ALBERT

Description: The composition and abundance of algal pigments provide information on characteristics of a phytoplankton community in respect to its photoacclimation, overall biomass, and taxonomic composition. Particularly, these pigments play a major role in photoprotection and in the light-driven part of photosynthesis. Most phytoplankton pigments can be measured by High Performance Liquid Chromatography (HPLC) techniques to filtered water samples. This method, like others when water samples have to be analysed in the laboratory, is time consuming and therefore only a limited number of data points can be obtained. In order to receive information on phytoplankton pigment composition with a higher temporal and spatial resolution, we have developed a method to assess pigment concentrations from continuous optical measurements. The method applies an Empirical Orthogonal Function (EOF) analysis to remote sensing reflectance data derived from ship-based hyper-spectral underwater radiometric and from multispectral satellite data (using the MERIS Polymer product developed by Steinmetz et al., 2011) measured in the Eastern Tropical Atlantic. Subsequently we developed statistically linear models with measured (collocated) pigment concentrations as the response variable and EOF loadings as predictor variables. The model results, show that surface concentrations of a suite of pigments and pigment groups can be well predicted from the ship-based reflectance measurements, even when only a multi-spectral resolution is chosen (i.e. eight bands similar to those used by MERIS). Based on the MERIS reflectance data, concentrations of total and monovinyl chlorophyll a and the groups of photoprotective and photosynthetic carotenoids can be predicted with high quality. The fitted statistical model constructed on the satellite reflectance data as input was applied to one month of MERIS Polymer data to predict the concentration of those pigment groups for the whole Eastern Tropical Atlantic area. Bootstrapping explorations of cross-validation error indicate that the method can produce reliable predictions with relatively small data sets (e.g., 〈 50 collocated values of reflectance and pigment concentration). The method allows for the derivation of time series from continuous reflectance data of various pigment groups at various regions, which can be used to study variability and change of phytoplankton composition and photo-physiology.

Description: Sea ice thickness information is important for sea ice modelling and ship operations. Here a method to detect the thickness of sea ice up to 50 cm during the freeze-up season based on high incidence angle observations of the Soil Moisture and Ocean Salinity (SMOS) satellite working at 1.4 GHz is suggested. By comparison of thermodynamic ice growth data with SMOS brightness temperatures, a high correlation to intensity and an anticorrelation to the difference between vertically and horizontally polarised brightness temperatures at incidence angles between 40 and 50° are found and used to develop an empirical retrieval algorithm sensitive to thin sea ice up to 50 cm thickness. The algorithm shows high correlation with ice thickness data from airborne measurements and reasonable ice thickness patterns for the Arctic freeze-up period.

Description: Following the launch of ESA's Soil Moisture and Ocean Salinity (SMOS) mission, it has been shown that brightness temperatures at a low microwave frequency of 1.4 GHz (L-band) are sensitive to sea ice properties. In the first demonstration study, sea ice thickness up to 50 cm has been derived using a semi-empirical algorithm with constant tie-points. Here, we introduce a novel iterative retrieval algorithm that is based on a thermodynamic sea ice model and a three-layer radiative transfer model, which explicitly takes variations of ice temperature and ice salinity into account. In addition, ice thickness variations within the SMOS spatial resolution are considered through a statistical thickness distribution function derived from high-resolution ice thickness measurements from NASA's Operation IceBridge campaign. This new algorithm has been used for the continuous operational production of a SMOS-based sea ice thickness data set from 2010 on. The data set is compared to and validated with estimates from assimilation systems, remote sensing data, and airborne electromagnetic sounding data. The comparisons show that the new retrieval algorithm has a considerably better agreement with the validation data and delivers a more realistic Arctic-wide ice thickness distribution than the algorithm used in the previous study (Kaleschke et al., 2012).

Description: The ice shelf caverns around Antarctica are sources of cold and fresh water which contributes to the formation of Antarctic bottom water and thus to the ventilation of the deep basins of the World Ocean. While a realistic simulation of the cavern circulation requires high resolution, because of the complicated bottom topography and ice shelf morphology, the physics of melting and freezing at the ice shelf base is relatively simple. We have developed an analytically solvable box model of the cavern thermohaline state, using the formulation of melting and freezing as in Olbers and Hellmer (2010). There is high resolution along the cavern's path of the overturning circulation whereas the cross-path resolution is fairly coarse. The circulation in the cavern is prescribed and used as a tuning parameter to constrain the solution by attempting to match observed ranges for outflow temperature and salinity at the ice shelf front as well as of the mean basal melt rate. The method, tested for six Antarctic ice shelves, can be used for a quick estimate of melt/freeze rates and the overturning rate in particular caverns, given the temperature and salinity of the inflow and the above mentioned constrains for outflow and melting. In turn, the model can also be used for testing the compatibility of remotely sensed basal mass loss with observed cavern inflow characteristics.

Description: The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO2 values) and extended data coverage (from 1968–2007 to 1968–2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models.

Description: In a feasibility study, the potential of proxy data for the temperature and salinity during the Last Glacial Maximum (LGM, about 19 000 to 23 000 years before present) in constraining the strength of the Atlantic meridional overturning circulation (AMOC) with a general ocean circulation model was explored. The proxy data were simulated by drawing data from four different model simulations at the ocean sediment core locations of the Multiproxy Approach for the Reconstruction of the Glacial Ocean surface (MARGO) project, and perturbing these data with realistic noise estimates. The results suggest that our method has the potential to provide estimates of the past strength of the AMOC even from sparse data, but in general, paleo-sea-surface temperature data without additional prior knowledge about the ocean state during the LGM is not adequate to constrain the model. On the one hand, additional data in the deep-ocean and salinity data are shown to be highly important in estimating the LGM circulation. On the other hand, increasing the amount of surface data alone does not appear to be enough for better estimates. Finally, better initial guesses to start the state estimation procedure would greatly improve the performance of the method. Indeed, with a sufficiently good first guess, just the sea-surface temperature data from the MARGO project promise to be sufficient for reliable estimates of the strength of the AMOC.

Description: We present first results from a coupled model setup, consisting of the state-of-the-art ice sheet model RIMBAY (Revised Ice Model Based on frAnk pattYn), and the community earth system model COSMOS. We show that special care has to be provided in order to ensure physical distributions of the forcings as well as numeric stability of the involved models. We demonstrate that a suitable statistical downscaling is crucial for ice sheet stability, especially for southern Greenland where surface temperatures are close to the melting point. The downscaling of net snow accumulation is based on an empirical relationship between surface slope and rainfall. The simulated ice sheet does not show dramatic loss of ice volume for pre-industrial conditions and is comparable with present-day ice orography. A sensitivity study with high CO2 level is used to demonstrate the effects of dynamic ice sheets onto climate compared to the standard setup with prescribed ice sheets.

Description: A Lagrangian advection scheme with shape matrix (LASM) for solving advection problems Geoscientific Model Development, 7, 2951-2968, 2014 Author(s): L. Dong, B. Wang, and L. Liu A new Lagrangian advection scheme with shape matrix (LASM) is proposed to take advantage of the extreme low numerical diffusion of the Lagrangian methods. The tracer is discretized into finite parcels, which move along the downstream trajectories. Different from other Lagrangian schemes, the parcel shape is simulated explicitly by a linear transformation matrix. By doing so, the aliasing error in the Lagrangian schemes is largely reduced without introducing substantial interparcel mixing in the pure advection stage, because the flow information will be respected when remapping tracer density onto the fixed model grids. An adaptive interparcel mixing algorithm is constructed to ensure the validity of the linear approximation of the parcel shape, where the mixing is only triggered when it is necessary and resembles the physical mixing. The total tracer mass on the parcels is conserved exactly. The new scheme is validated by using several test cases.

Description: Technical Note: Reducing the spin-up time of integrated surface water–groundwater models Hydrology and Earth System Sciences, 18, 5169-5179, 2014 Author(s): H. Ajami, J. P. Evans, M. F. McCabe, and S. Stisen One of the main challenges in the application of coupled or integrated hydrologic models is specifying a catchment's initial conditions in terms of soil moisture and depth-to-water table (DTWT) distributions. One approach to reducing uncertainty in model initialization is to run the model recursively using either a single year or multiple years of forcing data until the system equilibrates with respect to state and diagnostic variables. However, such "spin-up" approaches often require many years of simulations, making them computationally intensive. In this study, a new hybrid approach was developed to reduce the computational burden of the spin-up procedure by using a combination of model simulations and an empirical DTWT function. The methodology is examined across two distinct catchments located in a temperate region of Denmark and a semi-arid region of Australia. Our results illustrate that the hybrid approach reduced the spin-up period required for an integrated groundwater–surface water–land surface model (ParFlow.CLM) by up to 50%. To generalize results to different climate and catchment conditions, we outline a methodology that is applicable to other coupled or integrated modeling frameworks when initialization from an equilibrium state is required.

Description: Extending periodic eddy covariance latent heat fluxes through tree sapflow measurements to estimate long-term total evaporation in a peat swamp forest Hydrology and Earth System Sciences Discussions, 11, 13607-13661, 2014 Author(s): A. D. Clulow, C. S. Everson, M. G. Mengistu, J. S. Price, A. Nickless, and G. P. W. Jewitt A combination of measurement and modelling was used to find a pragmatic solution to estimate the annual total evaporation (ET) from the rare and indigenous Nkazana Peat Swamp Forest (PSF) on the east coast of Southern Africa to improve the water balance estimates within the area. Total evaporation was measured during three window periods (between seven and nine days each) using an eddy covariance (EC) system on a telescopic mast above the forest canopy. Sapflow of an understory and an emergent tree was measured using a low maintenance heat pulse velocity system for an entire hydrological year (October 2009 to September 2010). An empirical model was derived, describing the relationship between the observed ET of the Nkazana PSF measured during two of the window periods ( R 2 = 0.92 and 0.90) which, overlapped with sapflow measurements, thereby providing hourly estimates of predicted ET of the Nkazana PSF for a year, totalling 1125 mm (while rainfall was 650 mm). In building the empirical model, it was found that including the understory tree sapflow provided no benefit to the model performance. In addition, the observed emergent tree sapflow relationship with observed ET between the two field campaigns was consistent and could be represented by a single empirical model ( R 2 = 0.90; RMSE = 0.08 mm). During the window periods of EC measurement, no single meteorological variable was found to describe the Nkazana PSF ET satisfactorily. However, in terms of evaporation models, the hourly FAO56 Penman–Monteith equation best described the observed ET from EC during the August 2009 ( R 2 = 0.75), November 2009 ( R 2 = 0.85) and March 2010 ( R 2 = 0.76) field campaigns, compared to the Priestley–Taylor model ( R 2 = 0.54, 0.74 and 0.62 during the respective field campaigns). From the empirical model of ET and the FAO56 Penman–Monteith equation, a monthly crop factor ( K c ) was derived for the Nkazana PSF providing a method of estimating long-term swamp forest ET from meteorological data. The monthly crop factor indicated two distinct periods. From February to May, it was between 1.2 and 1.4 compared with June to January, when the crop factor was 0.8 to 1.0. The derived monthly K c values were verified as accurate (to one significant digit) using historical data measured at the same site, also using EC, from a~previous study. The measurements provided insights into the microclimate within a subtropical peat swamp forest and the contrasting sapflow of emergent and understory trees. They showed that expensive, high maintenance equipment can be used during manageable window periods in conjunction with low maintenance systems, dedicated to individual trees, to derive a model to estimate long-term ET over remote heterogeneous forests. In addition, the contrast in ET and rainfall emphasises the reliance of the Nkazana PSF on groundwater.

Description: Author(s): N. A. Sinitsyn We consider nonadiabatic transitions in explicitly time-dependent systems with Hamiltonians of the form Ĥ(t)=Â+B̂t+Ĉ/t, where t is time and Â, B̂, Ĉ are Hermitian N×N matrices. We show that in any model of this type, scattering matrix elements satisfy nontrivial exact constraints that follow fr... [Phys. Rev. A 90, 062509] Published Thu Dec 11, 2014

Description: Author(s): P. Szańkowski, M. Trippenbach, and J. Chwedeńczuk We demonstrate that memory in an N-qubit system subjected to decoherence, is a potential resource for the slowdown of the entanglement decay. We show that this effect can be used to retain the sub-shot-noise sensitivity of the parameter estimation in quantum interferometry. We calculate quantum Fish... [Phys. Rev. A 90, 063619] Published Thu Dec 11, 2014

Description: Author(s): J. Lam, C. J. Rennick, and T. P. Softley Near-threshold photodissociation of Br 2 from a supersonic beam produces slow bromine atoms that are trapped in the magnetic-field minimum formed between two opposing permanent magnets. Here we quantify the dominant trap-loss rate due to collisions with two sources of residual gas: the background lim... [Phys. Rev. A 90, 063419] Published Thu Dec 11, 2014

Description: Author(s): Y. Lutsyshyn, G. E. Astrakharchik, C. Cazorla, and J. Boronat We study the zero-temperature quantum phase transition between liquid and hcp solid 4 He. We use the variational method with a simple yet exchange-symmetric and fully explicit wave function. It is found that the optimized wave function undergoes spontaneous symmetry breaking and describes the quantum... [Phys. Rev. B 90, 214512] Published Thu Dec 11, 2014

Description: Author(s): L. Z. Deng, B. Lv, Z. Wu, Y. Y. Xue, W. H. Zhang, F. S. Li, L. L. Wang, X. C. Ma, Q. K. Xue, and C. W. Chu We report a detailed investigation on the superconductivity in eight 1–4 unit-cell (UC) FeSe films on SrTiO 3 substrates by measuring their magnetization and sheet resistance in a field between 5×10 −2 and 7×10 4  Oe over the last one and a half years as a function of temperature and frequency, from 2 t... [Phys. Rev. B 90, 214513] Published Thu Dec 11, 2014

Description: Author(s): Hiromi Otsuka We present an algorithm for Monte Carlo simulations of a nearest-neighbor spin-ice model based on its cluster representation. To assess its performance, we estimate a relaxation time, and find that, in contrast to the Metropolis algorithm, our algorithm does not develop spin freezing. Also, to demon... [Phys. Rev. B 90, 220406] Published Thu Dec 11, 2014

Description: Author(s): Hongbin Yao, Wei Guo, Mark R. Hoffmann, and Keli Han We demonstrate an efficient scheme for controlling the tunneling ionization of a H 2 + molecular ion. Our scheme is based on the idea that the tunneling ionization rate is highly dependent on the instantaneous magnitude of the electric field. By manipulating the relative phase of the synthesized 5-fs,... [Phys. Rev. A 90, 063418] Published Thu Dec 11, 2014

Description: Author(s): Wenkui Ding, Anqi Shi, J. Q. You, and Wenxian Zhang We numerically investigate the encoding and retrieval processes for quantum memory realized in a semiconductor quantum dot by focusing on the effect of inhomogeneously polarized nuclear spins whose polarization depends on the local hyperfine coupling strength. We find that the performance of quantum... [Phys. Rev. B 90, 235421] Published Thu Dec 11, 2014

Description: Author(s): Sam Morley-Short, Lawrence Rosenfeld, and Pieter Kok The study of quantum systems evolving from initial states to distinguishable, orthogonal final states is important for information processing applications such as quantum computing and quantum metrology. However, for most unitary evolutions and initial states the system does not evolve to an orthogo... [Phys. Rev. A 90, 062116] Published Thu Dec 11, 2014

Description: Author(s): Chaitanya Joshi, Patrik Öhberg, James D. Cresser, and Erika Andersson We investigate how to model Markovian evolution of coupled harmonic oscillators, each of them interacting with a local environment. When the coupling between the oscillators is weak, dissipation may be modeled using local Lindblad terms for each of the oscillators in the master equation, as is commo... [Phys. Rev. A 90, 063815] Published Thu Dec 11, 2014

Description: Author(s): Yoshihito Kuno, Keita Suzuki, and Ikuo Ichinose In this paper, we study an extended bosonic t-J model in an optical lattice, which describes two-component hard-core bosons with nearest-neighbor pseudospin interactions and, also, inter- and intraspecies dipole-dipole interactions. In particular, we focus on the case in which two-component hard-cor... [Phys. Rev. A 90, 063620] Published Thu Dec 11, 2014

Description: Author(s): Jixia Dai, Kristjan Haule, J. J. Yang, Y. S. Oh, S-W. Cheong, and Weida Wu Layered 5d transition metal dichalcogenide (TMD) IrTe 2 is distinguished from the traditional TMDs (such as NbSe 2 ) by the existence of multiple charge-density wave (CDW)-like stripe phases and superconductivity at low temperatures. Despite intensive studies, there is still no consensus on the physica... [Phys. Rev. B 90, 235121] Published Thu Dec 11, 2014

Description: Author(s): Martin Doškář, Jan Novák, and Jan Zeman The paper presents a concept to compress and synthesize complex material morphologies that is based on Wang tilings. Specifically, a microstructure is stored in a set of Wang tiles and its reconstruction is performed by means of a stochastic tiling algorithm. A substantial part of the study is devot... [Phys. Rev. E 90, 062118] Published Thu Dec 11, 2014

Description: Author(s): A. Le Yaouanc, L. Oliver, and J.-C. Raynal We pursue the group-theoretical method to study Isgur-Wise (IW) functions. We extend the general formalism, formerly applied to the baryon case j P =0 + (for Λ b →Λ c ℓν̅ ℓ ), to mesons with j P =1/2 - , i.e. B̅ →D(D (*) )ℓν. In this case, which is more involved from the angular momentum point of vi... [Phys. Rev. D 90, 114016] Published Thu Dec 11, 2014

Description: Author(s): D. Fuster, J. M. Conoir, and T. Colonius We study the influence of bubble-bubble interactions on the propagation of linear acoustic waves in bubbly liquids. Using the full model proposed by Fuster and Colonius [J. Fluid Mech. 688 , 253 (2011)JFLSA710.1017/jfm.2011.380], numerical simulations reveal that direct bubble-bubble interactions hav... [Phys. Rev. E 90, 063010] Published Thu Dec 11, 2014

Description: Author(s): Felix Yndurain Using ab initio methods based on the density functional theory, we study the magnetic properties of different point defects in graphene. We consider separately, atomic hydrogen, atomic fluorine, and single vacancies. The three defects have completely different magnetic properties. A local spin one-h... [Phys. Rev. B 90, 245420] Published Thu Dec 11, 2014

Description: Author(s): Kees Wapenaar In time-reversal acoustics, waves recorded at the boundary of a strongly scattering medium are sent back into the medium to focus at the original source position. This requires that the medium can be accessed from all sides. We discuss a focusing method for media that can be accessed from one side o... [Phys. Rev. E 90, 063202] Published Thu Dec 11, 2014

Description: Author(s): Alan Heavens, Raul Jimenez, and Licia Verde A measure of how galaxies are spatially distributed can be determined in a new, more robust way. [Phys. Rev. Lett. 113, 241302] Published Thu Dec 11, 2014

Description: Author(s): Ya-Bo Wu, Jun-Wang Lu, Wen-Xin Zhang, Cheng-Yuan Zhang, Jian-Bo Lu, and Fang Yu In the probe limit, we numerically construct a holographic p-wave superfluid model in the four-dimensional (4D) and five-dimensional (5D) anti-de Sitter black holes coupled to a Maxwell-complex vector field. We find that, for the condensate with the fixed superfluid velocity, the results are similar... [Phys. Rev. D 90, 126006] Published Thu Dec 11, 2014

Description: Author(s): Douglas Stanford and Leonard Susskind In this paper we refine a conjecture relating the time-dependent size of an Einstein-Rosen bridge (ERB) to the computational complexity of the dual quantum state. Our refinement states that the complexity is proportional to the spatial volume of the ERB. More precisely, up to an ambiguous numerical ... [Phys. Rev. D 90, 126007] Published Thu Dec 11, 2014

Description: Author(s): A. Ludwig, J. Maurer, B. W. Mayer, C. R. Phillips, L. Gallmann, and U. Keller We report the breakdown of the electric dipole approximation in the long-wavelength limit in strong-field ionization with linearly polarized few-cycle mid-infrared laser pulses at intensities on the order of 10 13   W/cm 2 . Photoelectron momentum distributions were recorded by velocity map imaging and ... [Phys. Rev. Lett. 113, 243001] Published Thu Dec 11, 2014

Description: Author(s): N. Y. Yao, C. R. Laumann, S. Gopalakrishnan, M. Knap, M. Müller, E. A. Demler, and M. D. Lukin Systems of strongly interacting dipoles offer an attractive platform to study many-body localized phases, owing to their long coherence times and strong interactions. We explore conditions under which such localized phases persist in the presence of power-law interactions and supplement our analytic... [Phys. Rev. Lett. 113, 243002] Published Thu Dec 11, 2014

Description: Stratospheric ozone depletion from future nitrous oxide increases Atmospheric Chemistry and Physics, 14, 12967-12982, 2014 Author(s): W. Wang, W. Tian, S. Dhomse, F. Xie, J. Shu, and J. Austin We have investigated the impact of the assumed nitrous oxide (N 2 O) increases on stratospheric chemistry and dynamics using a series of idealized simulations with a coupled chemistry-climate model (CCM). In a future cooler stratosphere the net yield of NO y from N 2 O is shown to decrease in a reference run following the IPCC A1B scenario, but NO y can still be significantly increased by extra increases of N 2 O over 2001–2050. Over the last decade of simulations, 50% increases in N 2 O result in a maximal 6% reduction in ozone mixing ratios in the middle stratosphere at around 10 hPa and an average 2% decrease in the total ozone column (TCO) compared with the control run. This enhanced destruction could cause an ozone decline in the first half of this century in the middle stratosphere around 10 hPa, while global TCO still shows an increase at the same time. The results from a multiple linear regression analysis and sensitivity simulations with different forcings show that the chemical effect of N 2 O increases dominates the N 2 O-induced ozone depletion in the stratosphere, while the dynamical and radiative effects of N 2 O increases are overall insignificant. The analysis of the results reveals that the ozone depleting potential of N 2 O varies with the time period and is influenced by the environmental conditions. For example, carbon dioxide (CO 2 ) increases can strongly offset the ozone depletion effect of N 2 O.

Description: Corrigendum to "Air-sea exchange and gas-particle partitioning of polycyclic aromatic hydrocarbons in the Mediterranean" published in Atmos. Chem. Phys., 14, 8905–8915, 2014 Atmospheric Chemistry and Physics, 14, 12965-12965, 2014 Author(s): M. D. Mulder, A. Heil, P. Kukučka, J. Klánová, J. Kuta, R. Prokeš, F. Sprovieri, and G. Lammel No abstract available.

Description: Mechanistic study of secondary organic aerosol components formed from nucleophilic addition reactions of methacrylic acid epoxide Atmospheric Chemistry and Physics, 14, 12951-12964, 2014 Author(s): A. W. Birdsall, C. R. Miner, L. E. Mael, and M. J. Elrod Recently, methacrylic acid epoxide (MAE) has been proposed as a precursor to an important class of isoprene-derived compounds found in secondary organic aerosol (SOA): 2-methylglyceric acid (2-MG) and a set of oligomers, nitric acid esters, and sulfuric acid esters related to 2-MG. However, the specific chemical mechanisms by which MAE could form these compounds have not been previously studied with experimental methods. In order to determine the relevance of these processes to atmospheric aerosol, MAE and 2-MG have been synthesized and a series of bulk solution-phase experiments aimed at studying the reactivity of MAE using nuclear magnetic resonance (NMR) spectroscopy have been performed. The present results indicate that the acid-catalyzed MAE reaction is more than 600 times slower than a similar reaction of an important isoprene-derived epoxide, but is still expected to be kinetically feasible in the atmosphere on more acidic SOA. The specific mechanism by which MAE leads to oligomers was identified, and the reactions of MAE with a number of atmospherically relevant nucleophiles were also investigated. Because the nucleophilic strengths of water, sulfate, alcohols (including 2-MG), and acids (including MAE and 2-MG) in their reactions with MAE were found to be of similar magnitudes, it is expected that a diverse variety of MAE + nucleophile product species may be formed on ambient SOA. Thus, the results indicate that epoxide chain reaction oligomerization will be limited by the presence of high concentrations of non-epoxide nucleophiles (such as water); this finding is consistent with previous environmental chamber investigations of the relative humidity dependence of 2-MG-derived oligomerization processes and suggests that extensive oligomerization may not be likely on ambient SOA because of other competitive MAE reaction mechanisms.

Description: Megacity emission plume characteristics in summer and winter investigated by mobile aerosol and trace gas measurements: the Paris metropolitan area Atmospheric Chemistry and Physics, 14, 12931-12950, 2014 Author(s): S.-L. von der Weiden-Reinmüller, F. Drewnick, Q. J. Zhang, F. Freutel, M. Beekmann, and S. Borrmann For the investigation of megacity emission plume characteristics mobile aerosol and trace gas measurements were carried out in the greater Paris region in July 2009 and January–February 2010 within the EU FP7 MEGAPOLI project (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation). The deployed instruments measured physical and chemical properties of sub-micron aerosol particles, gas phase constituents of relevance for urban air pollution studies and meteorological parameters. The emission plume was identified based on fresh pollutant (e.g., particle-bound polycyclic aromatic hydrocarbons, black carbon, CO 2 and NO x ) concentration changes in combination with wind direction data. The classification into megacity influenced and background air masses allowed a characterization of the emission plume during summer and winter environmental conditions. On average, a clear increase of fresh pollutant concentrations in plume compared to background air masses was found for both seasons. For example, an average increase of 190% (+ 8.8 ng m −3 ) in summer and of 130% (+ 18.1 ng m −3 ) in winter was found for particle-bound polycyclic aromatic hydrocarbons in plume air masses. The aerosol particle size distribution in plume air masses was influenced by nucleation and growth due to coagulation and condensation in summer, while in winter only the latter process (i.e., particle growth) seemed to be initiated by urban pollution. The observed distribution of fresh pollutants in the emission plume – its cross sectional Gaussian-like profile and the exponential decrease of pollutant concentrations with increasing distance to the megacity – are in agreement with model results. Differences between model and measurements were found for plume center location, plume width and axial plume extent. In general, dilution was identified as the dominant process determining the axial variations within the Paris emission plume. For in-depth analysis of transformation processes occurring in the advected plume, simultaneous measurements at a suburban measurement site and a stationary site outside the metropolitan area using the mobile laboratory have proven to be most useful. Organic aerosol oxidation was observed in summer, while in winter transformation processes seemed to occur at a slower rate.

Description: A regional CO 2 observing system simulation experiment for the ASCENDS satellite mission Atmospheric Chemistry and Physics, 14, 12897-12914, 2014 Author(s): J. S. Wang, S. R. Kawa, J. Eluszkiewicz, D. F. Baker, M. Mountain, J. Henderson, T. Nehrkorn, and T. S. Zaccheo Top–down estimates of the spatiotemporal variations in emissions and uptake of CO 2 will benefit from the increasing measurement density brought by recent and future additions to the suite of in situ and remote CO 2 measurement platforms. In particular, the planned NASA Active Sensing of CO 2 Emissions over Nights, Days, and Seasons (ASCENDS) satellite mission will provide greater coverage in cloudy regions, at high latitudes, and at night than passive satellite systems, as well as high precision and accuracy. In a novel approach to quantifying the ability of satellite column measurements to constrain CO 2 fluxes, we use a portable library of footprints (surface influence functions) generated by the Stochastic Time-Inverted Lagrangian Transport (STILT) model in combination with the Weather Research and Forecasting (WRF) model in a regional Bayesian synthesis inversion. The regional Lagrangian particle dispersion model framework is well suited to make use of ASCENDS observations to constrain weekly fluxes in North America at a high resolution, in this case at 1° latitude × 1° longitude. We consider random measurement errors only, modeled as a function of the mission and instrument design specifications along with realistic atmospheric and surface conditions. We find that the ASCENDS observations could potentially reduce flux uncertainties substantially at biome and finer scales. At the grid scale and weekly resolution, the largest uncertainty reductions, on the order of 50%, occur where and when there is good coverage by observations with low measurement errors and the a priori uncertainties are large. Uncertainty reductions are smaller for a 1.57 μm candidate wavelength than for a 2.05 μm wavelength, and are smaller for the higher of the two measurement error levels that we consider (1.0 ppm vs. 0.5 ppm clear-sky error at Railroad Valley, Nevada). Uncertainty reductions at the annual biome scale range from ~40% to ~75% across our four instrument design cases and from ~65% to ~85% for the continent as a whole. Tests suggest that the quantitative results are moderately sensitive to assumptions regarding a priori uncertainties and boundary conditions. The a posteriori flux uncertainties we obtain, ranging from 0.01 to 0.06 Pg C yr −1 across the biomes, would meet requirements for improved understanding of long-term carbon sinks suggested by a previous study.

Description: Estimating regional fluxes of CO 2 and CH 4 using space-borne observations of XCH 4 : XCO 2 Atmospheric Chemistry and Physics, 14, 12883-12895, 2014 Author(s): A. Fraser, P. I. Palmer, L. Feng, H. Bösch, R. Parker, E. J. Dlugokencky, P. B. Krummel, and R. L. Langenfelds We use the GEOS-Chem global 3-D atmospheric chemistry transport model to interpret XCH 4 :XCO 2 column ratios retrieved from the Japanese Greenhouse Gases Observing Satellite (GOSAT). The advantage of these data over CO 2 and CH 4 columns retrieved independently using a full physics optimal estimation algorithm is that they are less prone to scattering-related regional biases. We show that the model is able to reproduce observed global and regional spatial (mean bias =0.7%) and temporal variations (global r 2 =0.92) of this ratio with a model bias 〈 2.5%. We also show that these variations are driven by emissions of CO 2 and CH 4 that are typically 6 months out of phase, which may reduce the sensitivity of the ratio to changes in either gas. To simultaneously estimate fluxes of CO 2 and CH 4 we use a maximum likelihood estimation approach. We use two approaches to resolve independent flux estimates of these two gases using GOSAT observations of XCH 4 :XCO 2 : (1) the a priori error covariance between CO 2 and CH 4 describing common source from biomass burning; and (2) also fitting independent surface atmospheric measurements of CH 4 and CO 2 mole fraction that provide additional constraints, improving the effectiveness of the observed GOSAT ratio to constrain flux estimates. We demonstrate the impact of these two approaches using numerical experiments. A posteriori flux estimates inferred using only the GOSAT ratios and taking advantage of the error covariance due to biomass burning are not consistent with the true fluxes in our experiments, as the inversion system cannot judge which species' fluxes to adjust. This reflects the weak dependence of XCH 4 :XCO 2 on biomass burning. We find that adding the surface data effectively provides an "anchor" to the inversion that dramatically improves the ability of the GOSAT ratios to infer both CH 4 and CO 2 fluxes. We show that the regional flux estimates inferred from GOSAT XCH 4 :XCO 2 ratios together with the surface mole fraction data during 2010 are typically consistent with or better than the corresponding values inferred from fitting XCH 4 or the full-physics XCO 2 data products, as judged by a posteriori uncertainties. We show that the fluxes inferred from the ratio measurements perform best over regions where there is a large seasonal cycle such as Tropical South America, for which we report a small but significant annual source of CO 2 compared to a small annual sink inferred from the XCO 2 data. We argue that given that the ratio measurements are less compromised by systematic error than the full physics data products, the resulting a~posteriori estimates and uncertainties provide a more faithful description of the truth. Based on our analysis we also argue that by using the ratios we may be reaching the current limits on the precision of these observed space-based data.

Description: Long-term variability of storm surge frequency in the Venice Lagoon: an update thanks to eighteenth century sea level observations Natural Hazards and Earth System Sciences Discussions, 2, 7465-7486, 2014 Author(s): F. Raicich Sea level observations made in the Venice Lagoon between 1751 and 1792 have been recovered, consisting of two time series of daily data on high and low waters at Venice and Chioggia. From comparisons with modern observations the quality of the 18th century data appears to be good enough to allow a useful analysis. A composite time series of daily mean sea level is obtained by merging the 18th century data and 1872–2004 observations at Venice Punta della Salute. The absence of reliable information on vertical references prevents the connection of the two 18th century time series with each other and with modern observations. However, daily sea level anomalies relative to the mean sea level enable to recognize storm surge events, that appear to occur more frequently in the second half of the 18th century than in the late 19th and 20th centuries, particularly during the 1751–1769 period. The record-breaking storm surge of 4 November 1966 turns out to be a remarkable event also in comparison with the events extracted from the 18th century time series. Further work is required to fill the gap between the old and modern observations.

Description: Ground-penetrating radar observations for estimating the vertical displacement of rotational landslides Natural Hazards and Earth System Sciences Discussions, 2, 7487-7506, 2014 Author(s): C. Lissak, O. Maquaire, J.-P. Malet, F. Lavigne, C. Virmoux, C. Gomez, and R. Davidson The objective of this paper is to demonstrate the applicability of Ground Penetrating Radar (GPR) for monitoring the displacement of slow-moving landslides. GPR data is used to estimate the vertical movement of rotational slides in combination with other surveying techniques. The experimental site is located along the Normandy coast (North East France) here several rotational landslides are continuously affected by a seasonal kinematic pattern (low displacement rates of 0.01 to 0.10 m yr −1 ) and periodically by major acceleration events (high displacement of 1.0 to 7.0 m per event).

Description: Global representation of tropical cyclone-induced ocean thermal changes using Argo data – Part 2: Estimating air–sea heat fluxes and ocean heat content changes Ocean Science Discussions, 11, 2907-2937, 2014 Author(s): L. Cheng, J. Zhu, and R. L. Sriver We use Argo temperature data to examine changes in ocean heat content (OHC) and air–sea heat fluxes induced by tropical cyclones (TC)s on a global scale. A footprint technique that analyzes the vertical structure of cross-track thermal responses along all storm tracks during the period 2004–2012 is utilized (see part I). We find that TCs are responsible for 1.87 PW (11.05 W m −2 when averaging over the global ocean basin) of heat transfer annually from the global ocean to the atmosphere during storm passage (0–3 days) on a global scale. Of this total, 1.05 ± 0.20 PW (4.80 ± 0.85 W m −2 ) is caused by Tropical storms/Tropical depressions (TS/TD) and 0.82 ± 0.21 PW (6.25 ± 1.5 W m −2 ) is caused by hurricanes. Our findings indicate that ocean heat loss by TCs may be a substantial missing piece of the global ocean heat budget. Net changes in OHC after storm passage is estimated by analyzing the temperature anomalies during wake recovery following storm events (4–20 days after storm passage) relative to pre-storm conditions. Results indicate the global ocean experiences a 0.75 ± 0.25 PW (5.98 ± 2.1W m −2 ) net heat gain annually for hurricanes. In contrast, under TS/TD conditions, ocean experiences 0.41 ± 0.21 PW (1.90 ± 0.96 W m −2 ) net ocean heat loss, suggesting the overall oceanic thermal response is particularly sensitive to the intensity of the event. The net ocean heat uptake caused by all storms is 0.34 PW.

Description: Author(s): M. A. Reshchikov, D. O. Demchenko, A. Usikov, H. Helava, and Yu. Makarov In high-purity GaN grown by hydride vapor phase epitaxy, the commonly observed yellow luminescence (YL) band gives way to a green luminescence (GL) band at high excitation intensity. We propose that the GL band with a maximum at 2.4 eV is caused by transitions of electrons from the conduction band t... [Phys. Rev. B 90, 235203] Published Fri Dec 12, 2014

Description: Author(s): M. N. Achasov et al. The process e + e - →nn̅ has been studied at the VEPP-2000 e + e - collider with the SND detector in the energy range from threshold up to 2 GeV. As a result of the experiment, the e + e - →nn̅ cross section and effective neutron form factor have been measured. [Phys. Rev. D 90, 112007] Published Fri Dec 12, 2014

Description: Author(s): S. Mohammad Moosavi Nejad and Mahboobe Balali We calculate the O (α s ) radiative corrections to the spin-dependent differential decay rates of the process t→b+W + . These are needed to study the angular distribution of the energy of hadrons produced in polarized top quark decays at next-to-leading order. In our previous work, we studied the angular... [Phys. Rev. D 90, 114017] Published Fri Dec 12, 2014

Description: Author(s): Rui Xu, Daowei He, Yuhan Zhang, Bing Wu, Fengyuan Liu, Lan Meng, Jun-Fang Liu, Qisheng Wu, Yi Shi, Jinlan Wang, Jia-Cai Nie, Xinran Wang, and Lin He Very recently, it was demonstrated that the carrier mobility of a molecular monolayer dioctylbenzothienobenzothiophene (C 8 -BTBT) on boron nitride can reach 10 cm 2 /Vs, the highest among the previously reported monolayer molecular field-effect transistors. Here we show that the high-quality single cry... [Phys. Rev. B 90, 224106] Published Fri Dec 12, 2014

Description: Author(s): C. Oswald et al. (Belle Collaboration) [Phys. Rev. D 90, 119901] Published Fri Dec 12, 2014

Description: Author(s): T. Appelquist, R. C. Brower, G. T. Fleming, J. Kiskis, M. F. Lin, E. T. Neil, J. C. Osborn, C. Rebbi, E. Rinaldi, D. Schaich, C. Schroeder, S. Syritsyn, G. Voronov, P. Vranas, E. Weinberg, and O. Witzel (Lattice Strong Dynamics (LSD) Collaboration) We study an SU(3) gauge theory with N f =8 degenerate flavors of light fermions in the fundamental representation. Using the domain wall fermion formulation, we investigate the light hadron spectrum, chiral condensate ⟨ψ̅ ψ⟩ and electroweak S parameter. We consider a range of light fermion mass... [Phys. Rev. D 90, 114502] Published Fri Dec 12, 2014

Description: Author(s): D. Hove, D. V. Fedorov, H. O. U. Fynbo, A. S. Jensen, K. Riisager, N. T. Zinner, and E. Garrido Borromean nuclear cluster structures are expected at the corresponding drip lines. We locate the regions in the nuclear chart with the most promising constituents, it being protons and α particles and investigate in details the properties of the possible Borromean two-α systems in medium-heavy nucle... [Phys. Rev. C 90, 064311] Published Fri Dec 12, 2014

Description: Author(s): P. Doornenbal et al. The reduced transition probability B(E2)↑ of the first excited 2 + state in the nucleus 104 Sn was measured via Coulomb excitation in inverse kinematics at intermediate energies. A value of 0.173(28) e 2 b 2 was extracted from the absolute cross section on a Pb target. Feeding contributions in 104 Sn from... [Phys. Rev. C 90, 061302] Published Fri Dec 12, 2014

Description: Author(s): A. Göök, F.-J. Hambsch, and M. Vidali The spontaneous fission of 252 Cf serves as an excellent benchmark of prompt emission in fission since experimental data can be obtained without the need of an incident beam. With the purpose of providing experimental data on the prompt fission neutron properties in correlation with fission-fragment ... [Phys. Rev. C 90, 064611] Published Fri Dec 12, 2014

Description: Author(s): Orest Hrycyna, Marek Szydłowski, and Michał Kamionka We investigate observational constraints on the Brans-Dicke cosmological model using observational data coming from distant supernovae type Ia, the Hubble function H(z) measurements, information coming from the Alcock-Paczyński test, and baryon acoustic oscillations. Our analysis is based on the mod... [Phys. Rev. D 90, 124040] Published Fri Dec 12, 2014

Description: Author(s): V. Barger, Lingjun Fu, J. G. Learned, D. Marfatia, S. Pakvasa, and T. J. Weiler The Glashow resonance at E ν =6.3  PeV is a measure of the ν̅ e content of the astrophysical neutrino flux. The fractional ν̅ e content depends on the neutrino production model at the cosmic neutrino source, and the environment at the source. Thus, the strength of the Glashow resonance e... [Phys. Rev. D 90, 121301] Published Fri Dec 12, 2014

Description: Author(s): Atsushi Taruya, Takahiro Nishimichi, Francis Bernardeau, Takashi Hiramatsu, and Kazuya Koyama Based on the multipoint propagator expansion, we present resummed perturbative calculations for cosmological power spectra and correlation functions in the context of modified gravity. In a wide class of modified gravity models that have a screening mechanism to recover general relativity (GR) on sm... [Phys. Rev. D 90, 123515] Published Fri Dec 12, 2014

Description: Author(s): Victor T. Kim and Grigorii B. Pivovarov A new approach to computing the amplitudes of multiparticle processes in renormalizable quantum field theories is presented. Its major feature is a separation of the renormalization from the computation. Within the suggested approach, new computational rules are formulated. According to the new rule... [Phys. Rev. D 90, 125009] Published Fri Dec 12, 2014

Description: Author(s): H. Berrehrah, P. B. Gossiaux, J. Aichelin, W. Cassing, and E. Bratkovskaya In this study we evaluate the dynamical collisional energy loss of heavy quarks, their interaction rate, as well as the different transport coefficients (drag and diffusion coefficients, q̂, etc). We calculate these different quantities for (i) perturbative partons (on-shell particles in the vacuum ... [Phys. Rev. C 90, 064906] Published Fri Dec 12, 2014

Description: Author(s): H. Ness We suggest a generalization of the expression of the nonequilibrium (NE) density matrix obtained by Hershfield's method for the cases where both heat and charge steady-state currents are present in a quantum open system. The finite-size quantum system, connected to two temperature and particle reser... [Phys. Rev. E 90, 062119] Published Fri Dec 12, 2014

Description: Author(s): N. Panza, H. Rodrigues, D. Cocuroci, and J. A. Helayël-Neto In this paper, we analyze a curvature- and torsion-square quantum gravity action with an additional Holst term minimally coupled to a massive Dirac field in four dimensions. The main purpose here is to try to estimate and compare the value of the Barbero-Immirzi parameter with its currently known re... [Phys. Rev. D 90, 125007] Published Fri Dec 12, 2014

Description: Author(s): Moupriya Das The states of an overdamped Brownian particle confined in a two-dimensional bilobal enclosure are considered to correspond to two binary values: 0 (left lobe) and 1 (right lobe). An ensemble of such particles represents bits of entropic information. An external bias is applied on the particles, equa... [Phys. Rev. E 90, 062120] Published Fri Dec 12, 2014

Description: Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer Atmospheric Measurement Techniques, 7, 4445-4453, 2014 Author(s): B. Xiang, D. D. Nelson, J. B. McManus, M. S. Zahniser, R. A. Wehr, and S. C. Wofsy We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO 2 ) with high precision (0.02 μmol mol −1 , or ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell with known CO 2 column density. Compared to a previously described prototype, the field instrument has better stability and benefits from more precise thermal control of the optics and more accurate pressure measurements in the sample cell (at the mTorr level). The instrument has been deployed at a long-term ecological research site (the Harvard Forest, USA), where it has measured for 8 months without on-site calibration and with minimal maintenance, showing drift bounds of less than 0.1 ppm. Field measurements agree well with those of a commercially available cavity ring-down CO 2 instrument (Picarro G2301) run with a standard calibration protocol. This field test demonstrates that ABC is capable of performing high-accuracy, unattended, continuous field measurements with minimal use of reference gas cylinders.

Description: Meteorological factors controlling low-level continental pollutant outflow across a coast Atmospheric Chemistry and Physics, 14, 13295-13312, 2014 Author(s): D. L. Peake, H. F. Dacre, J. Methven, and O. Coceal Coastal outflow describes the horizontal advection of pollutants from the continental boundary layer (BL) across a coastline. The outflow can ventilate polluted continental BLs and thus regulate air quality in highly populated coastal regions. This paper investigates the factors controlling coastal outflow and quantifies their importance as a ventilation mechanism. Tracers in the Met Office Unified Model (MetUM) are used to examine the magnitude and variability of coastal outflow over the eastern United States during summer 2004. Over the 4 week period examined, ventilation of tracer from the continental BL via coastal outflow occurs with the same magnitude as vertical ventilation via convection and advection. The relative importance of tracer decay rate, cross-coastal advection rate, and a parameter based on the relative continental and marine BL heights on coastal outflow is assessed by reducing the problem to a time-dependent box model. The ratio of the advection rate and decay rate is a dimensionless parameter which determines whether tracers are long-lived or short-lived. Long- and short-lived tracers exhibit different behaviours with respect to coastal outflow. Short-lived tracers exhibit large diurnal variability in coastal outflow but long-lived tracers do not. For short-lived tracers, increasing the advection rate increases the diurnally averaged magnitude of coastal outflow, but this has the opposite effect for very long-lived tracers. By using the box-model solutions to interpret the MetUM simulations, a land width is determined which represents the distance inland over which emissions contribute significantly to coastal outflow. A land width of between 100 and 400 km is found to be representative for a tracer with a lifetime of 24 h.

Description: Continental Portuguese Territory Flood Susceptibility Index – contribution for a vulnerability index Natural Hazards and Earth System Sciences Discussions, 2, 7521-7552, 2014 Author(s): R. Jacinto, N. Grosso, E. Reis, L. Dias, F. D. Santos, and P. Garrett This work defines a national flood susceptibility index for the Portuguese continental territory, by proposing the aggregation of different variables which represent natural conditions for permeability, runoff and accumulation. This index is part of the national vulnerability index developed in the scope of Flood Maps in Climate Change Scenarios (CIRAC) project, supported by the Portuguese Association of Insurers (APS). This approach expands on previous works by trying to bridge the gap between different floods mechanisms (e.g. progressive and flash floods) occurring at different spatial scales in the Portuguese territory through: (a) selecting homogeneously processed datasets, (b) aggregating their values to better translate the spatially continuous and cumulative influence in floods at multiple spatial scales. Results show a good ability to capture, in the higher susceptibility classes, different flood types: progressive floods and flash floods. Lower values are usually related to: mountainous areas, low water accumulation potential and more permeable soils. Validation with independent flood datasets confirmed these index characteristics, although some overestimation can be seen in the southern region of Alentejo where, due to a dense hydrographic network and an overall low slope, floods are not as frequent as a result of lower precipitation mean values. Future work will focus on: (i) including extreme precipitation datasets to represent the triggering factor, (ii) improving representation of smaller and stepper basins, (iii) optimizing variable weight definition process, (iii) developing more robust independent flood validation datasets.

Description: Author(s): James Schneeloch, Curtis J. Broadbent, and John C. Howell We postulate the existence of a universal uncertainty relation between the quantum and classical mutual informations between pairs of quantum systems. Specifically, we propose that the sum of the classical mutual information, determined by two mutually unbiased pairs of observables, never exceeds th... [Phys. Rev. A 90, 062119] Published Mon Dec 15, 2014

Description: Author(s): L. Gulyás, S. Egri, and T. Kirchner We study the process of single ionization of Li in collisions with H + and O 8+ projectile ions at 6-MeV and 1.5-MeV/amu impact energies, respectively. Using the frameworks of the independent-electron model and the impact parameter picture, fully (FDCS) and doubly (DDCS) differential cross sections ar... [Phys. Rev. A 90, 062710] Published Mon Dec 15, 2014

Description: Author(s): Fam Le Kien and A. Rauschenbeutel We study the propagation of nanofiber-guided light through an array of atomic cesium, taking into account the transitions between the hyperfine levels 6S 1/2 F=4 and 6P 3/2 F ′ =5 of the D 2 line. We derive the coupled-mode propagation equation, the input-output equation, the scattering matrix, the transfe... [Phys. Rev. A 90, 063816] Published Mon Dec 15, 2014

Description: Author(s): Yachin Ivry, Chung-Soo Kim, Andrew E. Dane, Domenico De Fazio, Adam N. McCaughan, Kristen A. Sunter, Qingyuan Zhao, and Karl K. Berggren Thin superconducting films form a unique platform for geometrically confined, strongly interacting electrons. They allow an inherent competition between disorder and superconductivity, which in turn enables the intriguing superconducting-to-insulating transition and is believed to facilitate the com... [Phys. Rev. B 90, 214515] Published Mon Dec 15, 2014

Description: Simple, affordable and sustainable borehole observatories for complex monitoring objectives Geoscientific Instrumentation, Methods and Data Systems Discussions, 4, 653-681, 2014 Author(s): A. Kopf, T. Freudenthal, V. Ratmeyer, M. Bergenthal, M. Lange, T. Fleischmann, S. Hammerschmidt, C. Seiter, and G. Wefer Seafloor drill rigs are remotely operated systems that provide a cost effective means to recover sedimentary records of the upper sub-seafloor deposits. Recent increases in their payload included downhole logging tools or autoclave coring systems. We here report on another milestone in using seafloor rigs: the development and installation of shallow borehole observatories. Three different systems have been developed for the MARUM-MeBo seafloor drill, which is operated by MARUM, University of Bremen, Germany. A simple design, the MeBoPLUG, separates the inner borehole from the overlying ocean by using o-ring seals at the conical threads of the drill pipe. The systems are self-contained and include data loggers, batteries, thermistors and a differential pressure sensor. A second design, the so-called MeBoCORK, is more sophisticated and also hosts an acoustic modem for data transfer and, if desired, fluid sampling capability using osmotic pumps. Of these MeBoCORKs, two systems have to be distinguished: the CORK-A (A = autonomous) can be installed by the MeBo alone and monitors pressure and temperature inside and above the borehole (the latter for reference). The CORK-B (B = bottom) has a higher payload and can additionally be equipped with geochemical, biological or other physical components. Owing to its larger size, it is installed by ROV and utilises a hotstab connection in the upper portion of the drill string. Either design relies on a hotstab connection from beneath which coiled tubing with a conical drop weight is lowered to couple to the formation. These tubes are fluid-saturated and either serve to transmit pore pressure signals or collect pore water in the osmo-sampler. The third design, the MeBoPUPPI ( P op- U p P ore P ressure I nstrument), is similar to the MeBoCORK-A and monitors pore pressure and temperature in a self-contained manner. Instead of transferring data upon command using an acoustic modem, the MeBoPUPPI contains a pop-up telemetry with Iridium link. After a predefined period, the data unit with satellite link is released, ascends to the sea surface, and remains there for up to two weeks while sending the long-term data sets to shore. In summer 2012, two MeBoPLUGs, one MeBoCORK-A and one MeBoCORK-B were installed with MeBo on German RV Sonne in the Nankai Trough area, Japan. We have successfully downloaded data from the CORKs, attesting that coupling to the formation worked and pressure records were elevated relative to the seafloor reference. In the near future, we will further deploy the first two MeBoPUPPIs. Recovery of all monitoring systems by ROV is planned for 2016.

Description: Dye tracing for investigating flow and transport properties of hydrocarbon-polluted Rabots glaciär, Kebnekaise, Sweden Hydrology and Earth System Sciences Discussions, 11, 13711-13744, 2014 Author(s): C. C. Clason, C. Coch, J. Jarsjö, K. Brugger, P. Jansson, and G. Rosqvist Over 11 000 L of hydrocarbon pollution was deposited on the surface of Rabots glaciär on the Kebnekaise Massif, northern Sweden, following the crash of a Royal Norwegian Air Force aircraft in March 2012. An environmental monitoring programme was subsequently commissioned, including water, snow and ice sampling. The scientific programme further included a series of dye tracing experiments during the 2013 melt season, conducted to investigate flow pathways for pollutants through the glacier hydrological system, and to gain new insight to the internal hydrological system of Rabots glaciär. Results of dye tracing reveal a degree of homogeneity in the topology of the drainage system throughout July and August, with an increase in efficiency as the season progresses, as reflected by decreasing temporary storage and dispersivity. Early onset of melting likely led to formation of an efficient, discrete drainage system early in the melt season, subject to decreasing sinuosity and braiding as the season progressed. Analysis of turbidity-discharge hysteresis further supports the formation of discrete, efficient drainage, with clockwise diurnal hysteresis suggesting easy mobilisation of readily-available sediments in channels. Dye injection immediately downstream of the pollution source zone revealed prolonged storage of dye followed by fast, efficient release. Twinned with a low dye recovery, and supported by sporadic detection of hydrocarbons in the proglacial river, we suggest that meltwater, and thus pollutants in solution, may be released periodically from this zone of the glacier hydrological system. The here identified dynamics of dye storage, dispersion and breakthrough indicate that the ultimate fate and permanence of pollutants in the glacier system is likely to be governed by storage of pollutants in the firn layer and ice mass, or within the internal hydrological system, where it may refreeze. This shows that future studies on the fate of hydrocarbons in pristine, glaciated mountain environments should address the extent to which pollutants in solution act like water molecules or whether they are more susceptible to, for example, refreezing into the surrounding ice, becoming stuck in micro-fractures and pore spaces, or sorption onto subglacial sediments.

Description: Author(s): T. J. Davis and D. E. Gómez A complete theoretical methodology of the interactions between chiral molecules and the evanescent fields of localized surface plasmons generated in a metallic nanostructure of arbitrary shape. The calculations confirm various previous results on the enhancement of the absorption of light and subsequent circular dichroism by surface plasmons. They also predict a chirality-dependent absorption arising from the metallic nanostructure illuminated with linearly polarized light. [Phys. Rev. B 90, 235424] Published Mon Dec 15, 2014

Description: Author(s): Tobias Meng and Eran Sela We extend the coupled-wire construction of quantum Hall phases, and search for fractional topological insulating states in models of weakly coupled wires at zero external magnetic field. Focusing on systems beyond double copies of fractional quantum Hall states at opposite fields, we find that spin-... [Phys. Rev. B 90, 235425] Published Mon Dec 15, 2014

Description: Author(s): Carmine Ortix, Carlo Di Castro, and José Lorenzana We show that in layered systems with electronic phase separation tendency, the long-range Coulomb interaction can drive the spontaneous formation of unidirectional superlattices of electronic charge in a completely homogeneous crystalline background. In this self-organized electronic heterostructure... [Phys. Rev. B 90, 241110] Published Mon Dec 15, 2014

Description: Author(s): Jonathan D. Mar, Jeremy J. Baumberg, Xiulai Xu, Andrew C. Irvine, and David A. Williams We demonstrate the initialization of a single quantum-dot hole spin with high fidelity (lower bound 〉97%), on picosecond time scales, and without the need for magnetic fields. Using the initialization scheme based on rapid electric-field ionization of a resonantly excited exciton, this is achieve... [Phys. Rev. B 90, 241303] Published Mon Dec 15, 2014

Description: Author(s): Pranay Patil, Ishita Dasgupta, and Kedar Damle We study bond and spin correlations of the nearest-neighbor resonating valence bond (RVB) wave function for a SU(2) symmetric S=1/2 antiferromagnet on the honeycomb lattice. We find that spin correlations in this wave function are short ranged, while the bond energy correlation function takes on an ... [Phys. Rev. B 90, 245121] Published Mon Dec 15, 2014

Description: Author(s): J. H. Pixley, Aditya Shashi, and Andriy H. Nevidomskyy The antiferromagnetic spin-1 chain has a venerable history and has been thought to be well understood. Here, we show that inclusion of both next-nearest-neighbor (α) and biquadratic (β) interactions results in a rich phase diagram with a multicritical point that has not been observed before. We stud... [Phys. Rev. B 90, 214426] Published Mon Dec 15, 2014

Description: Author(s): Andrea Di Cicco, Keisuke Hatada, Erika Giangrisostomi, Roberto Gunnella, Filippo Bencivenga, Emiliano Principi, Claudio Masciovecchio, and Adriano Filipponi High intensity pulses obtained by modern extreme ultraviolet (EUV) and x-ray photon sources allows the observation of peculiar phenomena in condensed matter. Experiments performed at the Fermi@Elettra FEL-1 free-electron-laser source at 23.7, 33.5, and 37.5 eV on Al thin films, for an intermediate-f... [Phys. Rev. B 90, 220303] Published Mon Dec 15, 2014

Description: Author(s): Eliot Gann, Anne Watson, John R. Tumbleston, Justin Cochran, Hongping Yan, Cheng Wang, Jaewook Seok, Michael Chabinyc, and Harald Ade The internal structures of thin films, particularly interfaces between different materials, are critical to system properties and performance across many disciplines, but characterization of buried interface topography is often unfeasible. In this work, we demonstrate that grazing resonant soft x-ra... [Phys. Rev. B 90, 245421] Published Mon Dec 15, 2014

Description: Author(s): P. N. Fountas, G. A. Souliotis, M. Veselsky, and A. Bonasera Detailed calculations of the yields of projectilelike fragments (with focus on the neutron-rich isotopes) are presented for the interaction of 86 Kr (15 MeV/nucleon) with 64 Ni, 58 Ni, and 124 Sn, 112 Sn, as well as 86 Kr (25 MeV/nucleon) with 124 Sn and compared with our recently published experimental da... [Phys. Rev. C 90, 064613] Published Mon Dec 15, 2014

Description: Author(s): G. A. Souliotis, P. N. Fountas, M. Veselsky, S. Galanopoulos, Z. Kohley, A. McIntosh, S. J. Yennello, and A. Bonasera The isoscaling of heavy projectile residues from peripheral heavy-ion reactions at 15–25 MeV/nucleon is employed to obtain information on the process of N/Z equilibration. Recent mass spectrometric data of projectile residues from the reactions of 86 Kr (15 MeV/nucleon) with 64,58 Ni and 124,112 Sn wer... [Phys. Rev. C 90, 064612] Published Mon Dec 15, 2014

Description: Author(s): Thomas Elghozi, William Nelson, and Mairi Sakellariadou We study the occurrence of cuspy events on a light string stretched between two Y-junctions with fixed heavy strings. We first present an analytic study and give a solid criterion to discriminate between cuspy and noncuspy string configurations. We then describe a numerical code, built to test this ... [Phys. Rev. D 90, 123517] Published Mon Dec 15, 2014

Description: Author(s): Kazuyuki Sekizawa and Kazuhiro Yabana Background: The time-dependent Hartree-Fock (TDHF) theory has been successful in describing low-energy heavy ion collisions. Recently, we have shown that multinucleon transfer processes can be reasonably described in the TDHF theory combined with the particle-number projection technique. [Phys. Rev. C 90, 064614] Published Mon Dec 15, 2014

Description: Author(s): Sylvain Joubaud, Tess Homan, Y. Gasteuil, Detlef Lohse, and Devaraj van der Meer We describe direct measurements of the acceleration of an object impacting on a loosely packed granular bed under various pressures, using an instrumented sphere. The sphere acts as a noninvasive probe that measures and continuously transmits the acceleration as it penetrates into the sand, using a ... [Phys. Rev. E 90, 060201] Published Mon Dec 15, 2014

Description: Author(s): M. Borówko and W. Rżysko The phase behavior of Janus disks on a square lattice is studied using the Monte Carlo method. A particle is composed of two different parts, A and B. The interactions between neighboring particles depend on their orientations. To control the strength of the interactions, we use energy parameters ch... [Phys. Rev. E 90, 062308] Published Mon Dec 15, 2014

Description: Author(s): T. P. Bennett, G. D'Alessandro, and K. R. Daly We use homogenization theory to develop a multiscale model of colloidal dispersion of particles in nematic liquid crystals under weak-anchoring conditions. We validate the model by comparing it with simulations by using the Landau–de Gennes free energy and show that the agreement is excellent. We th... [Phys. Rev. E 90, 062505] Published Mon Dec 15, 2014

Description: Author(s): Chanyong Park, Do-Young Gwak, Bum-Hoon Lee, Yumi Ko, and Sunyoung Shin [Phys. Rev. D 90, 129902] Published Mon Dec 15, 2014

Description: Author(s): Matthias Punk We develop a method for multidimensional optimization using flow equations. This method is based on homotopy continuation in combination with a maximum entropy approach. Extrema of the optimizing functional correspond to fixed points of the flow equation. While ideas based on Bayesian inference such... [Phys. Rev. E 90, 063307] Published Mon Dec 15, 2014

Description: Author(s): Christopher J. Moore and Jonathan R. Gair Posterior distributions on parameters computed from experimental data using Bayesian techniques are only as accurate as the models used to construct them. In many applications, these models are incomplete, which both reduces the prospects of detection and leads to a systematic error in the parameter... [Phys. Rev. Lett. 113, 251101] Published Mon Dec 15, 2014

Description: Author(s): A. Boyarsky, O. Ruchayskiy, D. Iakubovskyi, and J. Franse An x-ray feature recently detected by different astronomy groups may be the long-awaited signature of dark matter. [Phys. Rev. Lett. 113, 251301] Published Mon Dec 15, 2014

Description: Author(s): Marco Baggio, Vasilis Niarchos, and Kyriakos Papadodimas We report an exact solution of 2- and 3-point functions of chiral primary fields in SU(2) N =2 super-Yang-Mills theory coupled to four hypermultiplets. It is shown that these correlation functions are nontrivial functions of the gauge coupling, obeying differential equations which take the form of th... [Phys. Rev. Lett. 113, 251601] Published Mon Dec 15, 2014

Description: Author(s): Sumesh P. Thampi, Ramin Golestanian, and Julia M. Yeomans Active turbulence in dense active systems is characterized by high vorticity on a length scale that is large compared to that of individual entities. We describe the properties of active turbulence as momentum propagation is screened by frictional damping. As friction is increased, the spacing betwe... [Phys. Rev. E 90, 062307] Published Mon Dec 15, 2014

Description: Author(s): J. Upadhyay, Do Im, S. Popović, A.-M. Valente-Feliciano, L. Phillips, and L. Vušković Plasma-based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. We have demonstrated surface layer removal in an asymmetric nonplanar geometry, using a simple cylindrical cavity. The etching rate is highly correlated with the ... [Phys. Rev. ST Accel. Beams 17, 122001] Published Mon Dec 15, 2014

Description: Author(s): Zehui Deng, Jinshan Wu, and Wenan Guo The n-index Rényi mutual information and transfer entropies for the two-dimensional kinetic Ising model with arbitrary single-spin dynamics in the thermodynamic limit are derived as functions of ensemble averages of observables and spin-flip probabilities. Cluster Monte Carlo algorithms with differe... [Phys. Rev. E 90, 063308] Published Mon Dec 15, 2014

Description: Author(s): Y. Xu, J. T. Padding, and J. A. M. Kuipers The plunging of a large intruder sphere into a prefluidized granular bed with various constant velocities and various sphere diameters is investigated using a state-of-the-art hybrid discrete particle and immersed boundary method, in which both the gas-induced drag force and the contact force exerte... [Phys. Rev. E 90, 062203] Published Mon Dec 15, 2014

Description: Author(s): Adam Bzdak and Guo-Liang Ma Using a multiphase transport model (AMPT) we calculate the elliptic v 2 and triangular v 3 Fourier coefficients of the two-particle azimuthal correlation function in proton-nucleus (p-Pb) and peripheral nucleus-nucleus (Pb-Pb) collisions. Our results for v 3 are in a good agreement with the CMS data co... [Phys. Rev. Lett. 113, 252301] Published Mon Dec 15, 2014

Description: Air temperature variability over three glaciers in the Ortles-Cevedale (Italian Alps): effects of glacier disintegration, intercomparison of calculation methods, and impacts on mass balance modeling The Cryosphere Discussions, 8, 6147-6192, 2014 Author(s): L. Carturan, F. Cazorzi, F. De Blasi, and G. Dalla Fontana Glacier mass balance models rely on accurate spatial calculation of input data, in particular air temperature. Lower temperatures (the so-called glacier cooling effect), and lower temperature variability (the so-called glacier damping effect) generally occur over glaciers, compared to ambient conditions. These effects, which depend on the geometric characteristics of glaciers and display a high spatial and temporal variability, have been mostly investigated on medium- to large-size glaciers so far, while observations on smaller ice bodies are scarce. Using a dataset from 8 on-glacier and 4 off-glacier weather stations, collected in summer 2010 and 2011, we analyzed the air temperature variability and wind regime over three different glaciers in the Ortles-Cevedale. The magnitude of the cooling effect and the occurrence of katabatic boundary layer (KBL) processes showed remarkable differences among the three ice bodies, suggesting the likely existence of important reinforcing mechanisms during glacier decay and disintegration. None of the methods proposed in the literature for calculating on-glacier temperature from off-glacier data fully reproduced our observations. Among them, the more physically-based procedure of Greuell and Böhm (1998) provided the best overall results where the KBL prevail, but it was not effective elsewhere (i.e. on smaller ice bodies and close to the glacier margins). The accuracy of air temperature estimations strongly impacted the results from a mass balance model which was applied to the three investigated glaciers. Most importantly, even small temperature deviations caused distortions in parameter calibration, thus compromising the model generalizability.

Description: Mesoscale modeling study of the interactions between aerosols and PBL meteorology during a haze episode in China Jing–Jin–Ji and its near surrounding region – Part 1: Aerosol distributions and meteorological features Atmospheric Chemistry and Physics Discussions, 14, 31675-31717, 2014 Author(s): H. Wang, M. Xue, X. Y. Zhang, H. L. Liu, C. H. Zhou, S. C. Tan, H. Z. Che, B. Chen, and T. Li The urbanized region of Beijing–Tianjin–Hebei – often shortened to Jing–Jin–Ji and referred to as the 3JNS region in this paper – and its near surrounding region is becoming China's most polluted area by haze, exceeding even the Yangtze and Pearl river deltas. Aside from pollutant emission, the meteorology of the planetary boundary layer (PBL) is the most important factor affecting haze pollution. Focusing on July 2008, the aerosol optical properties and PBL meteorology features closely related with haze formation were simulated in 3JNS region using an online atmospheric chemical transport model. The relationship between regional PBL meteorology, PM 2.5 , and haze is discussed. Model results accurately simulated the aerosol optical depth (AOD), single scattering albedo (SSA) and asymmetry parameter (ASY), validate by comparison with observations from the MODerate Resolution Imaging Spectroradiometer (MODIS), the China Aerosol Remote Sensing NETwork (CARSNET) and the Aerosol Robotic NETwork (AERONET). Modeled PBL wind speeds showed reasonable agreement with those from the National Centers for Environmental Prediction (NCEP) Reanalysis 2. A monthly mean AOD value as high as 1.2 was found from both model and observations, with a daily mean larger than 2.0 during haze episodes in the 3JNS Region. Modeled and observed SSA values of 0.9–0.96 and ASY values of 0.72–0.74 demonstrated the high scattering characteristic of summer aerosols in this region. PBL wind speeds from modeled and NCEP data both showed a reversing trend of PM 2.5 variation, illustrating the importance of the "PBL window shadow" on haze formation. Turbulence diffusion and PBL height showed had opposite phases to surface PM 2.5 , indicating that lower PBL height and weaker PBL turbulence diffusion are essential to haze formation. It is noted that homogeneous air pressure does not occur at the surface but at an 85–950 hPa height during the haze episode. The momentum transmitting downward of the cold air from above the PBL to the low PBL and surface lead to an increase in surface wind speeds and haze dispersal.

Description: Impact of seawater Ca 2+ on the calcification and calcite Mg/Ca of Amphistegina lessonii Biogeosciences Discussions, 11, 17463-17489, 2014 Author(s): A. Mewes, G. Langer, S. Thoms, G. Nehrke, G.-J. Reichart, L. J. de Nooijer, and J. Bijma Mg/Ca ratios in foraminiferal tests are routinely used as paleo temperature proxy, but on long timescales, also hold the potential to reconstruct past seawater Mg/Ca. Impact of both temperature and seawater Mg/Ca on Mg incorporation in foraminifera have been quantified by a number of studies. The underlying mechanism responsible for Mg incorporation in foraminiferal calcite and its sensitivity to environmental conditions, however, is not fully identified. A recently published biomineralization model (Nehrke et al., 2013) proposes a combination of transmembrane transport and seawater leakage or vacuolization to link calcite Mg/Ca to seawater Mg/Ca and explains inter-species variability in Mg/Ca ratios. To test the assumptions of this model, we conducted a culture study in which seawater Mg/Ca was manipulated by varying [Ca 2+ ] and keeping [Mg 2+ ] constant. Foraminiferal growth rates, test thickness and calcite Mg/Ca of newly formed chambers were analyzed. Results showed optimum growth rates and test thickness at Mg/Ca closest to that of ambient seawater. Calcite Mg/Ca is positively correlated to seawater Mg/Ca, indicating that not absolute seawater [Ca 2+ ] and [Mg 2+ ], but the telative ratio controls Mg/Ca in tests. These results demonstrate that the calcification process cannot be based only on seawater vacuolization, supporting the mixing model proposed by Nehrke et al. (2013). Here we, however, suggest a transmembrane transport fractionation that is not as strong as suggested by Nehrke et al. (2013).

Description: Author(s): Yun-He Li, Jing-Fei Zhang, and Xin Zhang Dark energy can modify the dynamics of dark matter if there exists a direct interaction between them. Thus, a measurement of the structure growth, e.g., redshift-space distortions (RSDs), can provide a powerful tool to constrain the interacting dark energy (IDE) models. For the widely studied Q=3βHρ ... [Phys. Rev. D 90, 123007] Published Tue Dec 16, 2014

Description: Author(s): Mariam Bouhmadi-López, Che-Yu Chen, and Pisin Chen The Born-Infeld determinantal gravity has been recently proposed as a way to smooth the big bang singularity. This theory is formulated on the Weitzenböck space-time and the teleparallel representation is used instead of the standard Riemannian representation. We find that although this theory is sh... [Phys. Rev. D 90, 123518] Published Tue Dec 16, 2014

Description: Author(s): Xiao-Min Zhang and Jian-Yang Zhu We extend the warm inflationary scenario to the case of the noncanonical scalar fields. The equation of motion and the other basic equations of this new scenario are obtained. The Hubble damped term is enhanced in noncanonical inflation. A linear stability analysis is performed to give the proper sl... [Phys. Rev. D 90, 123519] Published Tue Dec 16, 2014

Description: Author(s): Alex Dahlen and Claire Zukowski The simplest flux compactifications are highly symmetric—a q-form flux is wrapped uniformly around an extra-dimensional q-sphere. In this paper, we investigate solutions that break the internal SO(q+1) symmetry down to SO(q)× Z 2 ; we find a large number of such lumpy solutions, and show that often at ... [Phys. Rev. D 90, 125013] Published Tue Dec 16, 2014