bluuebunny/crossref_metadata_2025 huggingface dataset:
The Rise of Architectural History in Belgium 1830–1914
Authors: van Impe Ellen
Published: October 2018

On the map of nineteenth-century architectural historiographies in Western Europe, Belgium has so far remained a blind spot. While the country’s architectural history of the nineteenth century has already received some (if selective) international attention, with a somewhat disproportionate focus on the Art Nouveau, the historiography arising alongside of it has largely remained outside the picture. Meanwhile, considerations as to Belgium’s particular situation, which presumably influenced its architecture, equally apply to its historiography; for instance its design as a crossroads of influences, as demonstrated in research into the Belgian Catholic Gothic Revival and into nineteenth-century (architectural) history in general, among cases one could cite. While interesting because of its own particularities, Belgium also represents a type of ‘smaller European country’ created in the nineteenth century, whose architectural history has been characterized as ‘often fascinating precisely in the extent to which [these countries] present attempts to resolve the inherent contradictions between the major interpretive models and prescriptions of the English Pugin-Ruskin tradition, French Rationalism, and the more archaeological approach of the Cologne school’. The relatively limited corpus of Belgian architectural historiography — at least when compared with the historiographies of the United Kingdom, France or Germany — is an additional advantage, since it makes the field of study more easily definable and thus allows for more detailed study.
Islam and the West: The Early Use of the Pointed Arch Revisited
Authors: Draper Peter
Published: October 2018

As this is a valedictory rather than an inaugural lecture, it seemed legitimate to be a little self-indulgent in the choice of theme. Every medievalist at some time or other has to take an interest in the role of the pointed arch in the transformation of medieval architecture from Romanesque to Gothic and in the ways that the pointed arch form was subsequently manipulated through the later Middle Ages. It is only a short step, but one that has been taken less often than you might expect, to pursue that interest back into the early use of the pointed arch in Islamic architecture: to ask how it came to replace the semicircular arch of classical architecture and why it was used.
Thomas Jefferson and François Cointereaux, Professor of Rural Architecture in Revolutionary Paris
Authors: Cellauro Louis , Richaud Gilbert
Published: October 2018

Little is known about the contacts Thomas Jefferson (1743–1826), Minister to the Court of Louis XVI between 1784 and 1789 and future President of the United States, had with French architects during his residence in Paris, except those with Charles-Louis Clérisseau (1721–1820), who collaborated with him on the design of the Capitol of Virginia in Richmond from 1785. We know, however, that, at the end of his stay in France, Jefferson was in close touch with the French architect and agriculturalist François Cointereaux (1740–1830), as is proven by several unpublished letters written by each of them.
Churches for a Changing Liturgy: Gillespie, Kidd & Coia and the Second Vatican Council
Authors: Proctor Robert
Published: October 2018

The relationship of Modernism in architecture with the symbolic needs of church- building was fraught with the dangers of betrayal: whether the architect indulged in personal spiritual expression, or used traditional forms, he could be accused of stylistic excess; if he applied a reductive functionalism, the result could be faulted as failing the brief. After the Second World War, expression and tradition were gradually admitted into Modernism to expand and enrich its vocabulary, and the limits of functionalism were reassessed. Churches were a field in which architects of the Modern Movement could explore their new concerns with poetic form and monumentality, in contrast to the more prosaic jobs in housing, schools, and so on; but few architects had the chance to work on churches in quite the same volume as the more pressing post-war building tasks. One firm of architects with an exceptional opportunity was Gillespie, Kidd & Coia, responsible for a series of Roman Catholic churches in Scotland, ‘the finest body of post-war church building in Britain’, according to Elain Harwood.1 This work has attracted attention from architectural historians before, particularly for its rich and humane interpretation of sacred architecture.
Three Romanesque Great Churches in Germany, France and England, and the Discipline of Architectural History
Authors: Fernie Eric
Published: October 2018

(This is the text of the SAFIGB Annual Lecture, delivered at the Courtauld Institute of Art, London, on 29 November 2010)

This is a lecture about architecture and politics in the eleventh century. First, however, I would like to say a few words about another aspect of architectural history, namely style, because it does not feature in the body of the lecture and because of the criticism it currently faces and has faced for some time. I shall append my comments to two recollections. The first of these relates to a presentation in the 1990s at which the speaker identified the different kinds of expertise needed to understand a building, including that of the palaeographer for the documentary history, of the petrologist if it was a masonry structure, and so on to the architectural historian, who was given the task of dealing with style. The second recollection concerns a conference a few years later at which one of the participants said they wished that discussion of style could be banned. The two remarks taken together lead to an amusing conclusion, but they were separate utterances and so should be considered separately. As to the first, there are of course many other contributions that the architectural historian can make, not least in terms of social history, but I am pleased to see the task of assessing the relevance of style assigned to them because, if they do not undertake it, it is unlikely that anyone else will. On the second, I have some sympathy with the speaker, because style can be such a slippery concept that at times one might think it better to do without it. But, however justified such criticism, the varying stylistic characteristics found in objects carry so much information about the choices made by innumerable individuals in the course of human history that it would be counterproductive to abandon them, regardless of the difficulties.
Adapting Glasshouses for Human Use: Environmental Experimentation in Paxton’s Designs for the 1851 Great Exhibition Building and the Crystal Palace, Sydenham
Authors: Schoenefeldt Henrik
Published: October 2018

When the horticulturist Joseph Paxton first published his proposal to house the 1851 Great Exhibition of the Works of Industry of All Nations inside a glasshouse of enormous scale at Hyde Park, London, the scheme was praised as a more practical alternative to an earlier idea that had been put forward by the Royal Commission for the Great Exhibition’s own Building Committee. However, the feasibility of Paxton’s idea soon became the subject of concern. The use of glasshouses for the cultivation of plants was well established, but could this type of building now be adapted to the task of accommodating artefacts? Could it also provide visitors to the Exhibition with a comfortable environment? A particular worry was the issue of cooling, given that the Exhibition was to take place in summer. Prospective exhibitors anxiously made reference to the hot and humid conditions inside greenhouses such as the Palm House at Kew Gardens and the Conservatory at Regent’s Park, and they criticized Paxton’s idea as a risky experiment. Paxton did not ignore the challenge. He pointed out that his design incorporated shading devices, provision for evaporative cooling and natural ventilation, all of which were intended to maintain comfortable temperatures on hot days. He argued that his proposals had been informed by his previous experience with conservatory design, claiming that he had validated the effectiveness of his ventilation and cooling strategy through smalls-cale experiments at Chatsworth House. That Paxton’s plans were accepted and realized was largely due to good fortune. His design was considered to be the only one that could be constructed in time for the opening of the exhibition, which had already been advertised internationally. The Executive Committee, however, requested that conditions inside the building be carefully monitored. In effect, the Great Exhibition Building at Hyde Park became a significant early experiment in what would now be termed ‘environmental design’ (Fig. 1).
Salisbury House in London, 1599-1694.: The Strand Palace of Sir Robert Cecil
Authors: Guerci Manolo
Published: October 2018

Salisbury House is but one example from a significant corpus of architectural patronage carried out by a single family. In two generations, the Cecils created three great ‘prodigy houses’ among a range of notable country houses including Cranborne Manor in Dorset, Pymmes in Hertfordshire, Wothorpe Lodge near Burghley House in Northamptonshire, and Snape Castle in Yorkshire. It was William Cecil, 1st Baron Burghley (1520/21-98), who from the early 1560s initiated this prolific campaign of building with Burghley House in Northamptonshire, Theobalds in Hertfordshire, and Burghley House in London. Both Thomas Cecil (1542-1623) and Robert Cecil (1563-1612) inherited their father’s passion for architecture. Even when Burghley House in the Strand was nearing completion, Thomas continued work on his remarkable Italianate villa in Wimbledon (begun 1588, demolished c. 1720), one of the most innovative houses of the period, with a three-sided plan, built on a steeply sloping hillside that prompted the composition of elaborate terraces. Like the family’s other properties, Wimbledon House was able to offer hospitality to Elizabeth I, while Hatfield House, built by Robert Cecil between 1607 and 1612, was specifically designed to entertain James I and his Queen, Anne of Denmark. In London, Robert Cecil’s architectural patronage started in about 1596 with the improvement and remodelling of Beaufort House in Chelsea, apparently in order to extend his influence into that area, although the scheme was quickly abandoned. Three years later, Robert began Salisbury House in the Strand, while in 1609 he built the first commercial centre in the West End, known as the ‘New Exchange’. From 1612, he also developed a strip of land along the west side of St Martin’s Lane as a new residential area, but did not live to see it completed.
Exchanging Looks: ‘Art Dekho’ Movie Theatres in Bombay
Authors: Windover Michael
Published: October 2018

Bombay of the interwar years was a city in transition. TheUrbs Prima in Indus, and second city of the British Empire, became increasingly both a site of nationalist sentiment and a conduit of cosmopolitan cultural and economic currents. Its urban fabric witnessed the shift from colonial, Victorian city tomodernemetropolis. Captured in A. R. Haseler’s dramatic aerial photograph from the mid-1930S (Fig. 1), the Regal Cinema stands out against the Indo-Saracenic monuments of late imperial Bombay — notably George Wittet’s Gateway of India (1924) seen at the top of the photograph, his Prince of Wales Museum (1923) — its gardens on the bottom left — and, on the right, his Royal Institute of Science (1920). Although not a government-commissioned building, to the right of the Gateway, on the waterside, is the Taj Mahal Hotel (1903), a luxurious structure intended by the Parsi industrialist, Jamsetji N. Tata, to be a location for inter-cultural relations. Extending this type of space to some degree, the Regal was built by another Parsi, Framji Sidhwa, in 1933. The cinema marked the beginning of a decade-long building boom that corresponded with a significant population increase, as more and more migrants joined the city’s growing industrial workforce.

The Art Deco styling of the new financial, residential, and commercial buildings, like the Regal, celebrated and framed a modern public culture which responded to the unique socio-political realities of interwar Bombay. ‘Public culture’, a term developed by Arjun Appadurai and Carol Breckenridge, is conceptualized here as a dynamic process of indigenization, one that takes into account the global flow of ideologies through human migration and especially by mass media, one that destabilizes the ‘high-low’ binary and avoids the homogenizing terminology of ‘westernization’ or ‘Americanization’. The Art Deco cinema might be considered a crossroads where the often interpenetrating and sometimes competing narratives of commerce, nation, empire and formations of modern subjectivities intermingled: a nexus of cultural, economic, technological and political flow. The use of Art Deco is important in the context of Bombay as the style signified modernity and a particular sense of cosmopolitanism on the one hand, and yet resonated with or extended pre-existing cultural traditions in a distinctly local manner on the other.
The effects of energy price changes: heterogeneous welfare impacts and energy poverty in Indonesia
Authors: Renner Sebastian , Lay Jann , Schleicher Michael
Published: October 2018

We study the welfare and energy poverty implications of energy price change scenarios in Indonesia. Our analysis extends previous analyses of energy price impacts at the household level in three ways. First, by employing a household energy demand system (QUAIDS), we are able to distinguish between first- and second-order welfare effects over the income distribution. Second, our results point to the ownership of energy-processing durables as another source of impact heterogeneity. Third, we extend the welfare analysis beyond the money-metric utility effects and look at energy poverty, which is understood as the absence of or imperfect access to reliable and clean modern energy services. The analysis indicates that energy prices may serve as an effective instrument to reduce energy use but also have important adverse welfare effects. The latter can, however, be mitigated by appropriate compensation policies.
Separation of environmental effects on community variation of a larch forest in north China
Authors: ZHANG Qindi , LI Zongshan , YANG Lei , WU Xing , ZHANG Jintun
Published: October 2018

Pangquangou National Nature Reserve is well known as ‘the distribution centre of Prince Rupprecht's larch (Larix principis-rupprechtii)' in China. Community variation in Prince Rupprecht's larch forest provides habitat heterogeneity for animals, especially for the endemic and endangered brown-eared pheasant (Crossoptlon mantchuricum). In this study a total of 120 quadrats (each 10×10m) were established to measure and record species composition and six environmental variables to examine the underlying variables that control community variation. We applied a multivariate regression tree analysis to detect community variation, and used redundancy analysis-based variation partitioning to separate the effects of environmental variables on community variation. The results show that Prince Rupprecht's larch forest in the Pangquangou National Nature Reserve can be represented by eight community types. The amount of total species variability captured by all environmental variables was 20.6%, and the cumulative percentage variance of species–environment relationships was 95.8%. However, analyses with a conditional effect approach revealed that elevation, aspect and litter thickness contribute the most to community variation. The pure and joint effects of these three explanatory variables were separated with variation partitioning analyses. The results highlight that the effect of elevation accounts for the largest fraction of community variation in Prince Rupprecht's larch forest.
Soil conservation on the Loess Plateau and the regional effect: impact of the ‘Grain for Green' Project
Authors: WANG Xiaofeng , XIAO Feiyan , FENG Xiaoming , FU Bojie , ZHOU Zixiang , CHAN Chang
Published: October 2018

Soil conservation on the Loess Plateau is important not only for local residents but also for reducing sediment downstream in the Yellow River. In this paper, we report a decrease in soil erosion from 2000 to 2010 as a result of the ‘Grain for Green' (GFG) Project. By using the Revised Universal Soil Loss Equation and data on land cover, climate and sediment yield, we found that soil erosion decreased from 6579.55tkm–2yr–1 in 2000 to 1986.66tkm–2yr–1 in 2010. During this period, there was a major land cover change from farmland to grassland in response to the GFG. The area of low vegetation coverage with severe erosion decreased dramatically, whereas the area of high vegetation coverage with slight erosion increased. Our study demonstrates that the reduction in soil erosion on the Loess Plateau contributed to the decrease in the sediment concentration in the Yellow River.
A Possible Tectonic Response Between the Qingchuan Faultand the Beichuan‐Yingxiu Fault of the Longmen Shan Fault Zone? Evidence From Geologic Observations by Paleoseismic Trenching and Radiocarbon Dating
Authors: Liang Mingjian , Ran Yongkang , Wang Hu , Li Yanbao , Gao Shuaipo
Published: October 2018

The Qingchuan fault is located along the eastern margin of the Tibetan Plateau and connects to the Beichuan‐Yingxiu fault of the Longmen Shan fault zone (LMSF), which produced the 2008 MW 7.9 Wenchuan earthquake and 2013 MW6.6 Lushan earthquake. After the two devastating earthquakes, whether the Qingchuan fault could produce a large earthquake or not and its tectonic activity is highly debated. Based on the detailed field investigations and paleoseismic trenching combined with multiple radiocarbon dating, we suggest that the Qingchuan fault might not show intense fault activity (or specific dextral strike‐slip deformation) since the late Quaternary. The deformation evidence revealed in the trench indicates a pattern of tensional deformation in the strata, which is inconsistent with the regional compressional tectonic stress field. Moreover, the timing of these deformation events coincides with that of paleoearthquakes that occurred on the Beichuan‐Yingxiu fault. Therefore, we speculate that the large earthquakes that occurred on the northern segment of the Beichuan‐Yingxiu fault highly likely contribute to the formation of the tensional structures observed along the Qingchuan fault. The uplift of the Minshan Mountain affects the tectonic deformation and seismic activity of the northern segment of the LMSF. However, considering that the LMSF shows forward‐thrust characteristics, the fault activity of the Qingchuan fault was possibly the most affected by the uplifting of the Minshan Mountain. In other words, this specific regional tectonic frame might constrain the buildup of tectonic stress and seismic potential for generating large earthquakes on the Qingchuan fault.
Water Resources Challenges Expected to Increase
Authors: Showstack Randy
Published: October 2018

A new report identifies the highest-priority challenges and recommendations for the U.S. Geological Survey’s water mission.
Are Paleomagnetic Records From U‐Channels Appropriate for Studies of Reversals and Excursions?
Authors: Philippe Édouard G. H. , Valet Jean‐Pierre , St‐Onge Guillaume , Thevarasan Anojh
Published: October 2018

Sampling of sediment cores using plastic U‐channels has made possible the acquisition of detailed records of paleomagnetic secular variation, geomagnetic polarity, environmental magnetic studies, and relative paleointensity over the past several million years. U‐channel measurements provide the great advantage of rapid measurements of long sediment cores, but the signal resolution is attenuated by the response function of the magnetometer sensors, which therefore restrains the recovery of rapid and large‐amplitude field changes. Here we focus on the suitability of the dynamics of reversals and excursions derived from U‐channel measurements. We compare successive individual paleomagnetic directions of 1.5 cm × 1.5 cm × 1.5 cm cubic discrete samples with those of a 1.5‐m equivalent U‐channel sample train obtained by placing the samples adjacent to each other. We use varying excursion and transition lengths and generate transitional directions that resemble those of the most detailed paleomagnetic records. Excursions with opposite polarity directions recorded over less than 7.5 cm are barely detected in U‐channel measurements. Regarding reversals, U‐channel measurements smooth the signal of low‐resolution records and generate artificial transitional directions. Despite producing misleading similarities with the overall structure of transition records, longer transitional intervals fail also to reproduce the complexity of field changes. Finally, we test the convolution of magnetization by different response functions. The simulation reveals that even small response function changes can generate significant differences in results.
A High‐Frequency Distance Metric in Ground‐Motion Prediction Equations Based on Seismic Array Backprojections
Authors: Feng Tian , Meng Lingsen
Published: October 2018

Typical ground‐motion prediction equations (GMPEs) measure source‐to‐site distances relative to the closest point on the rupture plane (Rrup). However, for megathrust earthquakes (Mw > 8), the oversimplification of the earthquake source characteristics in distance metrics results in significant bias. Recent studies suggest that the high‐frequency (HF) and low‐frequency (LF) energy tend to emanate from different portions of the megathrusts. This phenomenon motivates an alternative distance metric based on the array backprojection imaging technique that effectively captures regions releasing HF energy. Herein, we define an HF distance metric (Rhf) as the distance from the site to the high‐frequency radiation zone. We study five Mw > 7.2 megathrust earthquakes in Japan and Chile and find that Rhf outperforms Rrup in predicting the ground shaking intensity between 0.5 and 4 Hz. We consider Rhf as a complementary measure to conventional GMPE distance metrics and a more accurate ground‐motion predictor in many cases.
Martian Eolian Dust Probed by ChemCam
Authors: Lasue J. , Cousin A. , Meslin P.‐Y. , Mangold N. , Wiens R. C. , Berger G. , Dehouck E. , Forni O. , Goetz W. , Gasnault O. , Rapin W. , Schroeder S. , Ollila A. , Johnson J. , Le Mouélic S. , Maurice S. , Anderson R. , Blaney D. , Clark B. , Clegg S. M. , d'Uston C. , Fabre C. , Lanza N. , Madsen M. B. , Martin‐Torres J. , Melikechi N. , Newsom H. , Sautter V. , Zorzano M. P.
Published: October 2018

The ubiquitous eolian dust on Mars plays important roles in the current sedimentary and atmospheric processes of the planet. The ChemCam instrument retrieves a consistent eolian dust composition at the submillimeter scale from every first laser shot on Mars targets. Its composition presents significant differences with the Aeolis Palus soils and the Bagnold dunes as it contains lower CaO and higher SiO2. The dust FeO and TiO2 contents are also higher, probably associated with nanophase oxide components. The dust spectra show the presence of volatile elements (S and Cl), and the hydrogen content is similar to Bagnold sands but lower than Aeolis Palus soils. Consequently, the dust may be a contributor to the amorphous component of soils, but differences in composition indicate that the two materials are not equivalent.
Observations of Aseismic Slip Driven by Fluid Pressure Following the 2016 Kaikōura, New Zealand, Earthquake
Authors: Hamling Ian J. , Upton Phaedra
Published: October 2018

In this paper we examine a short‐lived aseismic slip episode which began immediately following the 2016 Kaikōura earthquake in the South Island of New Zealand. Using synthetic aperture radar data, we form an interferometric synthetic aperture radar time series over the epicentral region of the Kaikōura mainshock. Immediately following the earthquake, we observe 150 mm of localized uplift over an ∼25‐km2 region which is best explained by an increase in pore pressure within a shallow fluid trap as a result of a coseismic permeability change. After the initial uplift stops, deformation becomes focused along a NE‐SW trending discontinuity which cuts through the uplifted region. The fault lies within a large (∼−4 MPa) stress shadow induced by the coseismic stress change suggesting that failure should be inhibited. However, a reduction in the effective normal stress caused by the local pore pressure increase was sufficient to induce a short‐lived aseismic slip episode.
The Changing Seasonality of Extreme Daily Precipitation
Authors: Marelle Louis , Myhre Gunnar , Hodnebrog Øivind , Sillmann Jana , Samset Bjørn Hallvard
Published: October 2018

Global warming is known to substantially increase extreme daily precipitation, but there has been little focus on changes to the seasonal timing of these extreme events. We investigate this question using global and regional climate models from the Coupled Model Intercomparison Project phase 5 and the Coordinated Regional Downscaling Experiment, in 1871–1900, 1976–2005, and 2071–2100 for an extreme future emission scenario (Representative Concentration Pathways, 8.5 W/m2). Models reproduce the observed seasonal timing and indicate very little seasonality changes during the past hundred years. However, by the end of the 21st century, extreme precipitation could substantially shift later in the year, in most regions from summer and early fall toward fall and winter. This projected shift is not regionally homogeneous, and, among analyzed regions, is strongest in Northern Europe and Northeastern America (+12 and +17 days, respectively), although local changes of more than a month are also possible.
Subglacial Conduit Roughness: Insights From Computational Fluid Dynamics Models
Authors: Chen Yunxiang , Liu Xiaofeng , Gulley Jason D. , Mankoff Kenneth D.
Published: October 2018

Flow resistance in subglacial conduits regulates the basal water pressure and sliding speeds of glaciers by controlling drainage efficiency and conduit enlargement and closure. Flow dynamics within subglacial conduits, however, remain poorly understood due to limited accessibility. Here we report the results of the first computational fluid dynamics simulations of flow within a realistic subglacial conduit beneath Hansbreen, a polythermal glacier in Svalbard, Norway. The simulated friction factor is 2.34 ± 0.05, which is around 5 to 230 times greater than values (0.01–0.5) commonly used in glacier hydrological modeling studies. Head losses from sinuosity and cross‐sectional variations dominate flow resistance (∼ 94%), whereas surface roughness from rocks and ice features contributes only a small portion (∼6%). Most glacier hydrology models neglect head losses due to sinuosity and cross‐sectional variations and thus severely underestimate flow resistance, overestimating the conduit peak effective pressure by 2 times and underestimating the conduit enlargement area by 3.4 times, respectively.
On the Connection Between Global Hydrologic Sensitivity and Regional Wet Extremes
Authors: Thackeray Chad W. , DeAngelis Anthony M. , Hall Alex , Swain Daniel L. , Qu Xin
Published: October 2018

A highly uncertain aspect of anthropogenic climate change is the rate at which the global hydrologic cycle intensifies. The future change in global‐mean precipitation per degree warming, or hydrologic sensitivity, exhibits a threefold spread (1–3%/K) in current global climate models. In this study, we find that the intermodel spread in this value is associated with a significant portion of variability in future projections of extreme precipitation in the tropics, extending also into subtropical atmospheric river corridors. Additionally, there is a very tight intermodel relationship between changes in extreme and nonextreme precipitation, whereby models compensate for increasing extreme precipitation events by decreasing weak‐moderate events. Another factor linked to changes in precipitation extremes is model resolution, with higher resolution models showing a larger increase in heavy extremes. These results highlight ways various aspects of hydrologic cycle intensification are linked in models and shed new light on the task of constraining precipitation extremes.
Resonant Scattering of Near‐Equatorially Mirroring Electrons by Landau Resonance With H+ Band EMIC Waves
Authors: Fu Song , Ni Binbin , Lou Yuequn , Bortnik Jacob , Ge Yasong , Tao Xin , Cao Xing , Gu Xudong , Xiang Zheng , Zhang Wenxun , Zhang Yang , Wang Qi
Published: October 2018

By investigating the resonant energy and latitudinal resonance region of Landau resonance between H+ band electromagnetic ion cyclotron (EMIC) waves and radiation belt electrons and performing calculations of quasi‐linear diffusion coefficients, we find that Landau resonance with EMIC waves, characterized by a very broad range of resonant energies from below 1 eV to above 10 MeV and the strikingly small extent of the latitudinal resonance region well below 0.1°, can be a feasible candidate accounting for the pitch angle scattering of near‐equatorially mirroring electrons. Compared to the dominant pitch angle scattering caused by the cyclotron resonance for greater than ~2‐MeV electrons at equatorial pitch angles less than ~80° with the rates well above 10−4 s−1, Landau resonance with H+ band EMIC waves has the potential to drive more efficient pitch angle scattering of radiation belt electrons from ~10 MeV down to tens of kiloelectron volts at equatorial pitch angles greater than ~ 85°.
The Ice‐Free Topography of Svalbard
Authors: Fürst Johannes J. , Navarro Francisco , Gillet‐Chaulet Fabien , Huss Matthias , Moholdt Geir , Fettweis Xavier , Lang Charlotte , Seehaus Thorsten , Ai Songtao , Benham Toby J. , Benn Douglas I. , Björnsson Helgi , Dowdeswell Julian A. , Grabiec Mariusz , Kohler Jack , Lavrentiev Ivan , Lindbäck Katrin , Melvold Kjetil , Pettersson Rickard , Rippin David , Saintenoy Albane , Sánchez‐Gámez Pablo , Schuler Thomas V. , Sevestre Heïdi , Vasilenko Evgeny , Braun Matthias H.
Published: October 2018

We present a first version of the Svalbard ice‐free topography (SVIFT1.0) using a mass conserving approach for mapping glacier ice thickness. SVIFT1.0 is informed by more than 1 million point measurements, totalling more than 8,700 km of thickness profiles. SVIFT1.0 is publicly available and represents the geometric state around the year 2010. Our estimate for the total ice volume is 6,199 km3, equivalent to 1.5‐cm sea level rise. The thickness map suggests that 13% of the glacierized area is grounded below sea level. A complementary map of error estimates comprises uncertainties in the thickness surveys as well as in other input variables. Aggregated error estimates are used to define a likely ice‐volume range of 5,200–7,300 km3. The ice front thickness of marine‐terminating glaciers is a key quantity for ice loss attribution because it controls the potential ice discharge by iceberg calving into the ocean. We find a mean ice front thickness of 135 m for the archipelago (likely range 123–158 m).
Vegetation Controls on Dryland Salinity
Authors: Perri Saverio , Suweis Samir , Entekhabi Dara , Molini Annalisa
Published: October 2018

In salt‐affected soils, salt stress causes a drastic reduction of plant transpiration. The extent of this reduction is a function of vegetation salt tolerance and can result in highly species‐specific controls on soil water budget and salinization levels. Despite their crucial role in regulating the hydrology of saline soils, the effects of salt tolerance on transpiration remain mostly unexplored. Here we propose a minimalist stochastic model of primary salinization which reproduces the hitherto overlooked feedback of salinity on the soil water balance and the active role of plant salt tolerance in modulating such an effect. We show that vegetation can exert significant control on leaching occurrence and soil salinization, thus imposing a species‐specific upper limit, Cmax, to the concentration of soluble salts in the soil. Since Cmax increases with plant salt tolerance, salt‐resilient species have the potential to sustain more saline conditions in the soil, eventually creating a favorable environment for their ecological success.
Anomalous Behavior of Vertical Wavenumber Spectra Over a Tropical Station of India
Authors: Ghosh Priyanka , Ramkumar T. K. , Sharma Som
Published: October 2018

The vertical wavenumber (VWN) spectra of height profiles of winds over a tropical station of Gadanki (13.5°N, 79.2°E; obtained using Indian Mesosphere Stratosphere Troposphere radar) show distinct nature of VWN spectra, which do not match with the so‐called universal wavenumber spectra. The universal wavenumber spectra have three distinct regions: unsaturated (having log‐log slope of 2), saturated (having log‐log slope of −3), and turbulence region (having log‐log slope of −5/3). In present work, we report the presence of positive slope at the higher end of the VWN spectra indicating the presence of unsaturated gravity waves, a kind of which is not reported so far. Many negative slopes of the order of ~−6, ~−9, and ~−12 are noticed at the end of the spectra beyond the turbulence region of the wavenumber spectra, which is also not reported in any previous studies up to now.
Madagascar Influence on the South Indian Ocean Convergence Zone, the Mozambique Channel Trough and Southern African Rainfall
Authors: Barimalala Rondrotiana , Desbiolles Fabien , Blamey Ross C. , Reason Chris
Published: October 2018

The rainfall mean state and variability of the tropical Southern Hemisphere are strongly affected by the Tropical Convergence Zones. Unlike the South Pacific and South Atlantic, the topography of Madagascar prevents, through the Mozambique Channel Trough, the direct transport of moisture from the Indian Ocean toward southern Africa that feeds the South Indian Ocean Convergence Zone (SICZ). Numerical experiments using regional climate models reveal that a flatter than actual topography over Madagascar results in a strengthening of the SICZ through anomalously high easterly moisture fluxes transported from the Indian Ocean and the Mozambique Channel. These in turn trigger a significant increase in precipitation over southern Africa extending from Mozambique to Angola and a decrease in rainfall over Madagascar. These results have important implications for the improvement of the representation of African rainfall mean state and variability, which has been identified as a persisting issue in different generations of state‐of‐the‐art climate models.
Anomalous Vp/Vs Ratios at Seismic Frequencies Might Evidence Highly Damaged Rocks in Subduction Zones
Authors: Pimienta Lucas , Schubnel Alexandre , Violay Marie , Fortin Jérôme , Guéguen Yves , Lyon‐Caen Hélène
Published: October 2018

Unusually high compressional (P) to shear (S) wave velocity ratios (Vp/Vs) were measured at different subduction zones and interpreted as fluid‐pressurized regions. Because no laboratory data reported such high values in isotropic rocks, mineralogical or anisotropic constrains were assumed. However, fluid‐saturated rocks' Vp/Vs is a frequency‐dependent property so that standard laboratory measurements cannot be directly upscaled to the field. Using a new methodology, we measured the property in the elastic regime relevant to field measurements for diverse lithologies. We obtained extreme Vp/Vs values, consistent with those reported at seismic frequency in the field. Consistently with a model, it shows that if high fluid pressure is a key factor, anomalous Vp/Vs values could evidence intense degrees of microfracturation in isotropic rocks, whichever its mineralogical content. The permeability of these regions could be larger than 10−16 m2.
The Regional, Seasonal, and Lagged Influence of the Amundsen Sea Low on Antarctic Sea Ice
Authors: Holland Marika M. , Landrum Laura , Raphael Marilyn N. , Kwok Ronald
Published: October 2018

The Amundsen Sea Low (ASL) is an important driver of Antarctic sea ice variations largely because of wind‐driven sea ice and ocean transport anomalies. However, the nature of the relationship between the ASL and sea ice is complicated by large seasonality in the ice cover and the ASL location and depth. Here we explore these relationships as a function of region, season, and lag. We find that the ASL can have a markedly different and sometimes opposite sign influence on sea ice in some regions, such as the western Ross Sea, depending on the season. This is in part due to differing influences of ASL‐related meridional and zonal winds for ice transport in different times of year. The sea ice response to ASL variations is often largest at a lag of some months and can persist for up to 8 months.
Seasonal Permeability Change of the Shallow Crust Inferred From Deep Well Monitoring
Authors: Liao Xin , Wang Chi‐Yuen
Published: October 2018

Permeability is a fundamental rock property that controls several important transport processes in Earth's crust. Here we use 10 years of continuous data to analyze the tidal response of water level in a well in SW China to Earth tides and show that permeability of the shallow crust may change seasonally. The relationship between permeability and the groundwater level suggests that the vertical permeability may increase ~6 folds in response to seasonal increases of water level over a threshold equivalent to ~0.1 MPa of pore pressure. The specific storage does not show corresponding change, suggesting that the change in permeability may be related to the clogging and unclogging of existing fractures in low‐porosity rock.
Long‐Lasting Poloidal ULF Waves Observed by Multiple Satellites and High‐Latitude SuperDARN Radars
Authors: Shi X. , Baker J. B. H. , Ruohoniemi J. M. , Hartinger M. D. , Murphy K. R. , Rodriguez J. V. , Nishimura Y. , McWilliams K. A. , Angelopoulos V.
Published: October 2018

Poloidal ultralow frequency (ULF) waves between 5 and 10 mHz were observed by multiple satellites and three high‐latitude Super Dual Auroral Radar Network radars during the recovery phase of a moderate geomagnetic storm on 24–27 January 2016. The long‐lasting ULF waves were observed in the magnetic field and energetic particle flux perturbations during three successive passes by two Geostationary Operational Environmental Satellites through the dayside magnetosphere, during which plasmasphere expansion and refilling were observed by two Time History of Events and Macroscale Interactions during Substorms probes. The radial magnetic field oscillation was in phase (∼180° out of phase) with the northward (southward) moving proton flux oscillation at 95 keV, consistent with high‐energy drift‐bounce resonance signatures of protons with second harmonic poloidal standing Alfvén waves. The longitudinal extent of the waves approached 10 hr in local time on the dayside and gradually decreased with time. High‐time‐resolution (∼6 s) data from three high‐latitude Super Dual Auroral Radar Network radars show that the wave intensification region was localized in latitude with a radial extent of ∼135–225 km in the subauroral ionosphere. No signature of these waves were observed by ground‐based magnetometers colocated with the Geostationary Operational Environmental Satellites suggesting that the poloidal waves were high‐m mode and thus screened by the ionosphere. During this interval one of the Time History of Events and Macroscale Interactions during Substorms probes observed a bump‐on‐tail ion distribution at 1–3 keV, which we suggest is the source of the long‐lasting second harmonic poloidal ULF waves.
Raindrop Size Distribution Characteristics of Summer and Winter Season Rainfall Over North Taiwan
Authors: Seela Balaji Kumar , Janapati Jayalakshmi , Lin Pay‐Liam , Wang Pao K. , Lee Meng‐Tze
Published: October 2018

Raindrop size distribution (RSD) characteristics of summer and winter seasons over north Taiwan are analyzed by using long‐term (~12 years) raindrop spectra from Joss‐Waldvogel disdrometer located at National Central University (24°58′N, 121°10′E), Taiwan. Along with the disdrometer data, radar reflectivity mosaic from six ground‐based radars, Tropical Rainfall Measuring Mission, Moderate Resolution Imaging Spectroradiometer, and ERA‐Interim data sets are used to establish the dynamical and microphysical characteristics of summer and winter rainfall. Significant differences in raindrop spectra of summer and winter rainfall are noticed. Winter rainfall has a higher concentration of small drops and a lower concentration of midsize and large drops when compared to summer rainfall. RSD stratified on the basis of rain rate showed a higher mass‐weighted mean diameter (Dm) and a lower normalized intercept parameter (log10Nw) in summer than winter. Similarly, diurnal variation of RSD showed higher Dm and lower log10Nw values in summer as compared to winter rainfall. In addition, for both seasons, the mean value of Dm is higher in convective precipitation than stratiform. Radar reflectivity (Z) and rain rate (R) relations (Z = A*Rb) showed a clear demarcation between summer and winter rainfall. Higher ground temperatures, deeply extended clouds with intense convective activity in summer modified the RSD through evaporation, drop sorting, and collision‐coalescence processes resulting with higher Dm and lower log10Nw values in summer as compared to winter rainfall.
Temporal Characteristics of Cloud Radiative Effects on the Greenland Ice Sheet: Discoveries From Multiyear Automatic Weather Station Measurements
Authors: Wang Wenshan , Zender Charles S. , van As Dirk
Published: October 2018

The impact of clouds on Greenland's surface melt is difficult to quantify due to the limited amount of in situ observations. To better quantify cloud radiative effects (CRE), we utilize 29 automatic weather stations and provide the first analysis on seasonal and hourly timescales in both accumulation and ablation zones. Seasonal CRE shows opposing cycles across geographical regions. CRE generally increases during melt season in the north of Greenland, mainly due to longwave CRE enhancement by cloud fraction and liquid water. CRE decreases from May to July and increases afterwards in the middle and south of Greenland, mainly due to strengthened shortwave CRE caused by surface albedo reduction. This finding resolves the contrasting seasonal distributions in previous studies at different Arctic locations. Longwave seasonal cycle also shifts from increasing in the north to decreasing in the south, implying spatial variations in cloud and atmospheric conditions. On hourly timescales, longwave downwelling radiation exhibits a bimodal distribution peaking at ∼−70 W/m2 (i.e., clear state) and ∼0 W/m2 (i.e., cloudy state), suggesting that Greenland alternates between fairly clear and overcast. In the cloudy state, CRE strongly correlates with the combined influence of solar zenith angle and albedo (r = 0.85, p < 0.01) probably because clouds are thick enough for CRE to become saturated. The close relationship between CRE and albedo over dark surfaces suggests a stabilizing feedback: Net CRE is negative at low albedo caused by snow melt and snow metamorphism and thus tends to increase albedo and decelerate surface melt.
Improving Cloud Optical Property Retrievals for Partly Cloudy Pixels Using Coincident Higher‐Resolution Single Band Measurements: A Feasibility Study Using ASTER Observations
Authors: Werner F. , Zhang Z. , Wind G. , Miller D. J. , Platnick S. , Di Girolamo L.
Published: October 2018

Clear‐sky contamination is a challenging and long‐lasting problem for cloud optical thickness (τ) and effective droplet radius (reff) retrievals using passive satellite sensors. This study explores the feasibility of improving both τ and reff retrievals for partly cloudy (PCL) pixels by using available subpixel samples in a visible to near‐infrared band, which many satellite sensors offer. Data are provided by high‐resolution reflectance (R) observations and cloud property retrievals by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) at horizontal resolutions between 30‐960m. For partly cloudy 960‐m observations, the clear‐sky component of the pixels induces significant underestimations of up to 58% for τ, while overestimations in reff can exceed 41%. This yields underestimations in the derived liquid water path and cloud droplet number concentration of up to 68% and 72%, respectively. By means of three different assumptions it is shown that subpixel R observations in the visible to near‐infrared band can be used to estimate higher‐resolution R for the second band in the retrieval scheme, as well as the subpixel cloud cover. The estimated values compare well to actually observed ASTER results and are used to retrieve cloud properties, which are unbiased by the clear‐sky component of PCL pixels. While the presented retrieval approach is only evaluated for marine boundary layer clouds, it is computationally efficient and can be easily applied to observations from different imagers. As an example, the PCL retrieval scheme is applied to data by the Moderate Resolution Imaging Spectroradiometer, where similar biases for PCL pixels are observed.
The Simulation of Stratospheric Water Vapor Over the Asian Summer Monsoon in CESM1(WACCM) Models
Authors: Wang Xinyue , Wu Yutian , Tung Wen‐wen , Richter Jadwiga H. , Glanville Anne A. , Tilmes Simone , Orbe Clara , Huang Yi , Xia Yan , Kinnison Douglas E.
Published: October 2018

Previous observational studies have found a persistent maximum in stratospheric water vapor (SWV) in the upper troposphere lower stratosphere (UTLS) confined by the upper‐level anticyclone over the Asian summer monsoon region. This study investigates the simulation of SWV in the Community Earth System Model, version 1 with the Whole Atmosphere Community Climate Model as its atmospheric component [CESM1(WACCM)]. CESM1(WACCM) generally tends to simulate a SWV maximum over the central Pacific Ocean, but this bias is largely improved in the high vertical resolution version. The high vertical resolution model with increased vertical layers in the UTLS is found to have a less stratified UTLS over the central Pacific Ocean compared with the low vertical resolution model. It therefore simulates a steepened potential vorticity gradient over the central Pacific Ocean that better closes the upper‐level anticyclone and confines the SWV within the enhanced transport barrier.
Post Cold Frontal Clouds at the ARM Eastern North Atlantic Site: An Examination of the Relationship Between Large‐Scale Environment and Low‐Level Cloud Properties
Authors: Naud Catherine M. , Booth James F. , Lamraoui Fayçal
Published: October 2018

Using cloud and environment observations from the Atmospheric Radiation Measurement (ARM) program Eastern North Atlantic site and an automated cold front detection routine, cloud properties in post cold front (PCF) periods are examined and compared to similar conditions of subsidence (non‐PCF). PCF periods exhibit stronger subsidence and wind speed than non‐PCF periods, with weaker inversions and stronger surface temperature contrasts. Low‐level clouds are predominant and are found to have higher cloud base and top heights, colder cloud top temperature, and greater vertical extent and liquid water path during PCF than non‐PCF periods. The environmental metric that is best correlated with cloud boundaries for both PCF and non‐PCF periods is the difference in potential temperature between the sea surface and 800 hPa, a parameter used to locate cold air outbreak conditions. However, the cloud vertical extent and liquid water path are found to be better correlated with sea‐air temperature contrast, a parameter related to turbulent surface fluxes. The strength of the relationships between the cloud characteristics and these metrics does not differ for PCF and non‐PCF periods. However, the strength of the metrics differs between PCF and non‐PCF periods and can explain cloud property differences. The results suggest both the properties of the boundary layer and the presence of an upper‐level cyclone associated with the cold front determine PCF cloud properties.