responses to climate change to understand changes in carbon and nitrogen dynamics. We investigated the effects of increased temperature and precipitation on microbial biomass and community structure in dry tundra using two depths of soil samples (organic and mineral layers) under four treatments (control, warming, increased precipitation, and warming with increased precipitation) during the growing season (June-September) in Cambridge Bay, Canada (69°N, 105°W). A phospholipid fatty acid (PLFA) analysis method was applied to detect active microorganisms and distinguish major functional groups (e.g., fungi and bacteria) with different roles in organic matter decomposition. The soil layers featured different biomass and community structure; ratios of fungal/bacterial and gram-positive/-negative bacteria were higher in the mineral layer, possibly connected to low substrate quality. Increased temperature and precipitation had no effect in either layer, possibly due to the relatively short treatment period (seven years) or the ecosystem type. Mostly, sampling times did not affect PLFAs in the organic layer, but June mineral soil samples showed higher contents of total PLFAs and PLFA biomarkers for bacteria and fungi than those in other months. Despite the lack of response found in this investigation, long-term monitoring of these communities should be maintained because of the slow response times of vegetation and other parameters in high-Arctic ecosystems.

• Korean Journal of Remote Sensing
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• v.33 no.6_1
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• pp.901-915
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• 2017

Recently, global climate change has caused a catastrophic event in the Arctic Ocean, directly and indirectly. The air-sea interaction has caused the significant sea-ice reduction in the Arctic Ocean, and has been accelerating the Arctic warming. Many scientists are worried about the Arctic environment change, suggesting that many of anomalous events will produce direct or indirect biophysical effects on the Arctic. The aim of this study is to understand the inter-annual variability of the Arctic Ocean in wide-view using multi-satellite-derived measurements. Sea surface temperature (SST) and sea ice concentration (SIC) data were obtained from Optimum Interpolation Sea Surface Temperature (OISST) and ECMWF ERA-Interim, respectively. Chlorophyll-a concentration (CHL) was obtained from Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) and Aqua sensor from MODerate resolution Imaging Spectroradiometer (MODIS-Aqua) sensor which has continuously observed since 1998. From 1998 to 2016 summer in the Arctic Ocean which was defined as regions over $60^{\circ}N$ in this study, there were three consequences that CHL increase ($0.15mg\;m^{-3}\;decade^{-1}$), SST warming ($0.43^{\circ}C\;decade^{-1}$) and SIC decrease ($-5.37%\;decade^{-1}$). While SST and SIC highly correlated each other (r = -0.76), a relationship between CHL and SIC was very low ($r={\pm}0.1$) because of data limitations. And a relationship between CHL and SST shows meaningful results ($r={\pm}0.66$) with regional differences.