bluuebunny/crossref_metadata_2025 huggingface dataset:
ElectriCity Innovation Challenge 2015: Experiences
Authors: Smith Göran , Burden Håkan , Hjalmarsson Anders
Published: May 2018

ElectriCity Innovation Challenge 2015 was an open innovation contest in Gothenburg, Sweden. The main purpose was to surge public interest and involvement in ElectriCity, a demonstration arena for nextgeneration’s electrified bus systems. The contest furthermore aimed to catalyse innovation that can contribute to making public transport more attractive, and to test a novel innovation platform that assembles data from buses and bus stops. The outcome was six events with a total of more than 800 attendants, 48 viable prototypes with potential to increase the modal share of electrified public transport and feedback on the innovation platform’s potential for development.
Analysis of Consumers' Attitudes Towards Purchasing PHEVs and HEVs in Manitoba, Canada
Authors: Jiao Xun
Published: May 2018

This research focuses on Manitoba, Canada to explore the consumers’ attitudes towards purchasing plug-in hybrid electric vehicles (PHEVs) and hybrid electric vehicles (HEVs). An online survey will be adopted to help explore participants’ psychological distance to PHEVs and HEVs. Then, this study attempts to identify how psychological distance affects consumers’ purchasing decision. The results may help government make efficient incentive policies and improve PHEVs and HEVs adoption.
The Challenges of Hosting Major Events Owned by International Federations: A Case Study of the 2014 Chess Olympics
Authors: Solberg Harry Arne , Olderøien Lin
Published: May 2018

This article focuses on the challenges of hosting events owned by international federations. The empirical data is from the Chess Olympiad, which was hosted in Tromsø, Norway, in 2014. The organizers met several unforeseen problems, some of which were due to lack of experience
and strategic misjudgments. Some of the problems were also the result of conflicting interests with the owner of the event, the International Chess Federation (FIDE). The article gives insight into the strategies international federations can use to strengthen their power in such situations.
FIDE tried on several occasions to induce bidding wars, and the effort was successful when the auctions had the character of a secret auction. The local organizers came out of the auctions the best when they could communicate with their rival, in this case the city of Albena, Bulgaria. The
article paints the picture of an international federation that was willing to go quite far to exploit the power at hand, including the use of instruments of an unethical character.
Spatial Rabi oscillations between Majorana bound states and quantum dots
Authors: Zheng Jun-Hui , Yao Dao-Xin , Wang Zhi
Published: May 2018

Background: A Majorana bound state is a superconducting quasiparticle that is the superposition of particle and hole with equal amplitude. We propose a verification of this amplitude equality by analyzing the spatial Rabi oscillations of the quantum states of a quantum dot that is tunneling-coupled to the Majorana bound states.

Results: We find two resonant Rabi driving energies that correspond to the energy splitting due to the coupling of two spatially separated Majorana bound states. The resulting Rabi oscillating frequencies from these two different resonant driving energies are identical for the Majorana bound states, while different for ordinary Andreev bound states. We further study a double-quantum-dot setup and find a nonlocal quantum correlation between them that is mediated by two Majorana bound states. This nonlocal correlation has the signature of additional resonant driving energies.

Conclusion: Our method can be used to distinguish between Majorana bound states and Andreev bound states. It also gives a precise measurement of the energy splitting between two Majorana bound states.
HST Grism Confirmation of 16 Structures at 1.4 < z < 2.8 from the Clusters Around Radio-Loud AGN (CARLA) Survey
Authors: Noirot Gaël , Stern Daniel , Mei Simona , Wylezalek Dominika , Cooke Elizabeth A. , De Breuck Carlos , Galametz Audrey , Hatch Nina A. , Vernet Joël , Brodwin Mark , Eisenhardt Peter , Gonzalez Anthony H. , Jarvis Matt , Rettura Alessandro , Seymour Nick , Stanford S. A.
Published: May 2018

We report spectroscopic results from our 40-orbit Hubble Space Telescope slitless grism spectroscopy program observing the 20 densest Clusters Around Radio-Loud AGN (CARLA) candidate galaxy clusters at 1.4 < z < 2.8. These candidate rich structures, among the richest and most distant known, were identified on the basis of [3.6]–[4.5] color from a 408 hr multi-cycle Spitzer program targeting 420 distant radio-loud AGN. We report the spectroscopic confirmation of 16 distant structures at 1.4 < z < 2.8 associated with the targeted powerful high-redshift radio-loud AGN. We also report the serendipitous discovery and spectroscopic confirmation of seven additional structures at 0.87 < z < 2.12 not associated with the targeted radio-loud AGN. We find that 1010–1011
M
⊙ member galaxies of our confirmed CARLA structures form significantly fewer stars than their field counterparts at all redshifts within 1.4 ≤ z ≤ 2. We also observe higher star-forming activity in the structure cores up to z = 2, finding similar trends as cluster surveys at slightly lower redshifts (1.0 < z < 1.5). By design, our efficient strategy of obtaining just two grism orbits per field only obtains spectroscopic confirmation of emission line galaxies. Deeper spectroscopy will be required to study the population of evolved, massive galaxies in these (forming) clusters. Lacking multi-band coverage of the fields, we adopt a very conservative approach of calling all confirmations “structures,” although we note that a number of features are consistent with some of them being bona fide galaxy clusters. Together this survey represents a unique and large homogenous sample of spectroscopically confirmed structures at high redshifts, potentially more than doubling the census of confirmed, massive clusters at z > 1.4.
TaxonWorks: a Use Case in Documenting of Etymology of Generic Names in Auchenorrhyncha (Hemiptera)
Authors: Dmitriev Dmitry
Published: May 2018

The 3i World Auchenorrhyncha database (http://dmitriev.speciesfile.org) is being migrated into TaxonWorks (http://taxonworks.org) and comprises nomenclatural data for all known Auchenorrhyncha taxa (leafhoppers, planthoppers, treehoppers, cicadas, spittle bugs). Of all those scientific names, 8,700 are unique genus-group names (which include valid genera and subgenera as well as their synonyms). According to the Rules of Zoological Nomenclature, a properly formed species-group name when combined with a genus-group name must agree with the latter in gender if the species-group name is or ends with a Latin or Latinized adjective or participle. This provides a double challenge for researchers describing new or citing existing taxa. For each species, the knowledge about the part of speech is essential information (nouns do not change their form when associated with different generic names). For the genus, the knowledge of the gender is essential information. Every time the species is transferred from one genus to another, its ending may need to be transformed to make a proper new scientific name (a binominal name). In modern day practice, it is important, when establishing a new name, to provide information about etymology of this name and the ways it should be used in the future publications: the grammatical gender for a genus, and the part of speech for a species. The older names often do not provide enough information about their etymology to make proper construction of scientific names. That is why in the literature, we can find numerous cases where a scientific name is not formed in conformity to the Rules of Nomenclature. An attempt was made to resolve the etymology of the generic names in Auchenorrhyncha to unify and clarify nomenclatural issues in this group of insects. In TaxonWorks, the rules of nomenclature are defined using the NOMEN onthology (https://github.com/SpeciesFileGroup/nomen).
Biodiversity Information Services: A (not-so-) little knowledge that acts
Authors: Ariño Arturo , Noesgaard Daniel , Hjarding Angel , Schigel Dmitry
Published: May 2018

Standards set up by Biodiversity Information Standards-Taxonomic Databases Working Group (TDWG), initially developed as a way to share taxonomical data, greatly facilitated the establishment of the Global Biodiversity Information Facility (GBIF) as the largest index to digitally-accessible primary biodiversity information records (PBR) held by many institutions around the world. The level of detail and coverage of the body of standards that later became the Darwin Core terms enabled increasingly precise retrieval of relevant records useful for increased digitally-accessible knowledge (DAK) which, in turn, may have helped to solve ecologically-relevant questions.

After more than a decade of data accrual and release, an increasing number of papers and reports are citing GBIF either as a source of data or as a pointer to the original datasets. GBIF has curated a list of over 5,000 citations that were examined for contents, and to which tags were applied describing such contents as additional keywords. The list now provides a window on what users want to accomplish using such DAK.

We performed a preliminary word frequency analysis of this literature, starting at titles, which refers to GBIF as a resource. Through a standardization and mapping of terms, we examined how the facility-enabled data seem to have been used by scientists and other practitioners through time: what concepts/issues are pervasive, which taxon groups are mostly addressed, and whether data concentrate around specific geographical or biogeographical regions. We hoped to cast light on which types of ecological problems the community believes are amenable to study through the judicious use of this data commons and found that, indeed, a few themes were distinctly more frequently mentioned than others. Among those, generally-perceived issues such as climate change and its effect on biodiversity at global and regional scales seemed prevalent. The taxonomic groups were also unevenly mentioned, with birds and plants being the most frequently named.

However, the entire list of potential subjects that might have used GBIF-enabled data is now quite wide, showing that the availability of well-structured data has spawned a widening spectrum of possible use cases. Among them, some enjoy early and continuous presence (e.g. species, biodiversity, climate) while others have started to show up only later, once a critical mass of data seemed to have been attained (e.g. ecosystems, suitability, endemism). Biodiversity information in the form of standards-compliant DAK may thus already have become a commodity enabling insight into an increasingly more complex and diverse body of science. Paraphrasing Tennyson, more things were wrought by data than TDWG dreamt of.
Leveraging Industry Visualization Tools for Biodiversity Science
Authors: Pender Jocelyn
Published: May 2018

Widespread technology usage has resulted in a deluge of data that is not limited to scientific domains. For example, technology companies accumulate vast amounts of data on their users to support their applications and platforms. The participation of many domains in big data collection, data analysis and visualization, and the need for fast data exploration has provided a stellar market opportunity for high quality data visualization software to emerge. In this talk, leading industry visualization software (Tableau) will be used to explore a biodiversity dataset (Carex spp. distribution and morphology). The advantages and disadvantages of using Tableau for scientific exploration will be discussed, as well as how to integrate data visualization tools early into the data pipeline. Lastly, the potential for developing a data visualization "stack" (i.e., a combination of software products and programming languages) using available tools will be discussed, as well as what the future might look like for scientists looking to capitalize on the growth of industry tools.
Homology of Hilbert schemes of points on a locally planar curve
Authors: Vold Rennemo Jørgen
Published: May 2018

Let

C

be a proper, integral, locally planar curve, and consider its Hilbert schemes of points

C^[n]

. We define four creation/annihilation operators acting on the rational homology groups of these Hilbert schemes and show that the operators satisfy the relations of a Weyl algebra. The action of this algebra is similar to that defined by Grojnowski and Nakajima for a smooth surface. As a corollary, we compute the cohomology of

C^[n]

in terms of the cohomology of the compactified Jacobian of

C

together with an auxiliary grading on the latter. This recovers and slightly strenghtens a formula recently obtained in a different way by Maulik and Yun and independently Migliorini and Shende.
Inverting the signature of a path
Authors: Lyons Terry J. , Xu Weijun
Published: May 2018

The aim of this article is to develop an explicit procedure that enables one to reconstruct any

\mathcal C^1

path (at natural parametrization) from its signature. We also explicitly quantify the distance between the reconstructed path and the original path in terms of the number of terms in the signature that are used for the construction and the modulus of continuity of the derivative of the path. A key ingredient in the construction is the use of a procedure of symmetrization that separates the behaviour of the path at small and large scales.
The frequency and the structure of large character sums
Authors: Bober Jonathan , Goldmakher Leo , Granville Andrew , Koukoulopoulos Dimitris
Published: May 2018

Let

M(\chi)

denote the maximum of

|\sum_{n\le N}\chi(n)|

for a given non-principal Dirichlet character

\chi

modulo

q

, and let

N_\chi

denote a point at which the maximum is attained. In this article we study the distribution of

M(\chi)/\sqrt{q}

as one varies over characters modulo

q

, where

q

is prime, and investigate the location of

N_\chi

. We show that the distribution of

M(\chi)/\sqrt{q}

converges weakly to a universal distribution

\Phi

, uniformly throughout most of the possible range, and get (doubly exponential decay) estimates for

\Phi

's tail. Almost all

\chi

for which

M(\chi)

is large are odd characters that are 1-pretentious. Now,

M(\chi)\ge |\sum_{n\le q/2}\chi(n)| = \frac{|2-\chi(2)|}\pi \sqrt{q} |L(1,\chi)|

, and one knows how often the latter expression is large, which has been how earlier lower bounds on

\Phi

were mostly proved. We show, though, that for most

\chi

with

M(\chi)

large,

N_\chi

is bounded away from

q/2

, and the value of

M(\chi)

is little bit larger than

\frac{\sqrt{q}}{\pi} |L(1,\chi)|

.
Bounded variation approximation of $L_p$ dyadic martingales and solutions to elliptic equations
Authors: Hytönen Tuomas , Rosén Andreas
Published: May 2018

We prove continuity and surjectivity of the trace map onto

L_p(\mathbb R^n)

, from a space of functions of locally bounded variation, defined by the Carleson functional. The extension map is constructed through a stopping time argument. This extends earlier work by Varopoulos in the BMO case, related to the Corona Theorem. We also prove

L_p

Carleson approximability results for solutions to elliptic non-smooth divergence form equations, which generalize results in the case

p=\infty

by Hofmann, Kenig, Mayboroda and Pipher.
DISTINÇÃO INCONSISTENTE E SUPERAÇÃO DE PRECEDENTES NO SUPREMO TRIBUNAL FEDERAL
Authors: Mello Patrícia Perrone Campos , Baqueiro Paula De Andrade
Published: May 2018

O artigo tem o objetivo de demonstrar que a adoção de precedentes vinculantes não esvazia as cortes vinculadas do poder de interferir sobre o conteúdo do direito em assunto que já foi objeto de decisão vinculante pelo Supremo Tribunal Federal. Demonstra-se, com base na literatura e por meio de estudo de casos, que a percepção de um precedente como profundamente injusto ou errado pode levar as cortes vinculadas a resistir à sua aplicação ou a produzir distinções inconsistentes em massa, e que essa postura, não raramente, levará à alteração ou à superação do precedente pelo próprio STF. O desenvolvimento judicial do direito ocorre em "rodadas". Cada novo julgado do Supremo encerra um ciclo de discussão, mas sua aplicação nas instâncias vinculadas pode reabrir o debate, reconduzindo-se a questão de volta ao STF e assim sucessivamente. O direito será o resultado da permanente interação entre corte vinculante e cortes vinculadas. A adoção de precedentes vinculantes confere, contudo, maior racionalidade a tal interação.
A PRIVATIZAÇÃO DE PRESÍDIOS E A IDEIA NEOLIBERAL DE CRIAÇÃO DE UM ESTADO MÍNIMO
Authors: Pompeu Gina Marcilio Vidal , Ferreira Carlos Lélio Lauria
Published: May 2018

O presente artigo aborda a possibilidade de privatização de presídios e a ideia neoliberal de criação de um Estado Mínimo. Examina-se a administração pública no Brasil com minúcia a partir de uma concepção burocrática e gerencial, bem como apresentam-se, de modo particular, os paradoxos da administração prisional brasileira. Justifica-se a escolha do tema por entender que se trata de questão desconsiderada no mundo jurídico brasileiro e, de certa forma, desconhecida no âmbito da execução penal internacional, mesmo com o reconhecimento da absoluta falência do Estado e seu caráter intervencionista. O objetivo da pesquisa é mostrar, inicialmente, que a crise do Estado autoriza considerar a ideia neoliberal da administração prisional em todos os seus aspectos. Trata-se de matéria que reclama pronunciamento acerca da vantagem de estatizar ou privatizar alguns setores da administração pública. O problema constatado na abordagem é a dicotomia entre as normas penal, administrativa e constitucional. A metodologia utilizada é a analítica, empírica, com conceitos jurídicos e normativos no âmbito do Direito Constitucional e Administrativo. Os conceitos utilizados levam em consideração a realidade do sistema penitenciário brasileiro e sua forma arcaica de administração, a aplicação de normas e princípios previstos na Constituição da República de 1988, assim como o entendimento doutrinário e jurisprudencial sobre o tema. Espera-se obter como resultado do trabalho a possibilidade de contribuir para o esclarecimento e a reflexão sobre modelos de gestão adequados à administração prisional no Brasil.
A JUSTIÇA RESTAURATIVA COMO INSTRUMENTO DE FORTALECIMENTO DA CULTURA DE PAZ: UMA NOVA PERSPECTIVA PARA A EXECUÇÃO DAS MEDIDAS SOCIOEDUCATIVAS NO BRASIL
Authors: Colet Gimenez Charlise Paula , Marion Spengler Fabiana
Published: May 2018

O objetivo do presente estudo é abordar a Justiça Restaurativa como instrumento de humanização da execução das medidas socioeducativas no Brasil. Para realizá-lo, adota-se o método de abordagem dedutivo. Aborda-se, inicialmente, o conflito na sociedade contemporânea, a fragilidade das relações sociais e a inclusão de métodos de tratamento de conflitos cujo escopo é atender as necessidades das pessoas envolvidas no conflito. Em um segundo momento, discorre-se acerca da Justiça Restaurativa como quebra da justiça retributiva ao propor, por meio do diálogo e consenso, o respeito absoluto aos direitos humanos e à dignidade da pessoa humana. Na sequência, a fim de consolidar o objetivo do artigo, abordam-se as práticas restaurativas na execução de medidas socioeducativas. A importância da proposta se verifica pela Justiça Restaurativa considerar o delito como um dano às pessoas envolvidas e às relações pessoais, razão pela qual propõe que vítima e ofensor assumam a resolução do conflito no tocante à responsabilidade, à reparação do dano, ao reconhecimento dos traumas causados e à restauração das relações rompidas. Insere-se, nesse contexto, as medidas socioeducativas, as quais são orientadas pela Doutrina da Proteção Integral, garantindo-se ao adolescente o seu desenvolvimento físico, mental, moral, espiritual e social, em condições de liberdade e de dignidade, o que é possibilitado pela Justiça Restaurativa, cumprindo-se, desse modo, o fim do Direito Penal, qual seja, a convivência pacífica entre os seres humanos.
A RELAÇÃO ENTRE CRIMINOGÊNESE E PRÁTICAS PENAIS E O DEBATE SOBRE A TEORIA DA AÇÃO ENTRE SUBJETIVISTAS E OBJETIVISTAS
Authors: Santos André Leonardo Copetti , Lucas Doglas Cesar
Published: May 2018

O objetivo do presente artigo é analisar criticamente uma hegemonia subjetivista no direito penal brasileiro e nas práticas penais por ele institucionalizadas. O artigo tenta demonstrar que há um esquecimento pelos penalistas do debate entre subjetivistas e objetivistas, que tem acontecido no campo das ciências sociais e da filosofia política, acerca das condições de acontecimento social do agir e do fazer humanos, o qual afeta profundamente a concepção normatizada de crime e das suas consequências legais, uma vez que o olvido atinge a consideração da influência de elementos objetivos na causação do delito e, por consequência, a concepção de práticas penais correspondentes à concepção de crime. O trabalho apresenta duas conclusões: primeiro, que se o crime é uma consequência de uma ação livre e deliberada do agente, sem qualquer espécie de coação externa, justificam-se as práticas penais dirigidas aos indivíduos atomizadamente, como tem sido com as penas privativas de liberdade; se, em sentido diverso, compreende-se o crime como sendo o corolário da influência de coerções e estruturas sobre a vontade e a autodeterminação individual, ou em conjunto com estas, então precisamos repensar nossas práticas penais, atribuindo responsabilidade penal não só ao indivíduo, mas ao próprio Estado como gerador de condições criminogênicas. A segunda conclusão do trabalho é que para modificarem-se as práticas penais, o ponto de vista deve mover-se do plano metodológico e epistemológico para o plano ontológico. O método utilizado foi o fenomenológico. A principal implicação prática do artigo reside na proposição de novas condições ontológicas para se pensar o fenômeno criminal e as práticas penais.
QUANDO A LUTA ANTIMANICOMIAL MIRA NO MANICÔMIO JUDICIÁRIO E PRODUZ DESENCARCERAMENTO: UMA ANÁLISE DOS ARRANJOS INSTITUCIONAIS PROVOCADOS PELA DEFENSORIA PÚBLICA NO CAMPO DA POLÍTICA PÚBLICA PENITENCIÁRIA E DE SAÚDE MENTAL
Authors: De Oliveira Patricia Fonseca Carlos Magno , Boiteux Luciana
Published: May 2018

A pesquisa delimita-se no encontro entre os saberes psiquiátrico e jurídico, buscando compreender se e como os reflexos jurídico-penais da Lei n. 10.216/01 no campo da execução das medidas de segurança são hábeis a produzir o exorcismo da noção da periculosidade e do estigma do louco perigoso. Diante da abolição do exame de verificação da cessação da periculosidade (EVCP), paradigmaticamente substituído pelo EMPAP – exame multiprofissional e pericial de avaliação psicossocial no Estado do Rio de Janeiro identifica-se um fenômeno de decréscimo de institucionalização. Seu objetivo do trabalho é analisar, à luz da criminologia crítica e da teoria crítica dos direitos humanos, a mudança paradigmática para o EMPAP para demonstrar quais os rearranjos institucionais tem sido alinhavados na execução das medidas de segurança, no sentido de desenhar um descontinuum do controle formal punitivo para o controle social informal. O trabalho trata da interação entre a política pública de saúde mental e se baseia em dados da atuação concreta da Defensoria Pública em casos de medida de segurança levantados no curso da pesquisa empírica que se utilizou de metodologia da pesquisa participante, com acesso direto a fontes primárias consistentes em bancos de dados públicos de acesso restrito e a acervos de processos judiciários. As conclusões apontam para a potência das articulações interinstitucionais entre atores e atrizes do sistema de justiça e a RAPS (Rede de Atenção Psicossocial) como a chave para compreender o decréscimo do número de pessoas manicomializadas no Estado, com nenhum caso de reiteração criminosa, até o momento.
Long-range transport of volcanic aerosol from the 2010 Merapi tropical eruption to Antarctica
Authors: Wu Xue , Griessbach Sabine , Hoffmann Lars
Published: May 2018

Abstract. Volcanic sulfate aerosol is an important source of sulfur for Antarctica where other local sources of sulfur are rare. Mid- and high latitude volcanic eruptions can directly influence the aerosol budget of the polar stratosphere. However, tropical eruptions can also enhance polar aerosol load following long-range transport. In the present work, we analyze the volcanic plume of a tropical eruption, Mount Merapi in October 2010, using the Lagrangian particle dispersion model Massive-Parallel Trajectory Calculations (MPTRAC), Atmospheric Infrared Sounder (AIRS) SO2 observations and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aerosol observations. We investigate the pathway and transport efficiency of the volcanic aerosol from the tropical tropopause layer (TTL) to the lower stratosphere over Antarctica. We first estimated the time- and height-resolved SO2 injection time series over Mount Merapi during the explosive eruption using the AIRS SO2 observations and a backward trajectory approach. Then the SO2 injections were tracked for up to 6 months using the MPTRAC model. The Lagrangian transport simulation of the volcanic plume was compared to MIPAS aerosol observations and showed good agreement. Both of the simulation and the observations presented in this study suggest that a significant amount of aerosols of the volcanic plume from the Merapi eruption was transported from the tropics to the south of 60 °S within one month after the eruption and even further to Antarctica in the following two months. This relatively fast meridional transport of volcanic aerosol was mainly driven by quasi-horizontal mixing from the TTL to the extratropical lower stratosphere, which was facilitated by the weakening of the subtropical jet during the seasonal transition from austral spring to summer and linked to the westerly phase of the quasi-biennial oscillation (QBO). When the plume went to southern high latitudes, the polar vortex was displaced from the south pole, so the volcanic plume was carried to the south pole without penetrating the polar vortex. Based on the model results, the most efficient pathway for the quasi-horizontal mixing was in between the isentropic surfaces of 360 and 430 K. Although only 4 % of the initial SO2 load was transported into the lower stratosphere south of 60 °S, the Merapi eruption contributed about 8800 tons of sulfur to the Antarctic lower stratosphere. This indicates that the long-range transport under favorable meteorological conditions enables tropical volcanic eruptions to be an important remote source of sulfur for the Antarctic stratosphere.
Black carbon-induced snow albedo reduction over the Tibetan Plateau: Uncertainties from snow grain shape and aerosol-snow mixing state based on an updated SNICAR model
Authors: He Cenlin , Flanner Mark G. , Chen Fei , Barlage Michael , Liou Kuo-Nan , Kang Shichang , Ming Jing , Qian Yun
Published: May 2018

Abstract. We implement a set of new parameterizations into the widely used SNow, ICe, and Aerosol Radiative (SNICAR) model to account for effects of snow grain shape (spherical versus nonspherical) and black carbon (BC)-snow mixing state (external versus internal). We find that nonspherical snow grains lead to higher pure albedo but weaker BC-induced albedo reductions relative to spherical snow grains, while BC-snow internal mixing significantly enhances albedo reductions relative to external mixing. The combination of snow nonsphericity and internal mixing suggests an important interactive effect on BC-induced albedo reduction. Comparisons with observations of clean and BC-contaminated snow albedo show that model simulations accounting for both snow nonsphericity and BC-snow internal mixing perform better than those using the common assumption of spherical snow grains and external mixing. We further apply the updated SNICAR model with comprehensive in-situ measurements of BC concentrations in the Tibetan Plateau snowpack to quantify the present-day (2000–2015) BC-induced snow albedo effects from a regional and seasonal perspective. The BC concentrations show distinct and substantial sub-regional and seasonal variations, with higher values in the non-monsoon season and low altitudes. As a result, the BC-induced regional mean snow albedo reductions and surface radiative effects vary by up to an order of magnitude across different sub-regions and seasons, with values of 0.7–30.7 (1.4–58.4) W m−2 for BC externally mixed with fresh (aged) snow spheres. The BC radiative effects are further complicated by uncertainty in snow grain shape and BC-snow mixing state. BC-snow internal mixing enhances the mean albedo effects over the plateau by 30–60 % relative to external mixing, while nonspherical snow grains decrease the mean albedo effects by up to 31 % relative to spherical grains. Based on this study, extensive measurements and improved model characterization of snow grain shape and aerosol-snow mixing state are urgently needed in order to precisely evaluate BC-snow albedo effects.
Assessing snow extent data sets over North America to inform and improve trace gas retrievals from solar backscatter
Authors: Cooper Matthew J. , Martin Randall V. , Lyapustin Alexei I. , McLinden Chris A.
Published: May 2018

Abstract. Accurate representation of surface reflectivity is essential to tropospheric trace gas retrievals from solar backscatter observations. Surface snow cover presents a significant challenge due to its variability and thus snow-covered scenes are often omitted from retrieval data sets; however, the high reflectance of snow is potentially advantageous for trace gas retrievals. We first examine the implications of surface snow on retrievals from the upcoming TEMPO geostationary instrument for North America. We use a radiative transfer model to examine how an increase in surface reflectivity due to snow cover changes the sensitivity of satellite retrievals to NO2 in the lower troposphere. We find that a substantial fraction (> 50 %) of the TEMPO field of regard can be snow covered in January and that the average sensitivity to the tropospheric NO2 column substantially increases (doubles) when the surface is snow covered.We then evaluate seven existing satellite-derived or reanalysis snow extent products against ground station observations over North America to assess their capability of informing surface conditions for TEMPO retrievals. The Interactive Multisensor Snow and Ice Mapping System (IMS) had the best agreement with ground observations (accuracy of 93 %, precision of 87 %, recall of 83 %). Multiangle Implementation of Atmospheric Correction (MAIAC) retrievals of MODIS-observed radiances had high precision (90 % for Aqua and Terra), but underestimated the presence of snow (recall of 74 % for Aqua, 75 % for Terra). MAIAC generally outperforms the standard MODIS products (precision of 51 %, recall of 43 % for Aqua; precision of 69 %, recall of 45 % for Terra). The Near-real-time Ice and Snow Extent (NISE) product had good precision (83 %) but missed a significant number of snow-covered pixels (recall of 45 %). The Canadian Meteorological Centre (CMC) Daily Snow Depth Analysis Data set had strong performance metrics (accuracy of 91 %, precision of 79 %, recall of 82 %). We use the Fscore, which balances precision and recall, to determine overall product performance (F = 85 %, 82 (82) %, 81 %, 58 %, 46 (54) % for IMS, MAIAC Aqua (Terra), CMC, NISE, MODIS Aqua (Terra), respectively) for providing snow cover information for TEMPO retrievals from solar backscatter observations. We find that using IMS to identify snow cover and enable inclusion of snow-covered scenes in clear-sky conditions across North America in January can increase both the number of observations by a factor of 2.1 and the average sensitivity to the tropospheric NO2 column by a factor of 2.7.
Exploring the applicability and limitations of selected optical scattering instruments for PM mass measurement
Authors: Zhang Jie , Marto Joseph P. , Schwab James J.
Published: May 2018

Abstract. Two optical scattering instruments for particle mass measurement, the Thermo Personal Data RAM (PDR-1500) and the TSI Environmental DustTrak DRX (Model 8543) were evaluated by (1) using poly- and mono-disperse test aerosol in the laboratory, and (2) sampling ambient aerosol. The responses of these optical scattering instruments to different particle characteristics (size, composition, concentration) were compared with responses from reference instruments. A Mie scattering calculation was used to explain the dependence of the optical instruments' response to aerosol size and composition. Concurrently, the detection efficiency of one Alphasense Optical Particle Counter (OPC-N2) was evaluated in the laboratory as well. The relationship between aerosol mass concentration and optical scattering was determined to be strongly dependent on aerosol size and to a lesser extent on aerosol composition (as reflected in the refractive indices of the materials tested) based on ambient measurements. This confirms that there is no simple way to use optical scattering instruments over a wide range of conditions without adjustments based on knowledge of aerosol size and composition. In particular, a test period measuring ambient aerosol with optical scattering instruments and a mass based method (an Aerodyne Aerosol Mass Spectrometer) determined that roughly two thirds of the variance (R2 = 0.64) of the optical to mass signal ratio is explained by the aerosol mass median diameter alone. These observations and calculations help evaluate the applicability and limitations of these optical scattering instruments, and provide guidance to designing suitable applications for each instrument by considering aerosol sources and aerosol size.
UK greenhouse gas measurements at two new tall towers for aiding emissions verification
Authors: Stavert Ann R. , O'Doherty Simon , Stanley Kieran , Young Dickon , Manning Alistair J. , Lunt Mark F. , Rennick Christopher , Arnold Tim
Published: May 2018

Abstract. Under the UK focused Greenhouse gAs and Uk and Global Emissions (GAUGE) project, two new tall tower greenhouse gas (GHG) observation sites were established in the 2013/2014 Northern Hemispheric winter. These sites were located at two existing telecommunications towers, Heathfield (HFD) and Bilsdale (BSD), utilised a combination of cavity ring-down spectroscopy (CRDS) and gas chromatography (GC) to measure key GHGs (CO2, CH4, CO, N2O and SF6). Measurements were made at multiple intake heights on each tower. The inclusion of the two additional tower stations within the existing UK Deriving Emissions linked to Climate Change (DECC) network of four stations was found to reduce the uncertainty of CH4 UK emission estimates by between 10–20 %. CO2 and CH4 dry mole fractions were calculated from either CRDS measurements of wet air which were post corrected with an instrument specific empirical correction or samples dried to between 0.05 and 0.3 % H2O using a Nafion dryer, with a smaller correction applied for the residual H2O. The impact of these two drying strategies was examined. Drying with a Nafion drier was not found to have a significant effect on the observed CH4 mole fraction; however, Nafion drying did cause a 0.02 µmol mol−1 CO2 bias. This bias was stable with sample CO2 mole fractions between 373 and 514 µmol mol−1 and for sample H2O up to 3.5 %. As the calibration and standard gases are treated in the same manner, this error is mostly calibrated out with the residual error below the World Meteorological Organization’s (WMO) reproducibility requirements. Of more concern was the error associated with both default factory and empirical instrument specific water correction algorithms. These corrections are relatively stable and reproducible for samples with H2O between 0.2 and 2.5 %, CO2 between 345 and 449 µmol mol−1 and CH4 between 1743 and 2145 nmol mol−1. However, the residual errors in these corrections increase to > 0.05 µmol mol−1 for CO2 and > 1 nmol mol−1 for CH4 (greater than the WMO internal reproducibility guidelines) at higher humidities and for samples with very low (
Testing the performance of field calibration techniques for low-cost gas sensors in new deployment locations: across a county line and across Colorado
Authors: Casey Joanna Gordon , Hannigan Michael P.
Published: May 2018

Abstract. We assessed the performance of ambient ozone (O3) and carbon dioxide (CO2) field calibration techniques when they were generated using data from one location and then applied to data collected at a new location. We also explored the sensitivity of these methods to the timing of field calibrations relative to deployments they are applied to. Employing data from a number of field deployments in Colorado and New Mexico that spanned several years, we tested and compared the performance of field-calibrated sensors using both linear models (LMs) and artificial neural networks (ANNs) for regression. Sampling sites covered urban, rural/peri-urban, and oil and gas production influenced environments. Generally, we found that the best performing model inputs and model type depended on circumstances associated with individual case studies. In agreement with findings from our previous study that was focused on data from a single location (Casey et al., 2017), ANNs remained more effective than LMs for a number of these case studies but there were some exceptions. In almost all cases the best CO2 models were ANNs that only included the NDIR CO2 sensor along with temperature and humidity. The performance of O3 models tended to be more sensitive to deployment location than to extrapolation in time while the performance of CO2 models tended to be more sensitive to extrapolation in time that to deployment location. The performance of O3 ANN models benefited from the inclusion of several secondary metal oxide type sensors as inputs in many cases.
Simulation of the Greenland Ice Sheet over two glacial–interglacial cycles: investigating a sub-ice- shelf melt parameterization and relative sea level forcing in an ice-sheet–ice-shelf model
Authors: Bradley Sarah L. , Reerink Thomas J. , van de Wal Roderik S. W. , Helsen Michiel M.
Published: May 2018

Abstract. Observational evidence, including offshore moraines and sediment cores,
confirm that at the Last Glacial Maximum (LGM) the Greenland ice sheet (GrIS)
expanded to a significantly larger spatial extent than seen at present,
grounding into Baffin Bay and out onto the continental shelf break. Given
this larger spatial extent and its close proximity to the neighbouring
Laurentide Ice Sheet (LIS) and Innuitian Ice Sheet (IIS), it is likely these
ice sheets will have had a strong non-local influence on the spatial and
temporal behaviour of the GrIS. Most previous paleo ice-sheet modelling
simulations recreated an ice sheet that either did not extend out onto the
continental shelf or utilized a simplified marine ice parameterization which
did not fully include the effect of ice shelves or neglected the sensitivity
of the GrIS to this non-local bedrock signal from the surrounding ice sheets. In this paper, we investigated the evolution of the GrIS over the two most
recent glacial–interglacial cycles (240 ka BP to the present day) using the
ice-sheet–ice-shelf model IMAU-ICE. We investigated the solid earth
influence of the LIS and IIS via an offline relative sea level (RSL) forcing
generated by a glacial isostatic adjustment (GIA) model. The RSL forcing governed the spatial and temporal pattern of sub-ice-shelf melting via changes in the water depth below the ice shelves. In the ensemble of simulations, at the glacial maximums, the GrIS coalesced
with the IIS to the north and expanded to the continental shelf break to the
southwest but remained too restricted to the northeast. In terms of the
global mean sea level contribution, at the Last Interglacial (LIG) and LGM
the ice sheet added 1.46 and −2.59 m, respectively. This LGM contribution
by the GrIS is considerably higher (∼ 1.26 m) than most previous
studies whereas the contribution to the LIG highstand is lower
(∼ 0.7 m). The spatial and temporal behaviour of the northern margin
was highly variable in all simulations, controlled by the sub-ice-shelf
melting which was dictated by the RSL forcing and the glacial history of the
IIS and LIS. In contrast, the southwestern part of the ice sheet was
insensitive to these forcings, with a uniform response in all simulations
controlled by the surface air temperature, derived from ice cores.
An Energy Balance Model for Paleoclimate Transitions
Authors: Dortmans Brady , Langford William F. , Willms Allan R.
Published: May 2018

Abstract. A new energy balance model (EBM) is presented and is used to study Paleoclimate transitions. While most previous EBMs dealt only with the globally averaged climate, this new EBM has three variants: Arctic, Antarctic and Tropical climates. This EBM incorporates the greenhouse warming effects of both carbon dioxide and water vapour, and also includes ice-albedo feedback. The main conclusion to be drawn from the EBM is that the climate system possesses multiple equilibrium states, both warm and frozen, which coexist mathematically. While the actual climate can exist in only one of these states at any given time, the climate can undergo transitions between the states, via mathematical saddlenode bifurcations. This paper proposes that such bifurcations have actually occurred in Paleoclimate transitions. The EBM is applied to the study of the Pliocene Paradox, the Glaciation of Antarctica and the so-called warm, equable climate problem of both the mid-Cretaceous Period and the Eocene Epoch. In all cases, the EBM is in qualitative agreement with the geological record.
Evaluation of terrestrial pan-Arctic carbon cycling using a data-assimilation system
Authors: López-Blanco Efrén , Exbrayat Jean-François , Lund Magnus , Christensen Torben R. , Tamstorf Mikkel P. , Slevin Darren , Hugelius Gustaf , Bloom Anthony A. , Williams Mathew
Published: May 2018

Abstract. There is a significant knowledge gap in the current state of the terrestrial carbon (C) budget. The Arctic accounts for approximately 50 % of the global soil organic C stock, emphasizing the important role of Arctic regions in the global C cycle. Recent studies have pointed to the poor understanding of C pools turnover, although remain unclear as to whether productivity or biomass dominate the biases. Here, we use an improved version of the CARDAMOM data-assimilation system, to produce pan-Arctic terrestrial C-related variables without using traditional plant functional type or steady-state assumptions. Our approach integrates a range of data (soil organic C, leaf area index, biomass, and climate) to determine the most likely state of the high latitude C cycle at a 1° × 1° resolution for the first 15 years of the 21st century, but also to provide general guidance about the controlling biases in the turnover dynamics. As average, CARDAMOM estimates 513 (456, 579), 245 (208, 290) and 204 (109, 427) g C m−2 yr−1 (90 % confidence interval) from photosynthesis, autotrophic and heterotrophic respiration respectively, suggesting that the pan-Arctic region acted as a likely sink −55 (−152, 157) g C m−2 yr−1, weaker in tundra and stronger in taiga, but our confidence intervals remain large (and so the region could be a source of C). In general, we find a good agreement between CARDAMOM and different sources of assimilated and independent data at both pan-Arctic and local scale. Using CARDAMOM as a benchmarking tool for global vegetation models (GVM), we also conclude that turnover time of vegetation C is weakly simulated in vegetation models and is a major component of error in their forecasts. Our findings highlight that GVM modellers need to focus on the vegetation C stocks dynamics, but also their respiratory losses, to improve our process-based understanding of internal C cycle dynamics in the Arctic.
Generation and analysis of a new global burned area product based
on MODIS 250 m reflectance bands and thermal anomalies
Authors: Chuvieco Emilio , Lizundia-Loiola Joshua , Pettinari M. Lucrecia , Ramo Ruben , Padilla Marc , Tansey Kevin , Mouillot Florent , Laurent Pierre , Storm Thomas , Heil Angelika , Plummer Stephen
Published: May 2018

Abstract. This paper presents a new global burned area (BA) product, generated from the MODIS red (R) and near infrared (NIR) reflectances and thermal anomalies data, thus providing the highest spatial resolution (approx. 250 m) among the existing global BA datasets. The product includes the full times series (2001–2016) of the MODIS archive. The BA detection 20 algorithm was based on temporal composites of daily images, using temporal and spatial distance to active fires. The algorithm has two steps, the first one aiming to reduce commission errors by selecting the most clearly burned pixels (seeds), and the second one aiming to reduce omission errors by applying contextual analysis around the seed pixels. The product was developed within the European Space Agency's (ESA) Climate Change Initiative programme, under the Fire Disturbance project (Fire_cci). The final output includes two types of BA products: monthly full-resolution continental tiles (http://doi.org/cpk7) and biweekly global grid files at a degraded resolution of 0.25 degrees (http://doi.org/gcx9gf). Each one includes several auxiliary variables that were defined by the climate users to facilitate the ingestion of the product into global dynamic vegetation and emission models. The validation was based on a stratified random sample of 1200 pairs of Landsat images, covering the whole globe from 2003 to 2014. The estimated commission and omission error rates of the pixel product was 0.512 (0.020) and 0.708 (0.030), respectively, lower 30 than previous ESA products but higher than the latest NASA MCD64A1 BA dataset. Examples of potential applications of this product to fire modelling based on burned patches analysis are included in this paper. They show greater sensitivity of our product to small burn patch detection than existing BA products.