• Title/Summary/Keyword: Pacific sea level

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Tides and Tidal Currents of the Yellow and East China Seas during the Last 13000 Years

  • Oh, Im-Sang;Lee, Dong-Eun
    • Journal of the korean society of oceanography
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    • v.33 no.4
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    • pp.137-145
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    • 1998
  • In order to investigate the paleotidal structure and current pattern in the Yellow and East China seas (YECS) since the late Wisconsin, which is the last glacial maximum period, a two-dimensional version of the Princeton ocean model is used. We assume that subtracting the sea-level differences from the present one can produce paleobasins and that the paleotide did not differ greatly from the present one in the adjacent deep seas, the northwestern Pacific Ocean and the East Sea. We could successfully simulate the paleo-M$_2$ tides and tidal currents of 9000, 11000 and 13000 yr B.P. The result of the model shows considerable differences in the tidal pattern in each period. As the eustatic sea level rose, the amplitudes of the paleotides and the number of the amphidromic points generally increased, but the tidal currents in each paleobasin were strong and about the same order as the present day's. Based on these paleotide calculations, we suggest that there should have been active erosion in the paleobasin as in the present YECS, and the erosion should have played an important role on widening the paleobasin to the present shape, YECS.

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Intensive land-based production of red and green macroalgae for human consumption in the Pacific Northwest: an evaluation of seasonal growth, yield, nutritional composition, and contaminant levels

  • Gadberry, Bradley A.;Colt, John;Maynard, Desmond;Boratyn, Diane C.;Webb, Ken;Johnson, Ronald B.;Saunders, Gary W.;Boyer, Richard H.
    • ALGAE
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    • v.33 no.1
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    • pp.109-125
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    • 2018
  • Turkish towel (Chondracanthus exasperatus), Pacific dulse (Palmaria mollis, also known as Red ribbon seaweed), and sea lettuce (Ulva spp.) were cultivated in a land-based intensive culture system at the Manchester Research Station, USA from August 2013 to September 2014. Macroalgae were grown in tumble-aerated tanks, harvested bimonthly for seasonal growth calculations, and analyzed for protein, lipid, ash, and amino acid content. Growth rate of all three species exhibited a similar pattern, with the highest specific growth rates occurring during the summer months (Turkish towel: 7.8%, Pacific dulse: 8.2%, and sea lettuce: 6.2%). Growth of all three species was lowest around winter solstice; with negative growth only observed in sea lettuce. On a dry weight basis significant differences in protein content existed between the three species with highest values for sea lettuce ($29.5{\pm}1.4%$). Lipid content varied between species (0.95-2.78%) with significantly higher lipid observed in sea lettuce (0.58-4.82%). No significant differences were detected on a seasonal basis among each species. Essential amino acids accounted for $43{\pm}0.9$ to $47{\pm}1.2%$ of total amino acids with Turkish towel having the highest value. Turkish towel had a significantly higher taurine level ($0.82{\pm}0.27$) than the other macroalgae. The levels of persistent organic pollutants and heavy metals were low. The estimated annual product of the three species ranged from 50- to $70-mt\;dry\;weight\;ha^{-1}\;y^{-1}$, significantly higher than conventional crops. Land-based culture of these species can produce year-round harvest, consistent product quality, and low contaminant levels.

Monitoring of Climatological Variability Using EOS and OSMl Data

  • Lim, Hyo-Suk;Kim, Jeong-Yeon;Lee, Sang-Hee
    • Korean Journal of Remote Sensing
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    • v.19 no.3
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    • pp.209-216
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    • 2003
  • Dramatic changes in the patterns of satellite-derived pigment concentrations, sea-level height anomaly, sea surface temperature anomaly, and zonal wind anomaly are observed during the 1997-1998 El Ni$\bar{n}$o. By some measures, the 1997-1998 El Ni$\bar{n}$o was the strongest one of the 20$^{th}$ century. A very strong El Ni$\bar{n}$o developed during 1997 and matured late in the year. A dramatic recovery occurred in mid-1998 and led to La Nina condition. The largest spatial extent of the phytoplankton bloom was fellowed recovery from El Ni$\bar{n}$o over the equatorial Pacific. The evolution towards a warm episode (El Ni$\bar{n}$o) started from spring of 2002 and continued during January 2003, while equatorial SSTA remained greater than +1$^{\circ}C$ in the central equatorial Pacific. The OSMI (Ocean Scanning Multispectral Imager) data are used for detection of dramatic changes in the patterns of pigment concentration during next El Ni$\bar{n}$o.

Development of a Probability Prediction Model for Tropical Cyclone Genesis in the Northwestern Pacific using the Logistic Regression Method

  • Choi, Ki-Seon;Kang, Ki-Ryong;Kim, Do-Woo;Kim, Tae-Ryong
    • Journal of the Korean earth science society
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    • v.31 no.5
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    • pp.454-464
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    • 2010
  • A probability prediction model for tropical cyclone (TC) genesis in the Northwestern Pacific area was developed using the logistic regression method. Total five predictors were used in this model: the lower-level relative vorticity, vertical wind shear, mid-level relative humidity, upper-level equivalent potential temperature, and sea surface temperature (SST). The values for four predictors except for SST were obtained from difference of spatial-averaged value between May and January, and the time average of Ni$\tilde{n}$o-3.4 index from February to April was used to see the SST effect. As a result of prediction for the TC genesis frequency from June to December during 1951 to 2007, the model was capable of predicting that 21 (22) years had higher (lower) frequency than the normal year. The analysis of real data indicated that the number of year with the higher (lower) frequency of TC genesis was 28 (29). The overall predictability was about 75%, and the model reliability was also verified statistically through the cross validation analysis method.

Steric sea level change due to global warming in the northwestern Pacific Ocean for a $CO_2$ quadrupling (북서 태평양에서의 지구온난화로 인한 $CO_2$ 4배증시 해수면의 공간적 변화)

  • 최병호;김동훈;최영진
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2000.09a
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    • pp.188-194
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    • 2000
  • 지역적 기후변동은 전구평균 변화와는 다른 양상을 가진다. 그러나, 현재 전구적 기후변동과 해수면의 변화가 국지적으로 미칠 영향에 대한 추정능력은 매우 제한되어 있다. 본 연구에서는 NCAR(국립 대기 연구소)의 CSM (Climate System Model) 버전 1.2를 이용하여 전구뿐만 아니라 국지적인 시뮬레이션을 함께 수행하였다, 특히 북서태평양과 그 부근지역에 대한 해수변화를 중점적으로 연구했다. (중략)

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Observational Characteristics of East Asian Monsoon during the Summers of 1993 and 1994 (1993, 1994년 여름철 동아시아몬순의 관측 특성)

  • Kim, Baek-Jo;Ryu, Chan-Su
    • 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.

A Study of a Heavy Rainfall Event in the Middle Korean Peninsula in a Situation of a Synoptic-Scale Ridge Over the Korean Peninsula (종관규모 기압능이 한반도를 덮고 있는 기간에 중부지방에서 나타난 호우의 발생 원인)

  • Kim, Ah-Hyun;Lee, Tae-Young
    • Atmosphere
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    • v.26 no.4
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    • pp.577-598
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    • 2016
  • Observational and numerical studies have been carried out to understand the cause and development processes of the heavy rainfall over the middle Korean Peninsula during 0300 LST-1500 LST 29 June 2011 (LST = UTC + 0900). The heavy rainfall event occurred as the synoptic-scale ridge extended from Western Pacific Subtropical High (WPSH) was maintained over East Asia. Observational analysis indicates that the heavy rainfall is mainly due to scattered convective systems, formed over the Yellow Sea, traveling northeastward across the middle peninsula without further organization into larger systems during 0300 LST-0800 LST, and mesoscale convective systems (MCSs) over the Yellow Sea, transformed into a squall line, traveling eastward during 0800 LST-1500 LST. Organization of convective systems into MCSs can be found over the area of mesoscale trough and convergence zone in the northern end of the low-level jet (LLJ) after 0600 LST. Both observational and numerical investigations indicate that a strong LLJ extended from the East China Sea to the Yellow Sea plays an essential role for the occurrence of heavy rainfall. The strong LLJ develops in between the WPSH and a pressure trough over eastern China. Numerical experiments indicate that the land-sea contrast of solar heating of surface and latent heating due to convective developments are the major factors for the development of the pressure trough in eastern China. Numerical study has also revealed that the mountainous terrain including the mountain complex in the northern Korean Peninsula contributes to the increase of rainfall amount in the middle part of the peninsula.

Evaluation of Head and Neck Cancer Awareness and Screening Status in Jeddah, Saudi Arabia

  • Alhazzazi, Turki Y
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1135-1139
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    • 2016
  • Background: Head and neck cancer (HNC) is one of the deadliest cancers worldwide. Early detection is a key determinant of HNC prognosis. Hence, raising awareness of this disease may improve survival rates. The present study evaluated the level of awareness and screening status for HNC in the general population of Jeddah, Saudi Arabia. Materials and Methods: An e-questionnaire was distributed during our HNC awareness campaign at the Red Sea Mall in Jeddah. The questions assessed HNC knowledge and screening status among participants. Results: Of the 112 respondents, 68% indicated that they had no knowledge of HNC. Social media was the major source of information (39%) for respondents. The majority (40%) believed that it was the joint responsibility of dentists, dental hygienists, and general physicians to screen for HNC; 82% had never been screened. Conclusions: Knowledge and awareness of HNC must be increased in the general population and among dental health professionals.

Study on Optimal Condition for Oyster Rack Culture in terms of tidal exposure and rack height in Wando Coast, Korea

  • Han, Hyon Sob;Cho, Sang-Man
    • The Korean Journal of Malacology
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    • v.29 no.1
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    • pp.43-50
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    • 2013
  • We investigated the growth performance of oysters (initial shell height $57.5{\pm}8.5$ mm) under differing conditions of tidal exposure time and culture rack height in an experiment that commenced in April, 2011. Significant differences were observed in shell height from June 2011, in total weight from August, and in meat weight from September. Fatness tended to decrease during the experimental period, but was not significantly different at the end of the experiment. Significant differences in survival rates were mainly observed from June to August. After September, further changes were not observed in any experimental treatment group. The greatest growth potential ($L_{\infty}$) and survival rate were observed at a sea level of approximately 116 cm. The results indicate that in the study area the use of oyster culture conditions involving 1 or 2 h of tidal exposure and 60 - 70 cm rack height could result in oysters reaching the favored commercial half shell size within 14 months, with > 80% survival.

Survival Rates and Physiological Response of Pacific Abalone Haliotis discus hannai Held in Live Fish Containers (적정 수송 조건하의 활어용 컨테이너 내 참전복(Haliotis discus hannai)의 생존 및 생리 변화 구명)

  • Yang, Sung Jin;Jun, Je-Cheon;Kang, Hee Woong;Park, Noh Back;Min, Byung Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.3
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    • pp.238-247
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    • 2018
  • This study investigated survival rates and physiological responses in Pacific abalone (Haliotis discus hannai) to 18 days of containment in live fish containers ($8^{\circ}C$, 34 psu). The investigation was divided into three periods: before, during, and recovery after transportation. The overall survival rate was greater than 99%. Glucose, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) rose immediately on the first day of containment, but then gradually returned to normal levels. $NH_3$ continued to rise after the first day, but during the recovery period it decreased to a level not significantly different from that of the control group. $Na^+$ and osmolality did not show any abnormal changes. After recovery, superoxide dismutase (SOD) was not significantly different from control. Abalone in the experimental group had lower glutathione reductase (GR) than control. The hyalinocyte ratio fell immediately after confinement, but then gradually increased until it reached a normal level. The ratios of apoptotic and necrotic cells indicated no specific variations in hemocyte viability. Histological changes in the epidermal layer and muscle layer of the foot were not significantly different from those seen in the control group. The experimental data obtained in this study suggest that live fish containers may be used for transport of Pacific abalone without significantly impacting their physiology or survival rates.