Temporal and Spatial Characteristics of Intraseasonal Oscillations in the Meridional Wind Field over the Subtropical Northern Pacific

Based on the NCEP/NCAR reanalysis I daily data from 1958 to 2002, climatic characteristics of the 30-60-day intraseasonal oscillations (ISOs) of the zonal wind (u), meridional wind (v), and geopotential height (h) over global areas and especially the ISO of v over the subtropical northern Pacific are analyzed using the space-time spectrum analysis and wavelet transform methods. The results show that the ISO of v is very different from those of u and h, with the former representing the meridional low-frequency disturbances, which are the most active in the subtropics and mid-high latitudes, but very weak in the tropics. In the subtropical Northern Hemisphere, the energies of the ISOs of u and h are both concentrated on the waves with wave number of 1 and periods of 30-60 days, while the main energy of the ISO of v is concentrated on the waves with wave numbers of 4-6 and periods of 30-60 and 70-90 days. The westward propagating energies for the 30-60-day oscillations of u, v, and h are all stronger than the eastward propagating energies in the subtropics. In addition, the ISO of v is the strongest (weakest) in summer (winter) over the subtropics of East Asia and northwestern Pacific, while the situation is reversed over the subtropical northeastern Pacific, revealing a "seesaw" of the ISO intensity with seasons over the subtropics from the northwestern to northeastern Pacific. In the subtropical northwestern Pacific, the interannual and interdecadal changes of the ISO for v at 850 hPa indicate that its activities are significantly strong during 1958 1975, while obviously weak during 1976-1990, and are the strongest during 1991-2000, and its spectral energy is obviously abnormal but ruleless during the ENSO periods. However, in the 2 7-yr bandpass filtering series, the interannual changes of the v ISO over the subtropical northwestern Pacific contain distinct ENSO signals. And in the 9-yr low-pass filtering series, the v ISO changes over the subtropical northwestern Pacific are significantly out of phase with the changes of the Ni(n)o -3.4 SST, whereas the v ISO changes in the subtropical northeastern Pacific are significantly in phase with the changes of the Ni(n)o-3.4 SST.     

全球变暖背景下热带大气季节内振荡的变化特征及数值模拟

利用欧洲中期数值预报中心的ERA40再分析逐日的200 hPa风场资料,选取1958-1977年和1980-1999年各20年,对比分析了在全球变暖背景下前后两个时段热带大气季节内振荡(ISO)的特征及其变化.研究表明: 近20 a来,原来在赤道中太平洋上活跃的ISO减弱,而在中印度洋、孟加拉湾地区ISO变得活跃;全球变暖背景下,ISO的强度变化幅度加大,表明ISO更加活跃,且季节变化明显,冬、春季强,夏、秋季弱;对流层上层的纬向风能量更集中于1-3波,ISO的频率有加大的趋势.还利用中国科学院大气物理研究所LASG发展的耦合气候系统模式FGOALS-1.0g中的控制试验及其二氧化碳浓度加倍试验结果,分别对应实测资料的前后20年进行对比分析.发现模式对ISO的空间结构模拟较好,但低估了ISO的强度;时空谱分析表明模式结果中包含有更多的纬向风的高频成分,由于能量的分散,导致对ISO活动强度的低估.但通过对模式的控制试验和温室气体增加试验结果的对比分析,发现耦合模式还是较好地反映出在全球变暖背景下ISO在中印度洋、孟加拉湾地区变得活跃、频率加大等变化特征.     

Numerical Simulation and Comparison Study of the Atmospheric Intraseasonal Oscillation

Daily mean outputs for 12 yr (1978-1989) from two general circulation models (SAMIL-R42L9 and CAM2.0.2) are analyzed and compared with the corresponding NCEP/NCAR reanalysis dataset, and results in two models show clearly that the root-mean square errors (RMSEs) from the simulation of intraseasonal oscillation can take 30-40 percent of the total RMSE, particularly, the distributions of the RMSE in simulating intraseasonal oscillation are almost identical with that of the total RMSE. The maximum RMSE of intraseasonal oscillation height at 500 hPa is shown in the middle latitude regions, but there are also large RMSEs of intraseasonal oscillation wind over the tropical western Pacific and tropical Indian Oceans. The simulated ISO energy in the tropic has very large difference from the result of the NCEP/NCAR reanalysis dataset which means the simulation of tropical atmospheric ISO still possesses serious insufficiency. Therefore, intraseasonal oscillation in the weather and climate numerical simulation is very important, and thus, how to improve the ability of the GCM to simulate the intraseasonal oscillation becomes very significant.     

Developments at ISO/REMCO and its Impact on the Production and Use of Geological Reference Materials

During the past decade the work of ISO/REMCO, the International Organization for Standardization’s Technical Committee on Reference Materials, was dedicated to achieving global harmonisation, and true involvement of the member countries. The first major accomplishment was the clarification of the terminology in the definitions for reference material and certified reference material, which were published as an amendment to ISO Guide 30 in 2008. The next milestone was the recognition that ISO Guide 34 (‘General requirements for the competence of reference material producers’) be used in conjunction with ISO/IEC 17025 for the accreditation of reference material producers. The third edition of ISO Guide 34 published in November 2009, clarifies the acceptable procedures for the certification of reference materials. This paper will discuss the role of ISO/REMCO in formalising the procedures for the accreditation of reference material producers and the evolution of the terms reference material and certified reference material. The paper will conclude with a case study, where a primary method in a single laboratory – one of the recognised acceptable metrologically valid procedures according to ISO Guide 34 – was used for the certification of reference materials. The reference materials are South African Reference Material SARM 2 (Syenite), SARM 3 (Lujavrite) and SARM 4 (Norite) from the suite of six NIMROCs that were originally certified by the Council for Mineral Technology (MINTEK) in South Africa in the 1970s.     

Role of reliability calculations in geotechnical design

ABSTRACT

This paper adds to the ongoing discussion on the role of reliability calculations in geotechnical design. It situates design calculations, be it verified by a global factor of safety, partial factors, or reliability-based design (RBD), in a larger context of quality management over the life cycle of the structure. It clarifies that uncertainties amenable to probabilistic treatment typically fall under the category of “known unknowns” where some measured data and/or past experience exist for limited site-specific data to be supplemented by both objective regional data and subjective judgement derived from comparable sites elsewhere. Within this category, reliability is very useful in handling complex real-world information (multivariate correlated data) and information imperfections (scarcity of information or incomplete information). It is also very useful in handling real-world design aspects such as spatial variability that cannot be easily treated using deterministic means. Examples are presented to illustrate how reliability calculations could relieve engineering judgement from the unsuitable task of performance verification in the presence of uncertainties so that the engineer can focus on setting up the right lines of scientific investigation, selecting the appropriate models and parameters for calculations, and verifying the reasonableness of the results.     

国际背景下的海洋调查技术标准化发展路径研究

通过对比分析我国与美国、欧盟的标准战略、标准化组织机构、标准体系和海洋调查技术标准具体的制订现状,综合比较了我国与发达国家之间的差异,建议借鉴以民间自由竞争为特点的美国标准模式和以高度国际化的标准体系为特点的欧洲标准模式,同时充分发挥国际标准化组织海洋技术分委会(ISO/TC8/SC13)主席和秘书处落户中国这一平台优势的桥梁作用,探索我国海洋调查技术标准国际化的有效路径。     

ISO19100地理信息系列标准特点及其本土化

采用国际标准和国外先进标准是国民经济发展的重要技术基础工作。文章简略介绍国际标准化组织地理信息技术委员会(ISO/TC211)研制ISO19100地理信息系列标准的概况，着重分析其结构体系、研制特点，讨论将这些标准转化为国家标准，即本土化工作应当遵循的原则、方法、国家标准与国际标准一致性程度划分等问题，并提出ISO19100地理信息系列标准本土化工作的建议。     

基于ISO元数据扩展模型的土地覆盖遥感分类体系框架研究

由于研究主题和应用目的的不同,国内外已经存在和正在产生着越来越多的遥感数据源的土地覆盖分类体系。这不仅使得分类体系缺乏可扩展性与互操作性,而且使得不同分类体系的土地覆盖数据难以对比、交换和集成。本文借鉴ISO 19115地理信息元数据的扩展经验,设计了基于ISO元数据扩展模型的土地覆盖分类体系框架,并研究其动态扩展方法。提出一种包括核心分类、全集分类和专题应用分类的三层土地覆盖可扩展分类体系框架。其中,核心分类是从国内外主要的土地利用/覆盖分类系统中抽取的共性分类元素;全集分类收集全部可能的土地覆盖分类元素;专题应用分类通过对核心分类的继承,和对全集分类的裁剪和扩展生成。该分类框架将为土地利用/覆盖的研究和应用提供一种科学的、可比的动态分类扩展模型和方法。     

The Infrared Spectrum of Comet Hele–Bopp as Seen by the Infrared Space Observatory

Spectra of comet C/1995 O1 (Hale-Bopp) were obtained with the Infrared Space Observatory (ISO) at medium resolution with the grating spectrometer in the photometer (PHT-S) and/or at high resolution with the short wavelength spectrometer (SWS) and long wavelength spectrometer (LWS) in April 1996 (Crovisier et al., 1996), September–October 1996 (Crovisier et al., 1997a, b) and December 1997, at distances from the Sun of 4.6, 2.9 and 3.9 AU, respectively. For the first time, high-resolution spectra of a comet covering the entire 2.4 to 200 μm spectral range were obtained. The vibrational bands of H₂O, CO₂ and CO are detected in emission with PHT-S. Relative production rates of 100:22:70 are derived for H₂O:CO₂:CO at 3 AU pre-perihelion. H₂O is observed at high spectral resolution in the ν₃ group of bands around 2.7 μm and the ν₂ group around 6 μm with SWS, and in several rotational lines in the 100–180 μm region with LWS. The high signal-to-noise ratio of the ν₃ band observed on September–October 1996 allows accurate determinations of the water rotational temperature (28 K) and of its ortho-to-para ratio(2.45 ± 0.10, which significantly differs from the high temperature limit and corresponds to a spin temperature of 25 K). Longward of 6 μm the spectrum is dominated by dust thermal continuum emission, upon which broad emission features are superimposed. The wavelengths of the emission peaks correspond to those of Mg-rich crystalline olivine (forsterite). In the September–October 1996 spectra, emission features at 45 and 65 μm and possible absorption at 2.9–3.2 μm suggest that grains of water ice were present at 3 AU from the Sun. The observations made post-perihelion in late December 1997 led to the detections of H₂O, CO₂ and CO at 3.9 AU from the Sun (Figures 1 and 2). The production rates were ≈3.0 × 10²⁸,3.5 × 10²⁸ and ≈1.5 × 10²⁹ s^-1, respectively. This corresponds to H₂O:CO₂:CO = 100:110:500 and confirms that at such distances from the Sun, cometary activity is dominated by sublimation of CO and CO₂ rather than by H₂O. This revised version was published online in July 2006 with corrections to the Cover Date.