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191.
????JASON1?????????к??????????????????????????????????????ERA??40????????????м????????????????????????CS??????????CSG2???????CSG1????Hwang????ZT???????????????CS?????????????????????????????????????????????????????????????????? 相似文献
192.
2012年中国沿海海平面上升显著成因分析 总被引：3，自引：0，他引：3
2012年,中国沿海海平面变化最突出的特点是海平面升高显著。海平面总体比常年高122mm,较2011年偏高53mm,达1980年以来最高位。本文使用中国沿海及西北太平洋区域近30a的水位、海温、气温、气压和风等水文气象资料,详细分析了中国沿海海平面2012年异常偏高的成因。结果表明:2010-2012年中国沿海海平面处于2~3a、8~9a和准19a周期震荡的高位,几个周期震荡高位叠加,对海平面上升起了明显的影响;2012年,沿海气温和海温分别较常年偏高0.4℃和0.3℃,气压较常年低1.2hPa,气压达历史最低位;2012年,中国南海夏季风爆发时间较常年偏早,结束较常年偏晚,季风持续时间较常年偏长,导致2012年5-6月和8月,在黄海和东海海域,东北风持续偏强,南海海域南风偏强,风场的异常导致黄海、东海和南海沿海海水长时间堆积,是造成海平面升高的原因之一;2012年,热带气旋登陆时间集中,影响范围广,北上和影响东北地区的台风数量均为历史之最,特别是2012年8月,有6个热带气旋相继影响我国沿海,对当月海平面升高影响明显;另外,2012年副热带高压偏北、偏东、偏弱的特点对东海和南海的海平面上升也有一定影响。 相似文献
193.
ZHENG Chongwei SHAO Longtan SHI Wenli SU Qin LIN Gang LI Xunqiang CHEN Xiaobin 《海洋学报(英文版)》2014,33(1):92-101
Against the background of the current world facing an energy crisis,and human beings puzzled by the problems of environment and resources,developing clean energy sources becomes the inevitable choice to deal with a climate change and an energy shortage.A global ocean wave energy resource was reanalyzed by using ERA-40 wave reanalysis data 1957–2002 from European Centre for Medium-Range Weather Forecasts(ECMWF).An effective significant wave height is defined in the development of wave energy resources(short as effective SWH),and the total potential of wave energy is exploratively calculated.Synthetically considering a wave energy density,a wave energy level probability,the frequency of the effective SWH,the stability and long-term trend of wave energy density,a swell index and a wave energy storage,global ocean wave energy resources were reanalyzed and regionalized,providing reference to the development of wave energy resources such as wave power plant location,seawater desalination,heating,pumping. 相似文献
194.
The regional changes of daily temperature extremes in North China caused by urbanization are studied further from observed facts and model estimates on the basis of homogenized daily series of maximum and minimum temperature observations from 268 meteorological stations, NCEP/DOE AMIP-Ⅱ reanalysis data(R-2), and the data of simulations by regional climate model(RegCM3). The observed facts of regional warming on long time scales are obtained by analyzing the indices of temperature extremes during two time periods of 1961–2010 and 1951–2010. For urbanization effect, the contributions to decreases in annual and winter diurnal temperature range(DTR) are 56.0% and 52.9%, respectively, and increases in the lowest minimum temperature(TNn) are 35.7% and 26.2% by comparison of urban and rural observations. Obtained by R-2 data with observations for contrast, on the other hand, increase in the number of annual warm nights(TN90p) contributed by urbanization is 60.9%. And observed facts of regional warming in daily temperature extremes are also reflected in the simulations, but what difference is urbanization progress at rural areas in North China would be prominent in the next few years relative to urban areas to some extent from model estimates. 相似文献
195.
196.
知识经济时代必将引起人类社会的产业结构和人们的生产、生活及思维方式的重大变革。面对２１世纪的地震档案必须抓住机遇、顺应变革,以此带动地震档案管理水平的提高,迎接知识经济的挑战。文章从地震档案的工作方式、工作重点及人员知识结构等方面试论面对知识经济时代地震档案管理的重大变革。 相似文献
197.
C. Diessel R. Boyd J. Wadsworth D. Leckie G. Chalmers 《International Journal of Coal Geology》2000,43(1-4)
Coal composition was investigated by means of photometric and maceral analyses on closely spaced lithotype-based strip samples over the full thickness of several paralic coal seams from the Cretaceous Gates Formation of the Western Canadian Sedimentary Basin. The aim of this investigation was to test various methods of identifying accommodation trends in coal and use them to refine sequence-stratigraphic interpretation of continental sediments. Conventional sequence stratigraphy derives its subdivisions and significant surfaces from the records left by relative sea-level oscillations. These records either do not project into the continental realm, or are difficult to recognise in clastic non-marine sediments. Paralic coal seams have been selected to study this problem, because they are not entirely removed from marine influence and, compared with most inorganic deposits, coal has stored a greater wealth of information that can be analysed at a higher level of resolution. The study has led to the identification of five new surfaces with chronostratigraphic potential in the sequence-stratigraphic analysis of non-marine sediments. Two of these surfaces, called paludification surface (PaS) and terrestrialisation surface (TeS), occur at the bases of the investigated coal seams, while two other surfaces, referred to as non-marine flooding surface (NFS) and give-up transgressive surface (GUTS), form the tops of the coal. The fifth and probably most important new surface, called the accommodation-reversal surface (ARS), is independent of any particular facies and may either coincide with some of the other surfaces or occur separately. The proportion of detrital minerals has been used as the chief discriminator between different mire types and accommodation trends. Other useful indicators of mire type and peat dispersal have been the proportions of sporinite and inertodetrinite, as well as some derived maceral and/or mineral ratios, e.g., the groundwater influence index and the tissue preservation index. Isometamorphic variations of telovitrinite reflectance and fluorescence, as well as their coefficients of variation were also found to contribute to the identification of cyclic shifts between balanced and unbalanced accommodation/peat accumulation ratios. Some of these cycles, which are backed up by clastic stratigraphy, appear to correspond to the development of shallowing-upward and deepening-upward parasequences. Superimposed high-frequency, low-amplitude perturbations in the coal cycles relate to smaller-scale accommodation cycles of sub-parasequence level, not always recognised in non-marine strata. These sub-parasequence coal cycles do not always continue the shallowing-upward trend typical of conventional parasequences. Several coals were found to contain stacks of small-scale cycles with upward increasing accommodation signatures either in their lower or upper halves, or over the whole seam section. 相似文献
198.
199.
To explore new operational forecasting methods of waves, a forecasting model for wave heights at three stations in the Bohai Sea has been developed. This model is based on long short-term memory(LSTM) neural network with sea surface wind and wave heights as training samples. The prediction performance of the model is evaluated,and the error analysis shows that when using the same set of numerically predicted sea surface wind as input, the prediction error produced by the proposed LSTM model at Sta. N01 is 20%, 18% and 23% lower than the conventional numerical wave models in terms of the total root mean square error(RMSE), scatter index(SI) and mean absolute error(MAE), respectively. Particularly, for significant wave height in the range of 3–5 m, the prediction accuracy of the LSTM model is improved the most remarkably, with RMSE, SI and MAE all decreasing by 24%. It is also evident that the numbers of hidden neurons, the numbers of buoys used and the time length of training samples all have impact on the prediction accuracy. However, the prediction does not necessary improve with the increase of number of hidden neurons or number of buoys used. The experiment trained by data with the longest time length is found to perform the best overall compared to other experiments with a shorter time length for training. Overall, long short-term memory neural network was proved to be a very promising method for future development and applications in wave forecasting. 相似文献
200.
持时对工程场地或构筑物的非线性地震响应存在显著影响,但目前有关地震动持时的研究相对振幅与频谱的研究较少。本文基于太平洋地震工程中心的NGA-East强震数据库和NGA-West2强震数据库的地震动记录,对5%～95%显著持时进行了研究。分析了地震动两分量时程的显著持时差异及差异产生的原因,进而探讨了显著持时定义自身的缺陷。借助考虑随机效应的多参数非线性回归给出了NGA-East和NGA-West2数据的5%～95%显著持时的预测公式,可在适用的震级和断层距范围内为估计构造稳定区和构造活跃区的显著持时提供参考。 相似文献