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151.
A Numerical Modeling of the Upper and the Intermediate Layer Circulation in the East Sea 总被引:1,自引:0,他引:1
Circulation in the upper and the intermediate layer of the East Sea is investigated by using a fine resolution, ocean general
circulation model. Proper separation of the East Korean Warm Current from the coast is achieved by adopting the isopycnal
mixing, and using the observed heat flux (Hirose et al., 1996) and the realistic wind stress (Na et al., 1992). The simulated surface circulation exhibits a remarkable seasonal variation in the flow patterns of the Nearshore
Branch, the East Korean Warm Current and the Cold Currents. East of the Oki Bank, the Nearshore Branch follows the isobath
of shelf topography from late winter to spring, while in summer and autumn it meanders offshore. The Nearshore Branch is accompanied
by cyclonic and anticyclonic eddies in a fully developed meandering phase. The meandering and the eddy formation of the Nearshore
Branch control the interior circulation in the Tsushima Current area. A recirculation gyre is developed in the region of the
East Korean Warm Current in spring and grown up to an Ulleung Basin scale in summer. A subsurface water is mixed with the
fresh surface water by winter convection in the northeastern coastal region of Korea. The well-mixed low salinity water is
transported to the south by the Cold Currents, forming the salinity minimum layer (Intermediate Water) beneath the East Korean
Warm Current water. The recirculation gyre redistributes the core water of the salinity minimum layer in the Ulleung Basin.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
152.
Five Oncaea species were recorded on the basis of specimens collected using three type nets from the South Sea and the East Sea of Korea. These included the clevei-group of one species (O. clevei) and the venusta-group of four species (O. media, O. mediterranea, O. scottodicarloi, O. waldemari). The former has a dorsoposterior projection on the second pedigerous somite, while the latter do not bear any dorsal projection on the somite. Also, their spatio-temporal distribution are discussed in relation to temperature-salinity. 相似文献
153.
This study employed direct numerical simulation to simulate the fully nonlinear interaction between the water waves, the submerged breakwater, and the seabed under differing wave conditions. In the numerical simulation, the laminar flow condition in the seabed was applied to evaluate the more exact fluid resistance acting on the porous media. Varying incident wave conditions were applied to the flow field resulting from the wave–structure–seabed interaction, and the variation in the pore water pressure beneath the submerged breakwater was investigated along the cross-section of the submerged breakwater. Structural safety and scouring were also considered on the basis of the numerical results for the flow field around the structure and the variation of the pore water pressure. 相似文献
154.
Feeding apparatus, mechanism and passage of ingested prey were described forNemopilema nomurai (Scyphozoa: Rhizostomeae).N. nomurai medusae without central mouths have developed complicated canal systems connecting the tip of the tentacle and oral arm to
the gut cavity. The number of junctions in the canal system increases with the bell diameter. The prey is gathered by paralyzing
nematocyst at the tentacles and by adhering cirri at the oral arms and scapulets. They are engulfed into the terminal pore
located at the oral arms and scapulets, and entered into the gut cavity via the canal system. The estimated digestion time
is 1 hour and 20 min. The diameter of terminal pore is always about 1 mm, implying that they could not eat prey larger than
that pore size. On the other hand, ephyrae have central mouths and could swallow prey as large as adults could. Exploitation
of the same size of food by adult and ephyra implies thatN. nomurai can affect seriously the whole food web, massively ingesting micro-and mesozoopl a n k t o n and cutting the energy transfer
toward the higher level of carnivores. 相似文献
155.
Tae Hyun Yoon Stephen B. Johnson Gordon E. Brown Jr. 《Geochimica et cosmochimica acta》2004,68(22):4505-4518
The types and structures of adsorption complexes formed by oxalate at boehmite (γ-AlOOH)/water and corundum (α-Al2O3)/water interfaces were determined using in situ attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy and quantum chemical simulation methods. At pH 5.1, at least four different oxalate species were found at or near the boehmite/water interface for oxalate surface coverages (Γox) ranging from 0.25 to 16.44 μmol/m2. At relatively low coverages (Γox < 2.47), strongly adsorbed inner-sphere oxalate species (IR peaks at 1286, 1418, 1700, and 1720 cm−1) replace weakly adsorbed carbonate species, and a small proportion of oxalate anions are adsorbed in an outer-sphere mode (IR peaks at 1314 and 1591 cm−1). IR peaks indicative of inner-sphere adsorbed oxalate are also observed for oxalate at the corundum/water interface at Γox = 1.4 μmol/m2. With increasing oxalate concentration (Γox > 2.47 μmol/m2), the boehmite surface binding sites for inner-sphere adsorbed oxalate become saturated, and excess oxalate ions are present dominantly as aqueous species (IR peaks at 1309 and 1571 cm−1). In addition to these adsorption processes, oxalate-promoted dissolution of boehmite following inner-sphere oxalate adsorption becomes increasingly pronounced with increasing Γox and results in an aqueous Al(III)-oxalate species, as indicated by shifted IR peaks (1286 → 1297 cm−1 and 1418 → 1408 cm−1). At pH 2.5, no outer-sphere adsorbed oxalate or aqueous oxalate species were observed. The similarity of adsorbed oxalate spectral features at pH 2.5 and 5.1 implies that the adsorption mechanism of aqueous HOx− species involves loss of protons from this species during the ligand-exchange reaction. As a consequence, adsorbed inner-sphere oxalate and aqueous Al(III)-oxalate complexes formed at pH 2.5 have coordination geometries very similar to those formed at pH 5.1.The coordination geometry of inner-sphere adsorbed oxalate species was also predicted using quantum chemical geometry optimization and IR vibrational frequency calculations. Geometry-optimized Al8O12 and Al14O22 clusters with the reactive surface Al site coordinated by three oxygens were used as model substrates for corundum and boehmite surfaces. Among the models considered, calculated IR frequencies based on a bidentate side-on structure with a 5-membered ring agree best with the observed frequencies for boehmite/oxalate/water samples at Γox = 0.25 to 16.44 μmol/m2 and pH 2.5 and 5.1, and for a corundum/oxalate/water sample at Γox = 1.4 μmol/m2 and pH 5.1. Based on these results, we suggest that oxalate bonding on boehmite and corundum surfaces results in 5-coordinated rather than 4- or 6-coordinated Al surface sites. 相似文献
156.
Kyung-Ja Ha Soon-Jo Yoon Kyung-Sook Yun Jong-Seong Kug Yeon-Soo Jang Johnny C. L. Chan 《Theoretical and Applied Climatology》2012,109(3-4):383-395
The effects of the El Ni?o-Southern Oscillation (ENSO) phase and the shifting of the ENSO sea surface temperature (SST) on the intensity of tropical cyclones (TC) have been extensively investigated in terms of TC genesis locations in the western North Pacific (WNP). To advance the hypothesis for a relation of genesis location–intensity that the TC formation location hints its intensity, two cases have been compared, which include the phase of the decaying El Ni?o turning over to La Ni?a (type I) and the phase that recovers to a neutral condition (type II). In addition, the shift of ENSO SST to the central Pacific warming (CPW) from the East Pacific warming (EPW) has been examined. The genesis potential index (GPI) and the accumulated cyclone energy have been applied to compare the differences between the ENSO phase and the TC formation location. It was apparent that ENSO influences the WNP typhoon formation location depending on the cycle of the ENSO phase. In addition, the typhoon activity was affected by the zonal shift of the El Ni?o SST. The CPW, which has maximum SST over the central Pacific, tends to have a persistently high GPI over the WNP in September–November and June–August, demonstrating that the formation locations of strong TCs significantly shift southeastward compared with the EPW having SST maximum over the eastern Pacific. CPW years revealed a distinguishable relationship between the TC formation location and the TC between the tropical depression (TD) + tropical storm (TS) and the intense typhoon of category 4?+?5. 相似文献
157.
Tianjun Zhou Bo Wu A. A. Scaife S. Brönnimann A. Cherchi D. Fereday A. M. Fischer C. K. Folland K. E. Jin J. Kinter J. R. Knight F. Kucharski S. Kusunoki N.-C. Lau Lijuan Li M. J. Nath T. Nakaegawa A. Navarra P. Pegion E. Rozanov S. Schubert P. Sporyshev A. Voldoire Xinyu Wen J. H. Yoon N. Zeng 《Climate Dynamics》2009,33(7-8):1051-1068
A multi-model set of atmospheric simulations forced by historical sea surface temperature (SST) or SSTs plus Greenhouse gases and aerosol forcing agents for the period of 1950–1999 is studied to identify and understand which components of the Asian–Australian monsoon (A–AM) variability are forced and reproducible. The analysis focuses on the summertime monsoon circulations, comparing model results against the observations. The priority of different components of the A–AM circulations in terms of reproducibility is evaluated. Among the subsystems of the wide A–AM, the South Asian monsoon and the Australian monsoon circulations are better reproduced than the others, indicating they are forced and well modeled. The primary driving mechanism comes from the tropical Pacific. The western North Pacific monsoon circulation is also forced and well modeled except with a slightly lower reproducibility due to its delayed response to the eastern tropical Pacific forcing. The simultaneous driving comes from the western Pacific surrounding the maritime continent region. The Indian monsoon circulation has a moderate reproducibility, partly due to its weakened connection to June–July–August SSTs in the equatorial eastern Pacific in recent decades. Among the A–AM subsystems, the East Asian summer monsoon has the lowest reproducibility and is poorly modeled. This is mainly due to the failure of specifying historical SST in capturing the zonal land-sea thermal contrast change across the East Asia. The prescribed tropical Indian Ocean SST changes partly reproduce the meridional wind change over East Asia in several models. For all the A–AM subsystem circulation indices, generally the MME is always the best except for the Indian monsoon and East Asian monsoon circulation indices. 相似文献
158.
Junyeon Yoon 《Aquatic Geochemistry》2010,16(1):189-206
The lithium concentration of the dissolved load from the Lena River, together with major element chemistry and GIS-based area
and runoff data demonstrate the importance of evaporites in controlling dissolved Li in river waters. Eighty-four percent
of the Li in the dissolved load of upper Lena tributaries comes from evaporites in these drainage basins. Altogether, at least
~20% of the total Li flux of the Lena River originates from this source. This finding has important implications for using
lithium as a proxy for silicate weathering. The Li flux and the 87Sr/86Sr ratio are compared in order to address a difference between the two silicate weathering rate proxies. The proposed controls
on the dissolved δ7Li values in rivers (kinetic vs. equilibrium isotopic fractionation; Rayleigh-type preferential extraction of the heavy isotope)
(Huh et al., Earth Planet Sci Lett 194:189–199, 2001) are evaluated using data from both the Siberian rivers and the Orinoco
River. Neither of the proposed mechanisms satisfactorily explains the comprehensive data set. Instead, a ‘mineralogy-specific
view’ that emphasizes the difference in the secondary mineralogy (i.e., fractionation factor) is presented as a potential
rationalization in the form of the refined Rayleigh-type extraction. 相似文献
159.
A. A. Scaife F. Kucharski C. K. Folland J. Kinter S. Brönnimann D. Fereday A. M. Fischer S. Grainger E. K. Jin I. S. Kang J. R. Knight S. Kusunoki N. C. Lau M. J. Nath T. Nakaegawa P. Pegion S. Schubert P. Sporyshev J. Syktus J. H. Yoon N. Zeng T. Zhou 《Climate Dynamics》2009,33(5):603-614
We use a simple methodology to test whether a set of atmospheric climate models with prescribed radiative forcings and ocean
surface conditions can reproduce twentieth century climate variability. Globally, rapid land surface warming since the 1970s
is reproduced by some models but others warm too slowly. In the tropics, air-sea coupling allows models to reproduce the Southern
Oscillation but its strength varies between models. We find a strong relationship between the Southern Oscillation in global
temperature and the rate of global warming, which could in principle be used to identify models with realistic climate sensitivity.
This relationship and a weak response to ENSO suggests weak sensitivity to changes in sea surface temperature in some of the
models used here. In the tropics, most models reproduce part of the observed Sahel drought. In the extratropics, models do
not reproduce the observed increase in the North Atlantic Oscillation in response to forcings, through internal variability,
or as a combination of both. 相似文献
160.