ALBERT

Description: Regional and local patterns in depth to water table, hydrochemistry and peat properties of bogs and their laggs in coastal British Columbia Hydrology and Earth System Sciences, 17, 3421-3435, 2013 Author(s): S. A. Howie and H. J. van Meerveld In restoration planning for damaged raised bogs, the lagg at the bog margin is often not given considerable weight and is sometimes disregarded entirely. However, the lagg is critical for the proper functioning of the bog, as it supports the water mound in the bog. In order to include the lagg in a restoration plan for a raised bog, it is necessary to understand the hydrological characteristics and functions of this rarely studied transition zone. We studied 13 coastal British Columbia (BC) bogs and identified two different gradients in depth to water table, hydrochemistry and peat properties: (1) a local bog expanse–bog margin gradient, and (2) a regional gradient related to climate and proximity to the ocean. Depth to water table generally increased across the transition from bog expanse to bog margin. In the bog expanse, pH was above 4.2 in the Pacific Oceanic wetland region (cooler and wetter climate) and below 4.3 in the Pacific Temperate wetland region (warmer and drier climate). Both pH and pH-corrected electrical conductivity increased significantly across the transition from bog expanse to bog margin, though not in all cases. Na + and Mg 2+ concentrations were generally highest in exposed, oceanic bogs and lower in inland bogs. Ash content in peat samples increased across the bog expanse–bog margin transition, and appears to be a useful abiotic indicator of the location of the bog margin. The observed variation in the hydrological and hydrochemical gradients across the bog expanse–bog margin transition highlights both local and regional diversity of bogs and their associated laggs.

Description: Imperfect scaling in distributions of radar-derived rainfall fields Hydrology and Earth System Sciences Discussions, 10, 11385-11422, 2013 Author(s): M. J. van den Berg, L. Delobbe, and N. E. C. Verhoest Fine scale rainfall observations for modeling exercises are often not available, but rather coarser data derived from a variety of sources are used. Effectively using these data sources in models often requires the probability distribution of the data at the applicable scale. Although numerous models for scaling distributions exist, these are often based on theoretical developments, rather than on data. In this study, we develop a model based on the α-stable distribution of rainfall fields, and tested on 5 min radar data from a Belgian weather radar. We use these data to estimate functions that describe parameters of the distribution over various scales. Moreover, we study how the mean of the distribution and the intermittency change with scale, and validate and design functions to describe the shape parameter of the distribution. This information was combined into an effective model of the distribution. Finally, the model was fitted to data from numerous storms, and the resulting parameters were compared to investigate the change in scaling behavior through time.

Description: Spatially resolved information on karst conduit flow from in-cave dye-tracing Hydrology and Earth System Sciences Discussions, 10, 11311-11335, 2013 Author(s): U. Lauber, W. Ufrecht, and N. Goldscheider Artificial tracers are powerful tools to investigate karst systems. Tracers are commonly injected into sinking streams or dolines, while springs serve as monitoring sites. The obtained flow and transport parameters represent mixed information from the vadose, epiphreatic and phreatic zones, i.e., the aquifer remains a black box. Accessible active caves constitute valuable but underexploited natural laboratories to gain detailed insights into the hydrologic functioning of the aquifer. Two multi-tracer tests in the catchment of a major karst spring (Blautopf, Germany) with injections and monitoring in two associated water caves aimed at obtaining spatially and temporally resolved information on groundwater flow in different compartments of the system. Two tracers were injected in the caves to characterize the hydraulic connections between them and with the spring. Two injections at the land surface, far from the spring, aimed at resolving the aquifer's internal drainage structure. Tracer breakthrough curves were monitored by field fluorimeters in caves and at the spring. Results demonstrate the dendritic drainage structure of the aquifer. It was possible to obtain relevant flow and transport parameters for different sections of this system. The highest mean flow velocities (275 m h −1 ) were observed in the near-spring epiphreatic section (open-channel flow), while velocities in the phreatic zone (pressurized flow) were one order of magnitude lower. Determined conduit water volumes confirm results of water balances and hydrograph analyses. In conclusion, experiments and monitoring in caves can deliver spatially resolved information on karst aquifer heterogeneity and dynamics that cannot be obtained by traditional investigative methods.

Description: On the lack of robustness of hydrologic models regarding water balance simulation – a diagnostic approach on 20 mountainous catchments using three models of increasing complexity Hydrology and Earth System Sciences Discussions, 10, 11337-11383, 2013 Author(s): L. Coron, V. Andréassian, C. Perrin, M. Bourqui, and F. Hendrickx This paper investigates the robustness of rainfall–runoff models when their parameters are transferred in time. More specifically, we studied their ability to simulate water balance on periods with different hydroclimatic characteristics. The testing procedure consisted in a series of parameter transfers between 10-yr periods and the systematic analysis of mean-volume errors. This procedure was applied to three conceptual models of different structural complexity over 20 mountainous catchments in southern France. The results showed that robustness problems are common. Errors on 10-yr-mean flows were significant for all three models and calibration periods, even when the entire record was used for calibration. Various graphical and numerical tools were used to show strong similarities between the shapes of mean flow biases calculated on a 10-yr-long sliding window when various parameter sets are used. Unexpected behavioural similarities were observed between the three models tested, considering their large differences in structural complexity. While the actual causes for robustness problems in these models remain unclear, this work stresses the limited transferability in time of the water balance adjustments made through parameter optimization. Although absolute differences between simulations obtained with different calibrated parameter sets were sometimes substantial, relative differences in simulated mean flows between time periods remained similar regardless of the calibrated parameter sets.

Description: Bayesian networks modelling in support to cross-cutting analysis of water supply and sanitation in developing countries Hydrology and Earth System Sciences, 17, 3397-3419, 2013 Author(s): C. Dondeynaz, J. López Puga, and C. Carmona Moreno Despite the efforts made towards the Millennium Development Goals targets during the last decade, improved access to water supply or basic sanitation still remains unavailable for millions of people across the world. This paper proposes a set of models that use 25 key variables and country profiles from the WatSan4Dev data set involving water supply and sanitation (Dondeynaz et al., 2012). This paper suggests the use of Bayesian network modelling methods because they are more easily adapted to deal with non-normal distributions, and integrate a qualitative approach for data analysis. They also offer the advantage of integrating preliminary knowledge into the probabilistic models. The statistical performance of the proposed models ranges between 20 and 5% error rates, which are very satisfactory taking into account the strong heterogeneity of variables. Probabilistic scenarios run from the models allow an assessment of the relationships between human development, external support, governance aspects, economic activities and water supply and sanitation (WSS) access. According to models proposed in this paper, gaining a strong poverty reduction will require the WSS access to reach 75–76% through: (1) the management of ongoing urbanisation processes to avoid slums development; and (2) the improvement of health care, for instance for children. Improving governance, such as institutional efficiency, capacities to make and apply rules, or control of corruption is positively associated with WSS sustainable development. The first condition for an increment of the HDP (human development and poverty) remains of course an improvement of the economic conditions with higher household incomes. Moreover, a significant country commitment to the environment, associated with civil society freedom of expression constitutes a favourable setting for sustainable WSS services delivery. Intensive agriculture using irrigation practises also appears as a mean for sustainable WSS thanks to multi-uses and complementarities. With a WSS sector organised at national level, irrigation practices can support the structuring and efficiency of the agriculture sector. It may then induce rural development in areas where WSS access often is set back compared to urban areas 1 . External financial support, called Official Development Assistance (ODA CI), plays a role in WSS improvement but comes last in the sensitivity analyses of models. An overall 47% of the Official Development Assistance goes first to poor countries, and is associated to governance aspects: (1) political stability and (2) country commitment to the environment and civil society degree of freedom. These governance aspects constitute a good framework for aid implementation in recipient countries. Modelling is run with the five groups of countries as defined in Dondeynaz et al. (2012). Models for profile 4 (essential external support) and profile 5 (primary material consumption) are specifically detailed and analysed in this paper. For countries in profile 4, fighting against water scarcity and progressing desertification should be the priority. However, for countries in profile 5, efforts should first concentrate on consolidation of political stability while supporting diversification of the economic activities. Nevertheless, for both profiles, reduction of poverty should remain the first priority as previously indicated. 1 JMP statistics, 2004 http://www.wssinfo.org/data-estimates/table/ , last access: 22 July 2013.

Description: Technical Note: A comparison of model and empirical measures of catchment-scale effective energy and mass transfer Hydrology and Earth System Sciences, 17, 3389-3395, 2013 Author(s): C. Rasmussen and E. L. Gallo Recent work suggests that a coupled effective energy and mass transfer (EEMT) term, which includes the energy associated with effective precipitation and primary production, may serve as a robust prediction parameter of critical zone structure and function. However, the models used to estimate EEMT have been solely based on long-term climatological data with little validation using direct empirical measures of energy, water, and carbon balances. Here we compare catchment-scale EEMT estimates generated using two distinct approaches: (1) EEMT modeled using the established methodology based on estimates of monthly effective precipitation and net primary production derived from climatological data, and (2) empirical catchment-scale EEMT estimated using data from 86 catchments of the Model Parameter Estimation Experiment (MOPEX) and MOD17A3 annual net primary production (NPP) product derived from Moderate Resolution Imaging Spectroradiometer (MODIS). Results indicated positive and significant linear correspondence ( R 2 = 0.75; P 〈 0.001) between model and empirical measures with an average root mean square error (RMSE) of 4.86 MJ m −2 yr −1 . Modeled EEMT values were consistently greater than empirical measures of EEMT. Empirical catchment estimates of the energy associated with effective precipitation ( E PPT ) were calculated using a mass balance approach that accounts for water losses to quick surface runoff not accounted for in the climatologically modeled E PPT . Similarly, local controls on primary production such as solar radiation and nutrient limitation were not explicitly included in the climatologically based estimates of energy associated with primary production ( E BIO ), whereas these were captured in the remotely sensed MODIS NPP data. These differences likely explain the greater estimate of modeled EEMT relative to the empirical measures. There was significant positive correlation between catchment aridity and the fraction of EEMT partitioned into E BIO ( F BIO ), with an increase in F BIO as a fraction of the total as aridity increases and percentage of catchment woody plant cover decreases. In summary, the data indicated strong correspondence between model and empirical measures of EEMT with limited bias that agree well with other empirical measures of catchment energy and water partitioning and plant cover.

Description: Author(s): G. Berner, A. Müller, F. Pfaff, J. Walde, C. Richter, J. Mannhart, S. Thiess, A. Gloskovskii, W. Drube, M. Sing, and R. Claessen We present a detailed study of the electronic structure and band alignment in LaAlO 3 /SrTiO 3 oxide heterostructures by hard x-ray photoelectron spectroscopy. Our spectroscopic measurements find no evidence for the strong potential gradient within the polar LaAlO 3 film predicted by band theory. Due to... [Phys. Rev. B 88, 115111] Published Fri Sep 06, 2013

Description: Author(s): Jifa Tian, Yongjin Jiang, Isaac Childres, Helin Cao, Jiangping Hu, and Yong P. Chen The Hall resistance of a homogeneous electron system is well known to be antisymmetric with respect to the magnetic field and the sign of charge carriers. We have observed that such symmetries no longer hold in planar hybrid structures consisting of partly single layer graphene (SLG) and partly bila... [Phys. Rev. B 88, 125410] Published Fri Sep 06, 2013

Description: Author(s): A. Tan, J. Li, C. A. Jenkins, E. Arenholz, A. Scholl, C. Hwang, and Z. Q. Qiu Py/FeMn/Cu(001) and Py/FeMn/Ni/Cu(001) films were grown and studied as a function of both the FeMn and the Ni thicknesses using rotating magneto-optic Kerr effect and x-ray magnetic circular dichroism. For Py/FeMn/Cu(001), we find that the FeMn antiferromagnetic order switches the sign of the Py fou... [Phys. Rev. B 88, 104404] Published Fri Sep 06, 2013

Description: Author(s): Bettina Gertjerenken and Christoph Weiss For the dynamics of Bose-Einstein condensates (BECs), differences between mean-field (Gross-Pitaevskii) physics and N -particle quantum physics often disappear if the BEC becomes larger and larger. In particular, the time scale for which both dynamics agree should thus become larger if the particle n... [Phys. Rev. A 88, 033608] Published Fri Sep 06, 2013

Description: Author(s): J. Ignacio Cirac, Spyridon Michalakis, David Pérez-García, and Norbert Schuch We analyze a criterion which guarantees that the ground states of certain many-body systems are stable under perturbations. Specifically, we consider PEPS, which are believed to provide an efficient description, based on local tensors, for the low energy physics arising from local interactions. In o... [Phys. Rev. B 88, 115108] Published Fri Sep 06, 2013

Description: Author(s): N. Drichko, R. Hackl, and J. Schlueter We compare the photoluminescence spectra of the low-temperature Mott insulator κ -(BEDT–TTF) 2 Cu[N(CN) 2 ]Cl ( T MIT =40 K) with spectra of metallic κ -(BEDT–TTF) 2 Cu[N(CN) 2 ]Br, which is superconducting below T c =11.8 K, in the temperature range between 300 and 20 K. In the Mott insulating state of κ -(BEDT–TT... [Phys. Rev. B 88, 115109] Published Fri Sep 06, 2013

Description: Author(s): G. Scherrer, M. Hofman, W. Śmigaj, M. Kadic, T.-M. Chang, X. Mélique, D. Lippens, O. Vanbésien, B. Cluzel, F. de Fornel, S. Guenneau, and B. Gralak Ground-plane cloaks, which transform a curved mirror into a flat one, and recently reported at wavelengths ranging from the optical to the visible spectrum, bring the realm of optical illusion a step closer to reality. However, all carpet-cloaking experiments have thus far been carried out in the fa... [Phys. Rev. B 88, 115110] Published Fri Sep 06, 2013

Description: Author(s): V. Kokoouline, A. Wearne, R. Lefebvre, and O. Atabek Exceptional points (EPs) corresponding to resonance coalescence (i.e., complex energy degeneracy and identical wave functions) occur in many areas of non-Hermitian physics and, in particular, in laser-induced molecular dynamics for specific choices of two control parameters. We have previously shown... [Phys. Rev. A 88, 033408] Published Fri Sep 06, 2013

Description: Author(s): Yiyan Sun, Houchen Chang, Michael Kabatek, Young-Yeal Song, Zihui Wang, Michael Jantz, William Schneider, Mingzhong Wu, E. Montoya, B. Kardasz, B. Heinrich, Suzanne G. E. te Velthuis, Helmut Schultheiss, and Axel Hoffmann Strong damping enhancement in nm-thick yttrium iron garnet (YIG) films due to Pt capping layers was observed. This damping is substantially larger than the expected damping due to conventional spin pumping, is accompanied by a shift in the ferromagnetic resonance field, and can be suppressed by the ... [Phys. Rev. Lett. 111, 106601] Published Fri Sep 06, 2013

Description: Author(s): Rintaro Inoue, Makoto Nakamura, Kazuya Matsui, Toshiji Kanaya, Koji Nishida, and Masahiro Hino We studied the distribution of glass transition temperature ( T g ) through neutron reflectivity in a poly(methyl methacrylate) (PMMA) thin film supported on a silicon substrate with a five-layered PMMA thin film consisting of deuterated-PMMA and hydrogenated-PMMA. The depth distribution of T g was succ... [Phys. Rev. E 88, 032601] Published Fri Sep 06, 2013

Description: Author(s): Volodymyr Borshch, Sergij V. Shiyanovskii, and Oleg D. Lavrentovich Electrically induced reorientation of nematic liquid crystal (NLC) molecules caused by dielectric anisotropy of the material is a fundamental phenomenon widely used in modern technologies. Its Achilles heel is a slow (millisecond) relaxation from the field-on to the field-off state. We present an el... [Phys. Rev. Lett. 111, 107802] Published Fri Sep 06, 2013

Description: Analysis of projected changes in the occurrence of heat waves in Hungary Advances in Geosciences, 35, 115-122, 2013 Author(s): R. Pongrácz, J. Bartholy, and E. B. Bartha Heat wave events are important temperature-related hazards due to their impacts on human health. In 2004, a Heat Health Warning System including three levels of heat wave warning was developed on the basis of a retrospective analysis of mortality and meteorological data in Hungary to anticipate heat waves that may result in a large excess of mortality. Projected changes in the frequency of different heat wave warning levels are analysed for the 21st century. For this purpose, outputs of regional climate model PRECIS (Providing REgional Climates for Impacts Studies) are used taking into account three different global emissions scenarios (A2, A1B, B2). The results clearly show an increase in occurrence and length of heat waves with respect to the underlying emissions scenarios and regional climate model used. Moreover, the potential season of heat wave occurrences is projected to be lengthened by two months in 2071–2100 compared to 1961–1990.

Description: Review Article: On the relation between the seismic activity and the Hurst exponent of the geomagnetic field at the time of the 2000 Izu swarm Natural Hazards and Earth System Science, 13, 2189-2194, 2013 Author(s): F. Masci and J. N. Thomas Many papers document the observation of earthquake-related precursory signatures in geomagnetic field data. However, the significance of these findings is ambiguous because the authors did not adequately take into account that these signals could have been generated by other sources, and the seismogenic origin of these signals have not been validated by comparison with independent datasets. Thus, they are not reliable examples of magnetic disturbances induced by the seismic activity. Hayakawa et al. (2004) claim that at the time of the 2000 Izu swarm the Hurst exponent of the Ultra-Low-Frequency (ULF: 0.001–10 Hz) band of the geomagnetic field varied in accord with the energy released by the seismicity. The present paper demonstrates that the behaviour of the Hurst exponent was insufficiently investigated and also misinterpreted by the authors. We clearly show that during the Izu swarm the changes of the Hurst exponent were strongly related to the level of global geomagnetic activity and not to the increase of the local seismic activity.

Description: Forest fire danger rating in complex topography – results from a case study in the Bavarian Alps in autumn 2011 Natural Hazards and Earth System Science, 13, 2157-2167, 2013 Author(s): C. Schunk, C. Wastl, M. Leuchner, C. Schuster, and A. Menzel Forest fire danger rating based on sparse meteorological stations is known to be potentially misleading when assigned to larger areas of complex topography. This case study examines several fire danger indices based on data from two meteorological stations at different elevations during a major drought period. This drought was caused by a persistent high pressure system, inducing a pronounced temperature inversion and its associated thermal belt with much warmer, dryer conditions in intermediate elevations. Thus, a massive drying of fuels, leading to higher fire danger levels, and multiple fire occurrences at mid-slope positions were contrasted by moderate fire danger especially in the valleys. The ability of fire danger indices to resolve this situation was studied based on a comparison with the actual fire danger as determined from expert observations, fire occurrences and fuel moisture measurements. The results revealed that, during temperature inversion, differences in daily cycles of meteorological parameters influence fire danger and that these are not resolved by standard meteorological stations and fire danger indices (calculated on a once-a-day basis). Additional stations in higher locations or high-resolution meteorological models combined with fire danger indices accepting at least hourly input data may allow reasonable fire danger calculations under these circumstances.

Description: The Mediterranean Sea system: a review and an introduction to the special issue Ocean Science, 9, 789-803, 2013 Author(s): T. Tanhua, D. Hainbucher, K. Schroeder, V. Cardin, M. Álvarez, and G. Civitarese The Mediterranean Sea is a semi-enclosed sea characterized by high salinities, temperatures and densities. The net evaporation exceeds the precipitation, driving an anti-estuarine circulation through the Strait of Gibraltar, contributing to very low nutrient concentrations. The Mediterranean Sea has an active overturning circulation, one shallow cell that communicates directly with the Atlantic Ocean, and two deep overturning cells, one in each of the two main basins. It is surrounded by populated areas and is thus sensitive to anthropogenic forcing. Several dramatic changes in the oceanographic and biogeochemical conditions have been observed during the past several decades, emphasizing the need to better monitor and understand the changing conditions and their drivers. During 2011 three oceanographic cruises were conducted in a coordinated fashion in order to produce baseline data of important physical and biogeochemical parameters that can be compared to historic data and be used as reference for future observational campaigns. In this article we provide information on the Mediterranean Sea oceanographic situation, and present a short review that will serve as background information for the special issue in Ocean Science on "Physical, chemical and biological oceanography of the Mediterranean Sea". An important contribution of this article is the set of figures showing the large-scale distributions of physical and chemical properties along the full length of the Mediterranean Sea.

Description: Corrigendum to "NEMO on the shelf: assessment of the Iberia–Biscay–Ireland configuration" published in Ocean Sci., 9, 745–771, 2013 Ocean Science, 9, 787-787, 2013 Author(s): C. Maraldi, J. Chanut, B. Levier, N. Ayoub, P. De Mey, G. Reffray, F. Lyard, S. Cailleau, M. Drévillon, E. A. Fanjul, M. G. Sotillo, P. Marsaleix, and the Mercator Research and Development Team No abstract available.

Description: Preface "Landslide hazard and risk assessment at different scales" Natural Hazards and Earth System Science, 13, 2169-2171, 2013 Author(s): P. Reichenbach, A. Günther, and T. Glade

Description: The Chemistry CATT-BRAMS model (CCATT-BRAMS 4.5): a regional atmospheric model system for integrated air quality and weather forecasting and research Geoscientific Model Development, 6, 1389-1405, 2013 Author(s): K. M. Longo, S. R. Freitas, M. Pirre, V. Marécal, L. F. Rodrigues, J. Panetta, M. F. Alonso, N. E. Rosário, D. S. Moreira, M. S. Gácita, J. Arteta, R. Fonseca, R. Stockler, D. M. Katsurayama, A. Fazenda, and M. Bela Coupled Chemistry Aerosol-Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CCATT-BRAMS, version 4.5) is an on-line regional chemical transport model designed for local and regional studies of atmospheric chemistry from the surface to the lower stratosphere suitable both for operational and research purposes. It includes gaseous/aqueous chemistry, photochemistry, scavenging and dry deposition. The CCATT-BRAMS model takes advantage of BRAMS-specific development for the tropics/subtropics as well as the recent availability of preprocessing tools for chemical mechanisms and fast codes for photolysis rates. BRAMS includes state-of-the-art physical parameterizations and dynamic formulations to simulate atmospheric circulations down to the meter. This on-line coupling of meteorology and chemistry allows the system to be used for simultaneous weather and chemical composition forecasts as well as potential feedback between the two. The entire system is made of three preprocessing software tools for user-defined chemical mechanisms, aerosol and trace gas emissions fields and the interpolation of initial and boundary conditions for meteorology and chemistry. In this paper, the model description is provided along with the evaluations performed by using observational data obtained from ground-based stations, instruments aboard aircrafts and retrieval from space remote sensing. The evaluation accounts for model applications at different scales from megacities and the Amazon Basin up to the intercontinental region of the Southern Hemisphere.

Description: Influence of microphysical schemes on atmospheric water in the Weather Research and Forecasting model Geoscientific Model Development Discussions, 6, 4563-4601, 2013 Author(s): F. Cossu and K. Hocke This study examines how different microphysical parameterization schemes influence orographically-induced precipitation and the distributions of hydrometeors and water vapour for mid-latitude summer conditions in the Weather Research and Forecasting (WRF) model. A high-resolution two-dimensional idealized simulation is used to assess the differences between the schemes in which a moist air flow is interacting with a bell-shaped 2 km high mountain. Periodic lateral boundary conditions are chosen to recirculate atmospheric water in the domain. It is found that the 13 selected microphysical schemes conserve the water in the model domain. The gain or loss of water is less than 0.81% over a simulation time interval of 61 days. The differences of the microphysical schemes in terms of the distributions of water vapour, hydrometeors and accumulated precipitation are presented and discussed. The Kessler scheme, the only scheme without ice-phase processes, shows final values of cloud liquid water 14 times greater than the other schemes. The differences among the other schemes are not as extreme, but still they differ up to 79% in water vapour, up to 10 times in hydrometeors and up to 64% in accumulated precipitation at the end of the simulation. The microphysical schemes also differ in the surface evaporation rate. The WRF single-moment 3-class scheme has the highest surface evaporation rate compensated by the highest precipitation rate. The different distributions of hydrometeors and water vapour of the microphysical schemes induce differences up to 49 W m −2 in the downwelling shortwave radiation and up to 33 W m −2 in the downwelling longwave radiation.

Description: Author(s): Azadeh Moradinezhad Dizgah, Scott Dodelson, and Antonio Riotto We study the impact of primordial non-Gaussianity on the density profile of dark matter halos by using the semianalytical model introduced recently by Dalal et al. which relates the peaks of the initial linear density field to the final density profile of dark matter halos. Models with primordial no... [Phys. Rev. D 88, 063513] Published Mon Sep 09, 2013

Description: Author(s): Sandipan Sengupta Motivated by a recent proposal (by Koslowski-Sahlmann) of a kinematical representation in loop quantum gravity (LQG) with a nondegenerate vacuum metric, we construct a polymer quantization of the parametrized massless scalar field theory on a Minkowskian cylinder. The diffeomorphism covariant kinema... [Phys. Rev. D 88, 064016] Published Mon Sep 09, 2013

Description: Author(s): Koji Ishiwata and Mark B. Wise We study the impact that a heavy generation of vectorlike leptons can have on the value of the electric dipole moment of the electron, and the rates for the flavor violating processes μ → e γ and μ →3 e . The smallness of the charged lepton masses suggests that at least some of the Yukawa coupling constan... [Phys. Rev. D 88, 055009] Published Mon Sep 09, 2013

Description: Author(s): Chiu Man Ho and Thomas J. Weiler [Phys. Rev. D 88, 069901] Published Mon Sep 09, 2013

Description: Author(s): Riccardo Borsato, Olof Ohlsson Sax, Alessandro Sfondrini, Bogdan Stefański, Jr., and Alessandro Torrielli We determine the all-loop dressing phases of the AdS 3 /CFT 2 integrable system related to type IIB string theory on AdS 3 ×S 3 ×T 4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearin... [Phys. Rev. D 88, 066004] Published Mon Sep 09, 2013

Description: Author(s): Swetaprovo Chaudhuri, Fujia Wu, and Chung K. Law In this paper we clarify the role of Markstein diffusivity, which is the product of the planar laminar flame speed and the Markstein length, on the turbulent flame speed and its scaling, based on experimental measurements on constant-pressure expanding turbulent flames. Turbulent flame propagation d... [Phys. Rev. E 88, 033005] Published Mon Sep 09, 2013

Description: Author(s): Cyril Desjouy, Pauline Labelle, Bruno Gilles, Jean-Christophe Bera, and Claude Inserra Acoustic cavitation-induced microbubbles in a cylindrical resonator filled with water tend to concentrate into ring patterns due to the cylindrical geometry of the system. The shape of these ring patterns is directly linked to the Bjerknes force distribution in the resonator. Experimental observatio... [Phys. Rev. E 88, 033006] Published Mon Sep 09, 2013

Description: Author(s): M. D. Campanell Most works on plasma-wall interaction predict that with strong electron emission, a nonmonotonic “space-charge-limited” (SCL) sheath forms where the plasma potential is positive relative to the wall. We show that a fundamentally different sheath structure is possible where the potential monotonicall... [Phys. Rev. E 88, 033103] Published Mon Sep 09, 2013

Description: The sensitivity of global climate to the episodicity of fire aerosol emissions Atmospheric Chemistry and Physics Discussions, 13, 23691-23717, 2013 Author(s): S. K. Clark, D. S. Ward, and N. M. Mahowald One of the major ways in which forest and grass fires have an impact on global climate is through the release of aerosols. Most studies focusing on calculating the radiative forcing and other climate impacts of fire aerosols use monthly mean emissions derived from the Global Fire Emissions Database that captures only the seasonal cycle of fire aerosol emissions. Here we present the results of a sensitivity study that investigates the climate response to the episodicity of the fires, based on the standard approach which releases emissions every day, and contrasts that to the response when fires are represented as intense pulses of emissions that occur only over 1–2 days on a monthly, yearly, or five-yearly basis. Overall we find that in the modified cases with increased levels of episodicity, the all sky direct effect radiative forcing increases, the clear sky direct effect radiative forcing remains relatively constant, and the magnitude of the indirect effect radiative forcing decreases by about 1 W m −2 (from −1.6 to −0.6 W m −2 ). In the long term, we find that an increase in aerosol emission episodicity leads to an asymmetric change in indirect radiative forcing in the Northern Hemisphere compared to the Southern Hemisphere contributes to a slight shift in the annual average position of the intertropical convergence zone (ITCZ). This shift is found to have a mixed effect on the overall performance of the model at predicting precipitation rates in the tropics. Given these results we conclude that future studies that look to assess the present day global climate impacts of fire aerosols should consider the need to accurately represent fire episodicity.

Description: Not all calcite ballast is created equal: differing effects of foraminiferan and coccolith calcite on the formation and sinking of aggregates Biogeosciences Discussions, 10, 14861-14885, 2013 Author(s): K. Schmidt, C. L. De La Rocha, M. Gallinari, and G. Cortese Correlation between particulate organic carbon (POC) and calcium carbonate sinking through the deep ocean has led to the idea that ballast provided by calcium carbonate is important for the export of POC from the surface ocean. While this idea is certainly to some extent true, it is worth considering in more nuance, for example, examining the different effects on the aggregation and sinking of POC of small, non-sinking calcite particles like coccoliths and large, rapidly sinking calcite like planktonic foraminiferan tests. We have done that here in a simple experiment carried out in roller tanks that allow particles to sink continuously without being impeded by container walls. Coccoliths were efficiently incorporated into aggregates that formed during the experiment, increasing their sinking speed compared to similarly sized aggregates lacking added calcite ballast. The foraminiferan tests, which sank as fast as 700 m d −1 , became associated with only very minor amounts of POC. In addition, when they collided with other, larger, foraminferan-less aggregates, they fragmented them into two smaller, more slowly sinking aggregates. While these effects were certainly exaggerated within the confines of the roller tanks, they clearly demonstrate that calcium carbonate ballast is not just calcium carbonate ballast- different forms of calcium carbonate ballast have notably different effects on POC aggregation, sinking, and export.

Description: Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles Atmospheric Chemistry and Physics, 13, 9097-9118, 2013 Author(s): Z. A. Kanji, A. Welti, C. Chou, O. Stetzer, and U. Lohmann Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature ( T ) and relative humidity (RH), as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulfate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long-range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 〈 T 〈 263 K. Heterogeneous ice nucleation of untreated kaolinite (Ka) and Arizona Test Dust (ATD) particles is compared to corresponding aged particles that are subjected to ozone concentrations of 0.4–4.3 ppmv in a stainless steel aerosol tank. The portable ice nucleation counter (PINC) and immersion chamber combined with the Zurich ice nucleation chamber (IMCA-ZINC) are used to conduct deposition and immersion mode measurements, respectively. Ice active fractions as well as ice active surface site densities ( n s ) are reported and observed to increase as a function of decreasing temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. We also present the first results to show a suppression of heterogeneous ice nucleation activity without the condensation of a coating of (in)organic material. In immersion mode, low ozone exposed Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka, whereas high ozone exposed ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low exposure Ka had ice active fractions of an order of magnitude higher than untreated Ka, whereas high ozone exposed ATD had ice active fractions up to a factor of 4 lower than untreated ATD. From our results, we derive and present parameterizations in terms of n s ( T ) that can be used in models to predict ice nuclei concentrations based on available aerosol surface area.

Description: Antecedent flow conditions and nitrate concentrations in the Mississippi River Basin Hydrology and Earth System Sciences Discussions, 10, 11451-11484, 2013 Author(s): J. C. Murphy, R. M. Hirsch, and L. A. Sprague The influence of antecedent flow conditions on nitrate concentrations was explored at eight sites in the Mississippi River Basin, USA. Antecedent moisture conditions have been shown to influence nutrient export from small, relatively homogenous basins, but this influence has not been observed at a regional or continental scale. Antecedent flow conditions were quantified as the ratio between the mean daily flow of the previous year and the mean daily flow from the period of record ( Q ratio), and the Q ratio was statistically related to nitrate anomalies (the unexplained variability in nitrate concentration after filtering out season, long-term trend, and contemporaneous flow effects) at each site. Nitrate anomaly and Q ratio were negatively related at three of the four major tributary sites and upstream in the Mississippi River, indicating that when the previous year was drier than average, at these sites, nitrate concentrations were higher than expected. The strength of these relationships increased when data were subdivided by contemporaneous flow conditions. Five of the eight sites had significant negative relationships ( p ≤ 0.05) at high or moderately high contemporaneous flows, suggesting nitrate that accumulates in these basins during a drought is flushed during subsequent storm events. At half of the sites, when flow during the previous year was 50% drier than average, nitrate concentration can be from 9 and 27% higher than nitrate concentrations that follow a year with average daily flow. Conversely, nitrate concentration can be from 8 and 21% lower than expected when the previous year was 50% wetter than average. These relationships between nitrate concentration and Q ratio serve as the basis for future studies that can better define specific hydrologic processes occurring during and after a drought, which influence nitrate concentration, such as the duration or magnitude of low flows, and the timing of low and high flows.

Description: Author(s): R. Aaij et al. (LHCb Collaboration) A broad peaking structure is observed in the dimuon spectrum of B + → K + μ + μ - decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with interference between the B + → K + μ + μ - decay and a resonance and has a statistical significance exceeding s... [Phys. Rev. Lett. 111, 112003] Published Tue Sep 10, 2013

Description: Author(s): Serge Mora, Corrado Maurini, Ty Phou, Jean-Marc Fromental, Basile Audoly, and Yves Pomeau Under the effect of surface tension, a blob of liquid adopts a spherical shape when immersed in another fluid. We demonstrate experimentally that soft, centimeter-size elastic solids can exhibit a similar behavior: when immersed into a liquid, a gel having a low elastic modulus undergoes large, reve... [Phys. Rev. Lett. 111, 114301] Published Tue Sep 10, 2013

Description: Author(s): V. P. Bhallamudi, C. S. Wolfe, V. P. Amin, D. E. Labanowski, A. J. Berger, D. Stroud, J. Sinova, and P. C. Hammel We present a new tool for imaging spin properties. We show that a spatially averaged spin signal, measured as a function of a scanned magnetic probe’s position, contains information about the local spin properties. In this first demonstration we map the injected spin density in GaAs by measuring spi... [Phys. Rev. Lett. 111, 117201] Published Tue Sep 10, 2013

Description: Author(s): Nicolas Desreumaux, Jean-Baptiste Caussin, Raphael Jeanneret, Eric Lauga, and Denis Bartolo We address the collective dynamics of non-Brownian particles cruising in a confined microfluidic geometry and provide a comprehensive characterization of their spatiotemporal density fluctuations. We show that density excitations freely propagate at all scales, and in all directions even though the ... [Phys. Rev. Lett. 111, 118301] Published Tue Sep 10, 2013

Description: Author(s): Uwe Thiele, Desislava V. Todorova, and Hender Lopez A thermodynamically consistent gradient dynamics model for the evolution of thin layers of liquid mixtures, solutions, and suspensions on solid substrates is presented which is based on a film-height- and mean-concentration-dependent free energy functional. It is able to describe a large variety of ... [Phys. Rev. Lett. 111, 117801] Published Tue Sep 10, 2013

Description: Tidally induced velocity variations of the Beardmore Glacier, Antarctica, and their representation in satellite measurements of ice velocity The Cryosphere, 7, 1375-1384, 2013 Author(s): O. J. Marsh, W. Rack, D. Floricioiu, N. R. Golledge, and W. Lawson Ocean tides close to the grounding line of outlet glaciers around Antarctica have been shown to directly influence ice velocity, both linearly and non-linearly. These fluctuations can be significant and have the potential to affect satellite measurements of ice discharge, which assume displacement between satellite passes to be consistent and representative of annual means. Satellite observations of horizontal velocity variation in the grounding zone are also contaminated by vertical tidal effects, the importance of which is highlighted here in speckle tracking measurements. Eight TerraSAR-X scenes from the grounding zone of the Beardmore Glacier are analysed in conjunction with GPS measurements to determine short-term and decadal trends in ice velocity. Diurnal tides produce horizontal velocity fluctuations of 〉50% on the ice shelf, recorded in the GPS data 4 km downstream of the grounding line. This variability decreases rapidly to 〈5% only 15 km upstream of the grounding line. Daily fluctuations are smoothed to 〈1% in the 11-day repeat pass TerraSAR-X imagery, but fortnightly variations over this period are still visible and show that satellite-velocity measurements can be affected by tides over longer periods. The measured tidal displacement observed in radar look direction over floating ice also allows the grounding line to be identified, using differential speckle tracking where phase information cannot be easily unwrapped.

Description: A new data set of soil mineralogy for dust-cycle modeling Atmospheric Chemistry and Physics Discussions, 13, 23943-23993, 2013 Author(s): E. Journet, Y. Balkanski, and S. P. Harrison The mineralogy of airborne dust affects the impact of dust particles on direct and indirect radiative forcing, on atmospheric chemistry and on biogeochemical cycling. It is determined partly by the mineralogy of the dust-source regions and partly by size-dependent fractionation during erosion and transport. Here we present a data set that characterizes the clay and silt sized fractions of global soil units in terms of the abundance of 12 minerals that are important for dust-climate interactions: quartz, feldspars, illite, smectite, kaolinite, chlorite, vermiculite, mica, calcite, gypsum, hematite and goethite. The basic mineralogical information is derived from the literature, and is then expanded following explicit rules, in order to characterize as many soil units as possible. We present three alternative realisations of the mineralogical maps that account for the uncertainties in the mineralogical data. We examine the implications of the new database for calculations of the single scattering albedo of airborne dust and thus for dust radiative forcing.

Description: Calibration of the passive cavity aerosol spectrometer probe for airborne determination of the size distribution Atmospheric Measurement Techniques, 6, 2349-2358, 2013 Author(s): Y. Cai, J. R. Snider, and P. Wechsler This work describes calibration methods for the particle sizing and particle concentration systems of the passive cavity aerosol spectrometer probe (PCASP). Laboratory calibrations conducted over six years, in support of the deployment of a PCASP on a cloud physics research aircraft, are analyzed. Instead of using the many calibration sizes recommended by the PCASP manufacturer, a relationship between particle diameter and scattered light intensity is established using three sizes of mobility-selected polystyrene latex particles, one for each amplifier gain stage. In addition, studies of two factors influencing the PCASP's determination of the particle size distribution – amplifier baseline and particle shape – are conducted. It is shown that the PCASP-derived size distribution is sensitive to adjustments of the sizing system's baseline voltage, and that for aggregates of spheres, a PCASP-derived particle size and a sphere-equivalent particle size agree within uncertainty dictated by the PCASP's sizing resolution. Robust determinations of aerosol concentration, and size distribution, also require calibration of the PCASP's aerosol flowrate sensor. Sensor calibrations, calibration drift, and the sensor's non-linear response are documented.

Description: Contribution of snow and glacier melt to discharge for highly glacierised catchments in Norway Hydrology and Earth System Sciences Discussions, 10, 11485-11517, 2013 Author(s): M. Engelhardt, T. V. Schuler, and L. M. Andreassen Glacierised catchments significantly alter the streamflow regime due to snow and glacier meltwater contribution to discharge. In this study, we modelled the mass balance and discharge rates for three highly glacierised catchments (〉50% glacier cover) in western Norway over the period 1961–2012. The spatial pattern of the catchments follows a gradient in climate continentality from west to east. The model uses gridded temperature and precipitation values from seNorge ( http://senorge.no ) as input which are available at a daily resolution. It accounts for accumulation of snow, transformation of snow to firn and ice, evaporation and melt. The model was calibrated for each catchment based on measurements of seasonal glacier mass-balances and daily discharge rates. For validation, daily melt rates were compared with measurements from sonic rangers located in the ablation zones of two of the glaciers and an uncertainty analysis was performed for the third catchment. The discharge contributions from snowmelt, glacier melt and rain were analysed with respect to spatial variations and temporal evolution. The model simulations reveal an increase of the relative contribution from glacier melt for the three catchments from less than 10% in the early 1990s to 15–30% in the late 2000s. The decline in precipitation by 10–20% in the same period was therefore overcompensated resulting in an increase of the annual discharge by 5–20%. Annual discharge sums and annual glacier melt are strongest correlated with annual and winter precipitation at the most maritime glacier and, with increased climate continentality, variations in both glacier melt contribution and annual discharge are becoming stronger correlated with variations in summer temperatures.

Description: Beyond multifractional Brownian motion: new stochastic models for geophysical modelling Nonlinear Processes in Geophysics, 20, 643-655, 2013 Author(s): J. Lévy Véhel Multifractional Brownian motion (mBm) has proved to be a useful tool in various areas of geophysical modelling. Although a versatile model, mBm is of course not always an adequate one. We present in this work several other stochastic processes which could potentially be useful in geophysics. The first alternative type is that of self-regulating processes : these are models where the local regularity is a function of the amplitude, in contrast to mBm where it is tuned exogenously. We demonstrate the relevance of such models for digital elevation maps and for temperature records. We also briefly describe two other types of alternative processes, which are the counterparts of mBm and of self-regulating processes when the intensity of local jumps is considered in lieu of local regularity: multistable processes allow one to prescribe the local intensity of jumps in space/time, while this intensity is governed by the amplitude for self-stabilizing processes .

Description: Author(s): Mahdi Ebrahimi Kahou and David L. Feder One approach to the development of quantum search algorithms is the quantum walk. A spatial search can be effected by the continuous-time evolution of a single quantum particle on a graph containing a marked site. In many physical implementations, however, one might expect to have multiple particles... [Phys. Rev. A 88, 032310] Published Wed Sep 11, 2013

Description: Author(s): Jun Jiang and J. Mitroy The influence of hyperfine interactions on the tune-out wavelengths of the 39 K, 40 K, and 41 K isotopes of the potassium atom was investigated. The hyperfine interaction of the 4 s 1/2 ground state results in a shift and splitting of the primary tune-out wavelength near 769 nm. The 4 s 1/2 state hyperfine... [Phys. Rev. A 88, 032505] Published Wed Sep 11, 2013

Description: Author(s): Sougata Mukhopadhyay and C. Sinha We study quantum mechanically the influence of an external laser field on the antihydrogen (H̅ ) formation cross sections in ground and excited states (2 s ,2 p ) via the three-body recombination process inside a dense plasma of antiprotons and positrons, supposed to be the most efficient mechani... [Phys. Rev. A 88, 033414] Published Wed Sep 11, 2013

Description: Author(s): Wenchen Luo and R. Côté At half-filling of the fourfold degenerate Landau levels | n |≥1 in graphene, the ground states are spin-polarized quantum Hall states that support spin skyrmion excitations for | n |=1,2,3. Working in the Hartree-Fock approximation, we compute the excitation energy of an unbound spin skyrmion-antiskyrm... [Phys. Rev. B 88, 115417] Published Wed Sep 11, 2013

Description: Author(s): Bruno Amorim and Francisco Guinea Out of plane vibrations are suppressed in graphene layers placed on a substrate. These vibrations, in suspended samples, are relevant for the understanding of properties such as the electrical resistivity, the thermal expansion coefficient, and others. We use a general framework to study the propert... [Phys. Rev. B 88, 115418] Published Wed Sep 11, 2013

Description: Author(s): Andreas Vogler, Ralf Labouvie, Felix Stubenrauch, Giovanni Barontini, Vera Guarrera, and Herwig Ott We investigate the thermodynamics of one-dimensional (1D) Bose gases in the strongly correlated regime. To this end, we prepare ensembles of independent 1D Bose gases in a two-dimensional optical lattice and perform high-resolution in situ imaging of the column-integrated density distribution. Using... [Phys. Rev. A 88, 031603] Published Wed Sep 11, 2013

Description: Author(s): Sergii Strelchuk There exist memoryless zero-capacity quantum channels that when used jointly result in a channel with positive capacity. This phenomenon is called superactivation. Making use of Parrondo's paradox, we exhibit examples of the superactivation-like effect for the capacity of classical communication cha... [Phys. Rev. A 88, 032311] Published Wed Sep 11, 2013

Description: Author(s): Benkang Liu, Yanqiu Wang, and Li Wang The photoelectron velocity-map image technique was employed to examine the one-photon detachment of Cu monomer and dimer anions using a linearly polarized infrared femtosecond laser. While the photoelectron angular distribution (PAD) in a single-photon detachment experiment of Cu − shows no dependenc... [Phys. Rev. A 88, 033413] Published Wed Sep 11, 2013

Description: Author(s): Zhang-qi Yin, Tongcang Li, Xiang Zhang, and L. M. Duan We propose a method to generate and detect large quantum superposition states and arbitrary Fock states for the oscillational mode of an optically levitated nanocrystal diamond. The nonlinear interaction required for the generation of non-Gaussian quantum states is enabled through the spin-mechanica... [Phys. Rev. A 88, 033614] Published Wed Sep 11, 2013

Description: Author(s): Sung Sakong, Peter Kratzer, Simone Wall, Annika Kalus, and Michael Horn-von Hoegen The dynamics of vibrations localized in a monolayer of Pb on Si(111) is studied using density functional theory and molecular dynamics methods. Recently, a pump-probe experiment has given direct access to the relaxation dynamics of the vibrational excitations in Pb, revealing two distinct time scale... [Phys. Rev. B 88, 115419] Published Wed Sep 11, 2013

Description: Author(s): R. L. Stillwell, D. E. Graf, W. A. Coniglio, T. P. Murphy, E. C. Palm, J. H. Park, D. VanGennep, P. Schlottmann, and S. W. Tozer We have observed a massive reconstruction of the Fermi surface of single crystal chromium as a function of high pressure and high magnetic fields caused by the spin-flip transition, with multiple new orbits appearing above 0.93 GPa. In addition, some orbits have field-induced effective masses of ∼0.... [Phys. Rev. B 88, 125119] Published Wed Sep 11, 2013

Description: Author(s): Florian Kühnel Stability about cosmological background solutions to the bimetric Hassan-Rosen theory is studied. The results of this analysis are presented, and it is shown that a large class of cosmological backgrounds is classically unstable. This sets serious doubts on the physical viability of the Hassan-Rosen... [Phys. Rev. D 88, 064024] Published Wed Sep 11, 2013

Description: Author(s): R. Raut, A. P. Tonchev, G. Rusev, W. Tornow, C. Iliadis, M. Lugaro, J. Buntain, S. Goriely, J. H. Kelley, R. Schwengner, A. Banu, and N. Tsoneva We have carried out photodisintegration cross-section measurements on 86 Kr using monoenergetic photon beams ranging from the neutron separation energy, S n =9.86  MeV, to 13 MeV. We combine our experimental 86 Kr( γ , n ) 85 Kr cross section with results from our recent 86 Kr( γ , γ ′ ) measurement below the neutr... [Phys. Rev. Lett. 111, 112501] Published Wed Sep 11, 2013

Description: Author(s): Eric A. Bergshoeff, Sjoerd de Haan, Olaf Hohm, Wout Merbis, and Paul K. Townsend We present a generally covariant and parity-invariant two-frame field (“zwei-dreibein”) action for gravity in three space-time dimensions that propagates two massive spin-2 modes, unitarily, and we use Hamiltonian methods to confirm the absence of unphysical degrees of freedom. We show how zwei-drei... [Phys. Rev. Lett. 111, 111102] Published Wed Sep 11, 2013

Description: Decadal trends in the Antarctic sea ice extent ultimately controlled by ice-ocean feedback The Cryosphere Discussions, 7, 4585-4632, 2013 Author(s): H. Goosse and V. Zunz The large natural variability of the Antarctic sea ice is a key characteristic of the system that might be responsible for the small positive trend in sea ice extent observed since 1979. In order to gain insight in the processes responsible for this variability, we have analysed in a control simulation performed with a coupled climate model a strong positive ice-ocean feedback that amplifies sea ice variations. When sea ice concentration increases in a region, in particular close to the ice edge, the mixed layer depth tends to decrease. This can be caused by a net inflow of ice and thus of freshwater that stabilizes the water column. Another stabilizing mechanism at interannual time scales that appears more widespread in our simulation is associated with the downward salt transport due to the seasonal cycle of ice formation: brine is released in winter when ice is formed and mixed over a deep layer while the freshwater flux caused by ice melting is included in a shallow layer, resulting in a net vertical transport of salt. Because of this stronger stratification due to the presence of sea ice, more heat is stored at depth in the ocean and the vertical oceanic heat flux is reduced, which contributes to maintain a higher ice extent. This positive feedback is not associated with a particular spatial pattern. Consequently, the spatial distribution of the trend in ice concentration is largely imposed by the wind changes that can provide the initial perturbation. A positive freshwater flux could alternatively be the initial trigger but the amplitude of the final response of the sea ice extent is finally set up by the amplification related to ice-ocean feedback. Initial conditions have also an influence as the chance to have a large increase in ice extent is higher if starting from a state characterized by a low value.

Description: Growth of sulphuric acid nanoparticles under wet and dry conditions Atmospheric Chemistry and Physics Discussions, 13, 24087-24125, 2013 Author(s): L. Škrabalová, D. Brus, T. Anttila, V. Ždímal, and H. Lihavainen New particle formation, which greatly influences the number concentrations and size distributions of an atmospheric aerosol, is often followed by a rapid growth of freshly formed particles. The initial growth of a newly formed aerosol is the crucial process determining the fraction of nucleated particles growing into cloud condensation nuclei sizes, which have a significant influence on climate. In this study, we report the laboratory observations of the growth of nanoparticles produced by nucleation of H 2 SO 4 and water in a laminar flow tube at temperatures of 283, 293 and 303 K, under dry (a relative humidity of 1%) and wet conditions (relative humidity of 30%) and residence times of 30, 45, 60 and 90 s. The initial H 2 SO 4 concentration spans the range from 2 × 10 8 to 1.4 × 10 10 molecule cm −3 and the calculated wall losses of H 2 SO 4 were assumed to be diffusion limited. The detected particle number concentrations, measured by the Ultrafine Condensation Particle Counter (UCPC) and Differential Mobility Particle Sizer (DMPS), were found to depend strongly on the residence time. Hygroscopic particle growth, presented by growth factors, was found to be in good agreement with the previously reported studies. The experimental growth rates ranged from 20 nm h −1 to 890 nm h −1 at RH 1% and from 7 nm h −1 to 980 nm h −1 at RH 30% and were found to increase significantly with the increasing concentration of H 2 SO 4 . Increases in the nucleation temperature had a slight enhancing effect on the growth rates under dry conditions. The influence of relative humidity on growth was not consistent – at lower H 2 SO 4 concentrations, the growth rates were higher under dry conditions while at H 2 SO 4 concentrations greater than 1×10 9 molecule cm −3 the growth rates were higher under wet conditions. The growth rates show only a weak dependence on the residence time. The experimental observations were compared with predictions made using a numerical model, which investigates the growth of particles with three different extents of neutralization by the ammonia NH 3 : (1) pure H 2 SO 4 – H 2 O particles (2) particles formed by ammonium bisulphate, (NH 4 )HSO 4 (3) particles formed by ammonium sulphate, (NH 4 ) 2 SO 4 . The highest growth rates were found for ammonium sulphate particles. Since the model accounting for the initial H 2 SO 4 concentration predicted the experimental growth rates correctly, our results suggest that the commonly presumed diffusional wall losses of H 2 SO 4 are not so significant. We therefore assume that there are not only losses of H 2 SO 4 on the wall but also a flux of H 2 SO 4 molecules from the wall into the flow tube, the effect being more profound under dry conditions and at higher temperatures of the tube wall. Based on a comparison with the atmospheric observations, our results indicate that sulphuric acid alone can not explain the growth rates of particles formed in the atmosphere.

Description: Experimental quantification of contact freezing in an electrodynamic balance Atmospheric Measurement Techniques, 6, 2373-2382, 2013 Author(s): N. Hoffmann, A. Kiselev, D. Rzesanke, D. Duft, and T. Leisner Heterogeneous nucleation of ice in a supercooled water droplet induced by external contact with a dry aerosol particle has long been known to be more effective than freezing induced by the same nucleus immersed in the droplet. However, the experimental quantification of contact freezing is challenging. Here we report an experimental method to determine the temperature-dependent ice nucleation probability of size-selected aerosol particles. The method is based on the suspension of supercooled charged water droplets in a laminar flow of air containing aerosol particles as contact freezing nuclei. The rate of droplet–particle collisions is calculated numerically with account for Coulomb attraction, drag force and induced dipole interaction between charged droplet and aerosol particles. The calculation is verified by direct counting of aerosol particles collected by a levitated droplet. By repeating the experiment on individual droplets for a sufficient number of times, we are able to reproduce the statistical freezing behavior of a large ensemble of supercooled droplets and measure the average rate of freezing events. The freezing rate is equal to the product of the droplet–particle collision rate and the probability of freezing on a single contact, the latter being a function of temperature, size and composition of the contact ice nuclei. Based on these observations, we show that for the types of particles investigated so far, contact freezing is the dominating freezing mechanism on the timescale of our experiment.

Description: δ 18 O water isotope in the i LOVECLIM model (version 1.0) – Part 1: Implementation and verification Geoscientific Model Development, 6, 1481-1491, 2013 Author(s): D. M. Roche A new 18 O stable water isotope scheme is developed for three components of the i LOVECLIM coupled climate model: atmospheric, oceanic and land surface. The equations required to reproduce the fractionation of stable water isotopes in the simplified atmospheric model ECBilt are developed consistently with the moisture scheme. Simplifications in the processes are made to account for the simplified vertical structure including only one moist layer. Implementation of these equations together with a passive tracer scheme for the ocean and a equilibrium fractionation scheme for the land surface leads to the closure of the (isotopic-) water budget in our climate system. Following the implementation, verification of the existence of usual δ 18 O to climatic relationships are performed for the Rayleigh distillation, the Dansgaard relationship and the δ 18 O –salinity relationship. Advantages and caveats of the approach taken are outlined. The isotopic fields simulated are shown to reproduce most expected oxygen-18–climate relationships with the notable exception of the isotopic composition in Antarctica.

Description: Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs Hydrology and Earth System Sciences, 17, 3473-3483, 2013 Author(s): Y. Seo, N.-J. Choi, and A. R. Schmidt This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA) to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute directly to the runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA), IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Description: δ 18 O water isotope in the i LOVECLIM model (version 1.0) – Part 3: A palaeo-perspective based on present-day data–model comparison for oxygen stable isotopes in carbonates Geoscientific Model Development, 6, 1505-1516, 2013 Author(s): T. Caley and D. M. Roche Oxygen stable isotopes (δ 18 O) are among the most useful tools in palaeoclimatology/palaeoceanography. Simulation of oxygen stable isotopes allows testing how the past variability of these isotopes in water can be interpreted. By modelling the proxy directly in the model, the results can also be directly compared with the data. Water isotopes have been implemented in the global three-dimensional model of intermediate complexity i LOVECLIM, allowing fully coupled atmosphere–ocean simulations. In this study, we present the validation of the model results for present-day climate against the global database for oxygen stable isotopes in carbonates. The limitation of the model together with the processes operating in the natural environment reveal the complexity of use the continental calcite-δ 18 O signal of speleothems for a global quantitative data–model comparison exercise. On the contrary, the reconstructed surface ocean calcite-δ 18 O signal in i LOVECLIM does show a very good agreement with the late Holocene database (foraminifers) at the global and regional scales. Our results indicate that temperature and the isotopic composition of the seawater are the main control on the fossil-δ 18 O signal recorded in foraminifer shells when all species are grouped together. Depth habitat, seasonality and other ecological effects play a more significant role when individual species are considered. We argue that a data–model comparison for surface ocean calcite δ 18 O in past climates, such as the Last Glacial Maximum (≈ 21 000 yr), could constitute an interesting tool for mapping the potential shifts of the frontal systems and circulation changes throughout time. Similarly, the potential changes in intermediate oceanic circulation systems in the past could be documented by a data (benthic foraminifers)-model comparison exercise whereas future investigations are necessary in order to quantitatively compare the results with data for the deep ocean.

Description: Author(s): Easwar Magesan, Alexandre Cooper, Honam Yum, and Paola Cappellaro Quantum systems have shown great promise for precision metrology thanks to advances in their control. This has allowed not only the sensitive estimation of external parameters but also the reconstruction of their temporal profile. In particular, quantum control techniques and orthogonal function the... [Phys. Rev. A 88, 032107] Published Thu Sep 12, 2013

Description: Author(s): Guang-Yin Chen, Neill Lambert, Che-Ming Li, Yueh-Nan Chen, and Franco Nori We investigate, using the hierarchy method, the entanglement and the excitation transfer efficiency of the Fenna-Matthews-Olson (FMO) complex under two different local modifications: the suppression of transitions between particular sites and localized changes to the protein environment. We find tha... [Phys. Rev. E 88, 032120] Published Thu Sep 12, 2013

Description: Author(s): M. J. B. Moura and M. Marder We examine the fracture mechanics of tearing graphene. We present a molecular dynamics simulation of the propagation of cracks in clamped, free-standing graphene as a function of the out-of-plane force. The geometry is motivated by experimental configurations that expose graphene sheets to out-of-pl... [Phys. Rev. E 88, 032405] Published Thu Sep 12, 2013

Description: Author(s): Fulvio Bisi, Giovanni De Matteis, and Silvano Romano We consider here a classical model, consisting of D 2 h -symmetric particles in a three-dimensional simple-cubic lattice; the pair potential is isotropic in orientation space, and restricted to nearest neighbors. The simplest potential model is written in terms of the squares of the scalar products bet... [Phys. Rev. E 88, 032502] Published Thu Sep 12, 2013

Description: Phenology as a strategy for carbon optimality: a global model Biogeosciences Discussions, 10, 15107-15152, 2013 Author(s): S. Caldararu, D. W. Purves, and P. I. Palmer Phenology is essential to our understanding of biogeochemical cycles and the climate system. We develop a global mechanistic model of leaf phenology based on the hypothesis that phenology is a strategy for optimal carbon gain at the canopy level so that trees adjust leaf gains and losses in response to environmental factors such as light, temperature and soil moisture, to achieve maximum carbon assimilation. We fit this model to five years of satellite observations of leaf area index (LAI) using a Bayesian fitting algorithm. We show that our model is able to reproduce phenological patterns for all vegetation types and use it to explore variations in growing season length and the climate factors that limit leaf growth for different biomes. Phenology in wet tropical areas is limited by leaf age physiological constraints while at higher latitude leaf seasonality is limited by low temperature and light availability. Leaf growth in grassland regions is limited by water availability but often in combination with other factors. This model will advance the current understanding of phenology for ecosystem carbon models and our ability to predict future phenological behaviour.

Description: Bias correction can modify climate model-simulated precipitation changes without adverse affect on the ensemble mean Hydrology and Earth System Sciences Discussions, 10, 11585-11611, 2013 Author(s): E. P. Maurer and D. W. Pierce When applied to remove climate model biases in precipitation, quantile mapping can in some settings modify the simulated trends. This has important implications when the precipitation will be used to drive an impacts model that is sensitive to changes in precipitation. We use daily precipitation output from 12 general circulation models (GCMs) over the conterminous United States interpolated to a common 1° grid, and gridded observations aggregated to the same scale, to compare precipitation differences before and after quantile mapping bias correction. The change in seasonal mean (winter, DJF, and summer, JJA) precipitation between different 30-yr historical periods is compared to examine (1) the consensus among GCMs as to whether the bias correction tends to amplify or diminish their simulated precipitation trends, and (2) whether the modification of the change in precipitation tends to improve or degrade the correspondence to observed changes in precipitation for the same periods. In some cases, for a particular GCM, the trend modification can be as large as the original simulated change, though the areas where this occurs varies among GCMs so the ensemble median shows smaller trend modification. In specific locations and seasons the trend modification by quantile mapping improves correspondence with observed trends, and in others it degrades it. In the majority of the domain the ensemble median is for little effect on the correspondence of simulated precipitation trends with observed. This highlights the need to use an ensemble of GCMs rather than relying on a small number of models to estimate impacts.

Description: Linking ICT and society in early warning and adaptation to hydrological extremes in mountains Natural Hazards and Earth System Science, 13, 2253-2270, 2013 Author(s): C. de Jong The assessment of the societal impact of hydrological extremes is particularly important in mountain regions, since mountains can be considered both as the generators and victims of extreme events. ICT can provide a powerful tool for transmitting hydro-meteorological information to predict, prepare and adapt to such events. However, in remote regions, such as mountains, the poles, deserts and islands, preventive and adaptive measures are often restricted by data availability and lack and/or incoherence of data networks. This paper distinguishes between early warning of floods and droughts, emphasising the latter in particular in mountains and explores the possibilities of enhancing the role of society in data collection, the identification, activation and application of stakeholder knowledge and transferral of data from gauged to ungauged catchments.

Description: Author(s): Hanjie Guo, Hiroshi Tanida, Riki Kobayashi, Ikuto Kawasaki, Masafumi Sera, Takashi Nishioka, Masahiro Matsumura, Isao Watanabe, and Zhu-an Xu The magnetic ground state of the Rh-doped Kondo semiconductor CeRu 2 Al 10 [Ce(Ru 1− x Rh x ) 2 Al 10 ] is investigated with the muon spin relaxation method. Muon spin precession with two frequencies is observed in the x =0 sample, while only one frequency is present in the x =0.05 and 0.10 samples, which is attr... [Phys. Rev. B 88, 115206] Published Fri Sep 13, 2013

Description: Author(s): A. Hillion, A. Tamion, F. Tournus, O. Gaier, E. Bonet, C. Albin, and V. Dupuis We propose a theoretical framework enabling the simulation of isothermal remanence magnetization (IRM) curves, based on the Stoner-Wohlfarth model combined with the Néel macrospin relaxation time description. We show how low temperature IRM curves, which have many advantages compared to hysteresis l... [Phys. Rev. B 88, 094419] Published Fri Sep 13, 2013

Description: Author(s): C. W. Xiao, J. Nieves, and E. Oset We present a coupled channel unitary approach to obtain states dynamically generated from the meson-baryon interaction with hidden charm, using constraints of heavy quark spin symmetry. As a basis of states, we use D ̅ B , D ̅ * B states, with B baryon charmed states belonging to the 20 re... [Phys. Rev. D 88, 056012] Published Fri Sep 13, 2013

Description: Author(s): A. A. Bush, N. Büttgen, A. A. Gippius, V. N. Glazkov, W. Kraetschmer, L. A. Prozorova, L. E. Svistov, A. M. Vasiliev, and A. Zheludev We present the results of magnetization, electron spin resonance (ESR), and nuclear magnetic resonance (NMR) measurements on single-crystal samples of the frustrated S =1/2 chain cuprate LiCu 2 O 2 doped with nonmagnetic Zn 2+ . As shown by the x-ray techniques, the crystals of Li(Cu 1− x Zn x ) 2 O 2 with x 〈0... [Phys. Rev. B 88, 104411] Published Fri Sep 13, 2013

Description: Author(s): Nicolai Friis, Antony R. Lee, and Jorma Louko We analyze quantized scalar, spinor, and photon fields in a mechanically rigid cavity that is accelerated in Minkowski spacetime, in a recently introduced perturbative small-acceleration formalism that allows the velocities to become relativistic, with a view to applications in relativistic quantum ... [Phys. Rev. D 88, 064028] Published Fri Sep 13, 2013

Description: Author(s): Parvendra Kumar and Amarendra K. Sarma We report a simple scheme to achieve ultrafast and selective population transfer in four-level atoms by utilizing a single nonlinearly chirped femtosecond pulse. It is demonstrated that the almost complete population may be transferred to the preselected state of atoms just by manipulating the so-ca... [Phys. Rev. A 88, 033823] Published Fri Sep 13, 2013

Description: Author(s): G. H. Gossel, V. A. Dzuba, and V. V. Flambaum We calculate magnetic dipole transition amplitudes in s − s and s − d transitions of Rb, Cs, Ba + , Fr, Ra + , Yb + , Ac 2+ and Th 3+ . These transitions were used or considered to be used for parity-nonconservation (PNC) measurements. We also calculate the magnetic g -factor anomalies for a selection of states, ... [Phys. Rev. A 88, 034501] Published Fri Sep 13, 2013

Description: Author(s): X. P. Shen, S. D. Chen, Q. Q. Ge, Z. R. Ye, F. Chen, H. C. Xu, S. Y. Tan, X. H. Niu, Q. Fan, B. P. Xie, and D. L. Feng We studied the low-lying electronic structure of the newly discovered iron-platinum-arsenide superconductor, Ca 10 (Pt 4 As 8 )(Fe 2− x Pt x As 2 ) 5 ( T c =22 K) with angle-resolved photoemission spectroscopy. We found that the Pt 4 As 8 layer contributes to a small electronlike Fermi surface, indicative of metallic c... [Phys. Rev. B 88, 115124] Published Fri Sep 13, 2013

Description: Author(s): U. C. Mendes, M. Korkusinski, A. H. Trojnar, and P. Hawrylak We present a microscopic theory of the optical properties of self-assembled quantum dots doped with a single magnetic manganese (Mn) impurity and containing a controlled number of electrons. The single-particle electron and heavy-hole electronic shells are described by two-dimensional harmonic oscil... [Phys. Rev. B 88, 115306] Published Fri Sep 13, 2013

Description: Author(s): F. Nilsson, R. Sakuma, and F. Aryasetiawan In this work we have calculated U from first principles for the early lanthanides (Ce-Gd) using the constrained random phase approximation (cRPA). We compare the static limit of U with experimental estimations from x-ray photoemission spectroscopy (XPS) and bremsstrahlung isochromat spectroscopy (BI... [Phys. Rev. B 88, 125123] Published Fri Sep 13, 2013

Description: Author(s): Lance J. Dixon and Ye Li We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for g g → γ γ . Previously, the apparent Higgs mass was found to shift by around 100 MeV in the sta... [Phys. Rev. Lett. 111, 111802] Published Fri Sep 13, 2013

Description: Author(s): M. R. Kamali, J. J. J. Gillissen, H. E. A. van den Akker, and Sankaran Sundaresan A lattice Boltzmann (LB) method is presented for solving the energy conservation equation in two phases when the phase change effects are included in the model. This approach employs multiple distribution functions, one for a pseudotemperature scalar variable and the rest for the various species. A ... [Phys. Rev. E 88, 033302] Published Fri Sep 13, 2013

Description: Author(s): C. Stock, S. R. Dunsiger, R. A. Mole, X. Li, and H. Luo A neutron scattering investigation of the magnetoelectric coupling in PbFe 1/2 Nb 1/2 O 3 has been undertaken. Ferroelectric order occurs below 400 K, as evidenced by the softening with temperature and subsequent recovery of the zone center transverse optic phonon mode energy ( ℏ Ω 0 ). Over the same tempera... [Phys. Rev. B 88, 094105] Published Fri Sep 13, 2013

Description: Author(s): Alessandro Roggero, Francesco Pederiva, and Giuseppina Orlandini An ab initio method for determining the dynamical structure function of an interacting many-body quantum system has been devised by combining a generalized integral transform method with quantum Monte Carlo (QMC) methods. A kernel has been found that (i) lets the transform be calculable with QMC met... [Phys. Rev. B 88, 094302] Published Fri Sep 13, 2013

Description: Author(s): D. T. Son and B. Z. Spivak We consider the classical magnetoresistance of a Weyl metal in which the electron Fermi surface possesses nonzero fluxes of the Berry curvature. Such a system may exhibit large negative magnetoresistance with unusual anisotropy as a function of the angle between the electric and magnetic fields. In ... [Phys. Rev. B 88, 104412] Published Fri Sep 13, 2013

Description: Author(s): P. Delugas, A. Filippetti, A. Gadaleta, I. Pallecchi, D. Marré, and V. Fiorentini Using advanced first-principles calculations we predict that the nonpolar SrTiO 3 /SrZrO 3 (001) interface, designed as either thin SrZrO 3 film deposited on SrTiO 3 or short-period (SrTiO 3 ) m /(SrZrO 3 ) n superlattice, hosts a two-dimensionally confined electron gas. Mobile electron charge due to native imp... [Phys. Rev. B 88, 115304] Published Fri Sep 13, 2013

Description: Author(s): Rafael Roldán and Luis Brey The screening properties and collective excitations (plasmons) in AA-stacked bilayer graphene are studied within the random phase approximation. Whereas long-lived plasmons in single-layer graphene and in AB-stacked bilayer graphene can exist only in doped samples, we find that coherent plasmons can... [Phys. Rev. B 88, 115420] Published Fri Sep 13, 2013

Description: Author(s): Stephan Michael, Weng W. Chow, and Hans Christian Schneider The slowdown of optical pulses due to quantum-coherence effects is investigated theoretically for an “active material” consisting of InGaAs-based double quantum dot molecules. These are designed to exhibit a long-lived coherence between two electronic levels, which is an essential part of a quantum-... [Phys. Rev. B 88, 125305] Published Fri Sep 13, 2013

Description: Author(s): V. Vandone et al. The K hindrance to the γ decay is studied in the warm rotating 174 W nucleus, focusing on the weakening of the selection rules of the K quantum number with increasing excitation energy. 174 W was populated by the fusion reaction of 50 Ti (at 217 MeV) on a 128 Te target, and its γ decay was detected by t... [Phys. Rev. C 88, 034312] Published Fri Sep 13, 2013

Description: Author(s): S. F. C. Shearer and M. R. Monteith The recent adiabatic saddle-point approach of Shearer et al. [ Phys. Rev. A 84 033409 (2011) ] is extended to multiphoton detachment of negative ions with outer p -state electrons. This theory is applied to investigate the strong-field photodetachment dynamics of F − ions exposed to few-cycle femtosec... [Phys. Rev. A 88, 033415] Published Fri Sep 13, 2013

Description: Author(s): H. Zhang, J. Tulpan, M. Shrestha, and D. M. Manley We present results of a new multichannel partial-wave analysis for K ̅ N scattering in the center-of-mass (c.m.) energy range from 1480 to 2100 MeV. Resonance parameters were extracted by fitting partial-wave amplitudes from all considered channels using a multichannel parametrization that is ... [Phys. Rev. C 88, 035205] Published Fri Sep 13, 2013

Description: Author(s): Nikolaos G. Fytas and Víctor Martín-Mayor [Phys. Rev. Lett. 111, 119903] Published Fri Sep 13, 2013

Description: Author(s): Subir Biswas, Debjyoti Basu, Rabindranath Pal, and Nikhil Chakrabarti Excitation of low frequency drift waves in a radial region of a weak density gradient is demonstrated experimentally by strong temporal modulation of the plasma density. Though a parallel electron current can destabilize drift waves throughout the region, we observe mode selection at the resonant lo... [Phys. Rev. Lett. 111, 115004] Published Fri Sep 13, 2013

Description: Author(s): Oliver Bäumchen, Michael Benzaquen, Thomas Salez, Joshua D. McGraw, Matilda Backholm, Paul Fowler, Elie Raphaël, and Kari Dalnoki-Veress The surface of a thin liquid film with nonconstant curvature flattens as a result of capillary forces. While this leveling is driven by local curvature gradients, the global boundary conditions greatly influence the dynamics. Here, we study the evolution of rectangular trenches in a polystyrene nano... [Phys. Rev. E 88, 035001] Published Fri Sep 13, 2013

Description: Author(s): J. Schachenmayer, B. P. Lanyon, C. F. Roos, and A. J. Daley Recent advances in quantum simulators allow the use of systems of trapped ions to create and simulate spin models with a controllable interaction range. Scientists report timely and counterintuitive theoretical findings about the temporal growth of quantum entanglement in a suddenly “quenched” quantum spin chain based on trapped ions. [Phys. Rev. X 3, 031015] Published Fri Sep 13, 2013

Description: A plume-in-grid approach to characterize air quality impacts of aircraft emissions at the Hartsfield–Jackson Atlanta International Airport Atmospheric Chemistry and Physics, 13, 9285-9302, 2013 Author(s): J. Rissman, S. Arunachalam, M. Woody, J. J. West, T. BenDor, and F. S. Binkowski This study examined the impacts of aircraft emissions during the landing and takeoff cycle on PM 2.5 concentrations during the months of June and July 2002 at the Hartsfield–Jackson Atlanta International Airport. Primary and secondary pollutants were modeled using the Advanced Modeling System for Transport, Emissions, Reactions, and Deposition of Atmospheric Matter (AMSTERDAM). AMSTERDAM is a modified version of the Community Multiscale Air Quality (CMAQ) model that incorporates a plume-in-grid process to simulate emissions sources of interest at a finer scale than can be achieved using CMAQ's model grid. Three fundamental issues were investigated: the effects of aircraft on PM 2.5 concentrations throughout northern Georgia, the differences resulting from use of AMSTERDAM's plume-in-grid process rather than a traditional CMAQ simulation, and the concentrations observed in aircraft plumes at subgrid scales. Comparison of model results with an air quality monitor located in the vicinity of the airport found that normalized mean bias ranges from −77.5% to 6.2% and normalized mean error ranges from 40.4% to 77.5%, varying by species. Aircraft influence average PM 2.5 concentrations by up to 0.232 μg m −3 near the airport and by 0.001–0.007 μg m −3 throughout the Atlanta metro area. The plume-in-grid process increases concentrations of secondary PM pollutants by 0.005–0.020 μg m −3 (compared to the traditional grid-based treatment) but reduces the concentration of non-reactive primary PM pollutants by up to 0.010 μg m −3 , with changes concentrated near the airport. Examination of subgrid-scale results indicates that median aircraft contribution to grid cells is higher than median puff concentration in the airport's grid cell and outside of a 20 km × 20 km square area centered on the airport, while in a 12 km × 12 km square ring centered on the airport, puffs have median concentrations over an order of magnitude higher than aircraft contribution to the grid cells. Maximum puff impacts are seen within the 12 km × 12 km ring, not in the airport's own grid cell, while maximum grid cell impacts occur within the airport's grid cell. Twenty-one (21)% of all aircraft-related puffs from the Atlanta airport have at least 0.1 μg m −3 PM 2.5 concentrations. Near the airport, median daily puff concentrations vary between 0.017 and 0.134 μg m −3 (0.05 and 0.35 μg m −3 at ground level), while maximum daily puff concentrations vary between 6.1 and 42.1 μg m −3 (7.5 and 42.1 μg m −3 at ground level) during the 2-month period. In contrast, median daily aircraft contribution to grid concentrations varies between 0.015 and 0.091 μg m −3 (0.09 and 0.40 μg m −3 at ground level), while the maximum varies between 0.75 and 2.55 μg m −3 (0.75 and 2.0 μg m −3 at ground level). Future researchers may consider using a plume-in-grid process, such as the one used here, to understand the impacts of aircraft emissions at other airports, for proposed future airports, for airport expansion projects under various future scenarios, and for other national-scale studies specifically when the maximum impacts at fine scales are of interest.