bluuebunny/crossref_metadata_2025 huggingface dataset:
Europe and its Historians
Authors: WOOLF STUART
Published: August 2003

Histories of Europe have a long genealogy, whose origins can probably be found in the defence of Christian Europe, above all in humanist circles, against the threat of Muslim Ottoman expansion. In the course of the Enlightenment and the Napoleonic years, earlier elements that were regarded as characterising all Europe crystallised into a sense common to European elites – described as ‘civilisation’ – of the distinctiveness and superiority of Europeans and Europe from all other regions of the world. If we analyse what was understood by this ‘idea of Europe’, as I have argued elsewhere, we can identify a number of constituent elements of Europe's progress that, for their authors, explain its distinctiveness, particularly when compared with the historical experiences or contemporary condition of states and societies elsewhere in the world. These elements can be summarised as: (i) a secular cultural tradition, originating in classical antiquity, that revived (after the ‘barbarian’ interlude) with the Renaissance and culminated in contemporary France; (ii) individual entrepreneurship as the motor of European economic dynamism and strength; (iii) liberty as the defining quality of governance; (iv) the balance of power between a limited number of leading states; and (v) civilised manners, or civilités, understood (in Norbert Elias's sense) as publicly accepted regulatory mechanisms of the forms of social relationships. The Restoration, as Federico Chabod has clarified, extended this corpus of values attributed to Europe through a recovery of the Middle Ages and Christianity.
Reply to Vinen
Authors: WOOLF STUART
Published: August 2003

It is possible, as Richard Vinen claims, that I arrange historians into categories that are too neat and selective. But I am puzzled by the relationship of his examples to the particular point that I was making. My argument was that the two world wars were experienced as a crisis that placed in doubt the assumptions underlying the interpretation of the long-term progress of European civilisation. I limited my illustration of this to historians who – during these thirty years – wrote histories of Europe that seemed to me to exemplify their responses, either through their vindication of what Europe had offered to humanity until its self-destruction, or, in Toynbee's case, through a comparative study of the cycle of civilisations. Marc Bloch was not included because his Strange Defeat was specific to France; whereas Braudel (whom I should have included) seems to me to strengthen my case, as his Mediterranean certainly carries the message of European civilisation. The fact that Pirenne's great work was only published posthumously is interesting, but it is when he wrote it that matters. His age, like Fisher's, seems to me irrelevant, or possibly even confirms the importance for historians of an earlier liberal period of the identification of Europe's history with progress.
Cash or Account? A Plea for a Comparative History of European Financial Systems
Authors: HAUTCOEUR PIERRE-CYRILLE
Published: August 2003

A number of recent events have shown that finance still has an important part to play in the modern economy: banks may take excessive risks; accounting and supervisory systems may prove inadequate; stock-market prices may collapse and leave rash undertakings perilously over-indebted. The stagnation of the Japanese economy from 1990 onwards is a stark reminder that such events may have a real impact. Can a knowledge of financial history help to make them better understood? The plethora of recent works in the field at least gives some background against which to measure the rapid changes now occurring. In this article I shall attempt an overview of the field, with particular attention to the recent works listed above. First I shall trace the evolution of the notion of ‘financial systems’ as a coherent and stable set of financial relationships and organisations, as it has emerged from cross-fertilisation of work by economists and historians. One difficulty about analysing such systems is that they can be long-lived (often forty years or more) and so change only slowly and in a way that can be hard to grasp. As a result, many historians tend to neglect the striking differences between countries, whereas economists like to compare snapshots of systems in different countries at a given moment. My object in this article is to alert the reader to the risk that recent advances in the study of the American financial system may become a stumbling block to the study of very different European models. On the other hand, some directions in the study of eighteenth- and nineteenth-century European history may throw fresh light both on contemporary European financial systems and on some dark corners in the financial history of the United States.
The 1968 Czechoslovak Crisis: Reconsidering its History and Politics
Authors: BRACKE MAUD
Published: August 2003

The past few years have seen the publication of a number of important contributions to the historiography of the Prague Spring of 1968, the Soviet-led invasion of Czechoslovakia in August that year and the process of so-called ‘normalisation’ in the country and the wider communist world. The Czechoslovak crisis of 1968–9 has never really ceased to inspire either scholarly research or passionate public and political debate. It has attracted even more attention, though, since its thirtieth anniversary in 1998, and a state-of-the-art essay seems appropriate.
Sounds of the city: the soundscape of early modern European towns
Authors: GARRIOCH DAVID
Published: August 2003

In European towns of the seventeenth, eighteenth and nineteenth
centuries, the sounds people heard were very different from those of today. Yet the
difference goes much deeper: whereas today we try to escape city noise, for the inhabitants of
early modern towns sound served as a crucial source of information. It formed a semiotic system,
conveying news, helping people to locate themselves in time and in space, and making them part of
an ‘auditory community’. Sound helped to construct identity and to structure

relationships. The evolution of this information system reflects changes in social and political organization and in attitudes towards time and urban space.
Chelmsford during the industrial revolution, c.1790–1840
Authors: RAVEN NEIL
Published: August 2003

Were England's old shire towns marginalized from the process of economic change during the period of the classical Industrial Revolution? A number of contributors to The Cambridge Urban History of Britain, Vol. II make this claim, others emphasize the continued relevance of these towns in the emerging industrial age. With few investigations undertaken into the county towns of the late eighteenth and early nineteenth centuries, detailed case study analysis is needed. Using trade directories to profile Chelmsford's business community, this article presents evidence of a dynamic and prosperous urban economy.
Leisure, consumption and the European city
Authors: LOWERSON JOHN
Published: August 2003

Producing and consuming studies of consumption has become a minor industry in its own right amongst the current generation of historians and it has moved significantly beyond the pioneering histories of shopping which we associate with Alison Adburgham and others. Instead, it has moved into the broader realms of cultural formation, both in wider terms of social change and in the context of regional and local identities, as well as international comparisons. So it comes as little surprise to find a batch of current studies which deal with the present complexities of scholarly approaches in distinctive but overlapping ways. In this development British historians have made significant pioneering contributions but it becomes apparent from some of the present offerings that initiatives may have moved elsewhere. That is hardly a cause for national mourning but at least some parts of the works reviewed here, written abroad, show an awareness of British developments which is too rarely reciprocated in studies originating on this side of the Channel and North Sea (or ‘German Ocean’ as more appropriate in view of the insularity which produces them). Perhaps the appalling inability to read European languages now so common amongst both under- and postgraduate students is also more widespread amongst academic historians than we have realized or are prepared to admit. It is also very likely that the situation is being exacerbated by the short termism of the Research Assessment Exercise's demands for a frequency of output which militates against the extended period necessary for sophisticated comparisons – so much of its classification of ‘international excellence’ seems more to do with single-focused rather than real international studies. Yet there is much on offer in Europe in particular which cries out for more systematic comparative analysis and some of the work reviewed here offers a good starting point.
French urban elites
Authors: FORREST ALAN
Published: August 2003

In France, as in the Anglo-Saxon world, social history has undergone a sea change in recent years with the growth of interest in issues of culture and representation, with the result that historians have come to ask rather different questions about cities and their social fabric. The change was not, of course, achieved overnight: since the 1930s the Annalistes have been opening up new approaches to the analysis of power and status, while in the development of micro-history Emmanuel Le Roy Ladurie's Montaillou occupies an honoured place. In this the lingering influence of a Marxist model has played an important part. For decades Marxist theory provided the key which opened up issues of social power and class division, the methodology which led to a widespread study of urban structures and social dominance. And though in some hands it might be criticized for leading to an over-arching concern with the urban economy and the growth of the industrial city, the same Marxist perspective also encouraged studies of such questions as the identity of urban elites, the extent of social mobility within cities and the development of suburbs. More recently French historians have been among the most innovative in exploring the culture of urban life in a variety of different contexts, whether – and here I shall simply cite representative examples – by the study of individual professions (Christophe Charle), of dress and public appearance (Daniel Roche), or of the appropriation of urban space (Bernard Lepetit). The three books under review here all, in their different ways, contribute to our understanding of that urban culture and of the changes which it has undergone. Yannec Le Marec takes up Charle's arguments through a micro-history of the professional development of lawyers and doctors in the south Breton city of Nantes during the nineteenth century. Natacha Coquery, looking at the eighteenth century, explains the representation of social power implicit in the transfer of sumptuous Paris hôtels from private use to that of government ministries and their fast-multiplying staff. And Claude Petitfrère presents an edited collection of papers, emanating from a conference organized by the highly influential Centre d'histoire de la ville moderne et contemporaine in his own university at Tours, which illuminates across time and place the ways in which an urban patriciate was first constructed, then reproduced and represented to contemporaries. Taken together the three volumes go far to illustrate current developments in historiography and offer an overview of the present state of urban social history in France.
Darwinian aesthetics: sexual selection and the biology of beauty
Authors: GRAMMER KARL , FINK BERNHARD , MØLLER ANDERS P. , THORNHILL RANDY
Published: August 2003

Current theoretical and empirical findings suggest that mate preferences are mainly cued on visual, vocal and chemical cues that reveal health including developmental health. Beautiful and irresistible features have evolved numerous times in plants and animals due to sexual selection, and such preferences and beauty standards provide evidence for the claim that human beauty and obsession with bodily beauty are mirrored in analogous traits and tendencies throughout the plant and animal kingdoms. Human beauty standards reflect our evolutionary distant and recent past and emphasize the role of health assessment in mate choice as reflected by analyses of the attractiveness of visual characters of the face and the body, but also of vocal and olfactory signals. Although beauty standards may vary between cultures and between times, we show in this review that the underlying selection pressures, which shaped the standards, are the same. Moreover we show that it is not the content of the standards that show evidence of convergence ‐ it is the rules or how we construct beauty ideals that have universalities across cultures. These findings have implications for medical, social and biological sciences.
Descent with modification: the unity underlying homology and homoplasy as seen through an analysis of development and evolution
Authors: HALL BRIAN K.
Published: August 2003

Homology is at the foundation of comparative studies in biology at all levels from genes to phenotypes. Homology similarity because of common descent and ancestry, homoplasy is similarity arrived at via independent evolution However, given that there is but one tree of life, all organisms, and therefore all features of organisms, share degree of relationship and similarity one to another. That sharing may be similarity or even identity of structure the sharing of a most recent common ancestor–as in the homology of the arms of humans and apes–or it reflect some (often small) degree of similarity, such as that between the wings of insects and the wings of groups whose shared ancestor lies deep within the evolutionary history of the Metazoa. It may reflect sharing entire developmental pathways, partial sharing, or divergent pathways. This review compares features classified homologous with the classes of features normally grouped as homoplastic, the latter being convergence, parallelism, reversals, rudiments, vestiges, and atavisms. On the one hand, developmental mechanisms may be conserved, when a complete structure does not form (rudiments, vestiges), or when a structure appears only in some individuals (atavisms). On the other hand, different developmental mechanisms can produce similar (homologous) features Joint examination of nearness of relationship and degree of shared development reveals a continuum within expanded category of homology, extending from homology → reversals → rudiments → vestiges → atavisms → parallelism, with convergence as the only class of homoplasy, an idea that turns out to be surprisingly old. realignment provides a glimmer of a way to bridge phylogenetic and developmental approaches to homology homoplasy, a bridge that should provide a key pillar for evolutionary developmental biology (evo‐devo). It will and in a practical sense cannot, alter how homoplastic features are identified in phylogenetic analyses. But rudiments, reversals, vestiges, atavisms and parallelism as closer to homology than to homoplasy should guide toward searching for the common elements underlying the formation of the phenotype (what some have called deep homology of genetic and/or cellular mechanisms), rather than discussing features in terms of shared independent evolution.
Cross‐coupled flow modeling of coincident streaming and electrochemical potentials and application to subglacial self‐potential data
Authors: Kulessa Bernd , Hubbard Bryn , Brown Giles H.
Published: August 2003

This study aims to demonstrate that self‐potential measurements can yield unique information about subglacial drainage conditions, which has so far been doubtful. At the bed of warm‐based glaciers arborescent and distributed drainage systems interact, and streaming and electrochemical potentials coincide. A key secondary aim of this study is, therefore, the development of a mathematical framework for the analysis of self‐potentials generated by such interacting flow systems. We consider cross coupling between hydraulic, electrical, and chemical driving forces, and apply the resulting model solution to self‐potential data recorded beneath Haut Glacier d'Arolla, Switzerland. We find that (1) the streaming and electrochemical contributions to the total self‐potential signal can be separated mathematically, (2) streaming potentials directly reflect the direction of water flow at the glacier bed, (3) combination of streaming potentials with hydraulic conductivity estimates from slug tests allows estimation of in situ subglacial water flow velocities, (4) the subglacial zeta potential, calculated from estimated values of the streaming coupling coefficient, is small (∼−0.022 V) due to systematic flushing of clay minerals from the channel area during the melt season, and (5) uncertainties in exact electrode location in the borehole are unlikely to produce self‐potential noise. Self‐potential measurements may therefore yield unique information about subglacial drainage conditions, and especially the direction and velocity of in situ subglacial water flow are difficult to obtain by other methods. We further anticipate that our mathematical framework will be applicable to other areas of subsurface hydrology, especially where spatially distributed seepage feeds preferential flow pathways.
Observations of the latitudinal structure of plasmaspheric convection plumes by IMAGE‐RPI and EUV
Authors: Garcia Leonard N. , Fung Shing F. , Green James L. , Boardsen Scott A. , Sandel Bill R. , Reinisch Bodo W.
Published: August 2003

Recent IMAGE Extreme Ultraviolet Imager (EUV) observations showed the first global images of plasmaspheric convection plumes, which have been interpreted as the plasmaspheric tails predicted theoretically 3 decades earlier. Using observations by the IMAGE Radio Plasma Imager (RPI), we show that these convection plumes have large latitudinal extent. These results complement those recently made by others in correlating IMAGE EUV data with measurements of total electron content in the ionosphere. By correlating in situ RPI density measurements with global plasmaspheric EUV images, we have shown that apparently detached plasma structures, as appear in RPI dynamic spectrograms, are in many cases plasmaspheric convection plumes. The temporal separation between the RPI and EUV observations help constrain the interpretation of one data set in the context of the other, thereby enabling an examination of the three‐dimensional plasma density structures outside the core plasmasphere. The data sets are mutually reinforcing because the data are collected within a few hours of one another. We used the EUV data to provide unambiguous identification of density enhancements in the region outside the plasmasphere and used the RPI data to obtain accurate number densities and extend information from the EUV data set by measuring densities below the EUV sensitivity threshold.
A study of the expansion and distortion of the cross section of magnetic clouds in the interplanetary medium
Authors: Hidalgo M. A.
Published: August 2003

Herein an approach is presented to determine the expansion and distortion of the cross section of magnetic clouds (MCs) in their evolution in the interplanetary medium. This approach, based on the improvement of our previous elliptical cross‐section model for the magnetic topology of MCs, gives analytical expressions for and which incorporate the expansion of the cross section of clouds. Our starting point is the assumption of a spatially uniform jη, the normal component of the plasma current density to the cross section of the cloud. As it is described in the text, this expansion provides a time dependency of the three components of the plasma current density. The main physical consequences of this behavior are discussed. Fittings to eight selected MCs of years 2000 and 2001 with different magnetic field profiles are presented.
Results of rock magnetic investigations and relative paleointensity determinations on lacustrine sediments from Birkat Ram, Golan Heights (Israel)
Authors: Frank Ute , Schwab Markus J. , Negendank Jörg. F. W.
Published: August 2003

Detailed rock magnetic investigations, including the analysis of the laboratory installed magnetizations, the measurement of hysteresis parameters, and the high temperature‐dependency of the saturation magnetization, were carried out on sediments from Birkat Ram, Golan Heights, Israel. The 550 cm long composite profile, composed of three single cores, is supposed to span the Late Holocene, i.e., the last 4400 years, at least. Titanomagnetites in the pseudo single‐domain range were identified as the main magnetic carrier minerals in the homogenous sediments. The variations in concentration and grain size of the magnetic fraction are only partly reflected in the sediment lithology. The relative paleointensity was estimated by normalizing the intensity of the natural remanent magnetization (NRM) after demagnetization at 20 mT (JNRM(20 mT)) by different concentration parameters. The median destructive field of the NRM (MDFNRM) is coherent with the relative paleointensity estimates, indicating that a sedimentary effect has not sufficiently been removed by the normalization process. The morphologies of these estimates, however, correspond to the archeomagnetic records from Bulgaria and Greece. Therefore a second normalization, based on the linear relationship between the paleointensity estimates and the MDFNRM, was applied, resulting in an improvement of the records.
Granular memory and its effect on the triggering and distribution of rock avalanche events
Authors: Friedmann S. J. , Kwon G. , Losert W.
Published: August 2003

Rock avalanches are uncommon, large, catastrophic events in which granular masses of rock flow at high speeds, commonly with unusually long runouts. Necessary conditions for rock avalanche occurrence include high relief, steep slopes, and a prefractured (granular) groundmass. An additional parameter, antecedent shear of the granular mass in the direction of failure, may be prerequisite. In many instances the basement mass of the eventual landslide underwent internal strain subparallel to the direction of mass wasting, commonly focused along a basal surface (e.g., fault). New experimental data from laboratory experiments indicate that shear of a granular mass produces subtle anisotropy in grain arrangements that strongly affects the subsequent distribution of deformation and rearrangement, the failure threshold, and the rate at which steady state conditions are reached. This phenomenon may help to explain the spatial clustering of rock avalanche deposits. If memory of prior shear is also relevant on larger scales, taking deformation history into account could greatly enhance prediction of rock avalanche occurrence.
Behavior of 137Cs concentrations in the North Pacific in an ocean general circulation model
Authors: Tsumune Daisuke , Aoyama Michio , Hirose Katsumi
Published: August 2003

We have carried out a first simulation of the spatial distributions and the temporal variations of 137Cs concentrations in the North Pacific in off line calculations by using archived output of an ocean general circulation model (OGCM) developed by the National Center of Atmospheric Research (NCAR). Artificial radionuclides including 137Cs are introduced into ocean surface due to global fallout originating from the large‐scale atmospheric nuclear weapons tests in 1961–1962. The distribution of radioactive deposition used as forcing for this simulation is estimated from global precipitation data and observed values of annual deposition of radionuclides at the Meteorological Research Institute (MRI) in Japan. 137Cs originating from global fallout have been transported into the ocean interior by advection and diffusion, and the 137Cs concentrations reduced by radioactive decay. We assess the skill of the model calculations by comparing simulated values of 137Cs in seawater with the observed values included in the database compiled by MRI because 137Cs is one of the most useful tracers regarding water motion in the ocean. The vertical and horizontal distributions of the calculated 137Cs concentrations were in good agreement with those of the observed 137Cs concentrations, except in the deep layer.
Variability of the subtropical “edges” in the stratosphere
Authors: Neu J. L. , Sparling L. C. , Plumb R. A.
Published: August 2003

It is well‐established that the air in the tropical stratosphere remains somewhat isolated from that in the midlatitudes over relatively long time scales. We examine the seasonal and interannual variability of the subtropical tracer gradients that mark the boundaries between tropical and extratropical air. We use probability distribution functions (PDFs) of satellite measurements of long‐lived tracers to identify the air in the transition region between the tropics and the extratropics in each hemisphere. This region is commonly called the subtropical “edge” region, and it appears as a valley in the tracer PDF. We provide a method to identify a single characteristic latitude for these edge regions as well as, when possible, their areal extent. We identify the subtropical edges in more than six years of measurements at eight pressure levels on quasi‐monthly time scales. We correlate the variability of the subtropical edges with variability in several transport parameters and thus shed light on the mechanisms of tropical isolation from a diagnostic standpoint. We also discuss the implications of our results in terms of large‐scale tracer transport in the context of simple models of tracer budgets.
Simultaneous measurements of particulate elemental carbon on the ground observation network over the western North Pacific during the ACE‐Asia campaign
Authors: Matsumoto Kiyoshi , Uematsu Mitsuo , Hayano Teruaki , Yoshioka Katsuhiro , Tanimoto Hiroshi , Iida Takao
Published: August 2003

The measurements of atmospheric aerosol and associated species have been carried out on the ground observation network over the western North Pacific as part of the Variability of Marine Aerosol Properties (VMAP) project. The network consists of four Japanese islands (Rishiri, Sado, Hachijo, and Chichi‐jima), ranging widely in latitudes from 25°N to 45°N along with the line of 140°E. In this paper, we report on simultaneous measurements of particulate elemental carbon (EC) on the four islands from March to May 2001, which cooperated with the Asia‐Pacific Regional Aerosol Characterization Experiment (ACE‐Asia) campaign, in order to characterize the outflow patterns of continental polluted air masses to the North Pacific. The mean concentrations of particulate EC in the four islands during this period ranged from 0.18 to 0.60 μg m−3. It is interesting to note that the temporal variations in the concentrations of particulate EC in Rishiri and Sado, which are located in the northern region of Japan (35°N–45°N), synchronized with each other. The EC concentrations in Hachijo and Chichi‐jima, located in the southern region of Japan (25°N–35°N), also showed similar temporal variations with each other but did not synchronize with those in Rishiri and Sado. These results demonstrate that the transport patterns of the polluted air masses from the east Asian continent to the northern regions of the northwestern Pacific are often different from those to the southern regions. It was also found that continental air masses are usually accompanied by pollutants over the southern regions but not over the northern regions of the northwestern Pacific.
Seasonal and annual modeling of reduced nitrogen compounds over the eastern United States: Emissions, ambient levels, and deposition amounts
Authors: Mathur Rohit , Dennis Robin L.
Published: August 2003

Detailed description of the distributions and seasonal trends of atmospheric nitrogen compounds is of considerable interest given their role in formation of acidic substances, tropospheric ozone and particulate matter and nutrient loading effects resulting from their deposition to sensitive ecosystems. While the oxidized nitrogen species have received considerable research and regulatory attention over the past several decades, little effort has been devoted toward quantifying the atmospheric budgets of reduced nitrogen compounds (NHx) associated with emissions of ammonia. The Regional Acid Deposition Model is enhanced to include detailed treatments of the physical and chemical processes regulating the fate of ammonia emissions and to model the interaction and chemical and thermodynamic coupling between atmospheric NOx‐SOx‐NHx species. To account for uncertainties in magnitude and seasonal variation of ammonia emissions, regional seasonal correction factors for ammonia emissions in the eastern United States are developed through successive model applications and comparison with measurements from regional networks of ambient concentrations and deposition amounts of various species. The resulting ammonia emissions show a distinct seasonal cycle with a maximum in summer followed by spring, fall, and winter. Our calculations suggest that the range between NH3 emissions during the cool and the warm season is a factor of 3–4. Correlations between model predicted ambient levels, gas/particle partitioning, and deposition amounts with measurements show good agreement on both an annual and seasonal basis with R2 in the 0.4–0.7 range for most species examined. Both model calculations and measurements indicate that during winter, large portions of the eastern U.S. are characterized by aerosols that are fully neutralized. Our model calculations for emission scenarios representative of the late 1980s–early 1990s period also indicate that reduced nitrogen species contribute 47(±8)% of the total nitrogen wet deposition in the eastern U.S.; this is in good agreement with 43(±9)% inferred from deposition measurements. These comparisons suggest that the model can capture the spatial and seasonal variability in distributions of various model species, the chemical interactions between reduced and oxidized nitrogen compounds in the troposphere, and the compositional characteristics of inorganic aerosol mass in the region.
Characteristics of cloud‐to‐ground lightning in severe and nonsevere storms over the central United States from 1989–1998
Authors: Carey Lawrence D. , Rutledge Steven A.
Published: August 2003

Over a region from the Kansas/Colorado border to Minnesota, previously associated with positive anomalies in the mean annual positive cloud‐to‐ground (CG) lightning percentage and positive peak current, we describe significant differences in the properties of CG lightning flashes between warm‐season severe (i.e., large hail or tornado producing) and nonsevere storms. The percentage of CG lightning flashes lowering positive charge to ground was substantially higher in severe storms (i.e., up to three times higher). The median positive peak current in severe storms was significantly larger (i.e., by about 25%). Finally, the median negative peak current in severe storms was very low (i.e., as low as 12–16 kA) and was noticeably smaller than in nonsevere storms (i.e., by at least 10%). Severe storms appeared to be significant producers of positive CG lightning in the anomaly region (AR). Up to 30%–70% of warm season positive flashes in the AR were associated with severe storms. Only 2%–30% of negative flashes were associated with severe storms in the AR. As a result, the mean warm season (and likely annual) positive anomalies in positive CG percentage and peak current are likely associated with a unique class of severe, organized storms that occur preferentially in this geographical region. We found substantial differences in the properties of CG lightning flashes associated with severe storms in other regions. For example, the mean warm season properties of CG lightning associated with severe storms in the region of peak large hail and tornado activity (e.g., Oklahoma) were fundamentally different (i.e., significantly lower positive CG percentage, lower positive peak currents and higher negative peak currents) compared to severe storms over the AR from western Kansas to Minnesota.
Quasi‐biennial oscillation in ozone in a coupled chemistry‐climate model
Authors: Butchart Neal , Scaife Adam A. , Austin John , Hare Sylvia H. E. , Knight Jeff R.
Published: August 2003

Tropical ozone variability is analysed in a version of the Met Office Unified Model with stratospheric chemistry and transport. The model reproduced the stratospheric quasi‐biennial oscillation (QBO) in the equatorial winds, forced by a broad spectrum of atmospheric waves. This resulted in a corresponding ozone QBO with vertical phase reversal near 10 hPa and amplitude consistent with observations. It was driven mainly by the QBO‐induced vertical velocity anomaly, with the 10 hPa phase reversal a consequence of the sign change in the mean ozone vertical gradient. Chemistry was important for determining phase differences between the ozone and dynamical QBOs. Simulated column ozone anomalies were in reasonable agreement with observations in the tropics, but too weak in the sub‐tropics. Nonetheless, the observed sub‐tropical to tropical phase reversal and seasonal synchronization of the sub‐tropical anomalies were reproduced. In contrast to some other studies our ozone QBO was obtained without QBO‐induced variations in NOy transport, implying that ozone transport is an important forcing term in the upper, as well as the lower, stratosphere. In the lower stratosphere (21.5 hPa), diabatic effects of the ozone QBO increased the amplitude of the temperature oscillation by 35%. The mean period of the wind oscillation was also extended by about 10%, due to a longer westerly phase. These results imply that a better representation of chemical, as well as dynamical processes, will be required for improving the inter‐annual variability in the tropical stratosphere in climate models.
Phase changes in internally mixed maleic acid/ammonium sulfate aerosols
Authors: Brooks Sarah D. , Garland Rebecca M. , Wise Matthew E. , Prenni Anthony J. , Cushing Melinda , Hewitt Erika , Tolbert Margaret A.
Published: August 2003

A temperature controlled flow tube system equipped with Fourier transform infrared (FTIR) detection of particle phase and relative humidity was used to measure the deliquescence and efflorescence of ammonium sulfate, maleic acid, and internally mixed maleic acid/ammonium sulfate particles. Our results indicate that maleic acid aerosols begin to take up water starting at a low relative humidity, ∼20%, and continue the constant uptake of water until the final deliquescence relative humidity (DRH), 89%, is reached. Internally mixed particles containing maleic acid and ammonium sulfate were found to deliquesce at a lower relative humidity (RH) than either of the pure species. Efflorescence studies indicated that while pure maleic acid particles crystallize at ∼18% RH, pure ammonium sulfate and all mixed aerosols effloresce at or just below 30% RH. Taken together, our results suggest that the presence of water‐soluble organics internally mixed with ammonium sulfate aerosol could increase the range of conditions under which the aerosol is a solution.
Characterization of carbonaceous aerosols outflow from India and Arabia: Biomass/biofuel burning and fossil fuel combustion
Authors: Guazzotti S. A. , Suess D. T. , Coffee K. R. , Quinn P. K. , Bates T. S. , Wisthaler A. , Hansel A. , Ball W. P. , Dickerson R. R. , Neusüß C. , Crutzen P. J. , Prather K. A.
Published: August 2003

A major objective of the Indian Ocean Experiment (INDOEX) involves the characterization of the extent and chemical composition of pollution outflow from the Indian Subcontinent during the winter monsoon. During this season, low‐level flow from the continent transports pollutants over the Indian Ocean toward the Intertropical Convergence Zone (ITCZ). Traditional standardized aerosol particle chemical analysis, together with real‐time single particle and fast‐response gas‐phase measurements provided characterization of the sampled aerosol chemical properties. The gas‐ and particle‐phase chemical compositions of encountered air parcels changed according to their geographic origin, which was traced by back trajectory analysis. The temporal evolutions of acetonitrile, a long‐lived specific tracer for biomass/biofuel burning, number concentration of submicrometer carbon‐containing particles with potassium (indicative of combustion sources), and mass concentration of submicrometer non‐sea‐salt (nss) potassium are compared. High correlation coefficients (0.84 < r2< 0.92) are determined for these comparisons indicating that most likely the majority of the species evolve from the same, related, or proximate sources. Aerosol and trace gas measurements provide evidence that emissions from fossil fuel and biomass/biofuel burning are subject to long‐range transport, thereby contributing to anthropogenic pollution even in areas downwind of South Asia. Specifically, high concentrations of submicrometer nss potassium, carbon‐containing particles with potassium, and acetonitrile are observed in air masses advected from the Indian subcontinent, indicating a strong impact of biomass/biofuel burning in India during the sampling periods (74 (±9)% biomass/biofuel contribution to submicrometer carbonaceous aerosol). In contrast, lower values for these same species were measured in air masses from the Arabian Peninsula, where dominance of fossil fuel combustion is suggested by results from single‐particle analysis and supported by results from gas‐phase measurements (63 (±9))% fossil fuel contribution to submicrometer carbonaceous aerosol). Results presented here demonstrate the importance of simultaneous, detailed gas‐ and particle‐phase measurements of related species when evaluating possible source contributions to aerosols in different regions of the world.
Modeling lidar waveforms with time‐dependent stochastic radiative transfer theory for remote estimations of forest structure
Authors: Kotchenova Svetlana Y. , Shabanov Nikolay V. , Knyazikhin Yuri , Davis Anthony B. , Dubayah Ralph , Myneni Ranga B.
Published: August 2003

Large footprint waveform‐recording laser altimeters (lidars) have demonstrated a potential for accurate remote sensing of forest biomass and structure, important for regional and global climate studies. Currently, radiative transfer analyses of lidar data are based on the simplifying assumption that only single scattering contributes to the return signal, which may lead to errors in the modeling of the lower portions of recorded waveforms in the near‐infrared spectrum. In this study we apply time‐dependent stochastic radiative transfer (RT) theory to model the propagation of lidar pulses through forest canopies. A time‐dependent stochastic RT equation is formulated and solved numerically. Such an approach describes multiple scattering events, allows for realistic representation of forest structure including foliage clumping and gaps, simulates off‐nadir and multiangular observations, and has the potential to provide better approximations of return waveforms. The model was tested with field data from two conifer forest stands (southern old jack pine and southern old black spruce) in central Canada and two closed canopy deciduous forest stands (with overstory dominated by tulip poplar) in eastern Maryland. Model‐simulated signals were compared with waveforms recorded by the Scanning Lidar Imager of Canopies by Echo Recovery (SLICER) over these regions. Model simulations show good agreement with SLICER signals having a slow decay of the waveform. The analysis of the effects of multiple scattering shows that multiply scattered photons magnify the amplitude of the reflected signal, especially that originating from the lower portions of the canopy.
Comparison of seasonal and spatial variations of albedos from Moderate‐Resolution Imaging Spectroradiometer (MODIS) and Common Land Model
Authors: Zhou L. , Dickinson R. E. , Tian Y. , Zeng X. , Dai Y. , Yang Z.‐L. , Schaaf C. B. , Gao F. , Jin Y. , Strahler A. , Myneni R. B. , Yu H. , Wu W. , Shaikh M.
Published: August 2003

This paper compares seasonal and spatial variations of Moderate Resolution Imaging Spectroradiometer (MODIS) albedos with those from the Common Land Model (CLM) by land cover type. MODIS albedo data in the year 2001 were used to determine seasonal, spatial, and land cover dependence at 1 km resolution and to investigate the biases in CLM. Albedo dependence on vegetation type is smaller than that on snow and soil. Snow causes the largest temporal and spatial variations, especially in the visible band (0.3–0.7 μm). CLM has visible albedos that are lower by up to 0.4–0.5 in winter over northern high latitudes but are globally higher by 0.02–0.04 in summer over most vegetation, mainly due to its overestimated leaf and stem area index in winter and slightly higher prescribed canopy albedos in summer, respectively. MODIS and CLM differ considerably in soil albedo over desert and semidesert regions, especially in the near‐infrared band (0.7–5.0 μm), with the largest low bias of about 0.1 in the Sahara. Adjustments of the prescribed albedos in CLM based on MODIS observations could reduce such biases. Therefore the model should better represent leaf and stem area index, vegetation albedo in the presence of snow, and soil albedo.
Effects of lithospheric properties on the formation of Type 2 coronae on Venus
Authors: Smrekar Suzanne E. , Stofan Ellen R.
Published: August 2003

Over 500 coronae occur on Venus. A recent survey defined Type 2 coronae as those with <50% complete fracture annuli. This paper synthesizes the results from a statistical study of the size, topographic morphology and geologic setting of the entire corona population and a study of the gravity and topography of the 32 Type 2 coronae resolved in the gravity data. Using the estimated lithospheric properties, loading signature, and geologic characteristics, we examine the factors controlling corona morphology, size and fracture completeness (Type 1 versus Type 2). We find no difference between lithospheric properties in the plains and fractures belts. Nearly half of the Type 2 coronae studied are isostatically compensated, and probably inactive. This implies that the final stage of a corona may have a wide range of topographic morphologies. Elastic thickness has no correlation with diameter and therefore does not limit corona size. The ratio of crustal thickness to plume diameter does not control morphology as a function of size, as predicted by a spreading drop model. However, rim‐only coronae, which are predicted to form via isostatic rebound of crust thickened by delamination, are supported by a density interface. Isostasy and delamination of the lower lithosphere are likely to have a greater effect on corona formation, and possibly in understanding the evolution of the Venusian lithosphere, than variations in elastic thickness. The role of isostasy in the formation of Type 2 coronae suggests that surface fractures may be reduced due to low strain rates.
A gravity survey of Type 2 coronae on Venus
Authors: Smrekar Suzanne E. , Comstock Robert , Anderson F. Scott
Published: August 2003

Coronae are roughly circular tectonic features believed to form as a result of small‐scale mantle upwellings. We examine the admittance signature for all the 32 Type 2 coronae (defined as having less than 50% complete fracture annuli) that are both well resolved in the gravity data and have fairly well constrained lithospheric parameters. We use top and bottom loading models to derive values of elastic thickness and crustal thickness or apparent depth of compensation. Both Cartesian and spatiospectral methods are used to calculate admittance. Overall we find reasonable agreement between the two methods. The shape of the filter used in the spatiospectral method [Simons et al., 1997] provides a means of isolating the signature of coronae that occur in close proximity to other geologic features. The narrow filters used in the Cartesian approach are useful for identifying transitions between different types of compensation, as well as for estimating error. We obtain a wide range of elastic thicknesses, from 25 to 80 km. Larger values are derived from bottom loading models, which have not been used in most prior studies of Venus. Fifteen of the coronae have elastic thickness values between 0 and 20 km and are probably isostatically compensated. Estimates of crustal and elastic thicknesses and apparent depth of compensation obtained for Type 2 coronae span the range obtained for Venus globally. Neither the thickness of the elastic lithosphere nor the crust appear to control whether Type 1 coronae, Type 2 coronae, or volcanoes form over small‐scale mantle upwellings.
Photochemical formation rates of organic aerosols through time‐resolved in situ laboratory measurements
Authors: Ádámkovics Máté , Boering Kristie A.
Published: August 2003

The fundamental kinetics of photochemical particle formation and the mechanism(s) for polymerization of hydrocarbons to form condensable species under anoxic conditions have yet to be determined experimentally. Thus these processes remain highly parameterized in models of planetary atmospheres. We have developed instrumentation for simultaneously measuring the net production rates of complex gas‐phase hydrocarbons and of organic aerosols formed from irradiating mixtures of simple precursor gases through online quadrupole mass spectrometry measurements of stable gas‐phase species and in situ optical scattering detection of the particulates at 633 nm. The new technique and results for the generation of hydrocarbon aerosol from the irradiation of pure, gas‐phase CH4 at a pressure of 70 Torr with 8.8 ± 0.8 × 1015 photons s−1 of vacuum ultraviolet light (120–300nm) are reported. The net production rates for the following gaseous species are measured: H2 = 9.9 ± 2.2 · 1011, C2H2 = 2.8 ± 0.5 · 1010, C2H4 = 5.5 ± 9.4 · 109, C2H6 = 8.6 ± 2.5 · 1010, C3H4 = 2.5 ± 1.2 · 109, C4H2 = 6.6 ± 5.0 · 108, C4H10 = 1.3 ± 0.5 · 1010 cm−3 s−1. The production of hydrocarbon particulates is detected by optical scattering, and the condensed phase C‐C bond formation rate is inferred to be 7.5 ± 3.1 · 1011 cm−3 s−1. Applications of this technique to the atmospheres of Titan and terrestrial‐like planets, such as the early Earth before the rise of molecular oxygen, are discussed.
Geochronological and geochemical constraints on Mesozoic suturing in east central Tibet
Authors: Roger Françoise , Arnaud Nicolas , Gilder Stuart , Tapponnier Paul , Jolivet Marc , Brunel Maurice , Malavieille Jacques , Xu Zhiqin , Yang Jingsui
Published: August 2003

This paper reports isotopic, major and minor element geochemistry of igneous and metamorphic rocks from the Kokoxili and Yushu regions of central and eastern Tibet. The first region lies along the Kunlun suture, which separates the Bayan Har‐Songpan Ganze (Songpan) terrane from the Tarim and Qaidam blocks. Two Kokoxili granitoids yield U‐Pb zircon dates of 217 ± 10 and 207 ± 3 Ma (Late Triassic), which represent the time of emplacement, and Rb‐Sr isochron dates of 195 ± 3 and 190 ± 3 Ma (Early Jurassic), which are interpreted as cooling ages. The geochemical signatures of these granitoids suggest that they are related to subduction continuing into the Late Triassic. In the Yushu area, three samples help constrain the age of the Jinsha suture, which separates the Songpan terranes from the Qiangtang blocks. A leucocratic granite and an orthogneiss in the suture zone yield U‐Pb zircon dates of 206 ± 7 and 204 ± 1 Ma, respectively, and a paragneiss south of it, a U‐Pb monazite date of 244 ± 4 Ma. The existence of coeval magmatism in both the Jinsha and Kunlun sutures suggests that the two subduction zones were simultaneously active. Combining isotopic dating with structural evidence on subduction polarity and paleomagnetic reconstructions, we propose that the Kunlun and Qinling block boundaries, which were distinct in the Permian, subsequently formed a continuous, Late Triassic, northward subducting plate margin. Our data suggest that the Jinsha suture correlates with the Benzilan and Nan‐Uttaradit sutures, which together belong to a major Late Triassic subduction zone.