Conceiving processes in atmospheric models—General equations,subscale parameterizations,and ‘superparameterizations’

The scientific understanding of atmospheric processes has been rooted in the mechanical and physical view of nature ever since dynamic meteorology gained ground in the late 19th century. Conceiving the atmosphere as a giant ‘air mass circulation engine’ entails applying hydro- and thermodynamical theory to the subject in order to describe the atmosphere’s behaviour on small scales. But when it comes to forecasting, it turns out that this view is far too complex to be computed. The limitation of analytical methods precludes an exact solution, forcing scientists to make use of numerical simulation. However, simulation introduces two prerequisites to meteorology: First, the partitioning of the theoretical view into two parts—the large-scale behaviour of the atmosphere, and the effects of smaller-scale processes on this large-scale behaviour, so-called parametrizations; and second, the dependency on computational power in order to achieve a higher resolution. The history of today’s atmospheric circulation modelling can be reconstructed as the attempt to improve the handling of these basic constraints. It can be further seen as the old schism between theory and application under new circumstances, which triggers a new discussion about the question of how processes may be conceived in atmospheric modelling.     

The development of general circulation models of climate

With the coming of digital computers in the 1950s, a small American team set out to model the weather, followed by attempts to represent the entire general circulation of the atmosphere. The work spread during the 1960s, and by the 1970s a few modelers had produced somewhat realistic looking models of the planet’s regional climate pattern. The work took on wider interest when modelers tried increasing the level of greenhouse gases, and invariably found serious global warming. Skeptics pointed to dubious technical features, but by the late 1990s these problems were largely resolved—thanks to enormous increases in computer power, the number and size of the closely interacting teams that now comprised the international modeling community, and the crucial availability of field experiments and satellite data to set against the models’ assumptions and outputs. By 2007 nearly all climate experts accepted that the climate simulations represented reality well enough to impel strong action to restrict gas emissions.     

大气污染优化控制理论的一些新进展

本文介绍了国内学者的最新研究成果，包括了大气污染优化控制理论在以下几个具体应用领域的进展：(1)工业污染源的优化布局。应用伴随方法计算目标函数的梯度以求解优化问题，给出了理论框架。进行了数值试验。(2)短期空气质量的动态控制。应用实际气象数据和污染源数据进行了优化控制数值模拟。(3)化学风险的预先评价与控制。应用伴随方法，对运动化学源进行风险评价。规划最佳运输路线；针对禁止化学武器公约中处理日本二战期间遗弃化学武器的有关问题。妥善选择化武销毁工厂的地址。以上优化控制问题，以气象预报模式和大气污染预报模式为基础，而以伴随方法和最优化算法为求解途径，数值试验表明理论的正确性和方法的高效率。新发展的理论和方法与数值模式和观测技术紧密结合，并且顺应了计算机速度和容量高速增长的趋势。从而具有广阔的应用前景。     

Paper tools in experimental cultures

The paper studies various functions of Berzelian formulas in European organic chemistry prior to the mid-nineteenth century from a semiotic, historical and epistemological perspective. I argue that chemists applied Berzelian formulas as productive ‘paper tools’ for creating a chemical order in the ‘jungle’ of organic chemistry. Beginning in the late 1820s, chemists applied chemical formulas to build models of the binary constitution of organic compounds in analogy to inorganic compounds. Based on these formula models, they constructed new classifications of organic substances. They further applied Berzelian formulas in a twofold way to experimentally investigate organic chemical reactions: as tools which supplemented laboratory tools and as tools for constructing interpretive models of organic reactions. The scrutiny of chemists' performances with chemical formulas on paper also reveals a dialectic which contributed considerably to the formation of the new experimental culture of synthetic carbon chemistry that emerged between the late 1820s and the early 1840s. In an unintended and unforeseen way, the tools reacted back on the goals of their users and contributed to conceptual development and a shift of scientific objects and practices (‘substitution’) which transcended the originally intended chemical order.     

Fibrosing alveolitis (pulmonary interstitial fibrosis) evoked by experimental inhalation of Gasoline vapours

Summary Rats exposed to an atmosphere contaminated with gasoline vapour for 6–12 weeks exhibit progressive focal interstitial fibrosis of the lung, which is associated with irregular alveolar collapse. It is suggested that this experimental model of diffuse fibrosing lung disease constitutes a useful tool for the study of the dynamics of pulmonary reactivity to atmospheric pollutants and which may facilitate an understanding of the pathogenesis of fibrosing alveolitis in man.This work was supported by a grant from the National Health and Medical Research Council of Australia.     

Connections between simulations and observation in climate computer modeling. Scientist’s practices and “bottom-up epistemology” lessons

Climate modeling is closely tied, through its institutions and practices, to observations from satellites and to the field sciences. The validity, quality and scientific credibility of models are based on interaction between models and observation data. In the case of numerical modeling of climate and climate change, validation is not solely a scientific interest: the legitimacy of computer modeling, as a tool of knowledge, has been called into question in order to deny the reality of any anthropogenic climate change; model validations thereby bring political issues into play as well. There is no systematic protocol of validation: one never validates a model in general, but the capacity of a model to account for a defined climatic phenomenon or characteristic. From practices observed in the two research centers developing and using a climate model in France, this paper reviews different ways in which the researchers establish links between models and empirical data (which are not reduced to the latter validating the former) and convince themselves that their models are valid. The analysis of validation practices—relating to parametrization, modes of variability, climatic phenomena, etc.—allows us to highlight some elements of the epistemology of modeling.     

History and Epistemology of Models: Meteorology (1946–1963) as a Case Study

An early example is von Neumann's and Charney's Princeton Meteorological Project in the period 1946–53 which ended with daily numerical prediction in less than 2 hours. After this stage, the questions of long-range forecasting and general circulation of the atmosphere became of greater importance. The late 1950s saw the emergence of an alternative: were atmospheric models used mainly for prediction or understanding? This controversial debate in particular occurred during an important colloquium in Tokyo in 1960 which gathered together J. Charney, E. Lorenz, A. Eliassen, and B. Saltzman, among others, and witnessed discussions on statistical methods for predictions and/or maximum simplification of dynamic equations. This phase ended in 1963 with Lorenzs seminal paper on “Deterministic non periodic flows.” (Received February 11, 2000)     

多环芳烃的毒理学特征与生物标记物研究

多环芳烃主要来自于碳氢化合物不充分燃烧,在大气、水体和土壤中广泛地存在,由于多环芳烃具有疏水性、致癌性、致畸性、致突变性和生物难降解性,因此多环芳烃被看作是持久性有机污染物的主要代表。目前,多环芳烃的毒理学研究是环境科学领域的热点问题之一,研究主要集中在多环芳烃及其在环境中的降解和转化产物在体内的吸收、分布、排泄和代谢转化,以及阐明多环芳烃对人体毒作用的发生、发展和消除的各种条件和机理。生物标记物是有机污染物风险评价的核心内容,可以探索多环芳烃对人体健康损害的早期观察指标,即用最灵敏的探测手段,找出环境污染物作用于机体后最初出现的生物学变化,以便及早发现并设法排除。本文阐述了环境中多环芳烃的来源、性质和分布,评述了多环芳烃的毒理学研究进展,并对今后多环芳烃的毒理学的发展方向进行了论述。     

Spheres of Influence: Illustration,Notation, and John Dalton's Conceptual Toolbox, 1803–1835

In the early years of the nineteenth century, the English chemist John Dalton (1766–1844) developed his atomic theory, a set of theoretical commitments describing the nature of atoms and the rules guiding their interactions and combinations. In this paper, I examine a set of conceptual and illustrative tools used by Dalton in developing his theory as well as in presenting it to the public in printed form as well as in his many public lectures. These tools—the concept of ‘atmosphere’, the pile of shot analogy, and Dalton's system of chemical notation—served not just to guide Dalton's own thinking and to make his theories clear to his various audiences, but also to bind these theories together into a coherent system, presented in its definitive form in the three volumes of A New System of Chemical Philosophy (1808, 1810, and 1827). Despite these links, Dalton's contemporaries tended to pick and choose which of his theories to accept; his system of notation failed to be adopted in part because it embodied the whole of his system indivisibly.     

What do numerical (climate) models really represent?

The translation of a mathematical model into a numerical one employs various modifications in order to make the model accessible for computation. Such modifications include discretizations, approximations, heuristic assumptions, and other methods. The paper investigates the divergent styles of mathematical and numerical models in the case of a specific piece of code in a current atmospheric model. Cognizance of these modifications means that the question of the role and function of scientific models has to be reworked. Neither are numerical models pure intermediaries between theory and data, nor are they autonomous tools of inquiry. Instead, theory and data are transformed into a new symbolic form of research due to the fact that computation has become an essential requirement for every scientific practice. Therefore the question is posed: What do numerical (climate) models really represent?     

常温、常压、常态的大气环境下黏性土微观孔隙的缓慢变异特征

作为建筑材料和地基的土体处于常温、常压、常态的大气环境下,大气氧化过程是缓慢的、不易察觉的,但对土质长期劣化效果不容忽视.本文以此命题为出发点,以大气氧化过程中微观孔隙变化特征为突破口,联合扫描电镜测试、压汞法及氮吸附法研究大气环境作用对湛江黏土的微观结构改造作用及其对土性影响机理.研究表明,大气氧化后土色由青灰色、绿灰色变为淡黄棕、黄棕色,颗粒团聚程度增强,塑性降低,膨胀性与收缩性减弱,灵敏性与结构屈服强度明显降低.大气环境作用对d0.1?m孔隙组产生"缩合"效果,对d1?m孔隙组产生"胀散"效果,表现为氧化土的总孔隙体积减小,但d1?m的孔隙体积明显增大,局部出现断裂孔隙,"墨水瓶"型孔隙减少,开放性孔隙向封闭性孔隙转化.湛江黏土在大气影响下土性发生异变并不是土的矿物本性变化所引起,而是水-土-电解质-大气间的化学反应与运动导致颗粒联结形式更改进而重塑微观结构所导致,土的超微观结构形态变化是发生这一现象的根本因素.鉴于大气氧化过程导致的结构强度的减损效果对土体稳定性的影响是长期的且潜在危害较大,应加强监测环境物化因素变化对岩土工程的影响.     

An Inhomogeneous Hidden Markov Model for Efficient Virtual Machine Placement in Cloud Computing Environments

In a cloud environment virtual machines are created with different purposes, such as providing users with computers or handling web traffic. A virtual machine is created in such a way that a user will not notice any difference from working on a physical computer. A challenging problem in cloud computing is how to distribute the virtual machines on a set of physical servers. An optimal solution will provide each virtual machine with enough resources and at the same time not using more physical services (energy/electricity) than necessary to achieve this. In this paper we investigate how forecasting of future resource requirements (CPU consumption) for each virtual machine can be used to improve the virtual machine placement on the physical servers. We demonstrate that a time‐dependent hidden Markov model with an autoregressive observation process replicates the properties of the CPU consumption data in a realistic way and forecasts future CPU consumption efficiently. Copyright © 2016 John Wiley & Sons, Ltd.     

大气折射的研究进展

介绍了近几年大气折射映射函数研究的进展、以及几个常用的映射函数。对如今广泛地应用在空间测量技术中的几种映射函数做出评述。讨论了目前在无线电波段中广泛使用的NMF模型的优点和不足之处,提出了改进方向。列出了近几年上海天文台发展的大气折射母函数方法,以及由此导出的大气折射解析解;并分析了大气折射母函数方法引出的大气延迟新连分式映射函数,以及天文大气折射的映射函数方法的优点;指出了光学波段测距精度改进的途径。结合探空气球资料,讨论了大气模式对大气折射计算的影响。     

Knowledge transfer in theoretical ecology: Implications for incommensurability,voluntarism, and pluralism

Well-known epistemologies of science have implications for how best to understand knowledge transfer (KT). Yet, to date, no serious attempt has been made to explicate these particular implications. This paper infers views about KT from two popular epistemologies; what we characterize as incommensurabilitist views (after Devitt, 2001; Bird, 2002, 2008; Sankey and Hoyningen-Huene 2013) and voluntarist views (after Van Fraassen, 1984; Dupré, 2001; Chakravartty, 2015). We argue views of the former sort define the methodological, ontological, and social conditions under which research operates within ‘different worlds’ (to use Kuhn's expression), and entail that genuine KTs under those conditions should be difficult or even impossible. By contrast, more liberal voluntarist views recognize epistemological processes that allow for transfers across different sciences even under such conditions. After outlining these antithetical positions, we identify two kinds of KTs present in well-known episodes in the history of ecology—specifically, successful model transfers from chemical kinetics and thermodynamics into areas of ecological research—which reveal significant limitations of incommensurabilitist views. We conclude by discussing how the selected examples support a pluralistic voluntarism regarding KT.     

An integrated bayesian vector auto regression and error correction model for forecasting electricity consumption and prices

The analysis and forecasting of electricity consumption and prices has received considerable attention over the past forty years. In the 1950s and 1960s most of these forecasts and analyses were generated by simultaneous equation econometric models. Beginning in the 1970s, there was a shift in the modeling of economic variables from the structural equations approach with strong identifying restrictions towards a joint time-series model with very few restrictions. One such model is the vector auto regression (VAR) model. It was soon discovered that the unrestricted VAR models do not forecast well. The Bayesian vector auto regression (BVAR) approach as well the error correction model (ECM) and models based on the theory of co integration have been offered as alternatives to the simple VAR model. This paper argues that the BVAF., ECM, and co integration models are simply VAR models with various restrictions placed on the coefficients. Based on this notion of a restricted VAR model, a four-step procedure for specifying VAR forecasting models is presented and then applied to monthly data on US electricity consumption and prices.     

Influence of atmospheric factors on the rheumatic diseases

There appears to be ample evidence to conclude that various meteorological factors do exert a significant impact on some people with various rheumatic diseases. The data is, however, crude relative to our general understanding. Most of this research on RA has dealt with the primary signs and symptoms of inflammation. We know, however, many of the chemical mediators of inflammation. It seems like a logical progression of research to determine the effects of the meteorological/atmospheric factors of concern on these specific intrinsic mediators of inflammation. In general, gout can be very well controlled through medication. The evidence suggests, however, that we may gain a much better understanding of how atmospheric factors such as temperature can effect the body through changes in its physico-chemical processes by using Gout as a model. The work with SLE has already yielded useful applications. Sun screening pharmaceuticals have been quite successful in reducing exacerbations of symptoms. But we don't know why only some people are photosensitive. The previous research on the effects of atmospheric factors on the rheumatic diseases has illustrated key issues in methodology: large sample sizes are critical, objective and quantifiable disease variables are important, the variables measured must be specific to the questions investigated, the diseases investigated must be as specifically and accurately defined as possible, and the various aspects of 'weather' to be investigated must be specifically defined and quantified. It is apparent that there is much more important and useful work to be performed before we can understand the effects of atmospheric factors on the rheumatic diseases.     

Measurement in French Experimental Physics from Regnault to Lippmann. Rhetoric and Theoretical Practice

This paper explores the legacy of the great French experimental physicist Victor Regnault through the example of Gabriel Lippmann, whose engagement with electrical standardization during the early 1880s was guided by Regnault's methodological precept to measure ‘directly’. Lippmann's education reveals that the theoretical practice of ‘direct’ measurement entailed eliminating extraneous physical effects through the experimental design, rather than, like physicists in Britain and Germany, making numerical ‘corrections’ to measured values. It also provides, paradoxically, exemplars of the qualitative theoretical practices that sustained Regnault's misguided ambition to avoid theory. By considering the largely negative reactions to Lippmann's proposals for selecting suitable electrical units and methods of measuring the ohm, this paper associates these theoretical practices with the ineffectual rhetorical strategies employed by Lippmann to promote his work, and thereby indicates that the practice of direct measurement was limited to French experimental physics. Whilst this result aligns readily with the existence of divergent nineteenth century British and German cultures of precision, it emerges from a very different disciplinary context in which the practice of precision electrical measurement developed independently of submarine telegraphy. This is because, as this paper illustrates, telegraphic engineering and experimental physics remained separate professions in France.     

硅基高频器件与SiGe外延技术

本文描述了应用于SiGe外延的分子束外延(MBE)、超高真空化学气相沉积(UHV／CVD)、常压化学气相沉积(APCVD)、快速热化学气相沉积(RTCVD)等几种工艺及这几种工艺中的常见问题，并介绍了近来这些SiGe外延技术的改进，最后从器件角度对以上几种工艺特性进行了比较。     

Setting up a discipline, II: British history of science and “the end of ideology”, 1931-1948

For the history of science the 1940s were a transformative decade, when salient scholars like Herbert Butterfield or Alexandre Koyré set out to shape postwar culture by promoting new standards for understanding science. Some years ago I placed these developments in a tradition of enduring arts-science tensions and the contemporary notion that previous, “scientistic”, historical practices needed to be confronted with disinterested codes of historical craft (Mayer, 2000). Here, I want to further explore the ideological dimensions of the processes through which the academic study of science became institutionalized. Butterfield’s generation of science historians moulded perception of science in highly specific ways. Whereas the scientist-historians of the 1930s put scientific innovation into its socio-economic contexts, postwar accounts portrayed the birth of modern science as an intellectual revolution. Anti-Marxism formed a defining feature of the process by which the image of scientific work as a disinterested journey of the mind came to be institutionalized. Rather than spelling the end of ideology, appointments processes in the early Cold War years reveal disagreement about what science was to be invariably coextensive with dissent about social and political order. Rather than testifying to irreconcilable conflicts between interestedness and historical craft, the work of both the 1930s and 40s speaks of surprisingly productive relations between the two.