http://www.sciencedirect.com/science/article/pii/S1674987113000510

In this paper,we analyze lithospheric density distribution of China and surrounding regions on the basis of 300300gravity data and 1 1 P-wave velocity data.Firstly,we used the empirical equation between the density and the P-wave velocity difference as the base of the initial model of the Asian lithospheric density.Secondly,we calculated the gravity anomaly,caused by the Moho discontinuity and the sedimentary layer discontinuity,by the Parker formula.Thirdly,the gravity anomaly of the spherical harmonics with 2e40 order for the anomalous body below the lithosphere is calculated based on the model of EGM96.Finally,by using Algebra Reconstruction Techniques(ART),the inversion of 300300residual lithospheric Bouguer gravity anomaly caused by the lithosphere yields a rather detailed structural model.The results show that the lithospheric density distribution of China and surrounding regions has a certain connection with the tectonic structure.The density is relatively high in the Philippine Sea plate,Japan Sea,the Indian plate,the Kazakhstan shield and the Western Siberia plain,whereas the Tibetan Plateau has low-density characteristics.The minimum value of density lies in the north of Philippines,in the Taiwan province and in the Ryukyu island arc.     

Territorial behaviour in brown trout (Salmo trutta L.)

The recapture of tagged brown trout (Salmo trutta L.) in two experimental streams gave over 60% recapture in the section of stream where they were released, and over 80% when adjacent areas were included. Operation of a downstream trap showed that there was little emigration from the area above the trap and it is concluded that most of the fish which disappear die.     

New Zealand Caprellidae (Crustacea: Amphipoda)

The New Zealand Caprellidae (Crustacea: Amphipoda) are reviewed. Only two species previously recognised from New Zealand, Caprella equilibra Say and Caprellina longicollis (Nicolet) are accepted. A new monospecific genus near to Protomima is described.     

ENSO循环相联系的北太平洋低纬度异常西边界流

用SODA海洋同化和NCEP大气再分析资料,分析了热带太平洋次表层海温异常主要模态与北太平洋低纬度西边界流海域上层海洋环流和亚洲-北太平洋地区大气垂直和水平流场变化之间的关系,得到以下结果:（1） 在热带太平洋海洋次表层ENSO事件具有两种模态,二者组合构成ENSO循环。第一模态为ENSO成熟期,主要出现在冬季,第二模态为ENSO过渡期,主要出现夏季。（2） ENSO循环对北太平洋低纬度西边界流区上层海洋环流有重要影响。在El Niño发展期或La Niña 衰退期,该区出现气旋性异常环流,北赤道流（NEC）加强,NEC分叉位置北移,棉兰老海流（MC）加大,菲律宾以东黑潮（KC）减小,北赤道逆流（NECC）最强。在El Niño（La Niña）成熟期,该区气旋性（反气旋性）异常环流达最强,NEC最强（最弱）,NEC分叉位置最北（最南）,MC最大（最小）,KC最小（最大）,NECC减弱（加强）。在El Niño衰退期或La Niña发展期与El Niño发展期相反,该区出现反气旋性异常环流,由此导致相应流系异常发生反位相变化。（3） ENSO循环对北太平洋低纬度西边界流海域上层海洋环流的影响是通过ENSO事件期间热带太平洋热力状况异常改变上空大气环流来实现的。ENSO事件首先造成热带太平洋海洋热力状况异常,导致其上空对流活动异常,后者直接或间接通过“大气桥”能量传输引起相关地区大气环流场的变化,致使海面风应力场异常,进而强迫上层海洋环流场的相应变化。文章最后还分析了ENSO事件期间菲律宾附近异常反气旋或异常气旋性风场的产生和持续原因,讨论了北太平洋低纬度西边界流海域海气相互作用在ENSO循环中的贡献。     

Velocity measurements in the East Auckland Current north‐east of North Cape,New Zealand

Flow in the East Auckland Current (EAUC) system to the north‐east of North Cape, New Zealand is examined using data from two current meter mooring arrays, with supporting data from conductivity/temperature/depth (CTD) and satellite altimetry. Variable currents up to 45 cm s_–1 were observed. The variability was partly attributable to changes in position and strength of the North Cape Eddy whose centre lies some 150 km offshore. The observed flows across the mooring line correlate well with those estimated from satellite altimetry. This gives confidence in the use of the satellite data to estimate the transport variability in the EAUC in the 1992–2001 period. No seasonal cycle was found in the volume transports but rather broadband variability at periods longer than 100 days.     

TOPEX/Poseidon-Jason Comparison and Combination off Nova Scotia

Sea level observations from the tandem TOPEX/Poseidon (T/P) and Jason-1 altimetry missions (2002–2003) are used to study characteristics of sea level and surface currents over the Scotian Shelf and Slope off Nova Scotia. The consistency and error characteristics of T/P and Jason-1 measurements are examined not only in terms of sea level and cross-track current anomalies but also with respect to current anomalies at crossovers, kinematic properties associated with Gulf Stream warm core rings (WCR), and the shelf-edge current transport. Nominal absolute currents are constructed by adding the altimetric geostrophic current anomalies to an annual-mean model circulation field. The concurrent frontal analysis data are analyzed for occurrence of the WCRs and associated kinematic properties are derived from altimetric current anomalies. The comparison of the sea level and cross-track current anomalies from January to July 2002 shows overall good agreement between T/P and Jason, with correlation coefficients different from zero at the 5% significance level at essentially all locations for sea level and at most locations for currents. The cross-track geostrophic current anomalies from January to July 2002 and from September 2002 to December 2003 are further used to calculate the root-mean-square (rms) current magnitude, and the normalized relative vorticity associated with WCRs. The altimetric currents are consistent with each other and complementary to frontal analysis data in deriving the properties of the WCRs. The rms current magnitude is ～55 cm/s and the normalized relative vorticity is ～0.15. The model-altimetry combined absolute currents are used to estimate near-surface transport associated with the shelf-edge current, showing good correlation between T/P and Jason estimates and strong seasonal changes. The current anomalies derived from altimetry and moored measurements are significantly (at the 5% significance level) correlated and comparable in the rms magnitude.     

The Subtropical Convergence east of New Zealand

Hydrographic data from the region of the Subtropical Convergence east of New Zealand between 177°E and 179°E show that in spring the convergence occurs near the Chatham Rise. North of the Chatham Rise the structure is fairly regular with isolines of temperature and salinity sloping upwards towards the south. To the south of the Chatham Rise the structure is more complex with an apparent intrusion of Subtropical Water into the Sub‐antarctic Water below depths of about 150 m.     

Surface tidal currents in the open sea area to the east of the Zhoushan Islands measured with high frequency surface wave radar

Based on the quasi-harmonic analysis of 11 d vector ocean currents obtained from two high frequency sur- face wave radars located at Zhujiajian Island and Shengshan Island, the spatial distribution characteristics of surface tidal currents in the open sea area to the east of the Zhoushan Islands of Zhejiang Province, China are studied. The following conclusions are drawn from the analysis： the tidal current pattern in the open sea area to the east of Zhoushan Islands is primarily regular semidiurnal, which is significantly affected by the shallow water constituents. The directions of the major axes of tidal current ellipses of M2 lie approx- imately in the NW-SE direction. With the increasing of distance away from the coast, the directions of the tidal current ellipses gradually shift toward the E-W direction. The tidal currents are mainly reversing cur- rents. The spatial distribution of probable maximum current velocities decreases gradually from northeast to southwest which is basically in accordance with the spatial distribution of measured maximum current velocities. The residual currents near the coast are larger than those far away from the coast. The directions of the residual currents are basically north by east, and the angle to the due north increases gradually with the increasing distance away from the coast. The topography shows a certain impact on the spatial distri- bution of shallow water constituents, the rotation of tidal currents, the probable maximum currents and the residual currents.     

Upwelling and ocean structures off Algoa Bay and the south-east coast of South Africa

As the Agulhas Current flows along the south-east coast of South Africa, a number of processes operate that bring cold, deep water up onto the narrow shelf. As a consequence, upwelling along the coastline is enhanced farther southward and downstream. This situation is investigated off Algoa Bay and along the south-east coast to Port Alfred, where measurements demonstrate that marked temperature variability occurs at the coastline, particularly in summer when temperature structures are more intense and easterly-component winds more common. There is no indication that upwelling is more prevalent at Port Alfred; increasing variability farther south is evident at Woody Cape/Cape Padrone, where the coastline veers westwards, forming the eastern boundary of Algoa Bay. Here it is found that, after a wind change to north-easterly, cold water is upwelled along the shoreline between 19 hours and 2.5 days later. Such upwelling progresses north-eastwards with the movement of the wind and weather systems, although colder water also moves south-westwards into Algoa Bay. Winds, currents, sea level and sea temperatures are highly correlated, with fluctuations in sea level measuring >50 cm being associated with coastal trapped waves (CTWs). Such barotropic wind-driven CTWs are frequently active during upwelling, although it is unclear whether there is any interaction between the two phenomena.     

On the sensitivity of tidal residuals off the west coast of Britain to mesh resolution

An irregular mesh model of the west coast of Britain is used to examine the sensitivity of tidal residuals to mesh resolution in the region. Computed residuals are compared with earlier published results determined with a high resolution (1 km grid) finite difference model of the eastern Irish Sea. Initial calculations show that tidal residuals are largest in nearshore regions particularly in the vicinity of headlands. Local refinement of the mesh in these regions leads to a more detailed picture of the flow field, particularly adjacent to the coast. Although large scale offshore features of the flow can be resolved using the high resolution finite difference model, such an approach leads to a “stair case” representation of the coastal boundary with an adjacent near coastal region of spurious tidal residuals. By using an irregular mesh that follows the coast, this effect is removed. In the Mersey river region the tidal residual is resolved with a mesh resolution of 120 m, although calculations show that its distribution is particularly sensitive to small scale features of the topography. A variable mesh that can accurately represent the lateral variations in river width and details of topography in both the nearshore and estuarine environment appears essential in modelling the coastal spread of freshwater plumes from rivers and pollutants discharged into the near coastal environment.