Three-dimensional properties of interplanetary disturbances in 1978–1981     

Takashi Watanabe  Takakiyo Kakinuma 《Astrophysics and Space Science》1986,118(1-2):153-157

This paper presents the average three-dimensional configuration of solar flare- or disappearing filament-associated interplanetary disturbances on the basis of IPS (interplanetary scintillation) and spacecraft observations in 1978–1981. The angular distribution of the propagation speed at 1 AU is largely isotropic over the range of 110° in solar longitude centered at the normal of the solar source. In the latitudinal direction, the characteristic angular extent is about 60°. Thus the three-dimensional shape of an interplanetary disturbance can be approximated by a half of an ellipsoid having an axial ratio of about 1.8.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.  相似文献   

Adsorption—desorption control of phosphate in anoxic sediment of a coastal sea,Funka Bay,Japan     

Y. Watanabe  S. Tsunogai 《Marine Chemistry》1984,15(1):71-83

Sediment core samples were taken once a month from July 1980 to September 1981 at a station in Funka Bay (92-m depth) for the determination of phosphate, silicate and alkalinity in interstitial water. A remarkable seasonal variation was found for interstitial phosphate, that is, distinct maxima appeared in spring (March—April), just after a phytoplankton bloom which brought a large amount of settling particles to the bottom, and in summer (July—August) when the water was stratified and the dissolved oxygen content of the bottom water decreased due to the decomposition of organic matter. The high interstitial phosphate concentration was always accompanied by a sharp increase in alkalinity, indicating sulfate reduction. This large seasonal variation in interstitial phosphate cannot be explained by in situ decomposition of organic matter and/or the diffusive loss of interstitial phosphate. A more likely explanation is adsorption and desorption of interstitial phosphate coincident with the depth of the active sulfate reduction layer.  相似文献   

Effects of neutral wind on the electron temperature at a height of 600 km in the low latitude region     

S. Watanabe  K.-I. Oyama 《Annales Geophysicae》1996,14(3):290-296

Electron temperature observed by the Hinotori satellite with the low inclination at the height of \sim600 km was studied in terms of local time, season, latitude, magnetic declination and solar flux intensity during a 16-month period from 1981 to 1982. The electron temperatures show steep rise in the early morning (well known as morning overshoot), decrease after that and again increase at \sim18 hours (hereafter named as evening overshoot). Generally the morning overshoot becomes more enhanced in the winter hemisphere and for higher solar fluxes. The evening overshoot becomes more pronounced in the mid-latitude in all seasons and more enhanced in the winter hemisphere in the same way as the morning overshoot. A difference is seen between 210°-285° and 285°-360° longitudes where magnetic declination is different. The longitudinal dependence of electron temperature indicates that the neutral wind also contributes to the thermal structure in the low latitude ionosphere.  相似文献   

Comparative Measurements Of Co2flux Over A Forest Using Closed-Path And Open-Path Co2analysers     

Yukio Yasuda  Tsutomu Watanabe 《Boundary-Layer Meteorology》2001,100(2):191-208

An eddy covariance system using a closed-path CO₂analyser was constructed for long-term CO₂flux measurements above a forest, and its total frequency response was valuated experimentally. The amplitude and phase responses of the system wereexamined through a preliminary test, in which a prescribed pattern of CO₂fluctuation was input to the system. The result showed that the amplitude of the output from the system was attenuated as frequency increased, with a half-power frequency of 0.3 Hz. The phase was delayed by the air sampling through a long tube, but the delay in phase decreased asfrequency increased. We then presented a new technique for the correction of flux loss due to the inadequate system response for the eddy covariance measurements of CO₂ flux. Using the present system and the correction technique, diurnal variations in CO₂ flux were measured over a temperate deciduous forest on three days in 1997. The results were compared with the CO₂fluxes measured with a fast response open-path gas analyser. The CO₂fluxes from the closed-path system agreed with those from the open-path system after the Webb, Pearman and Leuning correction was made for the latter. In the present test over a forest, the contribution of the frequency-response correction to the CO₂fluxes was small and its averaged percentage was only 3%in the daytime. However, the percentage would likely increase, if the system were applied to a shorter vegetation site where high frequency components are more important. The comparison confirmed that we can obtain correct measurements of CO₂flux using the present closed-path system and the correction technique.  相似文献   

Influence of the greenhouse effect on yields of wheat,soybean and corn in the United States for different energy scenarios     

K. Okamoto  T. Ogiwara  T. Yoshizumi  Y. Watanabe 《Climatic change》1991,18(4):397-424

The increase of atmospheric carbon dioxide has positive effects on agricultural productivity (photosynthesis stimulation), but in some regions it has negative effects (drought due to the temperature rise) as well. The central part of the United States in summer is predicted to be one of such regions, where the influence of the CO₂ increase should be assessed considering both the effects. Such calculations have been made for spring wheat, soybean and corn in a series of papers, a summary of which is presented here. Since the CO₂ emission rate depends on fossil fuel consumption, energy scenarios with different fossil fuel consumption are assumed. Positive effects of CO₂ are expressed by a model which simulates actual data. In the absence of an appropriate model negative effects are assumed to be proportional to the temperature rise, which is shown to be unexpectedly good. The difference between C3 (soybean and wheat) and C4 (corn) plants is also considered. Changes of their yields in the next century are calculated. Results show that in this region (probably up to 42–45° N) in summer an unlimited increase of atmospheric CO₂ is not desirable for the above three crops even if positive effects of CO₂ are taken into account. This work is not intended to give prediction of future crop production, but to show illustrative examples for the above argument. Thus assumptions are made so as to overestimate positive effects and underestimate negative effects, but results show that even in such cases an unlimited increase of CO₂ is not necessarily desirable for the specified regions.All inquiries about this paper should be made to K. Okamoto.  相似文献   

Studies on the application of cyanophyta in Japan     

Prof.Dr. Atsushi Watanabe 《Aquatic Sciences - Research Across Boundaries》1970,32(2):566-569

Summary The paper gives a survey of the blue-green algae found in Japan and used as food, medicine and nitrogenous fertilizer. Since time immemorial four kinds (Aphanothece sacrum, Nostoc verrucosum, Nostoc commune, Blachytrichia quoyi) have been used for cooking purposes; yet it is only now that man is trying to cultivate a species, theAphanothece sacrum. Recently a bluegreen alga (Spirulina maxima), which is particularly rich in protein and vitamins and has always been eaten by the natives, became known in Africa. The medicinal effects of linolenic acid was examined connection with the circulation of fatty acid. Only two of the species analysed (Spirulina platensis, Arthrospira sp.) produce relatively large quantities of γ-linolenic acid. The effects of the nitrogen-producing blue-green algaTolypothrix tenuis were observed in over 40 rice fields in various regions in Japan. In some places a considerable increase in the yield was noticed, but this was never as high as in India. Presumably the difference can be traced back to 3 main factors: air temperature, alkalinity of the water and the amount of nitrogen fertilizer.

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Zusammenfassung Das Referat gibt eine übersicht über essbare, medizinisch wirksame und stickstoffdüngende Blaualgen speziell aus Japan. Vier Arten (Aphanothece sacrum, Nostoc verrucosum, Nostoc commune, Blachytrichia quoyi) werden seit alter Zeit als Zugabe zu den Mahlzeiten gebraucht, wobei man erst heute eine Art (Aphanothece sacrum) zu kultivieren versucht. Kürzlich wurde in Afrika eine Blaualge (Spirulina maxima), bekannt, die einen besonders hohen Gehalt an Eiweiss und Vitaminen aufweist und seit jeher von den Eingeborenen gegessen wird. Im Zusammenhang mit dem Kreislauf der Fetts?uren wurde die medizinische Wirkung der Linols?ure geprüft. Nur zwei der analysierten Arten (Spirulina platensis, Arthrospira sp.) bilden relativ grosse Mengen Linols?ure. In gut 40 Reisfeldern verschiedener Regionen in Japan wurde die Wirkung der stickstoff-bindenden BlaualgeTolypothrix tenuis beobachtet. Es konnten zum Teil betr?chtliche Steigerungen erzielt werden, doch nie so hohe wie in Indien. Vermutlich sind die Unterschiede haupts?chlich auf drei Faktoren: Lufttemperatur, Alkalinit?t des Wassers und Menge an Stickstoffdünger zurückzuführen.

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LES Study of the Energy Imbalance Problem with Eddy Covariance Fluxes   总被引：3，自引：1，他引：3  

Manabu Kanda  Atsushi Inagaki  Marcus Oliver Letzel  Siegfried Raasch  Tsutomu Watanabe 《Boundary-Layer Meteorology》2004,110(3):381-404

The spatial representativeness of heat fluxes on the basis of single-tower measurements, and the mechanism of the so-called energy imbalance problem, are investigated through numerical experiments using large-eddy simulation (LES). LES experiments are done for the daytime atmospheric boundary layer heated over a flat surface, as a best-case scenario completely free of sensor errors and the uncertainties of field conditions. Imbalance is defined as the deviation of the `turbulent' heat flux at a grid point from the horizontally averaged `total' heat flux. Both the theoretical and numerical results of the present study suggest the limitation of single-tower measurements and the necessity of horizontally-distributed observation networks.The temporally averaged `turbulent' flux based on a point measurement systematically underestimates the `total' flux (negative imbalance). This is attributed to local advection effects caused by the existence of turbulent organized structures (TOS), whose time scale is much longer than that of thermal plumes. The temporal and spatial change of TOS patterns causes low-frequency trends in the velocity and temperature data resulting in large scatter of the flux estimates. The influences of geostrophic wind speed, averaging time, observation height, computational domain size and resolution on tower-measured fluxes are also discussed. Finally, it is suggested that a weak inhomogenity in surface heating may reduce the negative bias of flux estimates.  相似文献   

Timing of the Mineralization and Volcanism at Cibaliung Gold Deposit, Western Java, Indonesia     

Agung Harijoko    Kenzo Sanematsu    Robert A. Duncan  Sukmandaru Prihatmoko  Koichiro Watanabe 《Resource Geology》2004,54(2):187-195

Abstract. The Cibaliung deposit is a low-sulfidation type epithermal gold deposit situated about 70 km west of the Bayah dome complex. The gold-bearing quartz veins are hosted by basaltic andesite of the Honje Formation, which is comparable to the host rock of gold deposits at the Bayah dome complex.
In order to clarify the timing of the mineralization and the volcanism at the Cibaliung area, two radiometric dating methods were applied. First, ⁴⁰Ar/³⁹Ar dating was conducted on six adularia samples to elucidate the age of mineralization. Second, K-Ar method was applied to two samples of the host rock, andesite and the Cibaliung tuff, in order to reveal the timing of volcanism.
The ⁴⁰Ar/³⁹Ar dating determined mineralization ages in the range from 11.18 to 10.65 Ma while the K-Ar dating indicated the age of the andesite and the Cibaliung tuff to be 11.4±0.8 Ma and 4.9±0.6 Ma, respectively. These results imply that the epithermal gold mineralization in the Cibaliung area is related to the volcanic activity that produced the Honje Formation, while the Cibaliung tuff played an important role in the preservation of the Cibaliung deposit. The Cibaliung deposit is the oldest epithermal gold deposit yet discovered in western Java.  相似文献   

Late Paleozoic faults of the Altai region, Central Asia: tectonic pattern and model of formation   总被引：4，自引：0，他引：4  

M. M. Buslov  T. Watanabe  Y. Fujiwara  K. Iwata  L. V. Smirnova  I. Yu Safonova  N. N. Semakov  A. P. Kiryanova 《Journal of Asian Earth Sciences》2004,23(5):655-671

The present kinematic and dynamic analysis of large-scale strike-slip faults, which enabled the formation of a collage of Altai terranes as a result of two collisional events. The Late Devonian–Early Carboniferous collision of the Gondwana-derived Altai-Mongolian terrane and the Siberian continent resulted in the formation of the Charysh–Terekta system of dextral strike-slip faults and later the Kurai and Kuznetsk–Teletsk–Bashkauss sinistral strike-slip faults. The Late Carboniferous–Permian collision of the Siberian and Kazakhstan continents resulted in the formation of the Chara, Irtysh and North-East sinistral strike-slip zones. The age of deformation of both collisional events becomes younger toward the inner areas of the Siberian continent. In the same direction the amount of displacement of strike-slip faulting decreases from several thousand to several hundred kilometers. The width of the Late Paleozoic zone of deformation reaches 1500 km. These events deformed the accretion-collision continental margins and their primary paleogeographic pattern.  相似文献   

A Study on the Formation of Smectite in Silica Scales Precipitated from Geothermal Water: The Effect of Magnesium     

Yoshinobu Aramaki    Takushi Yokoyama  Yoshihiro Okaue  Akira Imai  Koichiro Watanabe 《Resource Geology》2005,55(3):281-284

Abstract. Silica scales containing large amounts of smectite were recently found in the pipelines for geothermal water at a geothermal power plant. To elucidate the mechanism of smectite formation, seven silica scale samples were characterized by powder X-ray diffraction, chemical analysis and ²⁷A1 MAS NMR. Smectite was present in samples with MgO levels above 10 wt% and Al₂O₃ levels below 10 wt%. In ²⁷A1 MAS NMR spectra, peaks assigned to both tetrahedrally and octahedrally coordinated aluminum (Al(4) and Al(6)) were observed for Mg-rich samples, whereas a peak due to Al(4) alone appeared in Mg-poor samples. From these observation and comparison between ²⁷A1 MAS NMR spectra for synthesized precipitates of Al₂O₃-SiO₂ containing MgO and not containing MgO, it is concluded that magnesium plays an important role in the stabilization of Al(6), and results in the formation of smectite  相似文献