• Journal of the Korean earth science society
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• v.37 no.6
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• pp.359-372
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• 2016

The time-series of Walker circulation index (WCI) in this study shows the strengthening of the Walker circulation in recent years. To further understand the large-scale features related to the WCI strengthening, a difference between the averaged meteorological variables in two time periods 1999-2013 and 1984-1998 is analyzed. The difference in 850 hPa stream flows between the two periods shows that the anomalous easterlies (anomalous trade wind) are dominant due to the strengthening of anomalous anticyclonic circulations at the subtropical Pacific of both hemispheres. The difference between the averaged zonal atmospheric circulations over $5^oS-5^oN$ in the two periods confirms that upward flows are strengthened at the tropical western Pacific and downward flows are strengthened at the tropical central and eastern Pacific in recent years. It matches the WCI strengthening in recent years. The time-series of tropical cyclone (TC) genesis frequency from July to September shows that a mean TC genesis frequency from 1999-2013 decreases compared to that of the time period 1984-1998. The monsoon trough in the period 1984-1998 was located in the further east direction and stronger than that in the period 1999-2013. TCs in the recent period that are generated in further west than TCs in the past period moved from the west. Thus, the TC intensity along the coasts in East Asia becomes weaker in recent period. The intensification of Walker circulation in recent years is related to the weaker TC intensity in East Asia through strengthened anomalous anticyclones at the subtropical western Pacific.

• Atmosphere
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• v.33 no.1
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• pp.49-59
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• 2023

Blocking refers to a class of weather phenomena appearing in the mid and high latitudes, whose characteristics are blocked airflow of persistence. Frequently found over the Pacific and Atlantic regions of the Northern Hemisphere, blocking affects severe weather in the surrounding areas with different mechanisms depending on the type of blocking patterns. Along with lots of studies about persistent weather extremes focusing on the specific types of blocking, a new categorization using Rossby wave breaking has emerged. This study aims to apply this concept to the classification of blockings over the Pacific and examine how different wave breakings specify the associated cold weather in the Korean peninsula. At the same time, we investigate a strongly developing ridge around the Pacific by designing a new detection algorithm, where a reversal method is modified to distinguish ridge-type blocking patterns. As result, Kamchatka blocking (KB) and strong ridge over the Central Pacific are observed the most frequently during 20 years (2001~2020) of the studied period, and anomalous low pressures with cold air over the Korean Peninsula are accompanied by blocking events. When it considers the Rossby wave breaking, cyclonic wave-breaking is dominant in KB, which generates low-pressure anomalies over the Korean Peninsula. However, KB with anticyclone wave breaking appears with the high-pressure anomalies over the Korean Peninsula and it generates the warm temperature anomaly. Lastly, the low-pressure anomalies are also generated by the strong ridge over the Central Pacific, which persists for approximately three days and give a significant impact on cold surge on the Korean Peninsula.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2629-2633
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• 2012

Background: Raw betel nut (RBN) chewing is an important contributing factor for esophageal squamous cell carcinoma (ESCC), although associated genomic changes remain unclear. One difficulty in assessing the effects of exclusively RBN induced genetic alterations has been that earlier studies were performed with samples of patients commonly using tobacco and alcohol, in addition to betel-quid. Both CDKN2A (at 9p21) and Rb1 gene (at 13q14.2) are regarded as tumor suppressors involved in the development of ESCC. Therefore, the present study aimed to verify the RBN's ability to induce ESCC and assess the involvement of CDKN2A and Rb1 genes. Methods: A panel of dinucelotide polymorphic markers were chosen for loss of heterozygosity studies in 93 samples of which 34 were collected from patients with only RBN-chewing habit. Promoter hypermethylation was also investigated. Results: Loss in microsatellite markers D9S1748 and D9S1749, located close to exon $1{\beta}$ of CDKN2A/ARF gene at 9p21, was noted in 40% ESCC samples with the habit of RBN-chewing alone. Involvement of a novel site in the 9p23 region was also observed. Promoter hypermethylation of CDKN2A gene in the samples with the habit of only RBN-chewing alone was significantly higher (p=0.01) than Rb1 gene, also from the samples having the habit of use both RBN and tobacco (p=0.047). Conclusions: The data indicate that the disruption of 9p21 where CDKN2A gene resides, is the most frequent critical genetic event in RBN-associated carcinogenesis. The involvement of 9p23 as well as 13q14.2 could be required in later stages in RBN-mediated carcinogenesis.

• Ocean and Polar Research
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• v.33 no.1
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• pp.55-68
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• 2011

The distribution and inter-annual variation of nutrients (N, P, Si) and dissolved/particulate organic carbon were investigated in the equatorial thermocline ridge ($7^{\circ}{\sim}11.5^{\circ}N$, $131.5^{\circ}W$) of the northeast Pacific. From the Oceanic Nino Index and Multivariate ENSO Index provided by NOAA, normal condition was observed in July 2003 and August 2005 on the aspect of global climate/ocean change. However, La Ni$\~{n}$a and El Ni$\~{n}$o episodes occurred in July 2007 and August 2009, respectively. Thermocline ridge in the study area was located at $9^{\circ}N$ in July 2003, $8^{\circ}N$ in August 2005, $10^{\circ}N$ in July 2007, and $10.5^{\circ}N$ in August 2009 under the influence of global climate/ocean change and surface current system (North Equatorial Counter Current and North Equatorial Current) of the northeast Pacific. Maximum depth integrated values (DIV) of nutrients in the upper layer (0~100 m depth range) were shown in July 2007 (mean 21.12 gN/$m^2$, 4.27 gP/$m^2$, 33.72 gSi/$m^2$) and higher variability of DIV in the equatorial thermocline ridge was observed at $10^{\circ}N$ during the study periods. Also, maximum concentration of dissolved organic carbon (DOC) in the upper 50 m depth layer was observed in July 2007 (mean $107.48{\pm}14.58\;{\mu}M$), and particulate organic carbon (POC, mean $9.42{\pm}3.02\;{\mu}M$) was similar to that of DOC. Nutrient concentration in the surface layer increased with effect of upwelling phenomenon in the equatorial thermocline ridge and La Ni$\~{n}$a episode, which had formed in the central Pacific. This process also resulted in the increasing of organic carbon concentration (DOC and POC) in the surface layer. From these results, it is suggested that spatial and temporal variation of chemical and biological factors were generated by physical processes in the equatorial thermocline ridge.

• 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.

• Atmosphere
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• v.20 no.3
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• pp.239-246
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• 2010

In this study, the climatological characteristics of the landfall typhoons on North Korea are surveyed to estimate the frequency, the intensity, the track, and their damage. The data for the period of 1951-2008 are used from both RSMC (Regional Specialized Meteorological Center) Tokyo Typhoon Center and NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research), EM-DAT (Emergency Events Database). There are the ten highest frequencies from 1961 to 1965 and is one frequency for the period of both 1966-1979 and 1976-1980 respectively. Even if a clear trend on the frequency of typhoon is not defined, it is noticeable the intensity has been weak since the frequency of TS (Tropical Storm) decreased. In order to figure out both the characteristic of intensity and the relation between the typhoon track and the expansion of North Pacific High (NPH), Typhoon's tracks are classified into three types as follows: (I) landing on the west coast of North Korea through the mainland of China, (II) landing on the west coast of North Korea, (III) landing on a central/eastern part of the Korean peninsula through South Korea. More often than not, the characteristic of Type (I) is the case of a landfall after it becomes extratropical cyclone. Type(II) and Type(III) show a landfall as TS grade, by comparision. On the relation between the typhoon's track and the expansion of NPH analyzed, Type (I) shows the westward expansion while both Type (II) and Type (III) show the northward expansion and development of NPH. This means the intensity of a typhoon landfall on North Korea is variable depending on the development of NPH. Finally, only two cases are found among total five cases in EM-DAT, reportedly that North Korea was damaged. And therefore, the damage by the wind of Prapiroon (the $12^{th}$ typhoon, 2000) and heavy rainfall with Rusa (the $15^{th}$ typhoon, 2002) landing on North Korea was analyzed. Moreover, it is estimated both Prapiroon and Rusa have done badly damaged to North Korea as the economical losses of as much as six billion and five hundred-thousand US dollar, respectively.

• Journal of Preventive Medicine and Public Health
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• v.47 no.4
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• pp.183-200
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• 2014

Cancer is a major cause of mortality and morbidity throughout the world, including the countries of North-East and South-East Asia. Assessment of burden through cancer registration, determination of risk and protective factors, early detection and screening, clinical practice, interventions for example in vaccination, tobacco cessation efforts and palliative care all should be included in comprehensive cancer control programs. The degree to which this is possible naturally depends on the resources available at local, national and international levels. The present review concerns elements of cancer control programs established in China, Taiwan, Korea, and Japan in North-East Asia, Viet Nam, Thailand, Malaysia, and Indonesia as representative larger countries of South-East Asia for comparison, using the published literature as a guide. While major advances have been made, there are still areas which need more attention, especially in South-East Asia, and international cooperation is essential if standard guidelines are to be generated to allow effective cancer control efforts throughout the Far East.

• Animal Systematics, Evolution and Diversity
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• v.32 no.2
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• pp.123-132
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• 2016

Six species of springtails (Collembola) are reported for the first time from North Korea: Pachyotoma takeshitai (Kinoshita, 1916), Folsomia bisetosa Gisin, 1953 and Agrenia agilis Fjellberg, 1986 of Isotomidae, Entomobrya sibirica Stach, 1963 and Willowsia buski (Lubbock, 1870) of Entomobryidae, and Ptenothrix setosa (Krausbauer, 1898) of Dicyrtomidae. The genus Pachyotoma Bagnall, 1949 is mentioned for the first time from the Korean Peninsula. In order to facilitate the identification of these species, illustrations and short diagnoses are provided and the poorly known P. takeshitai is described in detail. Ptenothrix setosa and E. sibirica link the Korean peninsular fauna with Central Asia, P. takeshitai shows the zoogeographical connection of the Korean Peninsula with the Japanese Islands and A. agilis has a trans-pacific distribution. Folsomia bisetosa is an interesting circumpolar element in the Korean fauna while W. buski is a subcosmopolitan species.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.157-161
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• 2022

Parartotrogus minutus n. sp. is described as a parasite of the brittle star Ophiuroglypha kinbergi (Ljungman) from the intertidal zone on the Yellow Sea coast of Korea. The new species is characterized by a combination of morphological features that the body is small, less than 0.5 mm long, the caudal ramus is 1.73 times longer than wide, leg 3 bears three-segmented rami, and the exopod of leg 5 is armed with two setae. The new species is the third known species in the genus, following P. richardi Scott T. and Scott, A., 1893 known from European waters and P. arcticus Scott T., 1901 known from both North Atlantic and North Pacific.

• Journal of the Korean association of regional geographers
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• v.10 no.1
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• pp.151-157
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• 2004

In January the clo-values show two characteristic patterns on the insulation, Samjiyon has the highest clo-values while Changjon has the lowest in North Korea, and the coastal areas are lower than in the interior areas. This regional difference is a result of predominant temperature, wind speed and orographic effects. Particularly, in August the coastal areas are generally lower than the interior areas because of orographic effects(wind direction, wind speed). All regions except Samjiyon legions and northern interior regions have low values during the period from the early August to the middle of August. These are largely derived from the stable weather with the highest temperature, humidity and strong radiation by the North Pacific Anticyclone appears in Eastern Asia.