Volume transport of the Tsushima Warm Current, west of Tsugaru Strait bifurcation area     

Mitsuyo Onishi  Kiyotaka Ohtani 《Journal of Oceanography》1997,53(1):27-34

Northern and southern latitudinal transects were conducted west of Tsugaru Strait to estimate the volume transport in this area. It was found that the Tsushima Warm Current is the northward volume transport across the southern transect and the Northward Current is the northward volume transport across the northern transect. The current in Tsugaru Strait,viz. the Tsugaru Warm Current, is the flow remaining when the Northward Current is subtracted from the Tsushima Warm Current. Both CTD transects covered from near-shore to west of the subarctic front, and observed depths were from the surface to the bottom or to 1000-1500 m depth. Our estimations indicate that large interannual variations of volume transport occur, relative to the seasonal ones, with interannual variations sometimes exceeding seasonal variations in the Tsushima Warm Current and the Northward Current. The Tsugaru Warm Current has near-steady transport. Fluctuations in the Tsushima Warm Current are thus transmitted to the Northward Current. Further, our results revealed seasonal variations in the flow: the baloclinic structure became deeper in April and the current axis tended to shift in a near-shore direction in October. Therefore, previous studies, which had shallow reference levels and lacked nearshore stations, may have underestimated the transport and excessive seasonal variations.  相似文献   

"百合"台风近海加强成因分析   总被引：3，自引：0，他引：3  

林毅  刘爱鸣  刘铭 《台湾海峡》2005,24(1):22-26

利用卫星云图、常规观测资料对“百合”台风减弱为低压后在台湾海峡南部海面强度再次加强，又发展成强热带风暴的过程分析诊断结果表明：“百合”台风近海加强的主要原因是台风上层强辐散流场的叠加，加强了台风环流的垂直上升运动；台湾海峡南部的暖洋区的增暖增湿、中低层辐合流场的加强和低层适度冷空气的侵入对台风的加强也起了一定的作用．  相似文献   

Utility of an automatic water sampler to observe seasonal variability in nutrients and DIC in the Northwestern North Pacific     

Makio C. Honda  Shuichi Watanabe 《Journal of Oceanography》2007,63(3):349-362

Concentrations of nutrients (NO₃, NO₂, Si(OH)₄, PO₄ and dissolved inorganic carbon (DIC) were measured in a series of seawater samples collected over approximately 15 months in 2005 and 2006 by an automatic water sampler (Remote Access Sampler, RAS) in the Northwestern North Pacific. Seasonal variability and concentrations of NO₃ + NO₂ (NO_x and Si(OH)₄ were comparable to previous shipboard observations, although there were small errors associated with measurements of PO₄ and DIC. Concentrations of these nutrients began to decrease in late April. After the end of June, NO_x and Si(OH)₄ decreased rapidly, with large fluctuations. After October, these nutrients increased again until late spring 2006. The ratio of the decrease of Si(OH)₄ to that of NO_x suggests that numbers of biogenic opal-producing creatures, such as diatoms, increased after the end of June. This conclusion was supported by a rapid increase in biogenic opal flux recorded in a sediment trap at 150 m. The relationship between NO_x concentrations at the RAS depth of 35 m and NO_x integrated over the upper 100 m was determined using previous shipboard hydrocast data. This relationship was used to estimate integrated mixed layer NO_x concentration from RAS data. Estimated new production based on seasonal drawdown of integrated NO_x averaged approximately 156 mg-C m⁻²day⁻¹ annually, which agrees with previous estimates. Thus, an automatic seawater sampler that documents annual maximum and minimum nutrient concentrations and episodic events such as storms and spring blooms, which might be missed by an ordinary research vessel, will contribute to time-series observations of nutrients and, by extension, biological pump activity.  相似文献   

Application of in situ target-strength estimations in lakes: examples from rainbow-smelt surveys in Lakes Erie and Champlain   总被引：1，自引：0，他引：1  

Rudstam  L.G; Parker  S.L; Einhouse  D.W; Witzel  L.D; Warner  D.M; Stritzel  J.L; Parrish  D.L; Sullivan  P.J 《ICES Journal of Marine Science》2003,60(3):500-507

  相似文献   

Diurnal changes in the acoustic-frequency characteristics of Japanese anchovy (Engraulis japonicus) post-larvae "shirasu" inferred from theoretical scattering models     

Miyashita  Kazushi 《ICES Journal of Marine Science》2003,60(3):532-537

  相似文献   

Target strength of mesopelagic lanternfishes (family Myctophidae) based on swimbladder morphology   总被引：3，自引：1，他引：3  

Yasuma  Hiroki; Sawada  Kouichi; Ohshima  Tatsuki; Miyashita  Kazushi; Aoki  Ichiro 《ICES Journal of Marine Science》2003,60(3):584-591

  相似文献   

Potential acoustic discrimination within boreal fish assemblages     

Gauthier  Stephane; Horne  John K. 《ICES Journal of Marine Science》2004,61(5):836-845

  相似文献   

鱼类淋巴囊肿病毒靶器官的组织病理研究   总被引：9，自引：3，他引：9  

绳秀珍  战文斌 《中国海洋大学学报(自然科学版)》2006,36(5):749-753

探讨病毒传播途径,运用组织病理学技术,对患淋巴囊肿病毒病的牙鲆和鲈鱼的组织进行显微观察,并对病毒感染的靶器官进行了研究。结果表明,在牙鲆体表皮下结缔组织中,当大量成纤维细胞膨大、变圆,大小为10~18μm时,细胞膜外未出现囊壁,少数细胞的细胞质中观察到嗜碱性物质;18~20μm的膨大细胞在细胞膜外出现囊壁,细胞质内出现嗜碱性物质;>20μm的细胞具有了淋巴囊肿细胞的典型特征。另外,在牙鲆鳃、肠上皮下结缔组织和粘膜下层中,脾、头肾边缘组织和表面系膜、肝表面系膜,以及鲈鱼的鳃等部位均观察到淋巴囊肿细胞,并在牙鲆和鲈鱼脾内观察到膨大细胞。因此,淋巴囊肿病毒的靶器官主要是鱼体表皮下结缔组织,其次是鳃、体腔膜、肠、脾和头肾。鱼体表皮下结缔组织是淋巴囊肿病毒病的检测、检疫和早期诊断的最佳样品。  相似文献   

The influence of ontogeny, physiology, and behaviour on the target strength of walleye pollock (Theragra chalcogramma)     

Horne  John K 《ICES Journal of Marine Science》2003,60(5):1063-1074

  相似文献   

半封闭海湾纳潮量的一种直接观测方法   总被引：3，自引：0，他引：3  

熊学军  胡筱敏  王冠琳  云升军  赵鸣 《海洋技术学报》2007,26(4):17-19

文章推荐了一种半封闭海湾纳潮量的直接观测方法,主要利用ADCP在封闭湾口的观测断面上进行周期性的往还式周日连续走航观测,通过观测到的湾口流量变化序列直接计算海湾的纳潮量。文中提供了较为系统的观测方案以供借鉴。  相似文献