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281.
To find out the secular and seasonal trends of the 13C value and CO2 concentration in the surface air and the determination of the 13C in the atmospheric CO2 collected at Tsukuba Science City was carried out during the period from July 1981 to October 1983. The monthly average of the 13C value of CO2 in the surface air collected at 1400 LMT ranged from -7.52 to \s-8.45 with an average of -7.96±0.25 and the CO2 concentration in the air varied from 334.5 l 1-1 to 359 l 1-1 with an average of 347.2±6.3 l 1-1. The 13C value is high in summer and low in winter and is negatively correlated with the CO2 concentration. In general, the relationship between the 13C and the CO2 concentration is explainable by a simple mixing model of two different constant carbon isotopic species but the relationship does not always follow the model. The correlation between the 13C value and the CO2 concentration is low during the plant growth season and high at other times. The observed negative deviation of the 13C value from the simple mixing model in the plant growth season is partly due to the isotopic fractionation process which takes place in the land biota. 相似文献
282.
Anomalous sea level, anomalous observed dynamic height (0/400 db) and anomalous model dynamic height are examined at the locations
of 13 island sea level stations in the tropical Pacific for each bimonth of the four year period 1979 to 1982. Starting in
1981, the anomalous dynamic height data show off-equatorial Rossby waves propagated toward the W boundary of the Pacific basin.
At the W boundary, the model Rossby wave activity was found to have excited coastally trapped Kelvin-Munk waves which transmitted
the anomalous dynamic height equatorward. At the equator, coastally trapped wave activity excited eastward propagating equatorial
Kelvin waves, yielding a pair of anomalous peaks in dynamic height variability in the E equatorial Pacific associated with
the 1982–1983 ENSO event. The evolution of the peaks in dynamic height associated with the Rossby and Kelvin wave activity
reflects the redistribution of observed upper-ocean heat content in the W tropical Pacific, providing a qualitative hindcast
for the 1982–1983 ENSO event.
In consequence of these results, and the results of a related study (Inoue et al. 1985), the redistribution of both observed
and model heat content, as evidenced in dynamic height in the W Pacific during the 23-year period 1964–1985, is examined for
its ability to hindcast and forecast ENSO events in this period. Complex EOF analysis is applied to the Onset Phase of ENSO
events occurring in 1968–69, 1972–73, 1976–77, and 1982–83; it is used to determine the characteristic redistribution of heat
content (dynamic height) prior to the Mature Phase of ENSO events. This analysis found both model and observed dynamic height
in the N hemisphere to be characterized by wind-driven, westward propagating, baroclinic Rossby wave activity, having a remarkably
stable period of 3 years over the 23-year period. The complex time series associated with these first spatial eigen-functions
are used to construct observed and model hindcast indices that yield high values one year prior to the Mature Phase of ENSO
events of the period. These indices achieve these values due to the incidence upon the Philippine coast in fall/winter of
a positive anomaly in dynamic height propagating from the east at nondispersive Rossby long wave speeds. 相似文献
283.
Hidetaka Takeoka Yoshio Tanaka Yuichi Ohno Yukiharu Hisaki Akitsugu Nadai Hiroshi Kuroiwa 《Journal of Oceanography》1995,51(6):699-711
Observations of sea surface currents by HF radar were carried out in the Bungo Channel in summer 1992. The current ellipses of M2 constituent obtained by the observational results agree quite well with those obtained by the ADCP observations, showing that the accuracy of the HF radar measurements is of the same level as ADCP. The results revealed the current structures and their change with the Kyucho in detail. The Kyucho is influenced by the complicated coastal geometry and does not propagate straightly into the Bungo Channel. It propagates further inward after charging the coastal bays with warm water. The current directions change largely, since the currents turn around the stagnant region in the bay filled with the warm water. The northward intrusion begins to be weakened in the southern part of the channel, while it still persists in the northern part. The northward current speeds of the observed Kyucho are about 50 cm/s and sometimes attain 60 to 70 cm/s. 相似文献
284.
285.
286.
Distributions and taxonomy of phyllosoma larvae were examined in Taiwanese waters, based on ichthyoplankton samples collected
from May 1990 to July 1995. Phyllosoma larvae belonged to the two families Scyllaridae and Palinuridae representing 6 genera
and 13 species. Of the collected phyllosoma larvae, those of Scyllarus and Panulirus species were most abundant, forming 90% of total numbers. Early stage Scyllarus and Panulirus phyllosoma larvae were abundant in Taiwanese waters. Middle to late stages (except the final stage) of Panulirus phyllosoma larvae were absent from the waters throughout the year, while those of Scyllarus phyllosoma larvae were collected in the waters. This suggests that all stages of Scyllarus phyllosoma larvae may be retained in the northern part of the waters around northern Taiwan while middle to late stages of
Panulirus phyllosoma larvae may be flushed out from the waters, the sub-final and final stages then possibly returning to the waters.
An anticlockwise eddy existed in the waters off northeastern Taiwan, which may be closely related to flushing out and returning
of Panulirus phyllosoma larvae through a much longer planktonic period.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
287.
Akihiko Ito Koki Ouchi Isamu Hisa Susumu Seki Yoshio Seto Shoji Kurashina 《Journal of Oceanography》1984,40(2):98-104
In the consideration of safety it is required that packages containing radioactive wastes when dumped at sea should keep their
integrity and retain their contents until they reach the seabed. Packages containing simulated radioactive wastes (non-radioactive)
were tested by a free-fall method at depthsca. 4,300 m in an area for dumping industrial waste off Shikoku Island. Since the weight of the largest package was 4,300 kg,
special attention was paid to the connection of a buoyancy system with mooring rope. Descent and ascent velocities of the
free-fall system were calculated prior to the experiment. A free-fall experiment with an extremely heavy object, heavier than
ever previously reported, was accomplished without trouble by using the free-fall system. Recovery of a camera, flash-light,
and other components was successful in each of the three experiments. Successive photographing of the package during descent
was made and its integrity was observed using the photographs taken by the recovered camera. The packages remained intact
during descent and at least for a short time after arrival on the seabed. 相似文献
288.
Haruka Ozawa Kei Hirose Masanori Mitome Yoshio Bando Nagayoshi Sata Yasuo Ohishi 《Physics and Chemistry of Minerals》2009,36(6):355-363
Partitioning of oxygen and silicon between molten iron and (Mg,Fe)SiO3 perovskite was investigated by a combination of laser-heated diamond-anvil cell (LHDAC) and analytical transmission electron
microscope (TEM) to 146 GPa and 3,500 K. The chemical compositions of co-existing quenched molten iron and perovskite were
determined quantitatively with energy-dispersive X-ray spectrometry (EDS) and electron energy loss spectroscopy (EELS). The
results demonstrate that the quenched liquid iron in contact with perovskite contained substantial amounts of oxygen and silicon
at such high pressure and temperature (P–T). The chemical equilibrium between perovskite, ferropericlase, and molten iron at the P–T conditions of the core–mantle boundary (CMB) was calculated in Mg–Fe–Si–O system from these experimental results and previous
data on partitioning of oxygen between molten iron and ferropericlase. We found that molten iron should include oxygen and
silicon more than required to account for the core density deficit (<10%) when co-existing with both perovskite and ferropericlase
at the CMB. This suggests that the very bottom of the mantle may consist of either one of perovskite or ferropericlase. Alternatively,
it is also possible that the bulk outer core liquid is not in direct contact with the mantle. Seismological observations of
a small P-wave velocity reduction in the topmost core suggest the presence of chemically-distinct buoyant liquid layer. Such
layer physically separates the mantle from the bulk outer core liquid, hindering the chemical reaction between them. 相似文献
289.
A series of experiments was conducted on the decomposition of natural and chemically mixed chlorites to examine the stable hydrous phases in the MgO–FeO–Al2O3–SiO2–H2O (MFASH) system under 5–12 GPa and 700–1100 °C. The upper pressure and temperature limits of the stability region of chlorite are consistent with those observed in previous studies. The hydrous aluminum bearing pyroxene (phase HAPY) and Mg-sursassite (Sur) were observed just above the temperature stability region of chlorite (Chl); clinohumite (cHm) was observed coexisting with phase HAPY at 6 GPa and 800 °C and coexisting with the 23-Å phase at 7 GPa and 800 °C, which may suggest the transportation of water through Chl → (HAPY → cHm) → 23-Å phase along a relatively warm slab. The 23-Å phase has a wider stability region in the pure MASH system (up to 12 GPa and 1100 °C) than it does in the MFASH system (7–10 GPa, up to 1000 °C). The stability of the 23-Å phase beyond the chlorite breakdown pressure indicates that it may play an important role in transporting water into the deep Earth and even into the mantle transition zone. 相似文献
290.
Diurnal Cycle of Sound Scatterers and Measurements of Turbidity Using ADCP in Beppu Bay 总被引:2,自引:0,他引:2
Xiao-Hua Zhu Yoshio Takasugi Masayuki Nagao Eisuke Hashimoto 《Journal of Oceanography》2000,56(5):559-565
From September 20 to 22 in 1994, the vertical profiles of echo intensity and three-component velocities were measured with a bottom-mounted 300 kHz broadband acoustic Doppler current profiler (ADCP) in Beppu Bay in the Seto Inland Sea of Japan. A very strong thermocline was observed from 50 to 60 m. A pronounced diurnal cycle of backscatter strength (BS) was found above the thermocline. However, it was not found under the thermocline where there was a lack of dissolved oxygen. We suggest that the diurnal cycle of BS is caused by the vertical migration of zooplankton. The downward and upward migration occurred in early morning and late afternoon, respectively. The migration speeds estimated from BS isopleth displacements were about 1 cm s–1. Further, the contribution of turbidity (Tur) to BS was examined by separating out the effect of migrating zooplankton. There was a significant correlation between BS and turbidity under the thermocline. The maximum contributions of the Tur, migrating zooplankton and non-migrating plankton on BS were estimated at 3, 12, 25 dB, respectively. These data suggest that when using an ADCP to estimate Tur, it is very important to consider carefully the backscatter signal from zooplankton. 相似文献