Pub Date : 2016-12-30DOI: 10.4217/OPR.2016.38.4.339
Songyi Kim, Yeongcheol Han, S. Hur, Jeonghoon Lee
Stable water vapor isotopes have been utilized as a tracer for studying atmospheric global circulations, climate change and paleoclimate with ice cores. Recently, since laser spectroscopy has been available, water vapor isotopes can be measured more precisely and continuously. Studies of water vapor isotopes have been conducted over the world, but it is the early stage in south Korea. For vapor isotopes study, a cryogenic sampling device for water vapor isotopes has been developed. The cryogenic sampling device consists of the dewar bottle, filled with extremely low temperature material and impinger connected with a vacuum pump. Impinger stays put in the dewar bottle to change the water vapor which passes through the inside of impinger into the solid phase as ice. The fact that water vapor has not sampled completely leads to isotopic fractionation in the impinger. To minimize the isotopic fractionation during sampling water vapor, we have tested the method using a serial connection with two sets of impinger device in the laboratory. We trapped 98.02% of water vapor in the first trap and the isotopic difference of the trapped water vapor between two impinger were about 20‰ and 6‰ for hydrogen and oxygen, respectively. Considering the amount of water vapor trapped in each impinger, the isotopic differences for hydrogen and oxygen were 0.33‰ and 0.06‰, respectively, which is significantly smaller than the precision of isotopic measurements. This work can conclude that there is no significant fractionation during water vapor trapping.
{"title":"Applications of cryogenic method to water vapor sampling from ambient air for isotopes analysis","authors":"Songyi Kim, Yeongcheol Han, S. Hur, Jeonghoon Lee","doi":"10.4217/OPR.2016.38.4.339","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.4.339","url":null,"abstract":"Stable water vapor isotopes have been utilized as a tracer for studying atmospheric global circulations, climate change and paleoclimate with ice cores. Recently, since laser spectroscopy has been available, water vapor isotopes can be measured more precisely and continuously. Studies of water vapor isotopes have been conducted over the world, but it is the early stage in south Korea. For vapor isotopes study, a cryogenic sampling device for water vapor isotopes has been developed. The cryogenic sampling device consists of the dewar bottle, filled with extremely low temperature material and impinger connected with a vacuum pump. Impinger stays put in the dewar bottle to change the water vapor which passes through the inside of impinger into the solid phase as ice. The fact that water vapor has not sampled completely leads to isotopic fractionation in the impinger. To minimize the isotopic fractionation during sampling water vapor, we have tested the method using a serial connection with two sets of impinger device in the laboratory. We trapped 98.02% of water vapor in the first trap and the isotopic difference of the trapped water vapor between two impinger were about 20‰ and 6‰ for hydrogen and oxygen, respectively. Considering the amount of water vapor trapped in each impinger, the isotopic differences for hydrogen and oxygen were 0.33‰ and 0.06‰, respectively, which is significantly smaller than the precision of isotopic measurements. This work can conclude that there is no significant fractionation during water vapor trapping.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-30DOI: 10.4217/OPR.2016.38.3.209
Duckhee Jang, Yong-Jin Choi, Jin-Young Kim
The purpose of this study is to analyze research activities related to Antarctic science through a bibliographic study and to understand and evaluate the implications. This study is based on 78,445 articles which were retrieved from the Science Citation Index(SCI) database during the period 1998−2015. Through a quantitative analysis and a Social Network Analysis, we made several findings and drew out the implications. First, many countries, in general, have increased multi-national research cooperation in order to enhance research productivity. However, Korea’s cooperative research activity is below the average level. Second, considering the 4 centrality indexes, which are derived from the SNA, Korea had a lower score in terms of centrality indexes. Based on these findings, Korea should formulate a more dynamic or proactive strategy in order to enhance its participation in international research cooperation efforts. Korea, the 10th country to build two or more research bases in Antarctica, should make greater efforts to bring the appropriate level of the phase.
{"title":"Research Trend Analysis on International Research Collaboration in Regard to Antarctic Studies","authors":"Duckhee Jang, Yong-Jin Choi, Jin-Young Kim","doi":"10.4217/OPR.2016.38.3.209","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.3.209","url":null,"abstract":"The purpose of this study is to analyze research activities related to Antarctic science through a bibliographic study and to understand and evaluate the implications. This study is based on 78,445 articles which were retrieved from the Science Citation Index(SCI) database during the period 1998−2015. Through a quantitative analysis and a Social Network Analysis, we made several findings and drew out the implications. First, many countries, in general, have increased multi-national research cooperation in order to enhance research productivity. However, Korea’s cooperative research activity is below the average level. Second, considering the 4 centrality indexes, which are derived from the SNA, Korea had a lower score in terms of centrality indexes. Based on these findings, Korea should formulate a more dynamic or proactive strategy in order to enhance its participation in international research cooperation efforts. Korea, the 10th country to build two or more research bases in Antarctica, should make greater efforts to bring the appropriate level of the phase.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70345992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-30DOI: 10.4217/OPR.2016.38.3.225
Se-hun Park, Y. Yoo, S. Kang
This project sought to conduct an economic feasibility study regarding the commercial production of bio-hydrogen by the marine hyperthermophilic archaeon, Thermococcus onnurineus NA1 using carbon monoxide-containing industrial off-gas. We carried out the economic evaluation of the biohydrogen production process using the raw material of steel mill by-product gas. The process parameter was as follows: H2 production rate was 5.6 L/L/h; the conversion of carbon monoxide was 60.7%. This project established an evaluation criterion for about 10,000 tonne/year. Inflation factors were considered as 3%. The operating costs were recalculated based on prices in 2014. The total investment required for development was covered 30% by capital and 70% by a loan. The operation cost for the 0.5-year test and integration, and the cost for the first three months in the 50% production period were considered as the working capital in the cost estimation. The costs required for the rental of office space, facilities, and other related costs from the construction through to full-scale production periods were considered as continuing expenses. Materials, energy, waste disposal and other charges were considered as the operating cost of the development system. Depreciation, tax, maintenance and repair, insurance, labor, interest rate charges, general and administrative costs, lubrication and miscellaneous expenses were also calculated. The hydrogen price was set at US$ 4.15/kg for the economic evaluation. As a result, the process was considered to be economical with the payback period of 6.3 years, NPV of 18 billion Won and IRR of 26.7%.
{"title":"Economic Feasibility Study for Commercial Production of Bio-hydrogen","authors":"Se-hun Park, Y. Yoo, S. Kang","doi":"10.4217/OPR.2016.38.3.225","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.3.225","url":null,"abstract":"This project sought to conduct an economic feasibility study regarding the commercial production of bio-hydrogen by the marine hyperthermophilic archaeon, Thermococcus onnurineus NA1 using carbon monoxide-containing industrial off-gas. We carried out the economic evaluation of the biohydrogen production process using the raw material of steel mill by-product gas. The process parameter was as follows: H2 production rate was 5.6 L/L/h; the conversion of carbon monoxide was 60.7%. This project established an evaluation criterion for about 10,000 tonne/year. Inflation factors were considered as 3%. The operating costs were recalculated based on prices in 2014. The total investment required for development was covered 30% by capital and 70% by a loan. The operation cost for the 0.5-year test and integration, and the cost for the first three months in the 50% production period were considered as the working capital in the cost estimation. The costs required for the rental of office space, facilities, and other related costs from the construction through to full-scale production periods were considered as continuing expenses. Materials, energy, waste disposal and other charges were considered as the operating cost of the development system. Depreciation, tax, maintenance and repair, insurance, labor, interest rate charges, general and administrative costs, lubrication and miscellaneous expenses were also calculated. The hydrogen price was set at US$ 4.15/kg for the economic evaluation. As a result, the process was considered to be economical with the payback period of 6.3 years, NPV of 18 billion Won and IRR of 26.7%.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-30DOI: 10.4217/OPR.2016.38.3.247
Jung-Han Lee, Eun-soo Kim, Yong-Kuk Lee
The inter-comparison project for seawater salinity measurements, in which 25 laboratories from 16 countries took part, was conducted by JCOMM (Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology) for the first time in 2014. Two seawater samples of different salinity values ranging from 30−35 and 20−25 for Sample A and Sample B respectively and which had sufficient homogeneity and stability were distributed to all participants. Participants measured the salinity in their own laboratories at least 3 times and reported the results. Statistical treatments were applied to the results to assess discrepancies among laboratories. 20 out of the 25 laboratories used laboratory salinometers and statistics for this group were denoted as belonging to group α; while 5 out of the 25 laboratories used hand-held measuring instruments and statistics for this group were denoted as belonging to group β. Bias described as discrepancy among laboratories in group α was within ± 0.001 and expanded uncertainty (k = 2) was in the vicinity of 0.002. The bias and the uncertainty of Korea Institute of Ocean Science and Technology (KIOST), in group α, were 0.000 and 0.002, respectively. The biases of group β were greater than group α because of constraints related to instrument accuracy. Biases from 3 laboratories in group β exceed the accuracy specification of the corresponding instruments. Considering that the uncertainty of Standard Seawater (SSW) is of the order 0.001 to 0.002, the inter-comparison results show that 16 laboratories among the 25 laboratories made high quality measurements, largely indistinguishable from one another.
{"title":"Summary of 2014 JCOMM Pilot Inter-Comparison Project for Seawater Salinity Measurements","authors":"Jung-Han Lee, Eun-soo Kim, Yong-Kuk Lee","doi":"10.4217/OPR.2016.38.3.247","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.3.247","url":null,"abstract":"The inter-comparison project for seawater salinity measurements, in which 25 laboratories from 16 countries took part, was conducted by JCOMM (Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology) for the first time in 2014. Two seawater samples of different salinity values ranging from 30−35 and 20−25 for Sample A and Sample B respectively and which had sufficient homogeneity and stability were distributed to all participants. Participants measured the salinity in their own laboratories at least 3 times and reported the results. Statistical treatments were applied to the results to assess discrepancies among laboratories. 20 out of the 25 laboratories used laboratory salinometers and statistics for this group were denoted as belonging to group α; while 5 out of the 25 laboratories used hand-held measuring instruments and statistics for this group were denoted as belonging to group β. Bias described as discrepancy among laboratories in group α was within ± 0.001 and expanded uncertainty (k = 2) was in the vicinity of 0.002. The bias and the uncertainty of Korea Institute of Ocean Science and Technology (KIOST), in group α, were 0.000 and 0.002, respectively. The biases of group β were greater than group α because of constraints related to instrument accuracy. Biases from 3 laboratories in group β exceed the accuracy specification of the corresponding instruments. Considering that the uncertainty of Standard Seawater (SSW) is of the order 0.001 to 0.002, the inter-comparison results show that 16 laboratories among the 25 laboratories made high quality measurements, largely indistinguishable from one another.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-30DOI: 10.4217/OPR.2016.38.3.171
G. Han, S. Hong, W. Shim, K. Ra, Kyung-Tae Kim, S. Ha, Mi Jang, G. Kim
{"title":"Assessment of Persistent Organic and Heavy Metal Contamination in Busan Coast: Application of Sediment Quality Index","authors":"G. Han, S. Hong, W. Shim, K. Ra, Kyung-Tae Kim, S. Ha, Mi Jang, G. Kim","doi":"10.4217/OPR.2016.38.3.171","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.3.171","url":null,"abstract":"","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-30DOI: 10.4217/OPR.2016.38.3.235
남종오, 박철형
The purpose of this study is to estimate the Willingness To Payment (WTP) of sea-anglers regarding the increase in the abundance of fish resources resulting from the Korean vessel buy-back program using the contingent valuation method. Data was collected through sample surveys of 352 seaanglers across the nation in 2015. If a 20% increase in the abundance of fish resources resulted from the vessel buy-back program, WTP estimates of sea-anglers per recreational fishing trip were 9,570 won on truncated mean, 16,528 won on mean, and 35,830 won on median, respectively. Additionally, when the number of annual total recreational fishing trips in Korea were estimated as 22,700 thousand trips, the annual increase in national welfare through recreational fishing was estimated to be 217.2 billion won on the truncated mean, 375.2 billion won on the mean, and 813.3 billion won on the median, respectively.
{"title":"CVM을 이용한 바다낚시 자원풍도 증가에 대한 지불의사액 추정에 관한 연구","authors":"남종오, 박철형","doi":"10.4217/OPR.2016.38.3.235","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.3.235","url":null,"abstract":"The purpose of this study is to estimate the Willingness To Payment (WTP) of sea-anglers regarding the increase in the abundance of fish resources resulting from the Korean vessel buy-back program using the contingent valuation method. Data was collected through sample surveys of 352 seaanglers across the nation in 2015. If a 20% increase in the abundance of fish resources resulted from the vessel buy-back program, WTP estimates of sea-anglers per recreational fishing trip were 9,570 won on truncated mean, 16,528 won on mean, and 35,830 won on median, respectively. Additionally, when the number of annual total recreational fishing trips in Korea were estimated as 22,700 thousand trips, the annual increase in national welfare through recreational fishing was estimated to be 217.2 billion won on the truncated mean, 375.2 billion won on the mean, and 813.3 billion won on the median, respectively.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-09-30DOI: 10.4217/OPR.2016.38.3.195
Sunghan Kim, B. Khim
Because the high latitude region in the North Pacific is characterized by high primary production in the surface water enriched with nutrients, it is important to understand the variation of surface water productivity and associated nutrient variability in terms of global carbon cycle. Surface water productivity change or its related nutrient utilization rate during the Northern Hemisphere Glaciation (NHG; ca. 2.73 Ma) has been reported, but little is known about such circumstances under gradual climate cooling since the NHG. Bulk nitrogen isotope (δ 15 N bulk ) of sedimentary organic matter has been used for the reconstruction of nutrient utilization rate in the surface water. However, sedimentary organic matter experiences diagenesis incessantly during sinking through the water column and after burial within the sediments. Thus, in this study we examine the degree of nitrate utilization rate during the early Pleistocene (2.4−1.25 Ma) since the NHG, using the diatom-bound nitrogen isotope (δ 15 N db ), which is known to be little influenced by diagenesis, from Site U1343 in the Bering slope area. δ 15 N db values range from ~0.5 to 5.5‰, which is lower than δ 15 N bulk values, but they vary with larger amplitude. Variation patterns between δ 15 N db values and biogenic opal concentration are generally consistent, which indicates that the nitrate utilization rate is closely related to opal productivity change in the surface water. A positive correlation between opal productivity and nitrate utilization rate was observed, which is different from the other high latitude regions in the North Pacific. The main reason for this contrasting relationship is that the primary production in the surface water at Site U1343 is influenced mostly by the degree of sea ice formation. Still, although concerns about diagenetic alteration have been avoided by using δ 15 N db , the effects of the preservation state of biogenic opal and the speciesdependent isotopic fractionation on δ 15 N db should be assessed in the future studies.
由于北太平洋高纬度地区具有丰富养分的地表水初级生产力高的特点，因此从全球碳循环的角度了解地表水生产力的变化及其相关的养分变异具有重要意义。北半球冰期地表水生产力变化及其相关养分利用率大约2.73 Ma)已经有报道，但是对于自NHG以来气候逐渐变冷的情况知之甚少。利用沉积有机质体积氮同位素(δ 15 N体积)重建了地表水的养分利用率。然而，沉积有机质在通过水柱下沉和埋藏于沉积物中后，经历了不断的成岩作用。因此，本研究利用白令海陆坡区U1343遗址的硅藻结合氮同位素(δ 15 N db)研究了NHG以来早更新世(2.4 ~ 1.25 Ma)的硝酸盐利用程度，该同位素已知受成岩作用影响较小。δ 15 N db值在~0.5 ~ 5.5‰之间，低于δ 15 N bulk值，但变化幅度较大。δ 15 N db值与生物成因蛋白石浓度的变化规律基本一致，表明硝酸盐利用率与地表水蛋白石生产力变化密切相关。与北太平洋其他高纬度地区不同，该地区蛋白石产量与硝酸盐利用率呈显著正相关。形成这种对比关系的主要原因是U1343站点地表水的初级产量主要受海冰形成程度的影响。尽管利用δ 15 N db可以避免对成岩蚀变的担忧，但生物成因蛋白石的保存状态和物种依赖的同位素分馏对δ 15 N db的影响应在未来的研究中进行评估。
{"title":"Reconstruction of Nitrate Utilization Rate Change Based on Diatom-bound Nitrogen Isotope Values in the Central Slope Area of the Bering Sea during the Early Pleistocene (2.4-1.25 Ma)","authors":"Sunghan Kim, B. Khim","doi":"10.4217/OPR.2016.38.3.195","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.3.195","url":null,"abstract":"Because the high latitude region in the North Pacific is characterized by high primary production in the surface water enriched with nutrients, it is important to understand the variation of surface water productivity and associated nutrient variability in terms of global carbon cycle. Surface water productivity change or its related nutrient utilization rate during the Northern Hemisphere Glaciation (NHG; ca. 2.73 Ma) has been reported, but little is known about such circumstances under gradual climate cooling since the NHG. Bulk nitrogen isotope (δ 15 N bulk ) of sedimentary organic matter has been used for the reconstruction of nutrient utilization rate in the surface water. However, sedimentary organic matter experiences diagenesis incessantly during sinking through the water column and after burial within the sediments. Thus, in this study we examine the degree of nitrate utilization rate during the early Pleistocene (2.4−1.25 Ma) since the NHG, using the diatom-bound nitrogen isotope (δ 15 N db ), which is known to be little influenced by diagenesis, from Site U1343 in the Bering slope area. δ 15 N db values range from ~0.5 to 5.5‰, which is lower than δ 15 N bulk values, but they vary with larger amplitude. Variation patterns between δ 15 N db values and biogenic opal concentration are generally consistent, which indicates that the nitrate utilization rate is closely related to opal productivity change in the surface water. A positive correlation between opal productivity and nitrate utilization rate was observed, which is different from the other high latitude regions in the North Pacific. The main reason for this contrasting relationship is that the primary production in the surface water at Site U1343 is influenced mostly by the degree of sea ice formation. Still, although concerns about diagenetic alteration have been avoided by using δ 15 N db , the effects of the preservation state of biogenic opal and the speciesdependent isotopic fractionation on δ 15 N db should be assessed in the future studies.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-06-30DOI: 10.4217/OPR.2016.38.2.149
Hong-Yeon Cho, Ki-Seop Lee, Soon-Mo Ahn
The statistical measures of the coastal environmental data are used in a variety of statistical inferences, hypothesis tests, and data-driven modeling. If the measures are biased, then the statistical estimations and models may also be biased and this potential for bias is great when data contain some outliers defined as extraordinary large or small data values. This study aims to suggest more robust statistical measures as alternatives to more commonly used measures and to assess the performance these robust measures through a quantitative evaluation of more typical measures, such as in terms of locations, spreads, and shapes, with regard to environmental monitoring data in the Busan coastal sea. The detection of outliers within the data was carried out on the basis of Rosner’s test. About 5−10% of the nutrient data were found to contain outliers based on Rosner’s test. After removal (zero-weighting) of the outliers in the data sets, the relative change ratios of the mean and standard deviation between before and after outlier-removal conditions revealed the figures 13 and 33%, respectively. The variation magnitudes of skewness and kurtosis are 1.36 and 8.11 in a decreasing trend, respectively. On the other hand, the change ratios for more robust measures regarding the mean and standard deviation are 3.7−10.5%, and the variation magnitudes of robust skewness and kurtosis are about only 2−4% of the magnitude of the non-robust measures. The robust measures can be regarded as outlier-resistant statistical measures based on the relatively small changes in the scenarios before and after outlier removal conditions.
{"title":"Impact of Outliers on the Statistical Measures of the Environmental Monitoring Data in Busan Coastal Sea","authors":"Hong-Yeon Cho, Ki-Seop Lee, Soon-Mo Ahn","doi":"10.4217/OPR.2016.38.2.149","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.2.149","url":null,"abstract":"The statistical measures of the coastal environmental data are used in a variety of statistical inferences, hypothesis tests, and data-driven modeling. If the measures are biased, then the statistical estimations and models may also be biased and this potential for bias is great when data contain some outliers defined as extraordinary large or small data values. This study aims to suggest more robust statistical measures as alternatives to more commonly used measures and to assess the performance these robust measures through a quantitative evaluation of more typical measures, such as in terms of locations, spreads, and shapes, with regard to environmental monitoring data in the Busan coastal sea. The detection of outliers within the data was carried out on the basis of Rosner’s test. About 5−10% of the nutrient data were found to contain outliers based on Rosner’s test. After removal (zero-weighting) of the outliers in the data sets, the relative change ratios of the mean and standard deviation between before and after outlier-removal conditions revealed the figures 13 and 33%, respectively. The variation magnitudes of skewness and kurtosis are 1.36 and 8.11 in a decreasing trend, respectively. On the other hand, the change ratios for more robust measures regarding the mean and standard deviation are 3.7−10.5%, and the variation magnitudes of robust skewness and kurtosis are about only 2−4% of the magnitude of the non-robust measures. The robust measures can be regarded as outlier-resistant statistical measures based on the relatively small changes in the scenarios before and after outlier removal conditions.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-06-30DOI: 10.4217/OPR.2016.38.2.161
Eunji Choi, D. Jeon
The interannual variability of the water masses was analyzed from the CTD data measured in the tropical northwestern Pacific from 2006 to 2014. There are two typical water masses NPTW and NPIW that reveal the interannual variability in the survey area, in addition to two other water masses; the surface water mass TSW with a large seasonal variability and the deep water mass AACDW with a constant temperature-salinity characteristic at the depths deeper than 2,000 meters. In 2012 and 2014 NPTW was the most widely extended horizontally and thicker than 100 meters vertically, which was found over the entire survey area. However, NPTW was reduced and became much narrower in 2009 than in the other years. NPIW seemed to expand southwards from the north of 21˚N to 15oN in 2008 and in 2012, which showed the salinity minimum in 2013 (＜ 34.15 psu). The sea surface height estimated by Absolute Dynamic Topography (ADT) approximately along 135˚E section showed the high peaks (＞ 1.45 dyn•m) between 16˚N and 18˚N during the periods between 2007 and 2009 and between 2012 and 2013; the former peak lasted wider and longer in latitude and time (about three times) than the latter. The vertical section of the geostrophic currents in the upper 1,000 meters shows that there was a mesoscale pattern of repeated eastward and westward flows a few times in some years (2010 and 2014), which seemed to disappear in some other years (2008 and 2012); the former was closely related to the mesoscale eddies and the latter implied the pattern with the permanent currents. The persistent eastward flow between 17oN and 19oN seems to be related to the Subtropical Countercurrent (STCC).
{"title":"Interannual Variability of the Water Masses Observed in the Tropical Northwestern Pacific","authors":"Eunji Choi, D. Jeon","doi":"10.4217/OPR.2016.38.2.161","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.2.161","url":null,"abstract":"The interannual variability of the water masses was analyzed from the CTD data measured in the tropical northwestern Pacific from 2006 to 2014. There are two typical water masses NPTW and NPIW that reveal the interannual variability in the survey area, in addition to two other water masses; the surface water mass TSW with a large seasonal variability and the deep water mass AACDW with a constant temperature-salinity characteristic at the depths deeper than 2,000 meters. In 2012 and 2014 NPTW was the most widely extended horizontally and thicker than 100 meters vertically, which was found over the entire survey area. However, NPTW was reduced and became much narrower in 2009 than in the other years. NPIW seemed to expand southwards from the north of 21˚N to 15oN in 2008 and in 2012, which showed the salinity minimum in 2013 (＜ 34.15 psu). The sea surface height estimated by Absolute Dynamic Topography (ADT) approximately along 135˚E section showed the high peaks (＞ 1.45 dyn•m) between 16˚N and 18˚N during the periods between 2007 and 2009 and between 2012 and 2013; the former peak lasted wider and longer in latitude and time (about three times) than the latter. The vertical section of the geostrophic currents in the upper 1,000 meters shows that there was a mesoscale pattern of repeated eastward and westward flows a few times in some years (2010 and 2014), which seemed to disappear in some other years (2008 and 2012); the former was closely related to the mesoscale eddies and the latter implied the pattern with the permanent currents. The persistent eastward flow between 17oN and 19oN seems to be related to the Subtropical Countercurrent (STCC).","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70346338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-06-30DOI: 10.4217/OPR.2016.38.2.103
Na Na Kim, Young Jae Choi, S. Lim, Bong-Seok Kim, C. Choi
This study aimed to examine the role of two aquaporin isoforms (AQP3 and AQP8) in response to the hyperosmotic challenge of transitioning from freshwater (FW) to seawater (SW) during parr and smoltification (smolt) using the rainbow trout, Oncorhynchus mykiss. We examined the changes in the expression of AQPs mRNAs in the gills and intestine of the parr and smolt stages of rainbow trout transferred from FW to SW using quantitative real-time PCR in an osmotically changing environment [FW, SW, and recombinant AQP3 (rAQP3) injection at two dosage rates]. Correspondingly, AQPs were greater during smoltification than during parr stages in the rainbow trout. Plasma osmolality and gill Na⁺/K⁺-ATPase activity increased when the fish were exposed to SW, but these parameters decreased when the fish were exposed to SW following treatment with rAQP3 during the transition to seawater. Our results suggest that AQPs play an important role in water absorbing mechanisms associated with multiple AQP isoforms in a hyperosmotic environment.
{"title":"Effects of Recombinant Aquaporin 3 and Seawater Acclimation on the Expression of Aquaporin 3 and 8 mRNAs in the Parr and Smolt Stages of Rainbow Trout, Oncorhynchus mykiss","authors":"Na Na Kim, Young Jae Choi, S. Lim, Bong-Seok Kim, C. Choi","doi":"10.4217/OPR.2016.38.2.103","DOIUrl":"https://doi.org/10.4217/OPR.2016.38.2.103","url":null,"abstract":"This study aimed to examine the role of two aquaporin isoforms (AQP3 and AQP8) in response to the hyperosmotic challenge of transitioning from freshwater (FW) to seawater (SW) during parr and smoltification (smolt) using the rainbow trout, Oncorhynchus mykiss. We examined the changes in the expression of AQPs mRNAs in the gills and intestine of the parr and smolt stages of rainbow trout transferred from FW to SW using quantitative real-time PCR in an osmotically changing environment [FW, SW, and recombinant AQP3 (rAQP3) injection at two dosage rates]. Correspondingly, AQPs were greater during smoltification than during parr stages in the rainbow trout. Plasma osmolality and gill Na⁺/K⁺-ATPase activity increased when the fish were exposed to SW, but these parameters decreased when the fish were exposed to SW following treatment with rAQP3 during the transition to seawater. Our results suggest that AQPs play an important role in water absorbing mechanisms associated with multiple AQP isoforms in a hyperosmotic environment.","PeriodicalId":35665,"journal":{"name":"Ocean and Polar Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70345757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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