scholarly journals Pliocene ostracods (Crustacea) from the Togakushi area, central Japan; palaeobiogeography of trans-Arctic taxa and Japan Sea endemic species

2008 ◽  
Vol 27 (2) ◽  
pp. 161-175 ◽  
Author(s):  
Hirokazu Ozawa ◽  
Hideaki Nagamori ◽  
Tomotaka Tanabe
Keyword(s):  
High Latitude ◽  
Endemic Species ◽  
Japan Sea ◽  
Kuroshio Current ◽  
The Arctic ◽  
Northwestern Pacific ◽  
Arctic Seas ◽  
Central Japan ◽  
The Japan Sea ◽  
Northern Atlantic

Abstract. Pliocene strata (4–3 Ma) in the Togakushi area, central Japan, yield significant ostracods, which allow investigation of the origins of high-latitude (Arctic–Atlantic) taxa and the Japan Sea endemic species, together with their post-Miocene history of extinction-speciation and migration. Three types of extinct species are found here: (1) cryophilic species in common with, or closely related to, species in Plio-Pleistocene assemblages described from the Japan Sea; (2) species closely related to, or comparable with, species that characterize Miocene Japan; and (3) species endemic to the Pliocene Japan Sea. Type (1) contains species closely related to high-latitude species known from the Arctic and northern Atlantic Oceans. Their presence suggests migration from the northwestern Pacific to the northern Atlantic through the Arctic seas since the Late Pliocene after the opening of the Bering Strait. Both Types (2) and (3) contain genera originating in the south, which show high specific diversity in regions affected by the modern warm Kuroshio Current. Ancestral ostracods of Types (2) and (3) invaded the Japan Sea from the Pacific from the Middle Miocene, and diversified to produce closely related species in the semi land-locked Japan Sea until the Early Pliocene. Two new species Aurila togakushiensis sp. nov. and Aurila shigaramiensis sp. nov. are described.

scholarly journals New ostracod (Crustacea) species of the genus <i>Robertsonites</i> from the Upper Pliocene Kuwae and Sasaoka formations, central and northeast Japan

2003 ◽  
Vol 22 (2) ◽  
pp. 169-181 ◽  
Author(s):  
Katsura Yamada
Keyword(s):  
New Taxa ◽  
Northern Hemisphere ◽  
High Latitude ◽  
Water Mass ◽  
Japan Sea ◽  
The Sea Of Japan ◽  
Central Japan ◽  
Marine Deposits ◽  
Japan Sea Proper Water ◽  
The Japan Sea

Abstract. The ostracod genus Robertsonites is widely distributed in high-latitude seas of the Northern Hemisphere. It also occurs abundantly in Plio-Pleistocene strata along the coast of the Sea of Japan, which were deposited under the influence of the Japan Sea Proper Water mass, below 150 m. The assemblages of the genus Robertsonites in the seas around Japan are quite different from those in the high-latitude seas of the Northern Hemisphere. A difference in the valve outlines of the genus in the two areas is also apparent. Nine species of the genus Robertsonites are restricted to strata and marine deposits around Japan, although only 12 species have been described world-wide, including the three new taxa described here. The Upper Pliocene Sasaoka and Kuwae formations in northeast and central Japan, contain seven species, including three new taxa, Robertsonites irizukii sp. nov., Robertsonites leptoreticulata sp. nov., and Robertsonites tabukii sp. nov., and one open-nomenclature taxon.

scholarly journals How Does the Arctic Sea Ice Affect the Interannual Variability of Tropical Cyclone Activity Over the Western North Pacific?

2021 ◽  
Vol 9 ◽  
Author(s):  
Hao Fu ◽  
Ruifen Zhan ◽  
Zhiwei Wu ◽  
Yuqing Wang ◽  
Jiuwei Zhao
Keyword(s):  
Sea Ice ◽  
Bering Sea ◽  
North Pacific ◽  
Western North Pacific ◽  
Japan Sea ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Arctic Sea ◽  
The Japan Sea ◽  
The Bering Sea

Although many studies have revealed that Arctic sea ice may impose a great impact on the global climate system, including the tropical cyclone (TC) genesis frequency over the western North Pacific (WNP), it is unknown whether the Arctic sea ice could have any significant effects on other aspects of TCs; and if so, what are the involved physical mechanisms. This study investigates the impact of spring (April-May) sea ice concentration (SIC) in the Bering Sea on interannual variability of TC activity in terms of the accumulated cyclone energy (ACE) over the WNP in the TC season (June-September) during 1981–2018. A statistical analysis indicates that the spring SIC in the Bering Sea is negatively correlated with the TC season ACE over the WNP. Further analyses demonstrate that the reduction of the spring SIC can lead to the westward shift and intensification of the Aleutian low, which strengthens the southward cold-air intrusion, increases low clouds, and reduces surface shortwave radiation flux, leading to cold sea surface temperature (SST) anomaly in the Japan Sea and its adjacent regions. This local cloud-radiation-SST feedback induces the persistent increasing cooling in SST (and also the atmosphere above) in the Japan Sea through the TC season. This leads to a strengthening and southward shift of the subtropical westerly jet (SWJ) over the East Asia, followed by an anomalous upper-level anticyclone, low-level cyclonic circulation anomalies, increased convective available potential energy, and reduced vertical wind shear over the tropical WNP. These all are favorable for the increased ACE over the WNP. The opposite is true for the excessive spring SIC. The finding not only has an important implication for seasonal TC forecasts but also suggests a strengthened future TC activity potentially resulting from the rapid decline of Arctic sea ice.

Chemical composition of fog water at Mt. Tateyama near the coast of the Japan Sea in central Japan

Erdkunde ◽  
2011 ◽  
Vol 65 (3) ◽  
pp. 233-245 ◽  
Author(s):  
Koichi Watanabe ◽  
Hideharu Honoki ◽  
Shinji Iwama ◽  
Kaname Iwatake ◽  
Shunya Mori ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Japan Sea ◽  
Central Japan ◽  
Fog Water ◽  
The Japan Sea

Historical Development of Fisheries Oceanography in Japan

1972 ◽  
Vol 73 ◽  
pp. 391-398 ◽  
Author(s):  
Michitaka Uda
Keyword(s):  
Historical Development ◽  
Japan Sea ◽  
Maritime History ◽  
The Arctic ◽  
Japan Trench ◽  
Submarine Cable ◽  
The Japan Sea ◽  
The World ◽  
Oceanographic Research ◽  
The Usa

The visit of Commander Perry's American fleet in 1853, followed by visits of European oceanographic research vessels, initiated Japanese interest in oceanography. Fortunately, because of a long maritime history and experience, such advanced sciences were speedily and easily absorbed in Japan. The U.S.S. Tuscarora (1874) discovered the Tuscarora Trough in the Japan Trench during her trans-Pacific sounding cruise as a preliminary to laying a submarine cable. During her epoch-making scientific expedition around the world (1872–76) the British Challenger visited Japan in 1875 and surveyed parts of the Inland Sea. This was followed by the Swedish Vega Expedition (1879) which first cruised across the Arctic Ocean to Tokyo, the Russian Vitiaz Expedition (1886–89) in the Japan Sea, etc., and the USA Albatross Expedition (1888–97) in the northern waters and Japan Sea.

Paleoenvironmental and paleoclimatic changes in the Japan Sea since the last glaciation

2020 ◽  
Author(s):  
Xuefa Shi ◽  
Jianjun Zou ◽  
Sergey Gorbarenko
Keyword(s):  
Sea Ice ◽  
Sea Level ◽  
East Asian ◽  
Japan Sea ◽  
Sediment Provenance ◽  
Last Deglaciation ◽  
Central Japan ◽  
Warm Current ◽  
Ice Coverage ◽  
The Japan Sea

&lt;p&gt;The Japan Sea, one of the marginal seas of the North Pacific, communicates with adjacent seas through four shallow straits (&lt;130 m) and the present environment in the Japan Sea is mainly forced by the Tsushima Warm Current (TWC), East Asia Monsoon (EAM) and seasonal sea ice. During the Quaternary, the pronounced effects of glacial eustatic sea level on the hydrography, ocean biogeochemistry and sediment depositions in the Japan Sea over glacial-interglacial cycles. However, the spatial heterogeneity of these forcings exerting on environment of the Japan Sea may results in contrasting response. On the basis of a suite of sediment cores collected during the China-Russia joint expedition in 2010, we investigate the sedimentary processes and paleoenvironment changes in the Japan Sea. We found enhanced extent of seasonal sea-ice coverage in the western Japan Sea, which is synchronous with the intensification of East Asian Winter Monsoon (EAWM) from 15ka to 8ka. During the early last deglaciation (17ka-15ka), perennial sea ice cover at investigated site occurs and thus inhibits the deepwater formation in the Japan Sea. Since 8 ka, increased deep ventilation and dampened sea ice coverage are closely related to enhanced EAWM and invasion of high-salinity TWC into the Japan Sea. In the southern Japan Sea, the sediment provenance is mainly derived from the Yangtze and old yellow rivers, while the terrigenous matter was mainly sourced from the Yangtze River after 7 ka, on the basis of elemental and radiogenic isotopic data (Sr and Nd) of fine-sized (&lt;63 &amp;#956;m) sediments. Abrupt shifts in sediment provenance occurred at ~18 ka and ~7 ka and these time periods are synchronous with changes in surface hydrography and deep ventilation in the Ulleung Basin. In the central Japan Sea, eolian dust sourced from central Asia and Chinese Loess Plateau by westerly was delivered to the central Japan Sea. In addition, deep ventilation in the southern and central Japan Sea evidenced by redox-sensitive elements and ventilation-like radiolarian species suggest intensified ventilation since 8ka and during cold spells of the last deglaciation, which is closely related to the invasion of the Tsushima Warm Current into the Japan Sea. Our data suggest that sea level is a first-order factor in controlling the environment and sediment deposition in the Japan Sea at orbital timescales, while the East Asian Monsoon and Kuroshio Current play a secondary role. Note: This study was supported by the National Natural Science Foundation of China (Grants No. 41420104005, U1606401) and National Program on Global Change and Air-Sea Interaction (GASI-GEOGE-03 &amp;-04).&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;/p&gt;

scholarly journals Chemical characteristics of the snow pits at Murododaira, Mount Tateyama, Japan

2011 ◽  
Vol 52 (58) ◽  
pp. 102-110 ◽  
Author(s):  
Koichi Watanabe ◽  
Yukiko Saito ◽  
Syoko Tamura ◽  
Yuki Sakai ◽  
Nagisa Eda ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Japan Sea ◽  
Coarse Grain ◽  
Central Japan ◽  
Low Concentrations ◽  
The Japan Sea ◽  
The Mean ◽  
High Concentrations ◽  
High Peroxide ◽  
Snow Precipitation

AbstarctMeasurements of the chemical composition of the snow pits at Murododaira (2450m a.s.l.), Mount Tateyama, near the coast of the Japan Sea in central Japan, were performed each spring from 2005 through 2008. The mean concentrations of nssSO42– and NO3– are higher than those in snowpack in the 1990s. The pH and nssCa2+ were usually high in the upper parts of 2–3m of snow deposited in the spring, when Asian dust (Kosa) particles are frequently transported. High concentrations of nssSO42– were detected in both the spring and winter layers. The high-nssCa2+ layers usually contained high concentrations of nssSO42–. The results show that not only Kosa particles but also air pollutants might have been transported long-range from the continent of Asia. The concentrations of peroxides were high in the new snow (precipitation particles) and granular snow (coarse grain, melt forms) layers. The peroxide concentrations in the snow layers were negatively correlated with the nssCa2+ concentrations. High peroxide concentrations may be preserved in granular snow layers having low concentrations of nssCa2+.

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