A comparative study of Calanus finmarchicus mortality patterns at five localities in the North Atlantic     

Ohman  M.D; Eiane  K; Durbin  E.G; Runge  J.A; Hirche  H.-J 《ICES Journal of Marine Science》2004,61(4):687-697

  相似文献   

An ocean bottom,microprocessor based seismometer     

Robert D. Moore  Leroy M. Dorman  Chin-Yen Huang  David L. Berliner 《Marine Geophysical Researches》1981,4(4):451-477

We describe the design and construction of an ocean bottom seismometer configured as a computer, based on an Intersil IM6100 microprocessor plus appropriate peripheral devices. The sensors consist of triaxial 1 Hz seismometers and a hydrophone, each sensor channel being filtered prior to digitizing so that typical noise spectra are whitened. Digital data are recorded serially on magnetic tape. The instrument is placed on the ocean bottom by allowing it to fall freely from just below the surface. An acoustic system allows precise determination of instrument position, acoustic recall, and transmission of operational information to the surface. Release from an expendable anchor is accomplished by redundant pyrotechnic bolts which can be fired by acoustic command or by precision timers.The operational flexibility provided by the micro-computer, which executes the DEC PDP8/E instruction set, enables optimum use of the 6-hr recording capacity (at 128 samples/second/channel) in the context of the particular experiment being performed.

---

  相似文献   

Model estimates for the mean gas exchange between the ocean and the atmosphere under the conditions of the present-day climate and its changes expected in the 21st century     

R. S. Bortkovskii  B. N. Egorov  V. M. Kattsov  T. V. Pavlova 《Izvestiya Atmospheric and Oceanic Physics》2007,43(3):378-383

Annual mean fluxes of CO₂ and oxygen across the sea surface are estimated with the use of numerical modeling for several regions located in the Gulf Stream and Kuroshio zones. The present-day climatic conditions and the climatic conditions expected in the middle and at the end of the 21st century are considered. Specific features of gas exchange under a strong wind that are associated with gas exchange by bubbles and with changes in the air-water difference of the gas concentrations were taken into account in the calculations. The estimates obtained differ substantially from the results based on the traditional approach, which disregards the above features. A considerable increase in the absorption of CO₂ by the ocean, which is mainly caused by the continuing increase in the CO₂ concentration in the air during its small changes in the ocean, is expected in the 21st century. At the same time, no trends are revealed in the annual mean fluxes of oxygen across the ocean surface. The conclusion is made that, in calculations of CO₂ absorption by the world ocean, it is necessary to take into account both specific features of gas transfer under a strong wind and an increase in the atmospheric concentration of CO₂.  相似文献   

Basement structure and sedimentary cover seismostratigraphy in the northern part of the Japan Basin in the region of the Tarasov Rise (Sea of Japan)     

V. N. Karnaukh  B. Ya. Karp  I. B. Tsoy 《Oceanology》2007,47(5):691-704

The results of continuous seismic profiling thermodynamics performed in the northern part of the Japan Basin in the region of the Tarasov Rise and the data of a micropaleontological examination of the diatom remains encountered in the sediment samples from the rise and continental slope are presented. In the area studied, the topography of the acoustic basement features a vast rise (plateau) buried under the sedimentary cover outlined by the depth contour 5.8 s. The plateau has a relatively smooth top surface crossed by a series of rises of the acoustic basement. The two largest rises are represented by the ridges of the Tarasov Rise. The plateau is separated from the continental slope by a depression in the acoustic basement with a depth up to 6.8 s. From the end of the Middle Miocene up to the beginning of the Paleocene, the region of the plateau represented an area of active volcanism; it coincided in time with the stage of subsidence of the floor of the acoustic basement depression. At the end of the Late Miocene, the ridges of the Tarasov Rise started to sink. In the Pliocene, this process accelerated, and, at the beginning of the Pleistocene, it stopped. In the Middle Miocene-Early Pleistocene time, the portion of the continental slope adjacent to the plateau remained stable and suffered no significant vertical movements.  相似文献   

Major variability modes and wind patterns over the Sea of Japan and adjacent areas   总被引：1，自引：0，他引：1  

O. O. Trusenkova  S. V. Stanichnyi  Yu. B. Ratner 《Izvestiya Atmospheric and Oceanic Physics》2007,43(5):634-648

The expansion of wind fields observed at fixed times (four times daily) in complex empirical orthogonal functions is performed for the Japan Sea area (34°–53° N, 127°–143° E). The wind fields are taken from the 1998–2004 NCEP/NCAR Reanalysis data with better spatial resolution (1° × 1°) than the standard product, which are publicly available on the Internet. Major modes of wind variability in the Japan Sea area are identified. The modes determine a general direction of air-mass transport throughout a year, zonal and meridional modulation, and a cyclonic and an anticyclonic eddy component. Objective classification of wind fields with respect to the prevailing flow direction is performed, and wind stress and wind-curl patterns are obtained for major events in the cold and warm periods of the year. The pattern obtained can be used in hydrodynamic numerical models of the general circulation of the Japan Sea.  相似文献   

Verification of first annulus formation in the illicia and otoliths of white anglerfish, Lophius piscatorius using otolith microstructure     

Wright  P. J.; Woodroffe  D. A.; Gibb  F. M.; Gordon  J. D. M. 《ICES Journal of Marine Science》2002,59(3):587-593

  相似文献   

Species, tissue and gender-related organochlorine bioaccumulation in white-sided dolphins, pilot whales and their common prey in the northwest Atlantic   总被引：5，自引：0，他引：5  

Weisbrod AV  Shea D  Moore MJ  Stegeman JJ 《Marine environmental research》2001,51(1):29-50

Organochlorine concentrations were measured in white-sided dolphins, pilot whales, and their prey from the Gulf of Maine and used to identify species, tissue, and gender differences, and trophic transfer trends, in bioaccumulation. Polychlorinated biphenyl concentrations ([PCB]) in dolphin blubber (13 +/- 7.1 micrograms/g fresh wt.) were twice those in pilot whales, but pesticide concentrations (20 +/- 13 micrograms/g fresh) were similar between species. 4,4'-DDE, trans-non-achlor, Cl6(153) and Cl6(138) concentrations were highest. Skin tissues had more recalcitrant organochlorines than the internal organs. Male dolphins bioaccumulated higher concentrations of nonmetabolizable PCBs and hexachlorocyclohexane (HCH) isomers, whereas pilot whales had no gender-related differences in bioaccumulation. Pilot whales, mackerel, and herring had proportionately higher concentrations of DDTs, whereas [PCB] were higher in dolphins and squid. Although these odontocetes feed at the same trophic level and store a similar suite of contaminants, dolphins bioaccumulated higher and potentially hazardous 4,4'-DDE and PCB concentrations from food in their more geographically restricted range.  相似文献   

Relationships between benthic macrofauna and habitat suitability for juvenile common sole (Solea solea, L.) in the Vilaine estuary (Bay of Biscay, France) nursery ground     

D. Nicolas  F. Le Loc'h  Y. Dsaunay  D. Hamon  A. Blanchet  O. Le Pape 《Estuarine, Coastal and Shelf Science》2007,73(3-4):639-650

  相似文献   

Water vapor in the atmosphere over the northern Tien Shan     

V. N. Aref’ev  F. V. Kashin  V. K. Semenov  R. M. Akimenko  N. E. Kamenogradskii  N. I. Sizov  V. P. Sinyakov  L. B. Upenek  V. P. Ustinov 《Izvestiya Atmospheric and Oceanic Physics》2006,42(6):739-751

Refined data of systematic measurements of total water vapor in the atmosphere from May 1980 to April 2005 are presented. The data were obtained at the Issyk Kul atmospheric-monitoring station by the method of solar molecular-absorption spectroscopy. Over 25 years, the annual mean water-vapor content in the atmosphere increased by 4.5% at a mean rate of increase of 0.18% per year. However, the water-vapor content decreased in the last five years. The results of statistical processing of experimental data (general statistical characteristics, correlation coefficients, composite oscillations) are described. A refined model is proposed for forecasts of temporal variations in the monthly mean and annual mean water-vapor contents for the coming years. The model includes a linear trend and the sum of oscillations with periods close to the periods of a number of well-known geophysical phenomena. Regression equations are proposed to relate the water-vapor content in the atmospheric column to the surface temperature and absolute humidity.  相似文献   

Sources and biogeochemical cycling of particulate selenium in the San Francisco Bay estuary     

Martina A. Doblin  Stephen B. Baines  Lynda S. Cutter  Gregory A. Cutter 《Estuarine, Coastal and Shelf Science》2006,67(4):681-694

As part of a study of estuarine selenium cycling, we measured the concentration, chemical form (speciation), and distribution of particulate selenium under various river flow conditions in the North San Francisco Bay (from the Golden Gate to the Sacramento and San Joaquin Rivers). We also conducted laboratory studies on the accumulation of selenium by phytoplankton, the critical first step in the transformation of dissolved to particulate selenium. Total particulate selenium concentration in the North SF Bay was relatively constant between high and low flow periods, ranging spatially from 0.05 to 0.35 nmol l⁻¹ and comprising between 5 and 12% of the total water column selenium inventory. Mean concentrations were generally highest in the Carquinez Strait–Suisun Bay region (salinity 0–17) and lowest in Central Bay. However, selenium content of suspended particles varied with river flow, with higher content during low flow (9.76 ± 4.17 nmol g⁻¹; mean ± sd; n = 67) compared to high flow (7.10 ± 4.24 nmol g⁻¹; n = 39). Speciation analyses showed that most particulate selenium is organic selenide (45 ± 27%), with a smaller proportion (typically <30%) of adsorbed selenite + selenate and a varying proportion (35 ± 28%) of elemental selenium. Based on the amount of elemental selenium in the seston (total suspended material), we calculate that resuspension of estuarine sediments could contribute 29–100% of particulate selenium in the water column. While selenium content of SF Bay seston (>0.4 μm) is relatively unenriched compared to phytoplankton (13.6–155 nmol g⁻¹ dry weight) on a mass basis, when normalized to carbon or nitrogen, seston contains a similar selenium concentration to SF Bay sediments or phytoplankton cultures. SF Bay seston is thus comprised of selenium-rich phytoplankton and phyto-detritus, but also inorganic clay mineral particles that effectively “dilute” total particulate selenium. Selenium concentrations in algal cultures (11 species) exposed to 90 nmol l⁻¹ selenite show relatively large differences in selenium accumulation, with the diatoms, chlorophytes and cryptophytes generally having lower selenium cell content (3.8 ± 2.7 × 10⁻⁹ nmol selenium cell⁻¹) compared to the dinoflagellates (193 ± 73 × 10⁻⁹ nmol selenium cell⁻¹). Because phytoplankton are such a rich (but variable) source of selenium, their dynamics could have a profound effect on the particulate selenium inventory in the North SF Bay.  相似文献