• Title/Summary/Keyword: western North Pacific

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First Record of Scytosiphon gracilis Kogame (Scytosiphonaceae,Phaeophyceae) for the Pacific coast of Mexico

  • Raul , Aguilar-Rosas;Luis E. , Aguilar-Rosas;Cho, Ga-Youn;Boo, Sung-Min
    • ALGAE
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    • v.21 no.1
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    • pp.11-13
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    • 2006
  • In this work we report the occurrence of Scytosiphon gracilis Kogame (Scytosiphonaceae, Phaeophyceae) on the Pacific coast of Mexico. This is the first report of S. gracilis outside its previously known distribution in the western North Pacific (Korea and Japan). The identification was based on a morphological revision and a comparison of the plastid-encoded RuBisCO spacer sequences determined for Korean and Mexican algal material. Thalli were collected from the intertidal zone of Saldamando Beach, Baja California, in January 2003. The vegetative structure, as well as habitat and geographic distribution of the species are described. Reproductive structures were not found in our specimens. The poor presence/absence of S. gracilis in previous floristic studies of the area could be due to its small size and low frequency.

Trace Metals in Airborne Particulates Collected at Cheju Island, Korea (제주도 대기 분진 중 미량금속의 농도 특성)

  • 최만식;박은주
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.6
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    • pp.727-738
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    • 1999
  • Total 76 aerosol samples were collected at Sungsan in Cheju Inland by high volume air sample for 1 year, from May 1995 to April 1996, and were analyzed for major elements(Na, Mg, Ca, Al, Fe) and trace elements(Mn, Co, Ni, Zn, Cd, Pb, U) by ICP/AES and ICP/MS. This study aims to determine the concentrations of trace metals and their seasonal variations in the atmosphere of Cheju Island, where is the remote area from pollution sources and also is the midway of transport of Asian continental materials into the western North Pacific. The concentrations of Na and Mg contributed by sea-salt aerosols were similar to those in the western part of Cheju island(Kosan) and in the western coast of Korea(Mallipo). They showed the highest value in summer and the lowest in spring and winter. Crustal metals(Al, Fe, Ca, Mn, Co, U) were 2~3 times lower than those of Mallipo. These metals showed the lowest values in summer and the highest in spring. Pollution-derived metals (Zn, Cd and Pb) were 2~4 times lower than those in Malipo. Some elemental ratios in aerosols grouped by three wind directions(north-northwest, east, and south-southwest) such as Fe/Al and Pb/Zn are presented as useful tracers indicating source areas, and their differentiation may be explained by geology and fuel types of source areas.

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Long-term rainfall prediction of Geum river basin using teleconnected climate indices (원격상관 기후지수를 이용한 금강유역 장기 강우량 예측)

  • Lee, Jeongwoo;Kim, Nam Won;Kim, ChuI-Gyum;Lee, Jeong Eun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.211-211
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    • 2018
  • 미해양대기청 기후예측센터(Climate Prediction Center, NOAA)에서 제공하고 있는 기후지수(climate indices)를 예측인자로 하고 금강유역의 5~6월의 강우량을 예측대상으로 하는 원격상관기반 통계모형을 구축하였다. 1988년부터 2017년까지의 30년 자료에 대해 예측인자와 예측대상간의 시간지연상관분석을 수행한 결과 NAO(North Atlantic Oscillation), EP/NP(East Pacific/North Pacific Oscillation), EA(East Atlantic Pattern), WP(Western Pacific Index) 등과 상관성이 높은 것으로 분석되었으며, 이러한 시간지연 기후지수를 이용하여 4개월전에 5,6월 강수량을 예측할 수 있는 다중회귀모형을 개발하였다. 관측 강우량 아노말리가 큰 경우에는 다소 과소 예측되고, 아노말리가 작은 경우에는 다소 과다 예측되는 경향을 보였지만 관측 강우량과 예측 강우량간의 상관계수가 0.75로서 비교적 우수한 예측 결과를 나타내었다. 5~6월 강우량 아노말리의 3분위 예측성을 평가한 결과 평년이상 적중률은 77.8%, 평년수준은 81.8%로서 예측 성공률이 높았으며, 5, 6월 누적강우량이 매우 작았던 92년과 95년을 제외하고는 강우량이 적은 해에도 예측성이 우수하여 평년이하 적중률이 70.0%를 나타내었다. 따라서 본 개발모형은 최소 4개월 이전 선행시간을 가지고 늦봄, 초여름강우량을 예측할 수 있는 저비용의 가뭄 예측 도구로 유용하게 활용될 수 있을 것이다.

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Analysis on the Variability of Korean Summer Rainfall Associated with the Tropical Low-frequency Oscillation (적도 저주파 진동과 관련된 한반도 여름철 강수의 변동성 연구)

  • Moon, Ja-Yeon;Choi, Youngeun;Park, Changyong
    • Journal of the Korean Geographical Society
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    • v.48 no.2
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    • pp.184-203
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    • 2013
  • This study analyzes the variability of Korean summer rainfall associated with the tropical low-frequency oscillation using long-term observation data. From the EOF analysis, the first mode showed opposite phase between the South and the North Korea with the regime shift in rainfall variability since the mid-1990s. The summer precipitation over South Korea tends to increase in southern part during strong El Ni$\tilde{n}$o where the warm sea surface temperature extends to far eastern tropical Pacific. In weak La Ni$\tilde{n}$a, the increased precipitation directly influences from the western tropical Pacific to the mid-latitude. In June, the rainfall over South Korea is positively correlated with the Indian Summer Monsoon while in July, it is negatively correlated with the Western North Pacific Summer Monsoon. In August, highly negative correlation between the rainfall over South Korea and the Indian Summer Monsoon is found.

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Pacific Sea Level Variability associated with Climate Variability from Altimetry and Sea Level Reconstruction Data (위성 고도계와 해수면 재구성 자료를 이용한 기후변동성에 따른 태평양 해수면 변화)

  • Cha, Sang-Chul;Moon, Jae-Hong
    • Ocean and Polar Research
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    • v.40 no.1
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    • pp.1-13
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    • 2018
  • Previous studies have indicated a great regional difference in Sea Level Rise (SLR) in the Pacific and it has been suggested that this is linked to climate variability over the past two decades. In this study, we seek to identify the possible linkage between regional sea level and Pacific climate variability from altimetry-based sea level data (1993-2012) and further investigate how the Pacific sea level has changed spatially and temporally over the past 60 years from long-term sea level reconstruction data (1953-2008). Based on the same method as Zhang and Church (2012), the Inter-annual Climate Index (ICI) associated with the El $Ni{\tilde{n}}o-Southern$ Oscillation (ENSO) and the Decadal Climate Index (DCI) associated with Pacific Decadal Oscillation (PDO) are defined and then the multiple variable linear regression is used to analyze quantitatively the impact of inter-annual and decadal climate variability on the regional sea levels in the Pacific. During the altimeter period, the ICI that represents ENSO influence on inter-annual time scales strongly impacts in a striking east-west "see-saw mode" on sea levels across the tropical Pacific. On the other hand, the decadal sea level pattern that is linked to the DCI has a broad meridional structure that is roughly symmetric in the equator with its North Pacific expression being similar to the PDO, which largely contributes to a positive SLR trend in the western Pacific and a negative trend in the eastern Pacific over the two most recent decades. Using long-term sea level reconstruction data, we found that the Pacific sea levels have fluctuated in the past over inter-annual and decadal time scales and that strong regional differences are presented. Of particular interest is that the SLR reveals a decadal shift and presents an opposite trend before and after the mid-1980s; i.e., a declining (rising) trend in the western (eastern) Pacific before the mid-1980s, followed by a rising (declining) trend from the mid-1980s onward in the western (eastern) Pacific. This result indicates that the recent SLR patterns revealed from the altimeters have been persistent at least since the mid-1980s.

Characteristics of tropical cyclones over the western North Pacific in 2007 (2007년 태풍 특징)

  • Cha, Eun-Jeong;Park, Yun-Ho;Kwon, H. Joe
    • Atmosphere
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    • v.18 no.3
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    • pp.183-197
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    • 2008
  • The purpose of this study is to summarize tropical cyclone activity in 2007. 24 tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2007. The total number is less than the thirty-year (1971~2000) average frequency of 26.7. Out of twenty four tropical cyclones, 14 TCs reached typhoon (TY) intensity, while the rest 10 only reached severe tropical storm (STS) and tropical storm (TS) intensity - four STS and six TS storms. The tropical cyclone season in 2007 began in April with the formation of KONG-REY (0701). From April to May, two TCs formed in the western North Pacific in response to enhanced convective activity there. From June to July, convective activity turned inactive over the sea around the Philippines and in the South China Sea, and the subtropical high was weak over the south of Japan. MAN-YI (0704) and USAGI (0705) moved northwestward and hit Japan, bringing serious damage to the country. After August, convective activity became enhanced over the sea east of the Philippines, and the subtropical high turned strong over the sea south of Japan. Many TCs, which formed over the sea east of the Philippines and in the South China Sea, moved westward and hit China and Vietnam. PABUK (0706), WUTIP (0707), SEPAT (0708), WIPHA (0712), LEKIMA (0714) and KROSA (0715) brought serious damage to some countries including China, the Philippines and Vietnam. On the other hand, FITOW (0709) and NARI (0711) moved northward, bringing serious damage to Japan and Korea. After HAIYAN (0716), all four TCs except FAXAI (0720) formed over the sea east of $140^{\circ}E$. Three typhoons among them affected Republic of Korea, MAN-YI (0704), USAGI (0705) and NARI (0711). Particularly, NARI (0711) moved northward and made landfall at Goheng Peninsula ($34.5^{\circ}N$, $127.4^{\circ}E$) in 1815 KST 16 September. Due to $11^{th}$ typhoon NARI, strong wind and record-breaking rainfall amount was observed in Jeju Island. It was reported that the daily precipitation was 420.0 mm at Jeju city, Jeju Island on 16 September the highest daily rainfall since Jeju began keeping records in 1927. This typhoon hit the southern part of the Korean peninsula and Jeju Island. 18 people lost their lives, 14,170 people were evacuated and US$ 1.6 billion property damage was occurred.

Possible Relationship between NAO and Western North Pacific Typhoon Genesis Frequency (북대서양 진동과 북서태평양 태풍발생빈도와의 관계)

  • Choi, Ki-Seon;Park, Sangwook;Chang, Ki-Ho;Lee, Jong-Ho
    • Journal of the Korean earth science society
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    • v.34 no.3
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    • pp.224-234
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    • 2013
  • This study examined a strong positive correlation between the North Atlantic Oscillation (NAO) index during June and the total tropical cyclone (TC) genesis frequency in the western North Pacific during July and August. To investigate a possible cause for this relationship, the mean difference between the highest positive NAO years and the lowest negative NAO years was analyzed by dividing into when the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were included and when the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were not included. When the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were included, for the positive NAO years, the TCs mostly occurred in the northwestern region of tropical and subtropical western Pacific, and showed a pattern that migrate from the sea northeast of the Philippines, pass the East China Sea, and move toward the mid-latitudes of East Asia. In contrast, for the negative NAO years, the TCs mostly occurred in the southeastern region of tropical and subtropical western Pacific, and showed a pattern that migrate westward from the sea southeast of the Philippines, pass the South China Sea, and move toward the southern coast of China and Indochinese peninsula. These two different TC migration patterns affect the recurving location of TC, and for the positive NAO years, the recurving of TC was averagely found to take place in the further northeast. In addition, the migration patterns also affect the TC intensity, and the TCs of positive NAO years had stronger intensity than the TCs of negative NAO years as sufficient energy can be absorbed from the ocean while moving north in the mid-latitudes of East Asia. The TCs of negative NAO years showed weak intensity as they get weaken or disappear shortly while landing on the southern coast of China and the Indochinese peninsula. On the other hand, the above result of analysis is also similarly observed when the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were not included.

The Annual Variation of Surface Circulation in the South China Sea

  • Jeon, Dongchull
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1995.10a
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    • pp.13-15
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    • 1995
  • The horizontal and vertical circulations are considered in the South China Sea, based on the 80 years' winds (COADS), 10 years' XBTs (NODC), and about 10 years' sea-level data at Kaoshiung, Taiwan and Singapore. The South China is largest marginal sea in the western North Pacific, which is predominantly governed by Southeast Asian Monsoons. (omitted)

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The Biology of the Pelagic Amphipod, Primno macropa Guer., in the Western North Pacific: 1. Systematics

  • Yoo, Kwang-Il
    • The Korean Journal of Zoology
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    • v.14 no.3
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    • pp.132-138
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    • 1971
  • 浮游性 端脚類의 一種인 Primno marcropa는 全世界의 海洋에 널리 分布하고 있는 普遍種으로 特히 西部 北太平洋에 있어서는 다른 海域에 비하여 優占的으로 出現한다. 한편 本種은 西部 北太平洋에서는 다른 어느 海域에 비하여 個體數나 生物量이 많으며 各種 有用魚族의 主要 飼料로 주목되고 있다. 그러나 아직도 西部 北太平洋産에 대한 分類學的인 검토가 없었을뿐더러 記載된 바도 전혀 없다. 筆者는 本種애 대한 生物學的 硏究의 一環으로 지금까지의 同種異名을 정리 검토하고 外部形態와 特히 口器의 構造를 처음으로 記載하였다.

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Distribution and Migration of Flying Squid, Ommastrephes bartrami (LeSueur), in the North Pacific (북태평양에 있어서 빨강오징어 Ommastrephes bartrami (LeSueur)의 분포 및 회유)

  • GONG Yeong;KIM Yeong Seung;KIM Soon Song
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.166-179
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    • 1985
  • The seasonal distribution and migration of flying squid, Ommastrephes bartrami (LeSueur), in the North Pacific were studied by means of mantle length, surface temperature, and catch and effort data of the Korean drift gillnet fishery from 1980 to 1983. The water temperature for the best fishing ranged from $15^{\circ}\;to\;16^{\circ}C$ in May through July and from $13^{\circ}\;to\;18^{\circ}C$ in August through January. High densities of flying squid were found in the thermal fronts with $18^{\circ}C$ isotherm in August and with $15^{\circ}C$ isotherm in September. The densities of flying squid were higher in the western region than in the eastern region in the North Pacific. The high densities of flying squid in the northwestern Pacific were attributed to the high gradients of oceanographic properties in the region. Migration models for flying squid were hypothesized based on the monthly distributions of catch per unit net, mantle length compositions by statistical blocks, and the hydrographic features of the North Pacific. The large flying squid moved to the northern region and to the central Pacific region earlier than the small sized group in the northward migration period (from June to August). Flying squid begin the reverse southward migration from the Subarctic Frontal Zone in autumn with onset of cooling and the development of Oyashio Current. The large sized group starts their southward return migration from more northern waters than the small sized group but the former moves past the later ana reaches the spawing ground first.

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