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81.
Three Kuroshio small meanders off the southeast coast of Kyushu that occurred during 1994 to 1995 were investigated by using
satellite-derived sea surface temperature (SST) and sea surface height (SSH) maps, World Ocean Circulation Experiment (WOCE)
Hydrographic Program (WHP) repeat section and Japan Meteorological Agency (JMA) hydrographic observations. Based on the satellite
data, we observed that the three small meanders are formed by different processes: the triggering and growth of these meanders
are caused by a cyclonic eddy propagating from the Kuroshio recirculation region or Kuroshio front meanders traveling from
the East China Sea. Investigation of the two small meanders in 1994 and 1995 spring that are captured by the WHP observation
showed quite consistent hydrographic features. On the nearshore side of the meandering Kuroshio, a countercurrent appears,
associated with vertically uniform upward lifts of the isopycnals from sea surface to bottom at the boundary between the countercurrent
and the Kuroshio. In the countercurrent region, the waters in the density ranges of the North Pacific subtropical mode water
(NPSTMW) and the North Pacific Intermediate Water (NPIW) are more saline and less saline than typical waters that the Kuroshio
carries in a non-small meander state, respectively. There are indications that high-salinity NPSTMW and low-salinity NPIW
distributed off the Kuroshio was supplied to the countercurrent region. In the meandering Kuroshio flow, while there is no
notable change in properties around the NPSTMW density range, salinity of the NPIW is significantly higher than that carried
by the Kuroshio in a non-small meander state, but not higher than that in the Kuroshio at the Tokara Strait, which suggests
that saline NPIW from the Tokara Strait, less mixed with low-salinity NPIW off the Kuroshio, may be carried by the meandering
Kuroshio.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
82.
The spatial evolution of vortices and transition to three-dimensionality in the wake of two circular cylinders in tandem arrangement have been numerically studied. An improved virtual body method developed from the virtual boundary method is used here. A Reynolds number range between 220 and 270 has been considered, and the spacing between two cylinders is selected as L/D = 3 and L/D = 3.5. When L/D = 3, the secondary vortices of Mode-A are seen to appear at Re = 240 and persist over the range of the Reynolds number of 240 - 270. When L/D = 3.5, the similar critical Reynolds number has been found at Re = 250. No obvious discontinuity has been found in the Strouhal-Reynolds number relationship, and this is different from three-dimensional flow around a single cylinder at the critical Reynolds number. The spanwise wavelength is about four times the diameter of the cylinder, and it is the characteristic wavelength for ModeA instability. This paper can give some foremost insight into the three-dimensional instability of flow by complicated geometrical configuration. 相似文献
83.
We examine changes in canopy cover for adult western juniper from the 1960s to 1994 in central Oregon using repeat aerial photography. We compare changes at four sites with a land‐use history of minimal anthropogenic disturbance to changes on adjacent sites that have a disturbance history more typical of central Oregon rangelands. Canopy cover increased at all sites, but afforestation on sites with domestic livestock grazing was greater. The potential driving forces common to all sites include a long fire‐free interval, early twentieth‐century favorable climatic conditions, biological inertia, and atmospheric CO2 enrichment. 相似文献
84.
对多普勒天气雷达在实际探测中出现的测速模糊现象作了初步分析,探讨了出现测速模糊现象的原因及其识别方法。并以阿克苏3830多普勒雷达的观测实例,介绍了具体解决测速模糊现象的主要方法。 相似文献
85.
86.
87.
Yun‐Guo Liu Tadahide Kurokawa Masashi Sekino Toru Tanabe Kazuhito Watanabe 《Marine Ecology》2014,35(3):273-280
We found that tandem repeat (TR) arrays were present in the ark shell Scapharca broughtonii mitochondrial genome, and we demonstrated the efficiency of using this TR region as a tool for the detection of genetic differentiation. In samples collected from seven populations off the Japanese, Chinese, Russian and Korean coasts, five TR types with length ranging from 481 to 601 bp (base pairs) were found, as were 18 haplotypes (n = 155). All the Japanese samples from SD, IK, AM and KG, which represented four geographically distinct populations, had the same type of tandem repeat array, 481‐TR. All the samples from China and all but one sample from Russia had the same TR type, 511‐TR; these finding may be strong evidence that the ark shell populations in China and Russia are very similar. Based on a neighbor‐joining dendrogram of haplotypes, the Korean population was divided into two groups as follows: samples with haplotype H481‐3 and samples with haplotypes H601‐1, H601‐2, H601‐3 or H541‐1. Based on the haplotype diversity and nucleotide diversity, the Chinese, Russian and Korean populations showed a higher diversity than Japanese populations (P < 0.05). 相似文献
88.
为了利用ISSR分子标记技术对坛紫菜(Porphyra haitanensis)种质资源进行遗传分析及种质鉴定,获得清晰稳定、重复性好、多态性高的扩增结果,对影响ISSR-PCR扩增的多个因素,包括DNA模板含量、Mg2+浓度、TaqDNA聚合酶含量、引物浓度、dNTP浓度以及复性温度进行了全面比较和优化,建立了坛紫菜种质资源ISSR-PCR扩增的最佳反应体系:25μL的反应体系中含2.5μL 10×PCR缓冲液,5 ng模板DNA,2.5 mmol/L Mg2+,1.5 UTaqDNA聚合酶,200 nmol/L引物,200μmol/L dNTP。最佳PCR扩增程序:94℃预变性7 min;每个循环94℃变性1 min,48℃复性45 s,72℃延伸2 min,共进行35个循环;循环结束后72℃再延伸7 min。 相似文献
89.
90.