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811.
Hyun-Cheol Kim Hisashi Yamaguchi Sinjae Yoo Jianrong Zhu Kazumaro Okamura Yoko Kiyomoto Katsuhisa Tanaka Sang-Woo Kim Taewook Park Im Sang Oh Joji Ishizaka 《Journal of Oceanography》2009,65(1):129-135
Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-a distribution in summer in the East China Sea during 1998–2007 was analyzed. Statistical analysis with K-means clustering
technique allowed us to define the proper satellite chlorophyll-a concentration indicating the Changjiang Diluted Water (CDW). The spatial distributions of the higher satellite chlorophyll-a concentrations (>0.48 mg m−3) corresponded well with the distributions of lower salinity CDW (<30–32) every year. Interannual variation of the CDW area,
indicated by the high satellite chlorophyll-a, correlated with the interannual variation of the Changjiang summer freshwater discharge. The correlation analysis indicated
that the CDW spread eastward in the East China Sea with a time lag of 1 to 2 months after the discharge. 相似文献
812.
Idealized numerical experiments with a depth level coordinate ocean circulation model (GFDL MOM3) have been conducted to investigate
the structure of interdecadal variability from thermally driven circulations. The model oceans are driven by steady surface
heat fluxes in the absence of surface wind stresses. Interdecadal variability is observed, with characteristics similar to
those reported in many previous studies. To explain the nature of the variability we propose a new mechanism based on two
local horizontal advective processes. This overcomes the limitations in previous theories based on the interplay between global
properties such as zonal and meridional temperature gradients and overturning. One of the two advective processes is a zonal
flow anomaly induced by a temperature anomaly along the northern wall through geostrophy southward of the temperature anomaly.
A cold (warm) anomaly along the northern wall produces a positive (negative) zonal flow anomaly that induces a warm (cold)
temperature anomaly by enhancing (weakening) warm advection from the western boundary along the path of the zonal flow anomaly.
The temperature and flow anomalies are transported toward the eastern boundary by the mean eastward zonal flow. When the positive
(negative) zonal flow anomaly that accompanies the warm (cold) temperature anomaly encounters the eastern wall, a downwelling
(upwelling) anomaly is produced. To dissipate the vorticity due to this downwelling (upwelling) anomaly, a northward (southward)
flow anomaly, which is another advective process governing the variability, is generated within a frictional boundary layer
next to the eastern wall. The northward (southward) flow anomaly circulates cyclonically along the perimeter of the basin
while enhancing (reducing) warm advection. So does the warm (cold) temperature anomaly carried to the eastern wall by the
mean zonal flow while pushing the cold (warm) anomaly that produced the positive (negative) zonal flow anomaly westward and
initiating the other half cycle of the variability. During the anomalous downwelling or upwelling, the available potential
energy stored in the anomalous density field is released to maintain the variability. Thus, neither barotropic nor baroclinic
instability supplies energy for the variability. The anomalous vertical velocity is stronger along the northern boundary and
the northern part of the eastern boundary. A shallow continental slope added along those boundaries prohibits the anomalous
vertical motion and weakens variability very effectively, while one along the western boundary does not. 相似文献
813.
郑华 朱小华 Nakamura Hirohiko Park Jae-Hun Jeon Chanhyung 赵瑞祥 Nishina Ayako 张传正 Na Hann 朱泽南 Min Hong-Sik 《海洋学报(英文版)》2020,39(7):91-106
在2015年6月至2017年6月期间,跨越庆良间水道的由2台加载压力传感器的倒置式回声仪(PIES)和5台加载压力传感器和海流计的倒置式回声仪(CPIES)组成的观测断面获得了近2年的海底压力时间序列。该时间序列中存在着显著的21天周期的振荡(Pbot21),该信号在2016年7月至10月期间尤为强烈。Pbot21与东海陆架上的风应力旋度存在较显著的3天延迟相关,其相关系数达到0.65。本文采用正压海洋模式解释了这一信号的产生、传播以及耗散过程,模式结果显示东海陆架上的风应力旋度驱动产生Pbot21并向琉球岛链传播,而深海上的风应力旋度不能驱动产生这一信号。在陆架上,Pbot21伴随21天周期的风应力旋度由海岸向东南方向传播,但由于摩擦作用,信号在离开风场后几天内即耗散。断面能否观测到Pbot21与陆架上21天周期风应力旋度场的分布相关,长江口东南方向风应力旋度驱动的Pbot21能被观测到,而长江口东北方向产生的Pbot21不能被观测到。 相似文献
814.
Pak Gyundo Park Jae-Hyoung Lee Seok-Joon Park Young-Gyu Chang You-Soon 《Ocean Science Journal》2020,55(4):477-493
Ocean Science Journal - This study focuses on the intercomparisons of 22 net heat flux (NHF) data sets in terms of mean, linear trend, and interannual variability during 1993–2007 over the... 相似文献
815.
Sojung Park Mansik Choi Dongjun Jang Dongjin Joe Kyunggue Park Hyojin Lee Junsik Woo Taeha Kim Jongkyu Park 《Ocean Science Journal》2020,55(1):69-84
In this study, we investigated the spatial and temporal distribution of heavy metals and nutrients in Gyeonggi Bay, Korea, to determine their present statu 相似文献
816.
We project changes of the Aleutian Low (AL) under global warming using ensemble simulations with a fully coupled ocean-atmosphere-sea ice model, the Kiel C 相似文献
817.
Natural Resources Research - This paper develops a reliable workflow for multi-objective history matching coupled with a distance-based model selection and ensemble-based data assimilation at a... 相似文献
818.
Effects of humic acid on heavy metal uptake by herbaceous plants in soils simultaneously contaminated by petroleum hydrocarbons 总被引:2,自引:0,他引:2
Soyoung Park Ki Seob Kim Daesok Kang Hansam Yoon Kijune Sung 《Environmental Earth Sciences》2013,68(8):2375-2384
The effects of humic acid (HA) on heavy metal uptake by herbaceous plants in soil simultaneously contaminated with heavy metals and petroleum hydrocarbons were investigated. The results showed that HA reduced readily soluble and exchangeable forms of heavy metals in the contaminated soil but increased their plant-available forms. Potential bioavailability and leachability factors became larger than 1 after adding HA to the soil, except for those of Ni, suggesting that more heavy metals could be potentially phytoavailable for plant uptake. Furthermore, HA increased the accumulation of Pb, Cu, Cd, and Ni in the shoots and roots of selected plants. The greatest increase in the accumulation of heavy metals was 264.7 % in the shoot of Festuca arundinacea, with the bioconcentration factor (BCF) increasing from 0.30 to 1.10. Humic acid also increased the BCFs of the roots of Brassica campestris for Ni and Pb. These results suggest that HA amendment could enhance plant uptake of heavy metals, while concurrently reducing heavy metal leachability and preventing subsurface contamination, even in soils simultaneously contaminated with petroleum hydrocarbons. 相似文献
819.
S. K. Behera S. Y. Oh H. S. Park 《International Journal of Environmental Science and Technology》2012,9(1):85-94
Pharmaceuticals have gained significant attention in recent years due to the environmental risks posed by their versatile application and occurrence in the natural aquatic environment. The transportation and distribution of pharmaceuticals in the environmental media mainly depends on their sorption behavior in soils, sediment?Cwater systems and waste water treatment plants, which varies widely across pharmaceuticals. Sorption of ibuprofen, a non-steroidal anti-inflammatory drug, onto various soil minerals, viz., kaolinite, montmorillonite, goethite, and activated carbon, as a function of pH (3?C11), ionic strength (NaCl concentration: 0.001?C0.5?M), and the humic acid concentration (0?C1,000?mg/L) was investigated through batch experiments. Experimental results showed that the sorption of ibuprofen onto all sorbents was highest at pH 3, with highest sorption capacity for activated carbon (28.5?mg/g). Among the minerals, montmorillonite sorbed more ibuprofen than kaolinite and goethite, with sorption capacity increasing in the order goethite (2.2?mg/g)?<?kaolinite (3.1?mg/g)?<?montmorillonite (6.1?mg/g). The sorption capacity of the selected minerals increased with increase in ionic strength of the solution in acidic pH condition indicating that the effect of pH was predominant compared to that of ionic strength. An increase in humic acid concentration from low to high values made the sorption phenomena very complex in the soil minerals. Based on the experimental observations, montmorillonite, among the selected soil minerals, could serve as a good candidate to remove high concentrations of ibuprofen from aqueous solution. 相似文献
820.
Qingjia Meng Mojib Latif Wonsun Park Noel S. Keenlyside Vladimir A. Semenov Thomas Martin 《Climate Dynamics》2012,38(9-10):1757-1773
Recent studies indicate a weakening of the Walker Circulation during the twentieth century. Here, we present evidence from an atmospheric general circulation model (AGCM) forced by the history of observed sea surface temperature (SST) that the Walker Circulation may have intensified rather than weakened. Observed Equatorial Indo-Pacific Sector SST since 1870 exhibited a zonally asymmetric evolution: While the eastern part of the Equatorial Pacific showed only a weak warming, or even cooling in one SST dataset, the western part and the Equatorial Indian Ocean exhibited a rather strong warming. This has resulted in an increase of the SST gradient between the Maritime Continent and the eastern part of the Equatorial Pacific, one driving force of the Walker Circulation. The ensemble experiments with the AGCM, with and without time-varying external forcing, suggest that the enhancement of the SST gradient drove an anomalous atmospheric circulation, with an enhancement of both Walker and Hadley Circulation. Anomalously strong precipitation is simulated over the Indian Ocean and anomalously weak precipitation over the western Pacific, with corresponding changes in the surface wind pattern. Some sensitivity to the forcing SST, however, is noticed. The analysis of twentieth century integrations with global climate models driven with observed radiative forcing obtained from the Coupled Model Intercomparison Project (CMIP) database support the link between the SST gradient and Walker Circulation strength. Furthermore, control integrations with the CMIP models indicate the existence of strong internal variability on centennial timescales. The results suggest that a radiatively forced signal in the Walker Circulation during the twentieth century may have been too weak to be detectable. 相似文献