Metabolism and chemical composition of mesopelagic ostracods in the western North Pacific Ocean     

Kaeriyama  Hideki; Ikeda  Tsutomu 《ICES Journal of Marine Science》2004,61(4):535-541

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Seasonal Changes in Nano/Micro-Zooplankton Herbivory and Heterotrophic Nano-Flagellates Bacterivory off Cape Esan, Southwestern Hokkaido, Japan     

Akiyoshi Shinada  Syuhei Ban  Tsutomu Ikeda 《Journal of Oceanography》2003,59(5):609-618

Seasonal changes in nano/micro-zooplankton grazing on pico-, nano- and micro-size phytoplankton and heterotrophic nano-flagellates (HNF) feeding on heterotrophic bacteria were quantified by the dilution technique in the surface layer off Cape Esan, southwestern Hokkaido, Japan. Pico- and nano-size phytoplankton were major components throughout the year except in spring when a diatom bloom was observed. Although there was little seasonal variation in bacteria and HNF biomass throughout the year, the micro-zooplankton biomass varied appreciably with a peak in spring. Nano/micro-zooplankton grazing or feeding on pico-size chl-a and bacteria were well balanced throughout the year. However, nano-size and micro-size chl-a growth were much greater than grazing in summer. Nano/micro-zooplankton ingestion of phytoplankton was greater than their ingestion of bacteria almost throughout the year, which suggests phytoplankton are more important as food sources of nano/micro-zooplankton in microbial food webs off Cape Esan than bacteria off Cape Esan. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The Optical Characteristics of the Water in the Three Oceans Part—IV     

Kanau Matsuike  Tsutomu Morinaga  Tadayoshi Sasaki 《Journal of Oceanography》1970,26(1):52-60

An attempt to the approximate figures of seasonal distribution of solar energy reached to and penetrated in the water of the oceans, as a preliminary step to the estimation of primary production in the oceans from the optical point, was performed in the Indian Ocean, North Pacific Ocean and Antarctic Ocean on the same lines in the part III. In consequence, the total amount of solar energy for the year in each depth showed marked differences in each zone of the oceans as illustrated in Fig. 5. By way of example, it could be said that underwater solar energy already came to 33.4 Kg·cal/cm²·year in 10 m deep in the equator of Indian Ocean and was 54% of that, in the Kuroshio region of the North Pacific Ocean, 44% in the Sub-Antarctic zone, 13% in the Antarctic zone and 6% in the Antarctic Convergence zone, respectively. Besides, on the assumption that a lower limit of the photic zone is marked by the depth here underwater surface solar energy is reduced to 1% or 5g·cal/cm²·day, the ratio of the total photic zone for the year in unit area of sea surface was approximately 100∶80∶60∶25 or 100∶75∶50∶20 in the equator of the Indian Ocean, Kuroshio region, Sub-Antarctic zone, and Antarctic and Antarctic Convergence zones, respectively.  相似文献   

Estimated respiration rate of myctophid fish from the enzyme activity of the electron-transport-system     

Tsutomu Ikeda 《Journal of Oceanography》1989,45(3):167-173

Whole animal respiration rates (R) of myctophid fishes which migrate up to the surface at night were estimated using enzyme activities of the electron-transport-system (ETS). The fish, currently unsusceptible to laboratory experimentation, were caught at sea and stored frozen at –20°C for 14–17 days prior to enzyme assay. Supplemental tests on two tropical marine fishes (gobies and poma-centrids) showed no measurable loss of ETS activity during storage for up to 36 d at –20°C. The ETS/R ratio for gobies and pomacentrids was 1.61. Respiration rates of myctophid fishes estimated using this ETS/R ratio ranged from 17.7 to 453µl O₂ individual^–1 hr^–1 for specimens weighing 26–1101 mg wet weight atin situ temperature of 24–27°C. The relationship between the respiration rate standardized to a temperature of 20°C (R:µl O₂ individual^–1hr^–1) and wet weight (WW: mg) of myctophid fishes was expressed asR=0.790 WW^0.84 (r=0.964,n=27). This relationship does not differ appreciably from the respiration rates of other marine fishes calculated from Winberg's equation.  相似文献   

Algal Growth Potential and the limiting nutrient in Mikawa Bay     

Masao Kondo  Tsutomu Sakai  Hajime Yamamoto  Yukio Arakawa 《Journal of Oceanography》1984,40(5):391-396

The Algal Growth Potential (AGP) of water samples collected off Gamagori in Mikawa Bay was measured from May 1978 through February 1979, and the limiting nutrient was determined using regression analysis and enrichment bioassays. The surface and bottom water samples had AGP that produced increments of chemical oxygen demand (COD) of 2.1 mg l^–1 and 3.1 mg l^–1, respectively, on average. These values ofCOD correspond to 46% and 97% of the average COD values of the raw water samples at the surface and bottom, respectively. Seasonal changes of AGP showed a close correlation with those of dissolved inorganic nitrogen (DIN) concentration. Enrichment bioassays showed that DIN was the most deficient nutrient. The DIN:phosphate-phosphorus (PO₄ ^3–-P) ratios and DIN: dissolved phosphorus (DP) ratios in the water samples were below the cellular N:P ratios of the natural algal populations. These results suggest that AGP was mainly limited by DIN concentration.  相似文献   

Evaluation of the internal radiation field in a composite planetary atmosphere with the lambert surface calculated by matrix method     

Tsutomu Takashima 《Astrophysics and Space Science》1974,30(2):309-313

If the atmosphere is simulated by a number of homogeneous sublayers, it was shown (Takashima, 1973a) that the intensity and polarization parameters emerging from any boundary of internal sublayer's field can be determined, provided that the diffuse reflection and transmission matrices of radiation of sublayers are known. Furthermore, if the surface (ground) is assumed to reflect light in accordance with the Lambert law, it is shown in this paper that the internal radiation field at boundary of any sublayer can be also computed in terms of the diffuse radiation matrices of sublayers rather than in terms of that of the entire atmosphere (Sekera, unpublished). The effect of polarization is included.  相似文献   

Coupling modes of hydromagnetic oscillations in non-uniform, finite pressure plasmas: Two-fluids model     

Tsutomu Tamao 《Planetary and Space Science》1978,26(12):1141-1148

Within a framework of the two-fluids approximation, basic modes constituting hydromagnetic coupling oscillations in non-uniform, finite-β plasmas are examined. It is shown that the oscillations consist of a coupling between a localized mode and a propagating one, and a strong peak appears at a resonance point. In the case of isothermal plasma (T_e = T_i), there are two localized modes, the Alfvén (or drift Alfvén) and the ion drift modes, and a propagating mode being known as the fast magnetosonic wave. Coupling oscillations associated with the Alfvén mode exhibit a nearly incompressible character, whereas those with the ion drift mode are compressional and diamagnetic. Furthermore, the slow magnetosonic wave also couples with the localized mode in the case of T_e > T_i. Based on characteristics of these oscillations, the origin of geomagnetic pulsations is discussed in connection with the distribution of plasma parameters in the outer magnetosphere.  相似文献   

Comparison between natural fractures and fracture parameters derived from VSP     

Yasuto Kuwahara  Hisao Ito  Tsutomu Kiguchi 《Geophysical Journal International》1991,107(3):475-483

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Thermal properties of the solar wind plasma     

Tsutomu Toichi 《Solar physics》1971,18(1):150-164

In the solar wind, electrostatic ion cyclotron waves can be excited by electrons when the flow velocity becomes supersonic. The waves reduce the proton temperature anisotropy and heat the protons effectively. Temperature equations for T _e ,T _p and T _p are solved numerically in the region from 1 AU to the Sun, with the non-thermal proton heating rate included as a parameter. Distributions of T _e ,T _p , T _p and the proton heating rate are determined and found to be in good agreement with the proton heating rate expected from the linear growth rate of electrostatic ion cyclotron waves. The electron thermal conductivity is reduced approximately 2–3 times smaller than the usual collisional one due to the plasma wave instabilities. Effective energy exchange rates from proton-proton and electron-proton interactions are 1–10 and 10–100 times larger than the Coulomb collision rates v ppand v ep,respectively.  相似文献   

Infrared spectral energy distribution model for extremely young galaxies     

Tsutomu T. Takeuchi †  Hiroyuki Hirashita ‡  Takako T. Ishii  Leslie K. Hunt  Andrea Ferrara 《Monthly notices of the Royal Astronomical Society》2003,343(3):839-850

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