bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini-Workshop: Mathematics of Differential Growth, Morphogenesis, and Pattern Selection
Authors: Garikipati Krishna , Goriely Alain , Kuhl Ellen , Menzel Andreas
Published: June 2016

Living structures are highly heterogeneous systems that consist of distinct regions made up of characteristic cell types with a specific structural organization. During evolution, development, disease, or environmental adaptation each region may grow at its own characteristic rate. Differential growth creates a balanced interplay between tension and compression and plays a critical role in biological function. In plant physiology, typical every-day examples include the petioles of celery, caladium, or rhubarb with a slower growing compressive outer surface and a faster growing tensile inner core. In developmental biology, differential growth is critical to the organogenesis of various structures including the gut, the heart, and the brain. From a structural point of view, these phenomena are close associated with instabilities, of twisting, looping, folding, and wrinkling. From a mathematical point of view, the governing equations of organogenesis are highly nonlinear and often characterized through multiple bifurcation points. Bifurcation is critical in symmetry breaking, pattern formation, and selection of shape. While biologists are studying differential growth, morphogenesis, and pattern selection merely by observation, our goal in this workshop is to explore, discuss, and advance the fundamental theory of differential growth to characterize morphogenesis and pattern selection by mathematical modeling. This workshop will bring together scientists with similar interests and complementary backgrounds in applied mathematics, mathematical biology, developmental biology, plant biology, dynamical systems, biophysics, biomechanics, and clinical sciences. We will identify common features of growth phenomena in living systems with the overall objectives to establish a unified mathematical theory for growing systems and to identify the necessary mathematical tools to address challenging questions in biology and medicine.
Geometric Partial Differential Equations: Surface and Bulk Processes
Authors: Deckelnick Klaus , Elliott Charles M. , Kornhuber Ralf , Sethian James A.
Published: June 2016

The workshop brought together experts representing a wide range of topics in geometric partial differential equations ranging from analyis over numerical simulation to real-life applications. The main themes of the conference were the analysis of curvature energies, new developments in pdes on surfaces and the treatment of coupled bulk/surface problems.
Cord Blood Hepcidin: Cross-Sectional Correlates and Associations with Anemia, Malaria, and Mortality in a Tanzanian Birth Cohort Study
Authors: Brickley Elizabeth B. , Spottiswoode Natasha , Kabyemela Edward , Morrison Robert , Kurtis Jonathan D. , Wood Angela M. , Drakesmith Hal , Fried Michal , Duffy Patrick E.
Published: June 2016

Hepcidin, the master regulator of bioavailable iron, is a key mediator of anemia and also plays a central role in host defense against infection. We hypothesized that measuring hepcidin levels in cord blood could provide an early indication of interindividual differences in iron regulation with quantifiable implications for anemia, malaria, and mortality-related risk. Hepcidin concentrations were measured in cord plasma from a birth cohort (N = 710), which was followed for up to 4 years in a region of perennial malaria transmission in Muheza, Tanzania (2002–2006). At the time of delivery, cord hepcidin levels were correlated with inflammatory mediators, iron markers, and maternal health conditions. Hepcidin levels were 30% (95% confidence interval [CI]: 12%, 44%) lower in children born to anemic mothers and 48% (95% CI: 11%, 97%) higher in placental malaria–exposed children. Relative to children in the lowest third, children in the highest third of cord hepcidin had on average 2.5 g/L (95% CI: 0.1, 4.8) lower hemoglobin levels over the duration of follow-up, increased risk of anemia and severe anemia (adjusted hazard ratio [HR] [95% CI]: 1.18 [1.03, 1.36] and 1.34 [1.08, 1.66], respectively), and decreased risk of malaria and all-cause mortality (adjusted HR [95% CI]: 0.78 [0.67, 0.91] and 0.34 [0.14, 0.84], respectively). Although longitudinal measurements of hepcidin and iron stores are required to strengthen causal inference, these results suggest that hepcidin may have utility as a biomarker indicating children's susceptibility to anemia and infection in early life.
A Socio-technical Approach to Preventing, Mitigating, and Recovering from Ransomware Attacks
Authors: Singh Hardeep , Sittig Dean
Published: June 2016

Recently there have been several high-profile ransomware attacks involving hospitals around the world. Ransomware is intended to damage or disable a user’s computer unless the user makes a payment. Once the attack has been launched, users have three options: 1) try to restore their data from backup; 2) pay the ransom; or 3) lose their data. In this manuscript, we discuss a socio-technical approach to address ransomware and outline four overarching steps that organizations can undertake to secure an electronic health record (EHR) system and the underlying computing infrastructure. First, health IT professionals need to ensure adequate system protection by correctly installing and configuring computers and networks that connect them. Next, the health care organizations need to ensure more reliable system defense by implementing user-focused strategies, including simulation and training on correct and complete use of computers and network applications. Concomitantly, the organization needs to monitor computer and application use continuously in an effort to detect suspicious activities and identify and address security problems before they cause harm. Finally, organizations need to respond adequately to and recover quickly from ransomware attacks and take actions to prevent them in future. We also elaborate on recommendations from other authoritative sources, including the National Institute of Standards and Technology (NIST). Similar to approaches to address other complex socio-technical health IT challenges, the responsibility of preventing, mitigating, and recovering from these attacks is shared between health IT professionals and end-users.

Citation: Sittig DF, Singh H. A socio-technical approach to preventing, mitigating, and recovering from ransomware attacks.
Using low density LiDAR data to map Mediterranean forest characteristics by means of an area-based approach and height threshold analysis
Authors: Guerra-Hernández J. , Tomé M. , González-Ferreiro E.
Published: June 2016

This study reports progress in forest inventory methods involving the use of low density airborne LiDAR data and an area-based approach (ABA). It also emphasizes the usefulness of the Spanish countrywide LiDAR dataset for mapping forest stand attributes in Mediterranean stone pine forest characterized by complex orography. Lowdensity airborne LiDAR data (0.5 first returns m–2) was used to develop individual regression models for a set of forest stand variables in different types of forest. LiDAR data is now freely available for most of the Spanish territory and is provided by the Spanish National Aerial Photography Program (Plan Nacional de Ortofotografía Aérea, PNOA). The influence of height thresholds (MHT: Minimun Height Threshold and BHT: Break Height Threshold) used in extracting LiDAR metrics was also investigated. The best regression models explained 61-85%, 67-98% and 74-98% of the variability in ground-truth stand height, basal area and volume, respectively. The magnitude of error for predicting structural vegetation parameters was higher in closed deciduous and mixed forest than in the more homogeneous coniferous stands. Analysis of height thresholds (HT) revealed that these parameters were not particularly important for estimating several forest attributes in the coniferous forest; nevertheless, substantial differences in volume modelling were observed when the height thresholds (MHT and BHT) were increased in complex structural vegetation (mixed and deciduous forest). A metric-by-metric analysis revealed that there were significant differences in most of the explanatory variables computed from different height thresholds (HBT and MHT).The best models were applied to the reference stands to yield spatially explicit predictions about the forest resources. Reliable mapping of biometric variables was implemented to facilitate effective and sustainable management strategies and practices in Mediterranean Forest ecosystems.
Evolución del comportamiento espectral y la composición química en el dosel arbóreo de una dehesa
Authors: González-Cascón R. , Pacheco-Labrador J. , Martín M. P.
Published: June 2016

In the context of the BIOSPEC and FLUXPEC projects (http://www.lineas.cchs.csic.es/fluxpec/), spectral and biophysical variables measurements at leaf level have been conducted in the tree canopy of a holm oak dehesa (Quercus ilex) ecosystem during four vegetative periods. Measurements of bi-conical reflectance factor of intact leaf (ASD Fieldspec 3® spectroradiometer), specific leaf mass (SLM), leaf water content (LWC), nutrient (N, P, K, Ca, Mg, Mn, Fe, and Zn) and chlorophyll concentration were performed. The spectral measurements have been related with the biophysical variables by stepwise and partial least squares regression analyses. These analyses allowed to identify the spectral bands and regions that best explain the evolution of the biophysical variables and to estimate the nutrient contents during the leaf maturation process. Statistically significant estimates of the majority of the variables studied were obtained. Wavelengths that had the highest contributions explaining the chemical composition of the forest canopy were located in spectral regions of the red edge, the green visible region, and the shortwave infrared.
Onverdraagzaam en repressief worden: de rol van school en media
Authors: Elchardus Mark , Herbots Sarah , Spruyt Bram
Published: June 2016

Jongeren die beroepsonderwijs volgen, zijn onverdraagzamer en repressiever dan leerlingen uit het algemeen onderwijs. In de loop van hun secundaire schoolloopbaan groeit dat verschil uit tot een kloof. De onderwijsvorm op zich heeft daar weinig mee te maken. De jongeren uit de verschillende vormen ontwikkelen een heel verschillende mediavoorkeur en deze veroorzaakt het verschil in houdingen. De scholen willen wel democratisch burgerschap bijbrengen, maar vormen geen partij voor de commerciële massamedia.
Aandeelhouders eerst! De opkomst en verspreiding van ‘aandeelhouderswaarde’ in de Verenigde Staten
Authors: Heilbron Johan , Verheul Jochem , Quak Sander
Published: June 2016

Hoewel over het streven naar het creëren van ‘aandeelhouderswaarde’ veel is geschreven, is weinig onderzoek gedaan naar de opkomst en eerste verspreiding van deze bedrijfsstrategie. In dit artikel onderzoeken we aan de hand van openbare bronnen als de Wall Street Journal en de Institutional Investor wanneer en op welke wijze het concept van ‘aandeelhouderswaarde’ opkwam en hoe het zich in eerste instantie in de VS heeft verspreid. Zowel de opkomst als de verspreiding van ‘aandeelhouderswaarde’ zijn vanuit economisch sociologisch perspectief tebegrijpen vanuit de veranderende machts- en afhankelijkheidsverhoudingen waarin ondernemingen zijn ingebed. De diepe economische recessie rond 1980 leidde tot een crisis van de heersende managementopvattingen, bood nieuwkomers de kans om alternatieve bedrijfsstrategieën te propageren, en daarvan werd het model waarin ‘aandeelhouderswaarde’ centraal stond dominant. De pleitbezorgers van het aandeelhoudersbelang waren aanvankelijk vermogende buitenstaanders, zogenoemde ‘raiders’. De lucratieve operaties van deze opkopers werden later een voorbeeld voor publieke pensioenfondsen. De spanningen tussen ‘raiders’ en pensioenfondsen leidden tot organisatievorming onder publieke pensioenfondsen, en de door hen opgerichte Council of Institutional Investors (1985)werd snel een toonaangevende partij, onder meer doordat het bedrijfsmanagement een profijtelijke manier vond om zich aan de nieuwe machtsverhoudingen aan te passen.
Bespreking van How professors think
Authors: Wilterdink Nico
Published: June 2016

Boekbespreking: Michèle Lamont (2009), How Professors Think. Inside the Curious World of Academic Judgment. Cambridge, Mass./London: Harvard University Press, 320 pp.
Populisme en de zorg over de samenleving
Authors: Elchardus Mark , Spruyt Bram
Published: June 2016

Terwijl populisme druk bestudeerd wordt op het niveau van de retoriek van politieke partijen en politici, vormt dit onderzoek een van de eerste studies naar de houdingen van kiezers ten aanzien van de kernstellingen van het populisme als dunne ideologie.
Gewone mensen. Populisme en het discours van verdringing in Amsterdam Nieuw West
Authors: Mepschen Paul
Published: June 2016

In analyses van het populisme wordt weinig aandacht besteed aan de betekenis van populistische constructies in het dagelijks leven van mensen. Om dat te onderzoeken is een etnografische benadering nodig, die populisme opvat als een frame of script dat de wereld voor mensen (her)kenbaar maakt. Dit paper bevat een etnografie van de perspectieven op de wereld van ‘autochtone’ bewoners van een sociaal en etnisch gemengdewijk in Amsterdam Nieuw West. Plannen voor grootschalige sloop creëerden de symbolische ruimte voor een verdringingsdiscours, waarin door autochtone wijkbewoners een ‘self-understanding’ werd gearticuleerd in een antagonistische relatie met ‘anderen’: elites en soms (post) migranten.
Populisme en de sociologische verbeelding
Authors: Uitermark Justus , Oudenampsen Merijn , van Heerikhuizen Bart , van Reekum Rogier
Published: June 2016

Populisme beperkt zich niet tot de politiek van Fortuyn of Wilders. In Latijns Amerika is populisme een stijlfiguur van links, terwijl sociale bewegingen als Occupy en Anonymous een populisme zonder leiderschap promoten. En ook buiten de politiek, van de reclame tot de kunst, worden populistische sentimenten en stijlfiguren ingezet tegen de gevestigde orde. Hoe kunnen we de verschillende uitingsvormen van het populisme herkennen, begrijpen en verklaren?
‘Je moet onder aan de ladder beginnen’. Distinctie en hiërarchie binnen de klassieke en hedendaagse muziek
Authors: Vermeulen Laura , van den Haak Marcel
Published: June 2016

‘Je moet onder aan de ladder beginnen’. Distinctie en hiërarchie binnen de klassieke en hedendaagse muziek
Effecten van culturele en economische hulpbronnen op toekomstverwachtingen van adolescenten
Authors: Keijer Micha G. , Liefbroer Aart C.
Published: June 2016

In de tweede helft van de twintigste eeuw is het mensbeeld sterk geïndividualiseerd. Het individu wordt gezien als de architect van zijn eigen leven en geeft aan de toekomst naar eigen inzicht betekenis. Onder sociologen is deze visie echter niet onomstreden, want velen van hen blijven het belang van de sociale, culturele en economische herkomst van individuen voor hun levensloop benadrukken. Dit artikel gaat in op deze thematiek door te bestuderen in welke mate en op welke manier de sociaaleconomische herkomst van adolescenten hun verwachtingen over toekomstige levensloopkeuzes, zowel op het vlak van werk en opleiding als op het terrein van relatievorming en gezin, beïnvloedt. Om die vraag te beantwoorden worden gegevens gebruikt uit een survey waaraan zowel 14- tot 17-jarige adolescenten als hun ouders hebben meegewerkt.
De protestantse ethiek van fitness. Een kwalitatief onderzoek naar de motivatie van hoogopgeleide fitnessbeoefenaars in Amsterdam
Authors: Elshout Judith , Velthuis Olav
Published: June 2016

In veel statistieken is fitness de meest beoefende sport in Nederland. De dominante verklaring hiervoor is dat mensen in een geïndividualiseerde cultuur meer gericht raken op het uiterlijk en de gezondheid. Met behulp van fitness kan het lichaam worden getraind en in de gewenste vorm gebracht. Ten tweede past fitness in een rationele en doelgerichte samenleving. Fitness kan worden gezien als efficiënt middel om te bewegen, net als fastfood een relatief snelle en efficiënte manier is om de honger te stillen. Op grond van empirisch onderzoek blijken deze verklaringen niet voldoende. Met behulp van de theorie van Max Weber over de protestantse ethiek en het kapitalisme laat dit artikel zien dat de motivatie om te blijven fitnessen dorgaans te simpel wordt fgespiegeld. Fitness moet niet alleen worden begrepen in het licht van een postmoderne consumptiesamenleving, maar ook in het licht van een moderne puriteinse fitnessethiek waar hard werken een doel op zich is.
Ik kan het niet alleen
Authors: van Heerikhuizen Bart
Published: June 2016

Ik kan het niet alleen
Geen verlichtende publieke sociologie zonder wetenschappelijke kwaliteit
Authors: Wittek Rafael
Published: June 2016

Meer verlichtende publieke sociologie – volgens het recent uitgebrachte advies van de Nederlandse Sociologische Vereniging zou dat de koers moeten zijn die vakgenoten, sociologieafdelingen en vooral universitaire bestuurders moeten inslaan om het evenwicht binnen de discipline te herstellen. Het is goed dat een beroepsvereniging haar rol als aanjager van een inhoudelijke discussie over de kwaliteit van de beoefening van haar vak serieus neemt, en er staan zonder meer verstandige dingen in het advies: observaties over de toegenomen wetenschappelijke reputatie van de Nederlandse sociologie, over de perverse prikkels die uitgaan van het huidige beoordelingsstelsel en zijn eenzijdige indicatoren, en over de nodige verbindingslijnen tussen fundamenteel onderzoek en ‘het publieksbereik’. Toch bekroop me nadat ik het advies een aantal keer had herlezen een onbehagen, waarvan ik in begin niet goed wist waar het vandaan kwam. Er staan immers toch alleen opmerkingen in die je hoort toe te juichen als goede vakgenoot en verantwoordelijke wetenschapper? Wie kan er nu voor perverse prikkels zijn, tegen een sociologie die ook een publieke rol speelt? Mijn onbehagen heeft met drie uitgaanspunten in het advies te maken. Ten eerste met het sterk vertekende beeld dat het advies van de huidige toestand van de discipline schetst; ten tweede met de eenzijdige manier waarop in de NSV-nota het bijna gelijktijdig verschenen KNAW-advies wordt verwerkt; en ten derde met het verwrongen ideaalbeeld dat het advies van de gelouterde discipline, haar wetenschappers en afdelingen schetst.
BDSM: transgressie van seksuele normen of een afspiegeling van de sociale werkelijkheid?
Authors: Harkes Ingvild
Published: June 2016

Boekbespreking: Danielle J. Lindemann (2012) Dominatrix: Gender, Eroticism, and Control in the Dungeon, en Margot Weiss (2011) Techniques of Pleasure: BDSM and the Circuits of Sexuality.
Kinderen, seks en zelfbepaling. Praten over pedofilie
Authors: Hekma Gert
Published: June 2016

Na de hoogtijdagen van de seksuele revolutie heten kinderen weer onschuldig te zijn en stuiten hun seksuele gevoelens op ontkenning en verbod. Hoe is deze omslag van seksuele zelfbepaling van jongeren naar juist bescherming tegen seksuele wensen van henzelf of derden te begrijpen?
Processen van ‘seksueel leren’ in de praktijk. Een studie naar seksueel labellen en handelen van tieners in Nederland
Authors: Holla Sylvia
Published: June 2016

Seks speelt een enorm belangrijke rol in het leven van Nederlandse tieners. Aan de hand van kwalitatieve data verkregen uit etnografisch onderzoek maakt dit artikel zichtbaar hoe tieners ontdekken wat ze leuk en lekker vinden aan seks, maar ook welk seksueel gedrag leidt tot roddel en achterklap onder klasgenoten. Dit ‘seksuele leren’ is fundamenteel voor de vorming van het seksuele zelf van tieners.
De relatie tussen opvattingen over gender en homoseksualiteit. Een casestudy van De Groene Amsterdammer sinds 1911
Authors: Savenije Tim , Duyvendak Jan Willem
Published: June 2016

Sinds het einde van de jaren zestig zijn de opvattingen over homoseksualiteit in Nederland flink positiever geworden. Vandaag de dag keuren nog maar weinig Nederlanders homoseksualiteit expliciet af. Tegelijkertijd gaat deze acceptatie vaak gepaard met de voorwaarde dat homoseksuele mannen en vrouwen ‘normaal’ moeten doen. Hoe zijn deze patronen te begrijpen?
Gebonden aan witheid: witte identiteiten en de onbedoelde (re)productie van racisme
Authors: Schaap Julian
Published: June 2016

Boekbespreking: Matthew W. Hughey (2012) White Bound: Nationalists, Antiracists, and the Shared Meanings of Race.
De seksparadox, wat is dat?
Authors: Wilterdink Nico
Published: June 2016

De seksparadox, wat is dat? (commentaar)
Over het ontstaan van culturele soorten. Een ecologische analyse van het ontstaan van nieuwe genres in de elektronische dansmuziek
Authors: van Venrooij Alex
Published: June 2016

Dit artikel onderzoekt of het ontstaan van nieuwe genres in het Britse veld van de elektronische dansmuziek verklaard kan worden door ecologische mechanismen. Door het combineren van twee omvangrijke databestanden, bestaande uit ongeveer achtduizend tekstdocumenten uit de Britse muziekpers en discografische informatie over bijna vijftigduizend releases in verschillende dancemuziekgenres, laat deze studie zien dat de kansen voor het ontstaan van nieuwe genres beïnvloed worden door de discursieve legitimatie en de stijging in productie van vergelijkbare genres. De mogelijkheden voor het ontstaan van nieuwe genres worden echter ook beperkt door een overmaat aan releases in vergelijkbare genres en door brede acceptatie van een type genre in de mainstream muziekpers. De conclusie van deze studie is dan ook dat het ontstaan van cultuurvormen, net als in het geval van organisatievormen, beïnvloed wordt door ecologische mechanismen van wederzijdse legitimatie en competitie.
De dingen een kwartslag draaien: in antwoord op vragen van de themaredactie van Sociologie
Authors: Mol Annemarie
Published: June 2016

De dingen een kwartslag draaien: in antwoord op vragen van de themaredactie van Sociologie
Nawoord: Actor-netwerk theorie als ironische sociologie
Authors: Aupers Stef
Published: June 2016

Nawoord: Actor-netwerk theorie als ironische sociologie
Verloren en gevonden in kwantificatie: het dubbelleven van een index in de Amsterdamse Wijkaanpak
Authors: de Wilde Mandy , Franssen Thomas
Published: June 2016

In dit artikel beschrijven we hoe het ‘Normaal Amsterdams Peil’ (NAP), dat ontwikkeld is als een evaluatie-instrument in de Amsterdamse Wijkaanpak, in de praktijk fungeert als een device waarmee buurten op een specifieke manier worden geordend. Daarnaast genereert het NAP ‘feiten’ over deze buurten en stelt ze daarmee beleidsmakers in staat de beleidsinterventie te legitimeren. Het is in en door het NAP dat buurten op een legitieme manier als ‘achterstandswijk’ of ‘probleemwijk’ kunnen worden gedefinieerd. We onderscheiden discursieve, statistische en visuele technieken die het NAP tot stand brengen in beleidsdocumenten en daarmee Amsterdamse buurten op een specifieke manier ordenen. Hiermee biedt de analyse ook een complexer begrip van beleidsdocumenten, die niet gezien moeten worden als representaties van beslissingen of beleidsplannen. Beleidsdocumenten zijn ‘levende documenten’ waarin bepaalde ordeningen tot stand worden gebracht. Toekomstig onderzoek in de beleidssociologie kan van deze materieel-semiotische benadering profiteren. Het helpt beleidssociologen om specifieker de technieken te analyseren die in beleidsdocumenten worden gebruikt om entiteiten met elkaar in relatie te brengen. Dit is nodig omdat een groot deel van de door sociologen bestudeerde beleidsinterventies juist in en door beleidsdocumenten en devices zoals het NAP ontstaan.
Sport als nieuwe religie
Authors: Pas Niek
Published: June 2016

Sport als nieuwe religie.Boekbespreking: Ruud Stokvis (2014) Lege kerken, volle stadions. Sport en de sociale functies van religie.
De docent als publiek socioloog – kritisch geëngageerd onderwijs voor de democratie
Authors: van den Berg Marguerite
Published: June 2016

De docent als publiek socioloog – kritisch geëngageerd onderwijs voor de democratie. Debat: Rethink Sociology.
Zijn kleinere concepten niet een veel groter probleem?
Authors: Duyvendak Jan Willem
Published: June 2016

Zijn kleinere concepten niet een veel groter probleem? Debat: ‘Over nut en nadeel van de sociologie voor het leven’
Zinc biodisponible en suelo para la nutrición del nogal pecanero
Authors: Madrigal-Soteno Nancy  A. , Ojeda-Barrios Dámaris  L. , Guerrero-Prieto Victor  M. , Ávila-Quezada Graciela , Parra-Quezada Rafael
Published: June 2016

El nogal pecanero es uno de los frutales más cultivados a nivel nacional por su alta rentabilidad. Este frutal tiene necesidades importantes de zinc (Zn), el cual se ubica como uno de los micronutrientes más requeridos por este cultivo. Los principales efectos del Zn en el metabolismo de la planta se observan en la síntesis de clorofila y triptófano. También está involucrado en la actividad de enzimas relacionadas con la detoxificación de las especies reactivas de oxígeno. La deficiencia de este nutriente se relaciona con el tipo de suelo. Con el objetivo de conocer los factores que inf luyen en la biodisponibilidad del Zn en el suelo para la nutrición del nogal pecanero se presenta la siguiente revisión. Se concluye que la deficiencia de Zn en las huertas de nogal es más común en periodos fríos, primaveras húmedas, y suelos arenosos con bajo contenido de materia orgánica, pH alcalino y altos contenidos de carbonatos. Esta deficiencia ocasiona un escaso desarrollo radical.
An urban agglomeration effect on surface UV doses: Comparison of the Brewer measurements in Warsaw and at Belsk, Poland, for the period 2013–2015
Authors: Czerwińska Agnieszka E. , Krzyścin Janusz W. , Jarosławski Janusz
Published: June 2016

Abstract. The specific aerosols and cloud properties over large urban regions seem to generate an island, similar to the well- know city heat island, leading to lower UV radiation intensity compared to the surrounding cleaner areas, thus creating a shield against excessive human exposure to the UV radiation. The present study focuses on differences in the erythemal and UV-A1 (340–400 nm) doses measured by the Brewer spectrophotometers in Warsaw (52.3° N, 21.0° E) and at Belsk (51.8° N, 20.8° E), which is located in a rural region at a distance of about 60 km in the south-west direction from the city. The ratio between erythemal and UV-A1 partly daily doses, obtained during all-sky and cloudless-sky conditions in the period May 2013–December 2015, are analyzed to infer specific cloud and aerosol forcing on the surface UV doses over Warsaw. Radiative model simulations are carried out to assess impact of the Warsaw-Belsk differences in total ozone, geographical location and albedo, on the mean ratio between the doses. Higher surface albedo over the city compensates the effect of solar elevation differences due to latitude differences as the mean total ozone values appear almost the same over both sites. It is found that urban agglomeration induced 8 % and 5 % attenuation of the erythemal and UV-A1 doses, respectively, which could be caused by larger aerosol absorption. It appears that a slightly increased optical depth of the urban aerosols and properties of clouds generated over Warsaw are less important for the UV attenuation. In this work we are showing that the higher city surface albedo compensates for the solar UV attenuation caused by urban aerosol load in the city of Warsaw.
Using δ13C-CH4 and δD-CH4 to constrain Arctic methane emissions
Authors: Warwick Nicola J. , Cain Michelle L. , Fisher Rebecca , France James L. , Lowry David , Michel Sylvia E. , Nisbet Euan G. , Vaughn Bruce H. , White James W. C. , Pyle John A.
Published: June 2016

Abstract. We present a global methane modelling study assessing the sensitivity of Arctic atmospheric CH4 mole fractions, δ13C-CH4 and δD-CH4 to uncertainties in Arctic methane sources. Model simulations include methane tracers coloured by source and isotopic composition and are compared with atmospheric data at four high northern latitude measurement sites. We find the model's ability to capture the magnitude and phase of observed seasonal cycles of CH4 mixing ratios, δ13C-CH4 and δD-CH4 in high northern latitudes is much improved using a later spring kick-off and autumn decline in high northern latitude wetland emissions than predicted by most process models. Results from our model simulations indicate that recent predictions of large methane emissions from thawing submarine permafrost in the East Siberian Arctic Shelf region could only be reconciled with global scale atmospheric observations by making large adjustments to high latitude emission inventories.
Satellite observations of atmospheric methane and their value for quantifying methane emissions
Authors: Jacob Daniel J. , Turner Alexander J. , Maasakkers Joannes D. , Sheng Jianxiong , Sun Kang , Liu Xiong , Chance Kelly , Aben Ilse , McKeever Jason , Frankenberg Christian
Published: June 2016

Abstract. Methane is a greenhouse gas emitted by a range of natural and anthropogenic sources. Atmospheric methane has been measured continuously from space since 2003, and new instruments are planned for launch in the near future that will greatly expand the capabilities of space-based observations. We review the value of current, future, and proposed satellite observations to better quantify and understand methane emissions through inverse analyses, down to the scale of point sources and in combination with suborbital (surface and aircraft) data. Current observations from GOSAT are of high quality but have sparse spatial coverage. They provide limited information to quantify methane emissions on a regional (100–1000 km) scale. TROPOMI to be launched in late 2016 is expected to quantify daily emissions on the regional scale and will also effectively detect large point sources. Future satellite instruments with much higher spatial resolution, such as the recently launched GHGSat with 50 × 50 m2 resolution over targeted viewing domains, have the potential to detect a wide range of methane point sources. Geostationary observation of methane, still in the proposal stage, will have unique capability for mapping source regions with high resolution while also detecting transient "super-emitter" point sources. Exploiting the rapidly expanding satellite measurement capabilities to quantify methane emissions requires a parallel effort to construct high-quality spatially and sectorally resolved emission inventories. Partnership between top-down inverse analyses of atmospheric data and bottom-up construction of emission inventories is crucial to better understand methane emission processes and from there to inform climate policy.
Biomass burning fuel consumption dynamics in the tropics and subtropics assessed from satellite
Authors: Andela Niels , van der Werf Guido R. , Kaiser Johannes W. , van Leeuwen Thijs T. , Wooster Martin J. , Lehmann Caroline E. R.
Published: June 2016

Abstract. Landscape fires occur on a large scale in (sub)tropical savannas and grasslands, affecting ecosystem dynamics, regional air quality and concentrations of atmospheric trace gasses. Fuel consumption per unit of area burned is an important but poorly constrained parameter in fire emission modelling. We combined satellite-derived burned area with fire radiative power (FRP) data to derive fuel consumption estimates for land cover types with low tree cover in South America, Sub-Saharan Africa, and Australia. We developed a new approach to estimate fuel consumption, based on FRP data from the polar-orbiting Moderate Resolution Imaging Spectroradiometer (MODIS) and the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) in combination with MODIS burned-area estimates. The fuel consumption estimates based on the geostationary and polar-orbiting instruments showed good agreement in terms of spatial patterns. We used field measurements of fuel consumption to constrain our results, but the large variation in fuel consumption in both space and time complicated this comparison and absolute fuel consumption estimates remained more uncertain. Spatial patterns in fuel consumption could be partly explained by vegetation productivity and fire return periods. In South America, most fires occurred in savannas with relatively long fire return periods, resulting in comparatively high fuel consumption as opposed to the more frequently burning savannas in Sub-Saharan Africa. Strikingly, we found the infrequently burning interior of Australia to have higher fuel consumption than the more productive but frequently burning savannas in northern Australia. Vegetation type also played an important role in explaining the distribution of fuel consumption, by affecting both fuel build-up rates and fire return periods. Hummock grasslands, which were responsible for a large share of Australian biomass burning, showed larger fuel build-up rates than equally productive grasslands in Africa, although this effect might have been partially driven by the presence of grazers in Africa or differences in landscape management. Finally, land management in the form of deforestation and agriculture also considerably affected fuel consumption regionally. We conclude that combining FRP and burned-area estimates, calibrated against field measurements, is a promising approach in deriving quantitative estimates of fuel consumption. Satellite-derived fuel consumption estimates may both challenge our current understanding of spatiotemporal fuel consumption dynamics and serve as reference datasets to improve biogeochemical modelling approaches. Future field studies especially designed to validate satellite-based products, or airborne remote sensing, may further improve confidence in the absolute fuel consumption estimates which are quickly becoming the weakest link in fire emission estimates.
Reviews and syntheses: Four decades of modeling methane cycling in terrestrial ecosystems
Authors: Xu Xiaofeng , Yuan Fengming , Hanson Paul J. , Wullschleger Stan D. , Thornton Peter E. , Riley William J. , Song Xia , Graham David E. , Song Changchun , Tian Hanqin
Published: June 2016

Abstract. Over the past 4 decades, a number of numerical models have been developed to quantify the magnitude, investigate the spatial and temporal variations, and understand the underlying mechanisms and environmental controls of methane (CH4) fluxes within terrestrial ecosystems. These CH4 models are also used for integrating multi-scale CH4 data, such as laboratory-based incubation and molecular analysis, field observational experiments, remote sensing, and aircraft-based measurements across a variety of terrestrial ecosystems. Here we summarize 40 terrestrial CH4 models to characterize their strengths and weaknesses and to suggest a roadmap for future model improvement and application. Our key findings are that (1) the focus of CH4 models has shifted from theoretical to site- and regional-level applications over the past 4 decades, (2) large discrepancies exist among models in terms of representing CH4 processes and their environmental controls, and (3) significant data–model and model–model mismatches are partially attributed to different representations of landscape characterization and inundation dynamics. Three areas for future improvements and applications of terrestrial CH4 models are that (1) CH4 models should more explicitly represent the mechanisms underlying land–atmosphere CH4 exchange, with an emphasis on improving and validating individual CH4 processes over depth and horizontal space, (2) models should be developed that are capable of simulating CH4 emissions across highly heterogeneous spatial and temporal scales, particularly hot moments and hotspots, and (3) efforts should be invested to develop model benchmarking frameworks that can easily be used for model improvement, evaluation, and integration with data from molecular to global scales. These improvements in CH4 models would be beneficial for the Earth system models and further simulation of climate–carbon cycle feedbacks.
Impacts of Tibetan Plateau uplift on atmospheric dynamics and associated precipitation δ18O
Authors: Botsyun Svetlana , Sepulchre Pierre , Risi Camille , Donnadieu Yannick
Published: June 2016

Abstract. Palaeoelevation reconstructions of mountain belts have become a focus of modern science since surface elevation provides crucial information for understanding both geodynamic mechanisms of Earth's interior and the influence of mountain growth on climate. Stable oxygen isotopes palaeoaltimetry is one of the most popular techniques nowadays, and relies on the difference between δ18O of palaeo-precipitation reconstructed using the natural archives, and modern measured values for the point of interest. Our goal is to understand where and how complex climatic changes linked with the growth of mountains affect δ18O in precipitation. For this purpose, we develop a theoretical expression for the precipitation composition based on the Rayleigh distillation and the isotope-equipped atmospheric general circulation model LMDZ-iso outputs. Experiments with reduced height over the Tibetan Plateau and the Himalayas have been designed. Our results show that the isotopic composition of precipitation is very sensitive to climate changes related to the growth of the Himalayas and Tibetan Plateau. Specifically our simulations suggest that only 40 % of sampled sites for palaeoaltimetry depict a full topographic signal, and that uplift-related changes in relative humidity (northern region) and precipitation amount (southern region) could explain absolute deviations of up to 2.5 ‰ of the isotopic signal, thereby creating biases in palaeoelevation reconstructions.
Spatial and temporal variations in plant water-use efficiency inferred from tree-ring, eddy covariance and atmospheric observations
Authors: Dekker Stefan C. , Groenendijk Margriet , Booth Ben B. B. , Huntingford Chris , Cox Peter M.
Published: June 2016

Abstract. Plant water-use efficiency (WUE), which is the ratio of the uptake of carbon dioxide through photosynthesis to the loss of water through transpiration, is a very useful metric of the functioning of the land biosphere. WUE is expected to increase with atmospheric CO2, but to decline with increasing atmospheric evaporative demand – which can arise
from increases in near-surface temperature or decreases in relative humidity.
We have used Δ13C measurements from tree rings, along with
eddy covariance measurements from Fluxnet sites, to estimate the
sensitivities of WUE to changes in CO2 and atmospheric humidity deficit.
This enables us to reconstruct fractional changes in WUE, based on changes in
atmospheric climate and CO2, for the entire period of the instrumental global climate record. We estimate that overall WUE increased from 1900 to
2010 by 48 ± 22 %, which is more than double that simulated by the
latest Earth System Models. This long-term trend is largely driven by
increases in CO2, but significant inter-annual variability and regional differences are evident due to variations in temperature and relative
humidity. There are several highly populated regions, such as western Europe
and East Asia, where the rate of increase of WUE has declined sharply in the
last 2 decades. Our data-based analysis indicates increases in WUE that
typically exceed those simulated by Earth System Models – implying that
these models are either underestimating increases in photosynthesis or
underestimating reductions in transpiration.
Avalanche fatalities in the European Alps: long-term trends and statistics
Authors: Techel Frank , Jarry Frédéric , Kronthaler Georg , Mitterer Susanna , Nairz Patrick , Pavšek Miha , Valt Mauro , Darms Gian
Published: June 2016

Abstract. Avalanche accidents, particularly those resulting in fatalities, attract substantial attention from policy makers and organizations, as well as from the media and the public. Placing fatal accidents in a wider context requires long-term and robust statistics. However, avalanche accident statistics, like most other accident statistics, often rely on relatively small sample sizes, with single multi-fatality events and random effects having a potentially large influence on summary and trend statistics. Additionally, trend interpretation is challenging because statistics are generally explored at a national level, and studies vary in both the period covered and the methods. Here, we addressed these issues by combining the avalanche fatality data from the European Alps (Austria, France, Germany, Liechtenstein, Italy, Slovenia, and Switzerland) for three different periods between 1937 and 2015 and applying the same data analysis methodology. During the last four decades, about 100 people lost their lives each year in the Alps. Despite considerable inter-annual variation, this number has remained relatively constant in the last decades. However, exploring fatality numbers by the location of the victims at the time of the avalanche revealed two partly opposing trends. The number of fatalities in controlled terrain (settlements and transportation corridors) has decreased significantly since the 1970s. In contrast to this development, the number of fatalities in uncontrolled terrain (mostly recreational accidents) almost doubled between the 1960s and 1980s and has remained relatively stable since then, despite a strong increase in the number of winter backcountry recreationists. Corresponding to these trends, the proportion of fatalities in uncontrolled terrain increased from 72 to 97 %. These long-term trends were evident in most national statistics. Further, the temporal correlation between subsets of the Alpine fatality data, and between some of the national statistics, suggests that time series covering a longer period may be used as an indicator for missing years in shorter-duration datasets. Finally, statistics from countries with very few incidents should be compared to, or analysed together with, those from neighbouring countries exhibiting similar economical and structural developments and characteristics.
Forecasting auroras from regional and global magnetic field measurements
Authors: Kauristie Kirsti , Myllys Minna , Partamies Noora , Viljanen Ari , Peitso Pyry , Juusola Liisa , Ahmadzai Shabana , Singh Vikramjit , Keil Ralf , Martinez Unai , Luginin Alexej , Glover Alexi , Navarro Vicente , Raita Tero
Published: June 2016

Abstract. We use the connection between auroral sightings and rapid geomagnetic field variations in a concept for a Regional Auroral Forecast (RAF) service. The service is based on statistical relationships between near-real-time alerts issued by the NOAA Space Weather Prediction Center and magnetic time derivative (dB∕dt) values measured by five MIRACLE magnetometer stations located in Finland at auroral and sub-auroral latitudes. Our database contains NOAA alerts and dB∕dt observations from the years 2002–2012. These data are used to create a set of conditional probabilities, which tell the service user when the probability of seeing auroras exceeds the average conditions in Fennoscandia during the coming 0–12 h. Favourable conditions for auroral displays are associated with ground magnetic field time derivative values (dB∕dt) exceeding certain latitude-dependent threshold values. Our statistical analyses reveal that the probabilities of recording dB∕dt exceeding the thresholds stay below 50 % after NOAA alerts on X-ray bursts or on energetic particle flux enhancements. Therefore, those alerts are not very useful for auroral forecasts if we want to keep the number of false alarms low. However, NOAA alerts on global geomagnetic storms (characterized with Kp values  >  4) enable probability estimates of  >  50 % with lead times of 3–12 h. RAF forecasts thus rely heavily on the well-known fact that bright auroras appear during geomagnetic storms. The additional new piece of information which RAF brings to the previous picture is the knowledge on typical storm durations at different latitudes. For example, the service users south of the Arctic Circle will learn that after a NOAA ALTK06 issuance in night, auroral spotting should be done within 12 h after the alert, while at higher latitudes conditions can remain favourable during the next night.
Improving the WRF model's (version 3.6.1) simulation over sea ice surface through coupling with a complex thermodynamic sea ice model (HIGHTSI)
Authors: Yao Yao , Huang Jianbin , Luo Yong , Zhao Zongci
Published: June 2016

Abstract. Sea ice plays an important role in the air–ice–ocean interaction, but it is often represented simply in many regional atmospheric models. The Noah sea ice scheme, which is the only option in the current Weather Research and Forecasting (WRF) model (version 3.6.1), has a problem of energy imbalance due to its simplification in snow processes and lack of ablation and accretion processes in ice. Validated against the Surface Heat Budget of the Arctic Ocean (SHEBA) in situ observations, Noah underestimates the sea ice temperature which can reach −10 °C in winter. Sensitivity tests show that this bias is mainly attributed to the simulation within the ice when a time-dependent ice thickness is specified. Compared with the Noah sea ice model, the high-resolution thermodynamic snow and ice model (HIGHTSI) uses more realistic thermodynamics for snow and ice. Most importantly, HIGHTSI includes the ablation and accretion processes of sea ice and uses an interpolation method which can ensure the heat conservation during its integration. These allow the HIGHTSI to better resolve the energy balance in the sea ice, and the bias in sea ice temperature is reduced considerably. When HIGHTSI is coupled with the WRF model, the simulation of sea ice temperature by the original Polar WRF is greatly improved. Considering the bias with reference to SHEBA observations, WRF-HIGHTSI improves the simulation of surface temperature, 2 m air temperature and surface upward long-wave radiation flux in winter by 6, 5 °C and 20 W m−2, respectively. A discussion on the impact of specifying sea ice thickness in the WRF model is presented. Consistent with previous research, prescribing the sea ice thickness with observational information results in the best simulation among the available methods. If no observational information is available, we present a new method in which the sea ice thickness is initialized from empirical estimation and its further change is predicted by a complex thermodynamic sea ice model. The ice thickness simulated by this method depends much on the quality of the initial guess of the ice thickness and the role of the ice dynamic processes.