Sea surface temperature distribution and its variability across the Tsushima Strait

The sea surface temperature distribution across the Tsushima Strait was monitored over a one-year period on board the ferry Kampu which runs between Shimonoseki, Japan and Pusan, Korea. A cold water region is always observed just near the Korean Coast, and a sharp temperature front is always present in the western channel. A temperature maximum or a warm core is usually found just on the southeast side of the front. The position of the warm core exhibits large short period fluctuations, but no significant seasonal variation is found. Sudden temperature increases followed by sudden temperature decreases are frequently observed in the temporal variation curves at fixed positions during the warming season from April to August. Such events are related to temperature maxima found sporadically in the temperature distribution in the eastern channel during this season, and seem to be caused by warm water intrusion into the Tsushima Strait from the East China Sea.     

Monthly variations of hydrographic structures and water mass distribution off the Doto area, Japan

Monthly variations of hydrographic structures and water mass distributions were investigated over a nearly 30-year period (January 1982–March 2011) off the Doto area, Japan, to examine temporal evolutions and devolutions of representative water masses in this area. In the continental shelf area, the Coastal Oyashio Water (COW) was distributed along the coast during January–May, when COW has been modified by relatively higher salinity water, which may have originated from the Oyashio Water (OW) off the Kuril Islands. On the other hand, the Surface COW (S-COW) may have formed with COW heated by solar radiation, simultaneously mixing with the Tokachi River freshwater and OW in the continental shelf area, and the area of this S-COW spread offshoreward during June and July, and stayed in the offshore area during June and October. Although coastal density current structures, probably due to the Modified Soya Warm Current Water (M-SWCW) inflows, were conspicuous in the continental shelf area during August–October, those structures were weak after November. These weakening structures may be due to developed surface mixed layer caused by surface cooling, and decay of volume transport of the Soya Warm Current in the Okhotsk Sea, and such weakening accordingly may lead to weakening of higher salinity water inflows from the upstream regions. M-SWCW was radically replaced by COW during December and January with rapid salinity decreases, which suggest extremely lower salinity water inflows, probably due to influences of the East Sakhalin Current Water.     

Degradation of outer membrane proteins of <Emphasis Type="Italic">Synechococcus</Emphasis> sp. <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in situ</Emphasis>

To examine the possibility that outer membrane proteins (OMP) of Synechococcus sp. remain in seawater, we investigated the stability of OMPs in vitro and in situ. Some fractions prepared from Synechococcus sp. CSIRO-94 were treated with trypsin and proteinase K. Four tightly bound OMPs were separated from Synechococcus. We designated the two major OMPs of 52 kDa and 48 kDa as Omp52Sy and Omp48Sy, respectively. Degradation of the OMP in natural seawater was monitored in microcosms to which intact Synechococcus cells and outer membrane (OM) were added. Omp52Sy and Omp48Sy were the most stable against trypsin and proteinase K among the OMPs when they were embedded in the OM. However, in the microcosm experiment using intact cells, Omp52Sy and Omp48Sy were detected in the particulate fraction only during the first 4 days, after which they could not longer be detected. Omp52Sy and Omp48Sy were the most stable proteins among the Synechococcus OMPs in vitro, but they might be degraded in situ. This indicates that stability of Synechococcus porin differs depending on complex formation with other membrane molecules, which might cause different preservation of microbial membrane proteins in the dissolved protein pool in the ocean. This study suggests that Gram negative bacterial OM with thin peptidoglycan forms a lipid bilayer that proptects OMP, but Synechococcus OM with thick peptidoglycan cannot form a lipid bilayer. The incomplete bilayer might not be able to protect from protease attack in the natural environment.     

The Reocín zinc–lead deposit,Spain: paleomagnetic dating of a late Tertiary ore body

The Reocín mine in northern Spain’s Basque–Cantabrian basin exploited a world-class Mississippi Valley-type Zn–Pb deposit. Its epigenetic mineralization is in Urgonian 116 ± 1 Ma dolomitized limestones of the Santillana syncline, which was formed by Oligocene and mid Miocene pulses of the Pyrenean orogeny. Paleomagnetic results (22 sites, 274 specimens) in mineralization isolated a stable remanence (ChRM) in pyrrhotite and minor magnetite inclusions in ore specimens, Zn concentrate, and tailings. A fold test shows that the ChRM is substantially post-folding. The mineralization’s paleopole lies on the European apparent polar wander path and indicates that the mineralization was formed at 15 ± 10 Ma. We postulate that brines originated in underlying Triassic and Lower Cretaceous sedimentary rocks and were driven upward into the host rocks by the hydraulic gradient created by the nearby Asturian massif.     

Summer Water Balance Characteristics of Koryto Glacier, Kamchatka Peninsula, Russia

The daily water balance for the drainage basin of Koryto Glacier, Kamchatka Peninsula, Russia, was calculated during the period from August to September 2000. The result shows that 14×10⁶ m³ of meltwater and 2×10⁶ m³ of rainwater entered the basin, while 26×10⁶ m³ of water drained from the basin through proglacial streams. Thus, about ?9×10⁶ m³ of water storage reduction occurred in the basin. Vertical displacements of the glacier surface showed that the volume change due to contraction of subglacial cavities was nearly 20% of the total storage change. The remaining fraction of water storage during the period is thought to be stored in englacial and supraglacial locations. The estimate of water balance components in the early ablation season in 2000 indicates that meltwater was already stored within the glacier before the spring, even during the previous year, and that the stored water drained through the ablation season.     

A 100 m laser strainmeter system installed in a 1 km deep tunnel at Kamioka, Gifu, Japan

We have installed a laser strainmeter system in a deep tunnel about 1,000 m below the ground surface at Kamioka, Gifu, Japan. The system consists of three types of independent interferometers: (1) an EW linear strainmeter of the Michelson type with unequal arms, (2) an NS-EW differential strainmeter of the Michelson type with equal arms and (3) a NS absolute strainmeter of the Fabry–Perot type. These are configured in L-shaped vacuum pipes, each of which has a length of 100 m. (1) and (2) are highly sensitive (order of 10⁻¹³ strain) and have wide dynamical range (10⁻¹³–10⁻⁶). Observations with strainmeters (1) and (2) started on June 11, 2003. (3) is a new device for absolute-length measurements of the order of 10⁻⁹ of a long-baseline (100 m) Fabry–Perot cavity by the use of phase-modulated light. This third strainmeter will be ready for operation before the end of 2004. The laser source of strainmeters (1) and (2) is a frequency-doubled YAG laser with a wavelength of 532 nm. The laser frequency is locked onto an iodine absorption line and a stability of 2 × 10⁻¹³ is attained. The light paths of the laser strainmeter system are enclosed in SUS304 stainless steel pipes. The inside pressure is kept to be 10⁻⁴ Pa. Consequently, quantitative measurement of crustal strains of the order of 10⁻¹³ can be attained by employing the laser strainmeter system of (1) and (2) at Kamioka. This resolving power corresponds to that of a superconducting gravimeter. Using the laser strainmeter system, we expect to determine parameters related to fluid core resonance, core modes and core undertone as well as other geodynamic signals such as slow strain changes caused by silent earthquakes or slow earthquakes.     

A possible current system associated with the Sqp variation

It is suggested that the quiet day daily magnetic variation in the polar cap region, S_q^p, results partly from the short-circuit effect of the magnetotail current by the polar ionosphere. This implies that there is an inward field-aligned current from the dawnside magnetopause to the forenoon sector of the auroral oval (positively charged) and an outward field-aligned current to the duskside magnetopause from the afternoon sector of the oval (negatively charged), together with the ionospheric (Pedersen and Hall) currents. The distribution of the magnetic field vectors of both combined current systems agrees with the observed S_q^pvector distribution. The space charges provide an electric field distribution which is similar to that which has been observed by polar orbiting satellites.     

Performance evaluation of a ground-source heat pump system utilizing a flowing well and estimation of suitable areas for its installation in Aizu Basin,Japan

Development of a ground-source heat pump (GSHP) system with higher efficiency, and evaluation of its operating performance, is essential to expand the growth of GSHP systems in Japan. A closed-loop GSHP system was constructed utilizing a flowing (artesian) well as a ground heat exchanger (GHE). The system was demonstrated for space-heating and space-cooling of a room (area 126.7 m²) in an office building. The average coefficient of performance was found to be 4.5 for space-heating and 8.1 for space-cooling. The maximum heat exchange rate was 70.8 W/m for space-heating and 57.6 W/m for space-cooling. From these results, it was determined that a GSHP system with a flowing well as a GHE can result in higher performance. With this kind of highly efficient system, energy saving and cost reduction can be expected. In order to assess appropriate locations for the installation of similar kinds of GSHP systems in Aizu Basin, a suitability map showing the distribution of groundwater up-flowing areas was prepared based on the results of a regional-scale three-dimensional analytical model. Groundwater up-flowing areas are considered to be suitable because the flowing well can be constructed at these areas. Performance evaluation of the GSHP system utilizing the flowing well, in conjunction with the prepared suitability map for its installation, can assist in the promotion of GSHP systems in Japan.     

Climatic physical snowpack properties for large-scale modeling examined by observations and a physical model

Here we have conducted an integral study using site observations and a model with detailed snow dynamics, to examine the capability of the model for deriving a simple relationship between the density and thermal conductivity of the snowpack within different climatic zones used in large-scale climate modeling. Snow and meteorological observations were conducted at multiple sites in different climatic regions (two in Interior Alaska, two in Japan). A series of thermal conductivity measurements in snow pit observations done in Alaska provided useful information for constructing the relationship. The one-dimensional snow dynamics model, SNOWPACK, simulated the evolution of the snowpack and compared observations between all sites. Overall, model simulations tended to underestimate the density and overestimate the thermal conductivity, and failed to foster the relationship evident in the observations from the current and previous research. The causes for the deficiency were analyzed and discussed, regarding a low density of the new snow layer and a slow compaction rate. Our working relationships were compared to the equations derived by previous investigators. Discrepancy from the regression for the melting season observations in Alaska was found in common.     

Hydrodynamical models of the Orion-KL Nebula

The interaction between an isotropic protostellar wind and an ambient molecular cloud is investigated by two-dimensional hydrodynamic computations. The wind-cloud interaction model is promising for explanation of the observed properties of the Orion-KL Nebula.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.