Cold deep water in the South China Sea   总被引：1，自引：0，他引：1  

Ya-Ting Chang  Wei-Lun Hsu  Jen-Hua Tai  Tswen Yung Tang  Ming-Huei Chang  Shenn-Yu Chao 《Journal of Oceanography》2010,66(2):183-190

Two deep channels that cut through the Luzon Strait facilitate deep (>2000 m) water exchange between the western Pacific Ocean and the South China Sea. Our observations rule out the northern channel as a major exchange conduit. Rather, the southern channel funnels deep water from the western Pacific to the South China Sea at the rate of 1.06 ± 0.44 Sv (1 Sv = 10⁶ m³s⁻¹). The residence time estimated from the observed inflow from the southern channel, about 30 to 71 years, is comparable to previous estimates. The observation-based estimate of upwelling velocity at 2000 m depth is (1.10 ± 0.33) × 10⁻⁶ ms⁻¹, which is of the same order as Ekman pumping plus upwelling induced by the geostrophic current. Historical hydrographic observations suggest that the deep inflow is primarily a mixture of the Circumpolar Deep Water and Pacific Subarctic Intermediate Water. The cold inflow through the southern channel offsets about 40% of the net surface heat gain over the South China Sea. Balancing vertical advection with vertical diffusion, the estimated mean vertical eddy diffusivity of heat is about 1.21 × 10⁻³ m²s⁻¹. The cold water inflow from the southern channel maintains the shallow thermocline, which in turn could breed internal wave activities in the South China Sea.  相似文献   

Nearshore scavenging phenomenon elucidated by <Superscript>234</Superscript>th/<Superscript>238</Superscript>u disequilibrium in the coastal waters off Western Taiwan     

Ching-Ling Wei  Jing-Ru Tsai  Liang-Saw Wen  Su-Cheng Pai  Jen-Hua Tai 《Journal of Oceanography》2009,65(2):137-150

Dissolved and particulate ²³⁴Th activities in surface seawater were determined at 27 stations along the coastline of western Taiwan during 19–23 November 2004. Contrasting scavenging settings were observed between the northern and southern regimes of the nearshore water off western Taiwan, separated by the Cho-Shui River. The northern regime is characterized by a large quantity of suspended load contributed by northward transport of a suspension plume from the Cho-Shui River, while the southern regime, low in suspended load and high in chlorophyll concentration, is a system controlled by biological activity. A scavenging model that takes account of the physical transport was used to estimate the ²³⁴Th budget in order to estimate the scavenging and removal rates from the nearshore water. The scavenging and removal rates ranged from 21 to 127 dpm m⁻³d⁻¹ and from 36 to 525 dpm m⁻³d⁻¹, for dissolved and particulate ²³⁴Th, respectively. The removal fluxes of particulate organic carbon (POC) and particulate organic nitrogen (PON) were estimated by multiplying the particulate ²³⁴Th removal flux to the organic carbon/²³⁴Th and nitrogen/²³⁴Th ratios in suspended particles, which ranged from 4.5 to 275.2 mmol-C m⁻²d⁻¹ and from 1.3 to 50.1 mmol-N m⁻²d⁻¹, respectively. These fluxes resulted in residence times of 1∼20 days for the POC in the surface water of nearshore water off western Taiwan.  相似文献   

Tyrosinase, a new innate humoral immune parameter in large yellow croaker （Pseudosciaena crocea R）     

王淑红  王艺磊  张子平  谢芳靖  林鹏  邰振刚 《中国海洋湖沼学报》2009,27(3):527-535

We evaluated the immune response to infection with a pathogen in large yellow croaker(Pseudosciaena crocea Richardson).The fish were given an intraperitoneal(i.p.) injection of Vibrio parahaemolyticus or sterile sea water(control).We collected blood sera from the fish 0.17,1,2,4,8,12,or 16 d after injection(dpi).We measured tyrosinase activity and the concentrations of lysozyme,NOS,and antibodies.Serum tyrosinase activity was significantly higher at 0.17 and 4 dpi than in the control group,and peaked at 8 d...  相似文献   

鲑鱼降钙素基因异源表达研究进展     

张学成  孙平楠  陈云松 《中国海洋大学学报(自然科学版)》2008,38(1):89-94

在不同来源降钙素中,鲑鱼降钙素的活性最高,在钙的代谢和治疗骨质疏松、Paget氏综合症、高钙血症等疾病中有巨大的药用价值.其C末端的酰胺化对它完整的生物活性起重要作用.本文综述了鲑鱼降钙素基因在大肠杆菌、链霉菌、乳酸杆菌和蓝藻等原核细胞,在酵母、昆虫、动植物等真核细胞中异源表达的研究进展,以及通过基因工程的方法能够改进生物表达系统,提高鲑鱼降钙素活性的动态.  相似文献