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561.
The Impact of Global Warming on the Pacific Decadal Oscillation and the Possible Mechanism简 总被引:1,自引:0,他引:1
The response of the Pacific Decadal Oscillation (PDO) to global warming according to the Fast Ocean Atmosphere Model (FOAM) and global warming comparison experiments of 11 IPCC AR4 models is investigated. The results show that North Pacific ocean decadal variability, its dominant mode (i.e., PDO), and atmospheric decadal variability, have become weaker under global warming, but with PDO shifting to a higher frequency. The SST decadal variability reduction maximum is shown to be in the subpolar North Pacific Ocean and western North Pacific (PDO center). The atmospheric decadal variability reduction maximum is over the PDO center. It was also found that oceanic baroclinic Rossby waves play a key role in PDO dynamics, especially those in the subpolar ocean. As the frequency of ocean buoyancy increases under a warmer climate, oceanic baroclinic Rossby waves become faster, and the increase in their speed ratio in the high latitudes is much larger than in the low latitudes. The faster baroclinic Rossby waves can cause the PDO to shift to a higher frequency, and North Pacific decadal variability and PDO to become weaker. 相似文献
562.
The bopyrid isopod species Rhopalione sinensis Markham, 1990, is recorded for only the second time, from a new locality in China outside Hong Kong, the type-locality. This is also the fi rst fi nding of the male R. sinensis, which is herein described. Its host, Arcotheres sinensis(Shen, 1932) is a new record. A review of the four known species of Rhopalione Pérez, 1920, an updated diagnosis of the genus and a key to species are provided. 相似文献
563.
SiB3对不同下垫面的模拟试验与验证 总被引:3,自引:1,他引:2
首先介绍简单生物圈模式版本3(Simple Biosphere Model 3,SiB3)相比SiB2的改进之处以及相应的参数化方案。为了检验SiB3模式能否模拟不同下垫面的地气之间水分和能量交换,本文在全球选择3个代表高、中、低纬度的典型实验站点(青藏高原安多站点、亚马逊流域的Km34站点和美国中西部的WLEF站点),利用SiB3进行模拟分析和实验验证。研究结果表明,SiB3能够较好地模拟出不同下垫面的地表感热通量、潜热通量和净辐射通量随时间的变化率以及变化趋势,模式模拟值和测量值的相关系数达到080左右。但与实测相比,SiB3模拟的感热通量值仍偏高。在安多站点,模式模拟的地表土壤水分比较干燥,且模拟的地表温度较测量值偏高。 相似文献
564.
Di-Cheng Zhu Zhi-Dan Zhao Yaoling Niu Xuan-Xue Mo Sun-Lin Chung Zeng-Qian Hou Li-Quan Wang Fu-Yuan Wu 《Earth and Planetary Science Letters》2011,301(1-2):241-255
The Lhasa Terrane in southern Tibet has long been accepted as the last geological block accreted to Eurasia before its collision with the northward drifting Indian continent in the Cenozoic, but its lithospheric architecture, drift and growth histories and the nature of its northern suture with Eurasia via the Qiangtang Terrane remain enigmatic. Using zircon in situ U–Pb and Lu–Hf isotopic and bulk-rock geochemical data of Mesozoic–Early Tertiary magmatic rocks sampled along four north–south traverses across the Lhasa Terrane, we show that the Lhasa Terrane has ancient basement rocks of Proterozoic and Archean ages (up to 2870 Ma) in its centre with younger and juvenile crust (Phanerozoic) accreted towards its both northern and southern edges. This finding proves that the central Lhasa subterrane was once a microcontinent. This continent has survived from its long journey across the Paleo-Tethyan Ocean basins and has grown at the edges through magmatism resulting from oceanic lithosphere subduction towards beneath it during its journey and subsequent collisions with the Qiangtang Terrane to the north and with the Indian continent to the south. Zircon Hf isotope data indicate significant mantle source contributions to the generation of these granitoid rocks (e.g., ~ 50–90%, 0–70%, and 30–100% to the Mesozoic magmatism in the southern, central, and northern Lhasa subterranes, respectively). We suggest that much of the Mesozoic magmatism in the Lhasa Terrane may be associated with the southward Bangong–Nujiang Tethyan seafloor subduction beneath the Lhasa Terrane, which likely began in the Middle Permian (or earlier) and ceased in the late Early Cretaceous, and that the significant changes of zircon εHf(t) at ~ 113 and ~ 52 Ma record tectonomagmatic activities as a result of slab break-off and related mantle melting events following the Qiangtang–Lhasa amalgamation and India–Lhasa amalgamation, respectively. These results manifest the efficacy of zircons as a chronometer (U–Pb dating) and a geochemical tracer (Hf isotopes) in understanding the origin and histories of lithospheric plates and in revealing the tectonic evolution of old orogenies in the context of plate tectonics. 相似文献
565.
Spatial variations of the 660-km discontinuity in the western Pacific subduction zones observed from CEArray triplication data 总被引:1,自引:0,他引:1
Baoshan Wang Fenglin Niu Institute of Geophysics China Earthquake Administration Beijing China 《地震学报(英文版)》2011,(1):77-85
We examined the spatial variation of velocity structures around the 660-km discontinuity at the western Pacific subduction zones by waveform modeling of triplication data.Data from two deep earthquakes beneath Izu-Bonin and Northeast China are used.Both events were well recorded by a dense broadband seismic network in China (CEArray).The two events are located at approximately the same distance to the CEArray,yet significant differences are observed in their records:(1) the direct arrivals traveling above t... 相似文献
566.
Multiple Critical Zone Observatories (CZO) have been established in recent years in the USA and other international settings to conduct collaborative research on processes that occur at and near Earth’s surface, also known as the Critical Zone (CZ). Data documentation and data sharing are two persistent problems facing the CZOs that impede the ability for cross-site comparisons and integrated analysis. In this study, a relational database was developed for CZ rock and regolith geochemical data – CZChemDB. There are a total of 24 interrelated tables in the database, each representing different aspects of CZ features. The main data group includes tables of locations, sites, samples, subsamples, preparation/treatments, laboratory-analysis and data values. The meta-data group includes tables of methods, references, and data quality. Lookup tables (variables, units, etc.) contain lists of “controlled” vocabularies. The CZChemDB is currently implemented in the MS Access database management system. It is expected to be integrated into the EarthChem portal by summer of 2011 for broader online accessibility and usability. This integration also complements the EarthChem’s global geochemistry database with CZ regolith data. The structure of the CZChemDB is simple, straightforward, and flexible so that it has potential to accommodate other chemical data collected from CZOs, such as pore fluid data. Furthermore, the development of CZChemDB represents the first attempt toward the standardization of geochemical data documentation and data sharing among CZOs. This effort will establish a model to bridge the connections between data acquisition, data management, data sharing, and data searching/discovering that are all essential but weak in terms of linkages within most geoscience research projects. 相似文献
567.
Comparison between the Xishimen gold deposit and the Shihu gold deposit in western Hebei and analysis of the potential for ore exploration 总被引:1,自引:1,他引:0
Chao Chen Shuyin Niu Zili Wang Zhong Guo Aiqun Sun Baode Wang Yincang Gao 《中国地球化学学报》2011,30(3):281-289
The Xishimen gold deposit is located in the tectonic zone southeast to the Shihu gold deposit, both of which belong to the same orefield. Then, how is the prospecting potential for the Xishimen gold deposit? A com-parison was made between the Xishimen gold deposit and the Shihu gold deposit on the basis of their geological background of metallogenesis, geological characteristics of the ore deposits, the sources of ore-forming materials, etc. The results showed that both the deposits possess many similarities in the respects mentioned above. And their met-allogeneses can be compared. Therefore, there is great potential for ore prospection in the periphery or at the deep levels of the Xishimen gold deposit. Ore exploration should be well programmed on the basis of a better dissection of the tectonic setting of the orefield. A breakthrough in ore prospection of the Xishimen gold deposit will be of great instructive significance in regionally geological prospecting. 相似文献
568.
Aiqun Sun Shuyin Niu Baode Wang Yuchou Han Minhui Wei Baojun Ma Zhiyuan Zhao Dong Xia 《中国地球化学学报》2011,30(1):1-13
The region of Northwest Hebei is an area where Au-Ag polymetallic ore depsits are concentrated in Hebei Province. There were divided the Au ore-concentrated region with the magmatic-metamorphic diamictite zone as the center and the perpheral cover-strata zone and Ag-polymetallic metallogenic zone along the line of Xuanhua-Songli-Chicheng. Research on mantle branch structure indicates that Au-Ag polymetallic ore-forming materials come mainly from the deep interior of the Earth. The ore-forming materials tend to migrate upwards through the multi-stage evolution of mantle plume, and are concentrated as ores in the favourable tectonic expansion zone of a mantle branch structure. As viewed in plane, from the center to the periphery and as viewed in space, from the lower part to the upper part there exists Au-Ag-Pb-Zn zonation, as evidenced by drilling data from a number of mines. So, there is still great potential for ore prospecting in the region of Northwest Hebei. 相似文献
569.
570.