• Title/Summary/Keyword: Polar mean

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Ocean Response to the Pinatubo and 1259 Volcanic Eruptions

  • Kim, Seong-Joong;Kim, Baek-Min
    • Ocean and Polar Research
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    • v.34 no.3
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    • pp.305-323
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    • 2012
  • The ocean's response to the Pinatubo and 1259 volcanic eruptions was investigated using an ocean general circulation model equipped with an energy balance model. Volcanic eruptions release gases into the atmosphere which increases the aerosol optical depth and acts to reduce the incoming short-wave radiation. For example, there was a huge volcanic eruption (Pinatubo) in 1991 which reduced the global mean radiative forcing by about 3 W $m^{-2}$. Two numerical experiments were simulated. The first experiment features the Pinatubo eruption and the second experiment simulates the much larger volcanic eruption that occurred in 1259 when the radiative forcing was reduced by 7 times compared to the Pinatubo event. With the reduced radiative forcing due to the Pinatubo eruption at about 3 W $m^{-2}$ and 1259 eruption at about 21 W $m^{-2}$, the global mean sea surface temperature (SST) decreased to its lowest in the second year after each event by about $0.4^{\circ}C$ and $1.6^{\circ}C$, respectively. Sea surface salinity (SSS) increased substantially in the northern North Pacific, northern North Atlantic, and the Southern Ocean. The reduced SST together with SSS increased ocean convection, which yielded an increase in North Atlantic Deep Water, Antarctic Bottom Water, and North Pacific Intermediate Water production and their outflows. The increase in overturning circulation eventually increased the pole-ward ocean heat fluxes. In conclusion, huge volcanic eruptions perturb the ocean substantially and their hallmarks last for more than a decade, confirming the importance of volcanic eruptions in illustrating the decadal-climate variability recorded in the paleoclimate proxy data for the past million years.

Thermal Physiological Response of Functional Knitwears for Health and Comfort (건강 쾌적 니트의류가 온열생리반응에 미치는 영향)

  • Kang, Mi-Jung;Kwon, Young-Ah;Kim, Tae-Kyu
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.11
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    • pp.1645-1652
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    • 2007
  • The purpose of this study was to evaluate physiological response and subjective sensation of functional knitwears with different materials and designs. The three different types of knitwears were knitted(polar-neck with cotton/chitosan-C, V-neck with cotton/chitosan-CV and polar neck with cotton/chitosan/silver yarn-CS) and evaluated by four healthy female subjects. Eardrum temperature, mean skin temperature, clothing microclimate, and heart rate were measured in climatic chamber($30^{\circ}C$, 50%RH, 0.5m/sec). The results were as follows. 1. Eardrum temperature was generally evaluated as lower in CV and CS than in C. Mean skin temperature was lower in knitwears with silver yarn than in knitwears without silver yarn. 2. Clothing microclimate temperature on the chest was lower in knitwears with silver yarn than in knitwears without silver yarn. 3. Clothing microclimate humidity was generally lower knitwears with silver yarn than knitwears without silver yarn. 4. Heart rate was lower in knitwears with silver yarn than in knitwears without silver yarn and lower in V-neck than in polar neck. 5. Thermal sensation was slightly warmer in knitwears without silver yarn than in knitwears with silver yarn. Overall comfort sensation was evaluated as more comfortable in CV and CS than in C.

Genetic Distances for Intra- and Between-Group of Scapharca subcrenata from Yeosu of the Korea

  • Yoon, Jong-Man
    • Development and Reproduction
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    • v.25 no.4
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    • pp.305-311
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    • 2021
  • The oligonucleotides polymers (ON-polymers) were used producing a total of 110 loci unique to each clam population (LUECP) in group one and 132 in group two, respectively, varying in amount of DNA fragments (FRs) from greater than near 50 to a smaller quantity than 1,050 bp. The larger FR amounts (>1,050 bp) are not noticed in the two Scapharca subcrenata groups. The ON-polymer OPD-01 produced 33 LUECP, which were defining each group, almost 300 bp, 450 bp, and 500 bp, in the group one. The OPD-15 recognized 22 loci shared by the two clam populations (Loci shared by the two clam populations, LSTCP), a variety of FRs of sizes 300 bp that were equivalent in all specimens. The mean number of LUECP was varied and 1.2-fold greater in the shellfish group two than in the group one. Respecting mean bandsharing (BS) grade outcomes, entities in the shellfish group one (0.779±0.011) had a little higher BS grades than did entities from the group two (0.756±0.009) (p<0.05). The entities of the shellfish group one are not tightly gathered with other entities of the group two. The genetic distance (GD) (0.422) of this invertebrate (SUBCRENATA 02 and 01) is 7.41-fold hereditarily distinct to the GD (0.057) of the other invertebrate (SUBCRENATA 22 and 19). The polar dendrogram (PDG) procured by the five ON-polymers underlines two characteristic groups.

Influence of microenvironment on the spatial distribution of Himantormia lugubris (Parmeliaceae) in ASPA No. 171, maritime Antarctic

  • Choi, Seung Ho;Kim, Seok Cheol;Hong, Soon Gyu;Lee, Kyu Song
    • Journal of Ecology and Environment
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    • v.38 no.4
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    • pp.493-503
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    • 2015
  • This study analyzed how spatial distribution of Himantormia lugubris is affected by the microenvironment in the Antarctic Specially Protected Area (ASPA) No. 171 located in the Barton Peninsula of King George Island that belongs to the maritime Antarctic. In order to determine the population structure of H. lugubris growing in Baekje Hill within ASPA No. 171, we counted the individuals of different size groups after dividing the population into 5 growth stages according to mean diameter as follows: ≤ 1 cm, 1-3 cm, 3-5 cm, 5-10 cm, and ≥ 10 cm. The count of H. lugubris individuals in each growth stage was converted into its percentage with respect to the entire population, which yielded the finding that stages 1 through 5 accounted for 32.8%, 25.3%, 15.9%, 22.5%, and 3.5%, respectively. This suggests that the population of H. lugubris in ASPA No. 171 has a stable reverse J-shaped population structure, with the younger individuals outnumbering mature ones. The mean density of H. lugubris was 17.6/0.25 m2, mean canopy cover 13.3%, and the mean dry weight 37.8 g/0.25 m2. It began to produce spore in the sizes over 3 cm, and most individuals measuring 5-10 cm were adults with sexually mature apothecia. The spatial distribution of H. lugubris was highly heterogeneous. The major factors influencing its distribution and performance were found to be the period covered by snow, wind direction, moisture, size of the substrate, and canopy cover of Usnea spp. Based on these factors, we constructed a prediction model for estimating the spatial distribution of H. lugubris. Conclusively, the major factors for the spatial distribution of H. lugubris were snow, wind, substrate and the competition with Usnea spp. These results are important for understanding of the distribution in the maritime Antarctic and evolution of H. lugubris that claims a unique life history and ecological niche.

Natural and Anthropogenic Heavy Metal Deposition to the Snow in King George Island, Antarctic Peninsula

  • Hong, Sung-Min;Lluberas, Albert;Lee, Gang-Woong;Park, Jun-Kun
    • Ocean and Polar Research
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    • v.24 no.3
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    • pp.279-287
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    • 2002
  • Successive 24 snow samples, collected from a 1.2m snow pit at a site on the summit of Main Dome in King George Island, Antarctic Peninsula, were measured for heavy metals such as Pb, Cd, Cu, and Zn and other chemical species. The mean concentrations of heavy metals are 3.48pg/g for Pb, 0.10pg/g for Cd, 16.6 pg/g for Cu and 15.8 pg/g for Zn, respectively. Pb and Cd concentrations observed in our samples are very comparable to those reported for recent snow at other Antarctic sites, while Zn and Cu levels are much higher than those at other sites. The annual fallout fluxes of all heavy metals approximately calculated are, however, much greater in King George Island than at other sites. With respect to the estimates of natural contributions, sea salt spray is found to be a major contributor to Cd and Zn inputs to the snow and minor to Cu inputs. On the other hand, the anthropogenic input can account for a large part of Pb concentrations. A tentative estimate represents that local emissions could be responsible for more than half of the excess Pb flux to the snow in King George Island.

Temporal Dynamics and Patterning of Meiofauna Community by Self-Organizing Artificial Neural Networks

  • Lee, Won-Cheol;Kang, Sung-Ho;Montagna Paul A.;Kwak Inn-Sil
    • Ocean and Polar Research
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    • v.25 no.3
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    • pp.237-247
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    • 2003
  • The temporal dynamics of the meiofauna community in Marian Cove, King George Island were observed from January 22 to October 29 1996. Generally, 14 taxa of metazoan meiofauna were found. Nematodes were dominant comprising 90.12% of the community, harpacticoid 6.55%, and Kinorhynchs 1.54%. Meiofauna abundance increased monthly from January to May 1996, while varying in abundance after August 1996. Overall mean abundance of metazoan meiofauna was $2634ind./10cm^2$ during the study periods, which is about as high as that found in temperate regions. Nematodes were most abundant representing $2399ind./10cm^2$. Mean abundance of harpacticoids, including copepodite and nauplius was $131ind./10cm^2$ by kinorhynchs $(26ind./10cm^2)$. The overall abundance of other identified organisms was $31ind./10cm^2$ Other organisms consisted of a total of 11 taxa including Ostracoda $(6ind./10cm^2)$, Polycheata $(7ind./10cm^2)$, Oligochaeta $(8ind./10cm^2)$, and Bivalvia $(6ind./10cm^2)$. Additionally, protozoan Foraminifera occurred at the study area with a mean abundance of $263ind./10cm^2$. Foraminiferans were second in dominance to nematodes. The dominant taxa such as nematodes, harpacticoids, kinorhynchs and the other tua were trained and extensively scattered in the map through the Kohonen network. The temporal pattern of the community composition was most affected by the abundance dynamics of kinorhynchs and harpacticoids. The neural network model also allowed for simulation of data that was missing during two months of inclement weather. The lowest meiofauna abundance was found in August 1996 during winter. The seasonal changes were likely caused by temperature and salinity changes as a result of meltwater runoff, and the physical impact by passing icebergs.

A Study of stability in ratings for clothing and their woven fabrics (의복과 그 직물에 대한 평가의 재현성 차이에 관한 연구)

  • 유경숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.3
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    • pp.560-568
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    • 2001
  • The aim of the present study was to measure intra-individual consistency in clothing and fabric evaluation and to examine its relation to the ratings. A sample of 93 female and 97 male university students rated clothing of 4 styles of daytime wear and 2 fabrics on 15 pairs of polar adjectives twice in 7-days interval. Correlation coefficients between the two ratings for each subject, intra-individual consistency in the evaluation, ranged from -0.12 to 0.89 and mean coefficient was 0.63 of female and -0.01 to 0.78 and mean coefficient was 0.54 of male. Based on the coefficients, the subjects were classified into three groups: high, medium, and low intra-individual consistency. Analysis of variance of mean ratings by the three groups revealed that significant difference existed in 24% of female and 23% of male in 90 combinations of 6 clothing and 15 semantic differential scales. Female of subjects with high intra-individual consistency were most likely definite to evaluate clothing, whereas the ones with low were least. But male subjects were not definite. Mean correlation coefficients for style evaluation subscales of female was 0.39, but male was 0.44. Among the semantic differential scales, high stability in the two ratings was observed for the synthetic clothing evaluation. Correlation coefficients for each clothing obtained from the mean score of the subjects in each semantics differential scale were around 0.98, including that the mean scores of the subjects in each scale could yield excellent stability in clothing evaluation.

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Surface Flux Measurements at King Sejong Station in West Antarctica: II. Turbulent exchanges of sensible heat and latent heat in the austral summer of 2002-2003 (남극 세종기지에서의 지표 플럭스 관측: II. 2002-2003년 남반구 여름 기간의 열과 수증기의 난류 교환)

  • Choi, Tae-Jin;Lee, Bang-Yong;Lee, Hee-Choon;Kim, Seong-Joong;Hong, Sung-Min
    • Journal of the Korean Geophysical Society
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    • v.8 no.3
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    • pp.159-167
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    • 2005
  • Turbulent fluxes of sensible heat and latent heat were analyzed at King Sejong station in the austral summer of 2002 (December) and 2003 (January and February). Monthly mean air temperatures of January and February (2.2oC) were similar to those averaged over 1988 to 2001. Precipitation was less in January and greater in February than those averaged over last 14 years. In December of 2002 and January, there was precipitation primarily when easterly wind blew usually. The frequency of snowfall was equal to or larger than that of rainfall. In the mean while, precipitation primarily in forms of rainfall occurred with westerly wind in February. In addition, while for easterly wind, temperature and humidity was low, temperature and humidity were high in case of westerly wind. Based on flux footprint, measured flux mainly came from within 300 m with maximum of 40 m upwind, indicating the insignificant role of the sea around the study site. Half-hourly downward short wave radiation amounted up to ∼ 1000 Wm-2 and net radiation ranged from -50 to 600 Wm-2. Half-hourly sensible heat flux was positive at daytime with maximum of ∼ 400 Wm-2, except the 27th and 28th in February of 2003 when it was negative all day despite of positive net radiation at short daytime. Latent heat flux was positive with maximum of ∼ 130 Wm-2. Depending on wind direction, the partitioning of net radiation into the sum of sensible heat flux and latent heat flux was larger than 0.8, indicating the strong source of the land surface for the atmospheric heating. The daytime averaged Bowen ratio (=sensible heat flux /latent heat flux) was significantly greater than 1, indicating that sensible heat flux was the main source to heat the atmosphere over the site.

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Spatial Characteristics of Meiobenthic Community of Kongfjorden Sediment in the Svalbard Island, the Arctic Sea (북극해 스발바드 군도 Kongsfjorden 퇴적물에 서식하는 중형저서동물 군집의 공간 특성)

  • Kim, Dong-Sung;Shin, Jae-Chul;Kang, Sung-Ho;Chung, Ho-Sung
    • Ocean and Polar Research
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    • v.27 no.3
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    • pp.299-309
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    • 2005
  • The community structure of meiobenthos was studied in the sediment of Kongfjorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34mm in internal diameter, and were taken from upper sediment to a depth of 3cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these low faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 $(3,583{\pm}1,137inds./10cm^2)$, and lowest at station $MeG9(28{\pm}1inds./10cm^2)$. Meiobenthos in general showed the highest density in the upper 1cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0-1cm, at especially at depths of 2-3m because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ford community was characterised by : 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner ford communities (a group of four nation: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by : 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner ford community was characterised by both a high density and great mean number of meiofaunal taxa.

Prediction Skill of GloSea5 model for Stratospheric Polar Vortex Intensification Events (성층권 극소용돌이 강화사례에 대한 GloSea5의 예측성 진단)

  • Kim, Hera;Son, Seok-Woo;Song, Kanghyun;Kim, Sang-Wook;Kang, Hyun-Suk;Hyun, Yu-Kyung
    • Journal of the Korean earth science society
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    • v.39 no.3
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    • pp.211-227
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    • 2018
  • This study evaluates the prediction skills of stratospheric polar vortex intensification events (VIEs) in Global Seasonal Forecasting System (GloSea5) model, an operational subseasonal-to-seasonal (S2S) prediction model of Korea Meteorological Administration (KMA). The results show that the prediction limits of VIEs, diagnosed with anomaly correlation coefficient (ACC) and mean squared skill score (MSSS), are 13.6 days and 18.5 days, respectively. These prediction limits are mainly determined by the eddy error, especially the large-scale eddy phase error from the eddies with the zonal wavenumber 1. This might imply that better prediction skills for VIEs can be obtained by improving the model performance in simulating the phase of planetary scale eddy. The stratospheric prediction skills, on the other hand, tend to not affect the tropospheric prediction skills in the analyzed cases. This result may indicate that stratosphere-troposphere dynamic coupling associated with VIEs might not be well predicted by GloSea5 model. However, it is possible that the coupling process, even if well predicted by the model, cannot be recognized by monotonic analyses, because intrinsic modes in the troposphere often have larger variability compared to the stratospheric impact.