A method for estimating the consumption of capelin by cod in the Barents Sea   总被引：1，自引：0，他引：1  

Bogstad  Bjarte; Gjosaeter  Harald 《ICES Journal of Marine Science》1994,51(3):273-280

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The Barents Sea capelin-a review of trophic interrelations and fisheries     

Ushakov  Nikolai G.; Prozorkevich  Dmitry V. 《ICES Journal of Marine Science》2002,59(5):1046-1052

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0407号台风"蒲公英"路径突然北折的原因分析   总被引：6，自引：0，他引：6  

高珊  何小宁  凌士兵 《台湾海峡》2005,24(4):448-454

本文主要从天气学的角度分析0407号台风“蒲公英”在巴士海峡上空突然北折的原因,发现双台风相互作用牵制了“蒲公英”,增加了台风路径北折的突然性,而其南侧高压环流的发展对台风路径北折有决定性作用．扩大传统中双台风发生作用的距离,将两个台风之间可以直接、半直接或间接作用的概念引入日常预报中。  相似文献   

Spatial variation in the feeding ecology, foraging ranges, and breeding energetics of northern fulmars in the north-east Atlantic Ocean     

Hamer  K. C.; Thompson  D. R.; Gray  C. M. 《ICES Journal of Marine Science》1997,54(4):645-653

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Transport of plankton and particles between the Chukchi and Beaufort Seas during summer 2002, described using a Video Plankton Recorder     

Carin J. Ashjian  Scott M. Gallager  Stphane Plourde 《Deep Sea Research Part II: Topical Studies in Oceanography》2005,52(24-26):3259

A key goal of the Western Arctic Shelf Basin Interactions program is to understand how physical and biological processes together impact shelf–basin exchange of biological, chemical, and physical properties. High-resolution vertical distributions of plankton and particles were obtained using an Auto Video Plankton Recorder from 29 locations on the Chukchi Shelf, in the deep Beaufort Sea, and across the Beaufort–Chukchi Shelf-break during a cruise on the USCGC Healy in July–August, 2002. Coincident velocity estimates were collected using hull-mounted acoustic Doppler current profilers. Images of plankton and particles were extracted automatically and identified manually to taxa and type. Copepods, diatom chains, decaying diatoms, marine snow, and radiolarians were the most abundant categories observed. Distinct regional differences in abundance were observed that were associated with different oceanographic regimes and with the prevailing circulation in the region. Vertical distributions were closely associated with the physical structure of the water column. A sharp horizontal discontinuity in abundance of all categories between shelf and basin was observed, located over the shelf break and potentially established and maintained by transport of plankton and particles along-shelf to the east rather than northwards towards the basin. Barrow Canyon and the shelf and shelf-break east of Barrow Canyon had very high concentrations of plankton and particles, especially marine snow, that may have resulted from elevated production on the eastern Chukchi Shelf that subsequently was advected out of Barrow Canyon and to the east. Comparisons of downward flux, estimated from particle sinking rates based on individual marine snow particle size, and horizontal velocities suggested that much of the marine snow carbon was sinking to the benthos of the Chukchi Sea prior to being advected off-shelf. Velocities and plankton concentrations together indicated that little off-shelf flux of plankton or particles to the basin was occurring except in an eddy located off of the Beaufort Shelf.  相似文献   

Nonlinear interactions between gravity waves and tides   总被引：1，自引：0，他引：1  

Liu Xiao  Xu JiYao  Ma RuiPing 《中国科学D辑(英文版)》2007,50(8):1273-1279

In this study, we present the nonlinear interactions between gravity waves (GWs) and tides by using the 2D numerical model for the nonlinear propagation of GWs in the compressible atmosphere. During the propagation in the tidal background, GWs become instable in three regions, that is z = 75―85 km, z = 90―110 km and z = 115―130 km. The vertical wavelength firstly varies gradually from the initial 12 km to 27 km. Then the newly generated longer waves are gradually compressed. The longer and shorter waves occur in the regions where GWs propagate in the reverse and the same direction of the hori-zontal mean wind respectively. In addition, GWs can propagate above the main breaking region (90—110 km). During GWs propagation, not only the mean wind is accelerated, but also the amplitude of tide is amplified. Especially, after GWs become instable, this amplified effect to the tidal amplitude is much obvious.  相似文献   

Continuity and change: (re)constructing environmental geographies in late Soviet and post-Soviet Russia     

Jessica K Graybill 《Area》2007,39(1):6-19

Environmental studies conducted worldwide often overlook the knowledge traditions of the locales where they are conducted. Addressing this issue, I investigated the geographic journal literature of late Soviet (1980–1989) and post-Soviet (1990–2003) Russia. Notable trends are increasing criticism of environmental and resource management in Russia and a (re)turn to pre-socialist Russian theorizations of society–nature interactions. Specifically, the noösphere, ethnogenesis and geosystems are trends in the literature that signify how Russian geographers (re)construct environmental knowledge. For non-Russian geographers working in Russia, awareness of these trends situates place-based knowledge relative to multiple cultures (ethnic, scientific) and time periods, promoting cross-cultural understanding of different traditions of geographic inquiry.  相似文献   

The high content of polyunsaturated fatty acids in Nannochloropsis limnetica (Eustigmatophyceae) and its implication for food web interactions, freshwater aquaculture and biotechnology     

Lothar Krienitz  Manfred Wirth 《Limnologica》2006,36(3):204-210

In the eustigmatophycean Nannochloropsis limnetica the content of polyunsaturated fatty acids (PUFA) is extremely high in comparison to different planktonic green algal taxa in freshwater ecosystems. The sums of n-6 and n-3 fatty acids in N. limnetica were ten-fold higher than in the other picoplankton Choricystis minor and Pseudodictyosphaerium jurisii, and higher than in the nanoplanktonic green algae Chlorella vulgaris, Monoraphidium neglectum and Scenedesmus obtusiusculus. The content of fatty acids in N. limnetica was highly variable under different culture conditions. The highest concentrations of PUFA in N. limnetica were found in non-aerated suspension cultures, with a high content of phosphate (40 mg l⁻¹ K₂HPO₄) in the culture medium: linoleic acid 22.19 mg g⁻¹ DW, arachidonic acid 10.52 mg g⁻¹ DW, and eicosapentaenoic acid 55.56 mg g⁻¹ DW. N. limnetica represent a high-quality food resource in freshwater food chains. Furthermore, cultures of this eustigmatophycean alga have a high potential for use in biotechnology and aquaculture.  相似文献   

Processes of tidal channel development in salt and freshwater marshes     

Gerardo M. E. Perillo  Oscar O. Iribarne 《地球表面变化过程与地形》2003,28(13):1473-1482

Mechanisms for the formation of creeks in tidal ?ats are rarely discussed in literature. There are some general theories about their formation but there are no data to support the evidence. It is generally believed that marshes inherit creeks from previous tidal ?ats that their plants colonize and further modify them. The aim of this paper is to present three mutually exclusive cases from marshes in Argentina where creeks are formed by either purely physical or biological–physical interactions. Except for Loyola Bay, this is the ?rst discussion of these mechanisms. They may represent special cases, but the fact that all three of them occur along the coast of Argentina, could indicate that similar cases may be found somewhere else. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

X-ray emission from the galaxies in Abell 2634     

Sakelliou  & Merrifield 《Monthly notices of the Royal Astronomical Society》1998,293(4):489-496

It is difficult to detect X-ray emission associated with galaxies in rich clusters, because the X-ray images of the clusters are dominated by the emission from their hot intracluster media (ICM). Only the nearby Virgo cluster provides us with information about the X-ray properties of galaxies in clusters. Here we report on the analysis of a deep ROSAT HRI image of the moderately rich cluster Abell 2634, by which we have been able to detect the X-ray emission from the galaxies in the cluster. The ICM of Abell 2634 is an order of magnitude denser than that of the Virgo cluster, and so this analysis allows us to explore the X-ray properties of individual galaxies in the richest environment yet explored.
By stacking the X-ray images of the galaxies together, we show that the emission from the galaxies appears to be marginally resolved by the HRI. This extent is smaller than for galaxies in poorer environments, and is comparable to the size of the galaxies in optical light. These facts suggest that the detected X-ray emission originates from the stellar populations of the galaxies, rather than from extended hot interstellar media. Support for this hypothesis comes from placing the optical and X-ray luminosities of these galaxies in the L_B–L_X plane: the galaxies of Abell 2634 lie in the region of this plane where models indicate that all the X-ray emission can be explained by the usual population of X-ray binaries. It is therefore probable that ram pressure stripping has removed the hot gas component from these galaxies.  相似文献