• Ocean and Polar Research
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• v.30 no.3
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• pp.277-287
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• 2008

We collected information on seasonal and interannual variability of surface chlorophyll a concentration between 1997-2007 from the Northwest Pacific Ocean. Satellite data were used to acquire chlorophyll a and sea surface temperature from six regions: East Sea/Ulleung Basin, East China Sea, Philippin Sea, Warm Pool region, Warm Pool North region, and Warm Pool East region. Mixed layer depth (MLD) was calculated from temperature profiles of ARGO floats data in four of the six regions during 2002-2007. In the East Sea/Ulleung Basin, seasonal variability of chlorophyll a concentration was attributed to seasonal change of MLD, while there was no significant relationship between chlorophyll a concentration and MLD in the Warm Pool region. Interannual anomaly in sea surface temperature were similar among the East Sea, East China Sea, Philippin Sea, and Warm Pool North region. The anomaly pattern was reversed in the Warm Pool East region. However, the anomaly pattern in the Warm Pool region was intermediate of the two patterns. In relation to chlorophyll a, there was a reversed interannual anomaly pattern between Warm Pool North and Warm Pool East, while the anomaly pattern in the Warm Pool region was similar to that of Warm Pool North except for the El $Ni\tilde{n}o$ years (1997/1998, 2002/2003, 2006/2007). However, there was no distinct relationship among other seas. Interestingly, in the Warm Pool and Warm Pool East regions, sea surface temperature showed a pronounced inverse pattern with chlorophyll a. This indicates a strong interrelationship among sea surface temperature-MLD-chlorophyll a in the regions. In the Warm Pool and Warm Pool East, zonal distribution of chlorophyll a concentration within the past 10 years has shown a good relationship with sea surface temperature which reflects ENSO variability.

• Korean Journal of Plant Taxonomy
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• v.37 no.4
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• pp.363-386
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• 2007

Endemic element of the Russian Far East (RFE) flora includes 497 species of 150 genera and 46 families. The level of endemism in structure of regional natural flora reaches 11.1% as a whole, and in structure of its native fraction - 13.1%. As a result of chorologic and ecocenotic analysis of RFE flora endemic element it is revealed that it consists of 8 main geographical groups and 7 main floristic complexes. The largest number of endemic species is concentrated in Arctic - Alpine & Montane (140, 28.2%), Forest (107, 21.5%) and Maritime (88, 17.7%) floristic complexes as well as in Russian Far East - West-Pacific (136, 27.4%), Japan Sea (88, 17.7%) and North-East-Asian - Beringian (69, 13.9%) geographical groups. It's possible to distinguish three main areas with similar eco-geographical differentiation of endemics on RFE as follows: (1) North-East Asia sector of RFE which North-East-Asian - Beringian and Maritime Okhotia - Beringian geographical groups approximately correspond to, (2) Continental part of East Asia sector of RFE (West - Okhotian, Amur - Okhotian, Amur - Ussirian, Okhotsk Sea and Japan Sea groups) and (3) Oceanic part of East Asia sector (Russian Far East - West Pacific group). Taxonomical variety of RFE endemics on these territories makes up accordingly (1) - 99 species (19.9%), (2) - 259 (52.8%) and (3) - 136 (27.4%).

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.369-379
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• 2002

The characteristics of the East Asian summer monsoon circulation associated with the cool and wet summer of 1993 and the warm and dry summer of 1994 are investigated by analyzing the atmospheric circulations features in the upper and lower troposphere and by examining the global SST and associated tropical convective precipitation fields. The negative geopotential height anomalies at 500 hPa and 200 hPa in 1993 over East Asia, the central North Pacific, and the western United States were replaced by positive ones in 1994. In addition, the 200 hPa zonal wind anomaly averaged over the East Asian summer monsoon region is negatively correlated with the Korean summer temperature anomaly. The subtropical jet stream in 1993 was displaced into the central part of Korea well south of its normal position. The western Pacific subtropical high was shifted southward, and the East Asian summer rainfall and temperature was above-normal and below-normal, respectively due to the southwestward extension of a cold and dry polar airmass from the Sea of Okhotsk to the Est Sea. In contrast, the subtropical jet stream in 1994 was displaced well north of its normal position. The abrupt northward shift of the western Pacific subtropical high was accompanied with the rapid northward movement of the rain band of the East Asian summer monsoon rainfall. The anomaly patterns of the East Asia summer rainfall and temperature were opposite to those of 1993. Large sea surface temperature anomalies of opposite signs existed in the tropical Pacific with a mature El $Ni{\~{n}o$ in 1993 and a weak La $Ni{\~{n}a$ condition in 1994. The role of the anomalous convective precipitation in the western Pacific and the Indian Ocean related with the variations in the low-level cross-equatorial flow along the northwestern periphery of the Australian high and the Mascarene high is probably to influence a large-scale atmospheric circulation over the East Asia during both the years.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.4
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• pp.320-328
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• 2007

Maturation and spawning of the Pacific cod, Gadus macrocephalus was investigated based on the samples captured in East Sea of Korea from April 2006 to July 2007. Gonadosomatic index began to increase in November, and reached maximum between December and January. After spawning it began to decrease from March. Reproductive season was estimated to November-February, with peak in January. Fecundity was proportional to the size of the female, with the clutch size varying from 753,985 eggs in the smallest female(TL＝58.6cm) to 9,311,520 eggs in the largest(TL＝101.0cm). Size at 50% sexual maturity(TL50%) determined from mature females was 56.3cm of TL. Annual reproductive cycles of this species could be divided into six successive stages; immature stage(March-September), nucleolus stage(September-October), yolk vesicle stage(October-November), vitellogenic stage (November-December), ripe stage and spent stage(December-February).

• Ocean and Polar Research
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• v.31 no.1
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• pp.51-61
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• 2009

In this study we define the two different types of El $Ni{\tilde{n}}o$, i.e., the eastern Pacific El $Ni{\tilde{n}}o$ (i.e., EP-El $Ni{\tilde{n}}o$) versus the central Pacific El $Ni{\tilde{n}}o$ (i.e., CP-El $Ni{\tilde{n}}o$), during the boreal summer (June-July-August, JJA) and winter (December-January-February, DJF) using the two NINO indices in the tropical Pacific. The two different types of El $Ni{\tilde{n}}o$ significantly differ in terms of the location of the maximum anomalous sea surface temperature (SST) in the tropical Pacific. The CP-El $Ni{\tilde{n}}o$ has been observed more frequently during recent decades compared to the EP-El $Ni{\tilde{n}}o$. In addition, our analysis indicates that the statistics of CP-El $Ni{\tilde{n}}o$ during JJA is closely associated with the warming trend in the central equatorial Pacific. We also examine the different responses of the East Asian marginal SST to the two types of El $Ni{\tilde{n}}o$ during JJA and DJF. The CP-El $Ni{\tilde{n}}o$ during both JJA and DJF is concurrent with warm SST anomalies around the Korean Peninsula including the East China Sea, which is in contrast to the EP-El $Ni{\tilde{n}}o$. Such different responses are associated with the difference in tropics/mid-latitude teleconnections via atmosphere between the two types of El $Ni{\tilde{n}}o$. Furthermore, our results indicate that atmospheric diabatic forcing in relation to the precipitation variability is different in the tropical Pacific between the EP-El $Ni{\tilde{n}}o$ and the CP-El $Ni{\tilde{n}}o$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.360-367
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• 2013

The mesh selectivity of the gillnet for Pacific herring (Clupea pallasii) was examined in field experiments with four different mesh sizes (63, 69, 75 and 81mm) from June to July, 2013 in the coastal areas of Imwon in Gangwon province. The fishing performance tests were conducted with a commercial Pacific herring gillnet and a biodegradable gillnet for Pacific herring together selectivity tests. The filed tests were carried out the total 11 times. The master curve of selectivity was estimated by the extended Kitahara's method. In the results, the catch number of Pacific herring was 9,409 (2,203kg) and occupied 84.2% in total catches weight. The optimal mesh size for 50% retention on first maturity size (female, 250mm) of Pacific herring was estimated as 64.5mm by master selectivity curves. The fishing performance of the biodegradable gillnet was showed to be equivalent with commercial gill for Pacific herring.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1371-1384
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• 2015

This study analyzes the characteristics of Western North Pacific (WNP) tropical cyclone (TC) activity and large-scale environments according to the Western Pacific (WP) teleconnection pattern in summer. In the positive WP phase, an anomalous cyclone and an anomalous anticyclone develop in the low and middle latitudes of the East Asia, respectively. As a result, southeasterlies are reinforced in the northeast area of the East Asia including Korea and Japan which facilitates the movement of TC to this area, whereas northwesterlies are reinforced in the southwest area of the East Asia including South China and Indochina Peninsula which blocks the movement of TC to this area. Due to the spatial distribution of this reinforced pressure system, TCs develop, move, and turn more to the northeast of WNP than those in the negative WP phase. Consequently, the characteristics of this TC activity in the positive WP phase are associated with the location of upper tropospheric jet further to the northeast. Meanwhile, TCs in the negative WP phase mainly move to the west from Philippines toward south China and Indochina Peninsula. Furthermore, due to the terrain effect caused by the high passage frequency of TCs in the mainland China, the intensity of TCs are weaker than those in the positive WP phase.

• East Asian Economic Review
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• v.20 no.2
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• pp.129-168
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• 2016

The Asia-Pacific region is not typically seen as one geographic or socio-economic space. Yet, 58 regional economies occupying the space of 28 million square kilometers from Turkey in the West, Russian Federation in the North, French Polynesia in the East and New Zealand in the South belong to the Economic and Social Commission of Asia and the Pacific (ESCAP). This commission provides a forum for member states that "promotes regional cooperation and collective action, assisting countries in building and sustaining shared economic growth and social equity". In 2013, ESCAP's members adopted the Bangkok Declaration to enhance efforts towards deeper regional economic integration. Yet this document neither proposes a concrete modality or modalities of achieving deeper integration, nor provides a sense of distance of individual countries to a "perceived" integrated Asia-Pacific.This paper aims to comprehensively quantify recent integration efforts of economies in the Asia-Pacific region. We provide an "index of integration effort" based on twelve metrics that measure the relative distance of a given economy to the region as an economic entity. Generally, we find that while the region has trended towards becoming integrated in general, both the level of integration and integration effort are inconsistent among Asia-Pacific economies. We discuss potential applications and extensions of the index in developing our perspective of the region's economic and social dynamics.

• Journal of the Korean earth science society
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• v.34 no.1
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• pp.102-106
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• 2013

The intensity of the East Asian summer monsoon has a negative correlation with that of the western North Pacific summer monsoon. Based on the relationship, we suggest the potential predictability of Northeast Asian summer precipitation by using the relationship. The western North Pacific subtropical high (WNPSH) properly represents the intensity of the western North Pacific summer monsoon. It also dominates climate anomalies in the western North Pacific-East Asian region in summertime. The estimates of the Northeast Asian summer rainfall anomalies using WNPSH variability have a greater benefit than those using the western North Pacific monsoon index.

• Journal of Ecology and Environment
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• v.35 no.1
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• pp.15-25
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• 2012

Time series of ocean climate indices and catch records were used to identify the alternation patterns of pelagic fish populations in relation to climate regime shifts. During 1910-2008, an orderly alternation of dominant pelagic fish groups was observed in the Tsushima Warm Current (TWC; Yellow Sea-East China Sea-East Sea/Japan Sea) and Kuroshio-Oyashio Current (KOC; Northwestern Pacific) regions. After the collapse of herring fishery in the late 1920s, the sardine (A group) dominated in the 1930s, 3 other species (C group; Pacific saury, jack mackerel, and anchovy) dominated in the 1950s-1960s, chub mackerel (B group) dominated in the 1970s, and then sardine (A group) dominated again during cool regime in the 1980s. As sardine biomass decreased in association with the climate regime shift that occurred in the late 1980s, catches of C group immediately increased after the regime shift and remained at high levels during warm regime in the 1990s. Alternations of dominant fish groups occurred 6 times between 1910 and 2008. The dominant period of the 7 species lasted for 10-20 years. The catch of Pacific sardine in the TWC and KOC regions showed a negative correlation with the catch of the other 5 species (Pacific herring, anchovy, jack mackerel, Pacific saury, and common squid), suggesting that the abundance of the 5 species is strongly affected by the abundance of Pacific sardine in relation to the climate regime shifts. The total catch level of the 7 species in the KOC region was generally higher than that in the TWC region before 1991 but was lower after 1992, suggesting that the fish populations in the Pacific side are shifted to the TWC region by zonal oscillation of the oceanic conditions in relation to the climate regime shift in the late 1980s.