ALBERT

Description: Author(s): Franz M. Weinert, Robert C. Brewster, Mattias Rydenfelt, Rob Phillips, and Willem K. Kegel The proteins associated with gene regulation are often shared between multiple pathways simultaneously. By way of contrast, models in regulatory biology often assume these pathways act independently. We demonstrate a framework for calculating the change in gene expression for the interacting case by... [Phys. Rev. Lett. 113, 258101] Published Tue Dec 16, 2014

Description: Author(s): Yaxing Zhang, J. Moser, J. Güttinger, A. Bachtold, and M. I. Dykman We study the spectral effect of the fluctuations of the vibration frequency. Such fluctuations play a major role in nanomechanical and other mesoscopic vibrational systems. We find that, for periodically driven systems, the interplay of the driving and frequency fluctuations results in specific spec... [Phys. Rev. Lett. 113, 255502] Published Tue Dec 16, 2014

Description: Author(s): Andreas Moor, Anatoly F. Volkov, and Konstantin B. Efetov On the basis of coupled Ginzburg-Landau equations we study nonhomogeneous states in systems with two order parameters (OPs). Superconductors with a superconducting OP Δ and a charge- or spin-density wave with amplitude W are examples of such systems. When one OP, say Δ, has a form of a topological d... [Phys. Rev. B 90, 224512] Published Tue Dec 16, 2014

Description: Author(s): Luis Seabra, Fabian H. L. Essler, Frank Pollmann, Imke Schneider, and Thomas Veness We consider single-particle properties in the one-dimensional repulsive Hubbard model at commensurate fillings in the metallic phase. We determine the real-time evolution of the retarded Green's function by matrix-product state methods. We find that at sufficiently late times the numerical results a... [Phys. Rev. B 90, 245127] Published Tue Dec 16, 2014

Description: Author(s): D. S. Delion, R. J. Liotta, Chong Qi, and R. Wyss We analyze the α-decay fine structure to excited 0 2 + states in Hg and Rn isotopes. These states are described as minima in the potential energy surface (PES) provided by the standard deformed Woods-Saxon plus pairing approach. We also investigate α decay from the excited state P(0 2 + ) in the parent n... [Phys. Rev. C 90, 061303] Published Tue Dec 16, 2014

Description: Author(s): S. D. Yang et al. (Belle Collaboration) Using data samples of 102×10 6 ϒ(1S) and 158×10 6 ϒ(2S) events collected with the Belle detector, a first experimental search has been made for double-charmonium production in the exclusive decays ϒ(1S,2S)→J/ψ(ψ ′ )+X, where X=η c , χ cJ (J=0,1,2), η c (2S), X(3940), and X(4160). No significant signal is obse... [Phys. Rev. D 90, 112008] Published Tue Dec 16, 2014

Description: Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation Climate of the Past, 10, 2215-2236, 2014 Author(s): H. Kuehn, L. Lembke-Jene, R. Gersonde, O. Esper, F. Lamy, H. Arz, G. Kuhn, and R. Tiedemann During the last glacial termination, the upper North Pacific Ocean underwent dramatic and rapid changes in oxygenation that lead to the transient intensification of oxygen minimum zones (OMZs), recorded by the widespread occurrence of laminated sediments on circum-Pacific continental margins. We present a new laminated sediment record from the mid-depth (1100 m) northern Bering Sea margin that provides insight into these deglacial OMZ maxima with exceptional, decadal-scale detail. Combined ultrahigh-resolution micro-X-ray-fluorescence (micro-XRF) data and sediment facies analysis of laminae reveal an alternation between predominantly terrigenous and diatom-dominated opal sedimentation. The diatomaceous laminae are interpreted to represent spring/summer productivity events related to the retreating sea ice margin. We identified five laminated sections in the deglacial part of our site. Lamina counts were carried out on these sections and correlated with the Bølling–Allerød and Preboreal phases in the North Greenland Ice Core (NGRIP) oxygen isotope record, indicating an annual deposition of individual lamina couplets (varves). The observed rapid decadal intensifications of anoxia, in particular within the Bølling–Allerød, are tightly coupled to short-term warm events through increases in regional export production. This dependence of laminae formation on warmer temperatures is underlined by a correlation with published Bering Sea sea surface temperature records and δ 18 O data of planktic foraminifera from the Gulf of Alaska. The rapidity of the observed changes strongly implies a close atmospheric teleconnection between North Pacific and North Atlantic regions. We suggest that concomitant increases in export production and subsequent remineralization of organic matter in the Bering Sea, in combination with oxygen-poor waters entering the Being Sea, drove down oxygen concentrations to values below 0.1 mL L −1 and caused laminae preservation. Calculated benthic–planktic ventilation ages show no significant variations throughout the last deglaciation, indicating that changes in formation rates or differing sources of North Pacific mid-depth waters are not prime candidates for strengthening the OMZ at our site. The age models established by our correlation procedure allow for the determination of calendar age control points for the Bølling–Allerød and the Preboreal that are independent of the initial radiocarbon-based chronology. Resulting surface reservoir ages range within 730–990 yr during the Bølling–Allerød, 800–1100 yr in the Younger Dryas, and 765–775 yr for the Preboreal.

Description: Author(s): Carolyn Auchter, Thomas W. Noel, Matthew R. Hoffman, Spencer R. Williams, and Boris B. Blinov We present a measurement of the branching fractions for decay from the long-lived 5D 5/2 level in 138 Ba + . The branching fraction for decay into the 6S 1/2 ground state was found to be 0.846(25) stat (4) sys . We also report an improved measurement of the 5D 5/2 lifetime, τ 5D 5/2 =31.2(0.9) s. Together these ... [Phys. Rev. A 90, 060501] Published Wed Dec 17, 2014

Description: Author(s): Kohtaro Kato, Fabian Furrer, and Mio Murao Anyonic systems are modeled by topologically protected Hilbert spaces which obey complex superselection rules restricting possible operations. These Hilbert spaces cannot be decomposed into tensor products of spatially localized subsystems, whereas the tensor product structure is a foundation of the... [Phys. Rev. A 90, 062325] Published Wed Dec 17, 2014

Description: Implication of methodological uncertainties for mid-Holocene sea surface temperature reconstructions Climate of the Past, 10, 2237-2252, 2014 Author(s): I. Hessler, S. P. Harrison, M. Kucera, C. Waelbroeck, M.-T. Chen, C. Anderson, A. de Vernal, B. Fréchette, A. Cloke-Hayes, G. Leduc, and L. Londeix We present and examine a multi-sensor global compilation of mid-Holocene (MH) sea surface temperatures (SST), based on Mg/Ca and alkenone palaeothermometry and reconstructions obtained using planktonic foraminifera and organic-walled dinoflagellate cyst census counts. We assess the uncertainties originating from using different methodologies and evaluate the potential of MH SST reconstructions as a benchmark for climate-model simulations. The comparison between different analytical approaches (time frame, baseline climate) shows the choice of time window for the MH has a negligible effect on the reconstructed SST pattern, but the choice of baseline climate affects both the magnitude and spatial pattern of the reconstructed SSTs. Comparison of the SST reconstructions made using different sensors shows significant discrepancies at a regional scale, with uncertainties often exceeding the reconstructed SST anomaly. Apparent patterns in SST may largely be a reflection of the use of different sensors in different regions. Overall, the uncertainties associated with the SST reconstructions are generally larger than the MH anomalies. Thus, the SST data currently available cannot serve as a target for benchmarking model simulations. Further evaluations of potential subsurface and/or seasonal artifacts that may contribute to obscure the MH SST reconstructions are urgently needed to provide reliable benchmarks for model evaluations.

Description: Stored-heat assessments: a review in the light of field experience Geothermal Energy Science, 2, 49-54, 2014 Author(s): M. A. Grant Stored-heat or volumetric assessments of geothermal resources are appealingly simple: the resource being exploited is heat. A stored-heat calculation simply computes the amount of heat in the resource, similarly to computing the amount of ore in an ore body. The method has theoretical support in numerical simulations of resource production. While there are significant unknowns in any resource, some of these can be covered by probabilistic approaches, notably a Monte Carlo method. The Australian Geothermal Reporting Code represents one specification of such stored-heat assessments. However the experience of recent decades, with the development of significant numbers of geothermal resources, has shown that the method is highly unreliable and usually biased high. The tendency to overestimates, in particular, has led to the reduced credibility of the method. An example is quoted where simple application of the apparently simple rules gives a ridiculous result. Much of the problem lies in the "recovery factor", the proportion of the resource that can actually be exploited, where comparison with actual performance shows past values have been in all cases too high, as is the current version of the Australian code. There are further problems, usually overlooked, in the way that the reservoir volume and "cutoff temperature" are defined. Differing approaches mean that results between different reports are not comparable. The different approaches also imply unrecognised assumptions about the physical processes controlling reservoir depletion. The failure of Monte Carlo methods is similarly due to unrecognised violation of logical consistency in the use of probabilities. The net effect of these problems is that the method is not a simple means to generate a rough resource estimate, and it often generates faulty results. Usually, such results are overestimates. Monte Carlo methods do not provide a protection against these errors. The Australian Geothermal Reporting Code should be used for hydrothermal systems with an average recovery factor of 10%. With this average, results are subject to an error of ±70%. For enhanced geothermal systems (EGS), the recovery factor should be a few percent.

Description: Sensitivity of the Mediterranean sea level to atmospheric pressure and free surface elevation numerical formulation in NEMO Geoscientific Model Development, 7, 3001-3015, 2014 Author(s): P. Oddo, A. Bonaduce, N. Pinardi, and A. Guarnieri The sensitivity of the dynamics of the Mediterranean Sea to atmospheric pressure and free surface elevation formulation using NEMO (Nucleus for European Modelling of the Ocean) was evaluated. Four different experiments were carried out in the Mediterranean Sea using filtered or explicit free surface numerical schemes and accounting for the effect of atmospheric pressure in addition to wind and buoyancy fluxes. Model results were evaluated by coherency and power spectrum analysis with tide gauge data. We found that atmospheric pressure plays an important role for periods shorter than 100 days. The free surface formulation is important to obtain the correct ocean response for periods shorter than 30 days. At frequencies higher than 15 days −1 the Mediterranean basin's response to atmospheric pressure was not coherent and the performance of the model strongly depended on the specific area considered. A large-amplitude seasonal oscillation observed in the experiments using a filtered free surface was not evident in the corresponding explicit free surface formulation case, which was due to a phase shift between mass fluxes in the Gibraltar Strait and at the surface. The configuration with time splitting and atmospheric pressure always performed best; the differences were enhanced at very high frequencies.

Description: Are seasonal calving dynamics forced by buttressing from ice mélange or undercutting by melting? Outcomes from full-Stokes simulations of Store Glacier, West Greenland The Cryosphere, 8, 2353-2365, 2014 Author(s): J. Todd and P. Christoffersen We use a full-Stokes 2-D model (Elmer/Ice) to investigate the flow and calving dynamics of Store Glacier, a fast-flowing outlet glacier in West Greenland. Based on a new, subgrid-scale implementation of the crevasse depth calving criterion, we perform two sets of simulations: one to identify the primary forcing mechanisms and another to constrain future stability. We find that the mixture of icebergs and sea ice, known as ice mélange or sikussak, is principally responsible for the observed seasonal advance of the ice front. On the other hand, the effect of submarine melting on the calving rate of Store Glacier appears to be limited. Sensitivity analysis demonstrates that the glacier's calving dynamics are sensitive to seasonal perturbation, but are stable on interannual timescales due to the strong topographic control on the flow regime. Our results shed light on the dynamics of calving glaciers and may help explain why neighbouring glaciers do not necessarily respond synchronously to changes in atmospheric and oceanic forcing.

Description: Deglaciation of the Caucasus Mountains, Russia/Georgia, in the 21st century observed with ASTER satellite imagery and aerial photography The Cryosphere, 8, 2367-2379, 2014 Author(s): M. Shahgedanova, G. Nosenko, S. Kutuzov, O. Rototaeva, and T. Khromova Changes in the map area of 498 glaciers located on the Main Caucasus ridge (MCR) and on Mt. Elbrus in the Greater Caucasus Mountains (Russia and Georgia) were assessed using multispectral ASTER and panchromatic Landsat imagery with 15 m spatial resolution in 1999/2001 and 2010/2012. Changes in recession rates of glacier snouts between 1987–2001 and 2001–2010 were investigated using aerial photography and ASTER imagery for a sub-sample of 44 glaciers. In total, glacier area decreased by 4.7 ± 2.1% or 19.2 ± 8.7 km 2 from 407.3 ± 5.4 km 2 to 388.1 ± 5.2 km 2 . Glaciers located in the central and western MCR lost 13.4 ± 7.3 km 2 (4.7 ± 2.5%) in total or 8.5 km 2 (5.0 ± 2.4%) and 4.9 km 2 (4.1 ± 2.7%) respectively. Glaciers on Mt. Elbrus, although located at higher elevations, lost 5.8 ± 1.4 km 2 (4.9 ± 1.2%) of their total area. The recession rates of valley glacier termini increased between 1987–2000/01 and 2000/01–2010 (2000 for the western MCR and 2001 for the central MCR and Mt.~Elbrus) from 3.8 ± 0.8, 3.2 ± 0.9 and 8.3 ± 0.8 m yr −1 to 11.9 ± 1.1, 8.7 ± 1.1 and 14.1 ± 1.1 m yr −1 in the central and western MCR and on Mt. Elbrus respectively. The highest rate of increase in glacier termini retreat was registered on the southern slope of the central MCR where it has tripled. A positive trend in summer temperatures forced glacier recession, and strong positive temperature anomalies in 1998, 2006, and 2010 contributed to the enhanced loss of ice. An increase in accumulation season precipitation observed in the northern MCR since the mid-1980s has not compensated for the effects of summer warming while the negative precipitation anomalies, observed on the southern slope of the central MCR in the 1990s, resulted in stronger glacier wastage.

Description: Inversion method for initial tsunami waveform reconstruction Natural Hazards and Earth System Sciences Discussions, 2, 7735-7772, 2014 Author(s): V. V. Voronin, T. A. Voronina, and V. A. Tcheverda This paper deals with the application of r-solution method to recover the initial tsunami waveform in a tsunami source area by remote water-level measurements. Wave propagation is considered within the scope of a linear shallow-water theory. An ill-posed inverse problem is regularized by means of least square inversion using a truncated SVD approach. The properties of obtained solution are determined to a large extent by the properties of an inverse operator, which were numerically investigated. The method presented allows one to control instability of the numerical solution and to obtain an acceptable result in spite of ill-posedness of the problem. It is shown that the accuracy of tsunami source reconstruction strongly depends on the signal-to-noise ratio, the azimuthal coverage of recording stations with respect to the source area and bathymetric features along the wave path. The numerical experiments were carried out with synthetic data and various computational domains including a real bathymetry. The method proposed allows us to make a preliminary prediction of the efficiency of the inversion with a given set of the recording stations and to find out the most informative part of the existing observation system. This essential property of the method can prove to be useful in designing a monitoring system for tsunamis.

Description: Author(s): Robert de Mello Koch, Rocky Kreyfelt, and Stephanie Smith We study the anomalous dimensions for scalar operators in Aharony-Bergman-Jafferis-Maldacena theory in the SU(2) sector. The operators we consider have a classical dimension that grows as N in the large N limit. Consequently, the large N limit is not captured by summing planar diagrams—nonplanar con... [Phys. Rev. D 90, 126009] Published Wed Dec 17, 2014

Description: Author(s): Malcolm Fairbairn and Philipp Grothaus In this paper, we show that positron data from AMS seem to rule out the explanation of the ARCADE isotropic radio background excess in terms of self-annihilating dark matter. In earlier works it was found that leptonic annihilation channels of light dark matter provide a good fit to the excess due t... [Phys. Rev. D 90, 127302] Published Wed Dec 17, 2014

Description: Author(s): Aurélien Barrau, Carlo Rovelli, and Francesca Vidotto Quantum gravity effects could make a black hole explode in a time shorter than the Hawking radiation time, via local tunneling through a white hole solution. Here we estimate the size of a primordial black hole exploding today via this process, using a simple generic model. Fast radio bursts, strong... [Phys. Rev. D 90, 127503] Published Wed Dec 17, 2014

Description: Author(s): Keisuke Harigaya, Masahiro Ibe, Kai Schmitz, and Tsutomu T. Yanagida Chaotic inflation based on a simple monomial scalar potential, V(ϕ)∝ϕ p , is an attractive large-field model of inflation capable of generating a sizable tensor-to-scalar ratio r. Therefore, assuming that future cosmic microwave background observations will confirm the large r value reported by BICEP2... [Phys. Rev. D 90, 123524] Published Wed Dec 17, 2014

Description: Author(s): Luis A. Correa, José P. Palao, Gerardo Adesso, and Daniel Alonso The derivation of general performance benchmarks is important in the design of highly optimized heat engines and refrigerators. To obtain them, one may model phenomenologically the leading sources of irreversibility ending up with results that are model independent, but limited in scope. Alternative... [Phys. Rev. E 90, 062124] Published Wed Dec 17, 2014

Description: Author(s): D. Z. Xu (徐大智), Sheng-Wen Li (李圣文), X. F. Liu (刘旭峰), and C. P. Sun (孙昌璞) The canonical statistics describes the statistical properties of an open system by assuming its coupling with the heat bath is infinitesimal in comparison with the total energy in thermodynamic limit. In this paper, we generally derive a noncanonical density matrix for the open system with a finite ... [Phys. Rev. E 90, 062125] Published Wed Dec 17, 2014

Description: Author(s): Simon Lang, Rolf Schilling, and Thomas Franosch We demonstrate how the matrix-valued mode-coupling theory of the glass transition and glassy dynamics in planar confinement converges to the corresponding theory for two-dimensional (2D) planar and the three-dimensional bulk liquid, provided the wall potential satisfies certain conditions. Since the... [Phys. Rev. E 90, 062126] Published Wed Dec 17, 2014

Description: Author(s): R. Loll and L. Pires We analyze different claims on the role of the coupling constant λ in so-called λ-R models, a minimal generalization of general relativity inspired by Hořava-Lifshitz gravity. The dimensionless parameter λ appears in the kinetic term of the Einstein-Hilbert action, leading to a one-parameter family ... [Phys. Rev. D 90, 124050] Published Wed Dec 17, 2014

Description: Author(s): W. van Dijk and F. M. Toyama We develop an approach to solving numerically the time-dependent Schrödinger equation when it includes source terms and time-dependent potentials. The approach is based on the generalized Crank-Nicolson method supplemented with an Euler-MacLaurin expansion for the time-integrated nonhomogeneous term... [Phys. Rev. E 90, 063309] Published Wed Dec 17, 2014

Description: Author(s): Jing Wang and Guo-Zhu Liu We perform a detailed renormalization group analysis to study a (2+1)-dimensional quantum field theory that is composed of two interacting scalar bosons, which represent the order parameters for two continuous phase transitions. This sort of field theory can describe the competition and coexistence ... [Phys. Rev. D 90, 125015] Published Wed Dec 17, 2014

Description: Author(s): [Phys. Rev. E 90, 060001] Published Wed Dec 17, 2014

Description: Author(s): Samiran Ghosh and Nikhil Chakrabarti Low-frequency nonlinear wave dynamics is investigated in a two-dimensional inhomogeneous electron magnetohydrodynamic (EMHD) plasma in the presence of electron viscosity. In the long-wavelength limit, the dynamics of the wave is found to be governed by a novel nonlinear equation. The result of the m... [Phys. Rev. E 90, 063111] Published Wed Dec 17, 2014

Description: Author(s): Jinlei Liu, Wenbo Chen, Bin Zhang, Jing Zhao, Jianhua Wu, Jianmin Yuan, and Zengxiu Zhao The three-dimensional classical-trajectory Monte Carlo method is employed to investigate low-energy photoelectron spectra in above-threshold ionization by strong laser fields. By connecting the tunneling coordinates with the final momentum-energy spectra, we identify the effects of the Coulomb poten... [Phys. Rev. A 90, 063420] Published Wed Dec 17, 2014

Description: Author(s): Ben Kain and Hong Y. Ling Yin and Radzihovsky [X. Yin and L. Radzihovsky, Phys. Rev. A 88 , 063611 (2013)PLRAAN10.1103/PhysRevA.88.063611] recently developed a self-consistent extension of a Bogoliubov theory, in which the condensate number density n c is treated as a mean field that changes with time, in order to analyze a JI... [Phys. Rev. A 90, 063626] Published Wed Dec 17, 2014

Description: Author(s): I. A. Chioar, B. Canals, D. Lacour, M. Hehn, B. Santos Burgos, T. O. Menteş, A. Locatelli, F. Montaigne, and N. Rougemaille The authors study a kagome artificial spin ice cooled from above its Curie temperature. They argue that the system after cooling, while appearing locally to be in the expected spin ice 2 phase, globally seems to be in some non-equilibrium state. [Phys. Rev. B 90, 220407] Published Wed Dec 17, 2014

Description: Author(s): E. A. Rothstein, B. Horovitz, O. Entin-Wohlman, and A. Aharony The ac conductance of a finite tubular two-dimensional electron gas is studied in the presence of the Rashba spin-orbit interaction. When the tube is coupled to two reservoirs, that interaction splits the steps in the dc current, introducing energy ranges with spin-polarized currents. For this setup... [Phys. Rev. B 90, 245425] Published Wed Dec 17, 2014

Description: Author(s): Francesca Sammarruca Short-range correlations in nuclear and neutron matter are examined through the properties of the correlated wave function obtained by solving the Bethe–Goldstone equation. Tensor correlations are explored through the dominant tensor-driven transition and central correlations through the singlet and... [Phys. Rev. C 90, 064312] Published Wed Dec 17, 2014

Description: Author(s): M. Schäpers, H. Rosner, S.-L. Drechsler, S. Süllow, R. Vogel, B. Büchner, and A. U. B. Wolter We present an extensive microscopic magnetic study of the quasi-one-dimensional frustrated s=1/2 spin-chain compound linarite. Angular-dependent susceptibility and 1 H-NMR measurements were performed at various temperatures in the paramagnetic state. All relevant NMR parameters, viz., the chemical, t... [Phys. Rev. B 90, 224417] Published Wed Dec 17, 2014

Description: Author(s): Noël Martin and Michael Urban We study collective excitations in a superfluid neutron gas at zero temperature within the quasiparticle random-phase approximation. The particle-hole residual interaction is obtained from a Skyrme functional, while a separable interaction is used in the pairing channel, which gives a BCS gap that i... [Phys. Rev. C 90, 065805] Published Wed Dec 17, 2014

Description: Reevaluation of stratospheric ozone trends from SAGE II data using a simultaneous temporal and spatial analysis Atmospheric Chemistry and Physics, 14, 13455-13470, 2014 Author(s): R. P. Damadeo, J. M. Zawodny, and L. W. Thomason This paper details a new method of regression for sparsely sampled data sets for use with time-series analysis, in particular the Stratospheric Aerosol and Gas Experiment (SAGE) II ozone data set. Non-uniform spatial, temporal, and diurnal sampling present in the data set result in biased values for the long-term trend if not accounted for. This new method is performed close to the native resolution of measurements and is a simultaneous temporal and spatial analysis that accounts for potential diurnal ozone variation. Results show biases, introduced by the way data are prepared for use with traditional methods, can be as high as 10%. Derived long-term changes show declines in ozone similar to other studies but very different trends in the presumed recovery period, with differences up to 2% per decade. The regression model allows for a variable turnaround time and reveals a hemispheric asymmetry in derived trends in the middle to upper stratosphere. Similar methodology is also applied to SAGE II aerosol optical depth data to create a new volcanic proxy that covers the SAGE II mission period. Ultimately this technique may be extensible towards the inclusion of multiple data sets without the need for homogenization.

Description: Investigating uptake of N 2 O in agricultural soils using a high-precision dynamic chamber method Atmospheric Measurement Techniques, 7, 4455-4462, 2014 Author(s): N. J. Cowan, D. Famulari, P. E. Levy, M. Anderson, D. S. Reay, and U. M. Skiba Uptake (or negative flux) of nitrous oxide (N 2 O) in agricultural soils is a controversial issue which has proved difficult to investigate in the past due to constraints such as instrumental precision and methodological uncertainties. Using a recently developed high-precision quantum cascade laser gas analyser combined with a closed dynamic chamber, a well-defined detection limit of 4 μg N 2 O-N m −2 h −1 could be achieved for individual soil flux measurements. 1220 measurements of N 2 O flux were made from a variety of UK soils using this method, of which 115 indicated uptake by the soil (i.e. a negative flux in the micrometeorological sign convention). Only four of these apparently negative fluxes were greater than the detection limit of the method, which suggests that the vast majority of reported negative fluxes from such measurements are actually due to instrument noise. As such, we suggest that the bulk of negative N 2 O fluxes reported for agricultural fields are most likely due to limits in detection of a particular flux measurement methodology and not a result of microbiological activity consuming atmospheric N 2 O.

Description: Comparison of spatial association approaches for landscape mapping of soil organic carbon stocks SOIL Discussions, 1, 757-802, 2014 Author(s): B. A. Miller, S. Koszinski, M. Wehrhan, and M. Sommer The distribution of soil organic carbon (SOC) can be variable at small analysis scales, but consideration of its role in regional and global issues demands the mapping of large extents. There are many different strategies for mapping SOC, among which are to model the variables needed to calculate the SOC stock indirectly or to model the SOC stock directly. The purpose of this research is to compare direct and indirect approaches to mapping SOC stocks from rule-based, multiple linear regression models applied at the landscape scale via spatial association. The final products for both strategies are high-resolution maps of SOC stocks (kg m −2 ), covering an area of 122 km 2 , with accompanying maps of estimated error. For the direct modelling approach, the estimated error map was based on the internal error estimations from the model rules. For the indirect approach, the estimated error map was produced by spatially combining the error estimates of component models via standard error propagation equations. We compared these two strategies for mapping SOC stocks on the basis of the qualities of the resulting maps as well as the magnitude and distribution of the estimated error. The direct approach produced a map with less spatial variation than the map produced by the indirect approach. The increased spatial variation represented by the indirect approach improved R 2 values for the topsoil and subsoil stocks. Although the indirect approach had a lower mean estimated error for the topsoil stock, the mean estimated error for the total SOC stock (topsoil + subsoil) was lower for the direct approach. For these reasons, we recommend the direct approach to modelling SOC stocks be considered a more conservative estimate of the SOC stocks' spatial distribution.

Description: Glacier-like forms on Mars The Cryosphere, 8, 2047-2061, 2014 Author(s): B. Hubbard, C. Souness, and S. Brough More than 1300 glacier-like forms (GLFs) are located in Mars' mid-latitudes. These GLFs are predominantly composed of ice–dust mixtures and are visually similar to terrestrial valley glaciers, showing signs of downhill viscous deformation and an expanded former extent. However, several fundamental aspects of their behavior are virtually unknown, including temporal and spatial variations in mass balance, ice motion, landscape erosion and deposition, and hydrology. Here, we investigate the physical glaciology of martian GLFs. We use satellite images of specific examples and case studies to build on existing knowledge relating to (i) GLF current and former extent, exemplified via a GLF located in Phlegra Montes; (ii) indicators of GLF motion, focusing on the presence of surface crevasses on several GLFs; (iii) processes of GLF debris transfer, focusing on mapping and interpreting boulder trains on one GLF located in Protonilus Mensae, the analysis of which suggests a best-estimate mean GLF flow speed of 7.5 mm a −1 ; and (iv) GLF hydrology, focusing on supra-GLF gulley networks. On the basis of this information, we summarize the current state of knowledge of the glaciology of martian GLFs and identify future research avenues.

Description: Strategy of valid 14 C dates choice in syngenetic permafrost The Cryosphere Discussions, 8, 5589-5621, 2014 Author(s): Y. K. Vasil'chuk and A. C. Vasil'chuk The main problem of radiocarbon dating within permafrost is the uncertain reliability of the 14 C dates. Syngenetic sediments contain allochthonous organic deposit that originated at a distance from its present position. Due to the very good preservation of organic materials in permafrost conditions and numerous re-burials of the fossils from ancient deposits into younger ones the dates could be both younger and older than the true age of dated material. The strategy for the most authentic radiocarbon date selection for dating of syncryogenic sediments is considered taking into account the fluvial origin of the syngenetic sediments. The re-deposition of organic material is discussed in terms of cyclic syncryogenic sedimentation and also the possible re-deposition of organic material in subaerial-subaqueous conditions. The advantages and the complications of dating organic micro-inclusions from ice wedges by the accelerator mass spectrometry (AMS) method are discussed applying to true age of dated material search. Radiocarbon dates of different organic materials from the same samples are compared. The younger age of the yedoma from cross-sections of Duvanny Yar in Kolyma River and Mamontova Khayata in the mouth of Lena River is substantiated due to the principle of the choice of the youngest 14 C date from the set.

Description: Modeling the elastic transmission of tidal stresses to great distances inland in channelized ice streams The Cryosphere, 8, 2007-2029, 2014 Author(s): J. Thompson, M. Simons, and V. C. Tsai Geodetic surveys suggest that ocean tides can modulate the motion of Antarctic ice streams, even at stations many tens of kilometers inland from the grounding line. These surveys suggest that ocean tidal stresses can perturb ice stream motion at distances about an order of magnitude farther inland than tidal flexure of the ice stream alone. Recent models exploring the role of tidal perturbations in basal shear stress are primarily one- or two-dimensional, with the impact of the ice stream margins either ignored or parameterized. Here, we use two- and three-dimensional finite-element modeling to investigate transmission of tidal stresses in ice streams and the impact of considering more realistic, three-dimensional ice stream geometries. Using Rutford Ice Stream as a real-world comparison, we demonstrate that the assumption that elastic tidal stresses in ice streams propagate large distances inland fails for channelized glaciers due to an intrinsic, exponential decay in the stress caused by resistance at the ice stream margins. This behavior is independent of basal conditions beneath the ice stream and cannot be fit to observations using either elastic or nonlinear viscoelastic rheologies without nearly complete decoupling of the ice stream from its lateral margins. Our results suggest that a mechanism external to the ice stream is necessary to explain the tidal modulation of stresses far upstream of the grounding line for narrow ice streams. We propose a hydrologic model based on time-dependent variability in till strength to explain transmission of tidal stresses inland of the grounding line. This conceptual model can reproduce observations from Rutford Ice Stream.

Description: Simulating the Antarctic ice sheet in the Late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project The Cryosphere Discussions, 8, 5539-5588, 2014 Author(s): B. de Boer, A. M. Dolan, J. Bernales, E. Gasson, H. Goelzer, N. R. Golledge, J. Sutter, P. Huybrechts, G. Lohmann, I. Rogozhina, A. Abe-Ouchi, F. Saito, and R. S. W. van de Wal In the context of future climate change, understanding the nature and behaviour of ice sheets during warm intervals in Earth history is of fundamental importance. The Late-Pliocene warm period (also known as the PRISM interval: 3.264 to 3.025 million years before present) can serve as a potential analogue for projected future climates. Although Pliocene ice locations and extents are still poorly constrained, a significant contribution to sea-level rise should be expected from both the Greenland ice sheet and the West and East Antarctic ice sheets based on palaeo sea-level reconstructions. Here, we present results from simulations of the Antarctic ice sheet by means of an international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP-ANT). For the experiments, ice-sheet models including the shallow ice and shelf approximations have been used to simulate the complete Antarctic domain (including grounded and floating ice). We compare the performance of six existing numerical ice-sheet models in simulating modern control and Pliocene ice sheets by a suite of four sensitivity experiments. Ice-sheet model forcing fields are taken from the HadCM3 atmosphere–ocean climate model runs for the pre-industrial and the Pliocene. We include an overview of the different ice-sheet models used and how specific model configurations influence the resulting Pliocene Antarctic ice sheet. The six ice-sheet models simulate a comparable present-day ice sheet, although the models are setup with their own parameter settings. For the Pliocene simulations using the Bedmap1 bedrock topography, some models show a small retreat of the East Antarctic ice sheet, which is thought to have happened during the Pliocene for the Wilkes and Aurora basins. This can be ascribed to either the surface mass balance, as the HadCM3 Pliocene climate shows a significant increase over the Wilkes and Aurora basin, or the initial bedrock topography. For the latter, our simulations with the recently published Bedmap2 bedrock topography indicate a significantly larger contribution to Pliocene sea-level rise from the East Antarctic ice sheet for all six models relative to the simulations with Bedmap1.

Description: Fluctuations of a Greenlandic tidewater glacier driven by changes in atmospheric forcing: observations and modelling of Kangiata Nunaata Sermia, 1859–present The Cryosphere, 8, 2031-2045, 2014 Author(s): J. M. Lea, D. W. F. Mair, F. M. Nick, B. R. Rea, D. van As, M. Morlighem, P. W. Nienow, and A. Weidick Many tidewater glaciers in Greenland are known to have undergone significant retreat during the last century following their Little Ice Age maxima. Where it is possible to reconstruct glacier change over this period, they provide excellent records for comparison to climate records, as well as calibration/validation for numerical models. These glacier change records therefore allow for tests of numerical models that seek to simulate tidewater glacier behaviour over multi-decadal to centennial timescales. Here we present a detailed record of behaviour from Kangiata Nunaata Sermia (KNS), SW Greenland, between 1859 and 2012, and compare it against available oceanographic and atmospheric temperature data between 1871 and 2012. We also use these records to evaluate the ability of a well-established one-dimensional flow-band model to replicate behaviour for the observation period. The record of terminus change demonstrates that KNS has advanced/retreated in phase with atmosphere and ocean climate anomalies averaged over multi-annual to decadal timescales. Results from an ensemble of model runs demonstrate that observed dynamics can be replicated. Model runs that provide a reasonable match to observations always require a significant atmospheric forcing component, but do not necessarily require an oceanic forcing component. Although the importance of oceanic forcing cannot be discounted, these results demonstrate that changes in atmospheric forcing are likely to be a primary driver of the terminus fluctuations of KNS from 1859 to 2012. We propose that the detail and length of the record presented makes KNS an ideal site for model validation exercises investigating links between climate, calving rates, and tidewater glacier dynamics.

Description: Rapid, optical measurement of the atmospheric pressure on a fast research aircraft using open-path TDLAS Atmospheric Measurement Techniques, 7, 3653-3666, 2014 Author(s): B. Buchholz, A. Afchine, and V. Ebert Because of the high travel speed, the complex flow dynamics around an aircraft, and the complex dependency of the fluid dynamics on numerous airborne parameters, it is quite difficult to obtain accurate pressure values at a specific instrument location of an aircraft's fuselage. Complex simulations using computational fluid dynamics (CFD) models can in theory computationally "transfer" pressure values from one location to another. However, for long flight patterns, this process is inconvenient and cumbersome. Furthermore, these CFD transfer models require a local experimental validation, which is rarely available. In this paper, we describe an integrated approach for a spectroscopic, calibration-free, in-flight pressure determination in an open-path White cell on an aircraft fuselage using ambient, atmospheric water vapour as the "sensor species". The presented measurements are realised with the HAI (Hygrometer for Atmospheric Investigations) instrument, built for multiphase water detection via calibration-free TDLAS (tunable diode laser absorption spectroscopy). The pressure determination is based on raw data used for H 2 O concentration measurement, but with a different post-flight evaluation method, and can therefore be conducted at deferred time intervals on any desired flight track. The spectroscopic pressure is compared in-flight with the static ambient pressure of the aircraft avionic system and a micro-mechanical pressure sensor, located next to the open-path cell, over a pressure range from 150 to 800 hPa, and a water vapour concentration range of more than 3 orders of magnitude. The correlation between the micro-mechanical pressure sensor measurements and the spectroscopic pressure measurements shows an average deviation from linearity of only 0.14% and a small offset of 9.5 hPa. For the spectroscopic pressure evaluation we derive measurement uncertainties under laboratory conditions of 3.2 and 5.1% during in-flight operation on the HALO airplane. Under certain flight conditions we quantified, for the first time, stalling-induced, dynamic pressure deviations of up to 30% (at 200 hPa) between the avionic sensor and the optical and mechanical pressure sensors integrated in HAI. Such severe local pressure deviations from the typically used avionic pressure are important to take into account for other airborne sensors employed on such fast flying platforms as the HALO aircraft.

Description: Long term measurements of optical properties and their hygroscopic enhancement Atmospheric Chemistry and Physics Discussions, 14, 27731-27767, 2014 Author(s): M. Hervo, K. Sellegri, J. M. Pichon, J. C. Roger, and P. Laj Optical properties of aerosols were measured from the GAW Puy de Dôme station (1465 m) over a seven year period (2006–2012). The impact of hygroscopicity on aerosol optical properties was calculated over a two year period (2010–2011). The analysis of the spatial and temporal variability of the optical properties showed that while no long term trend was found, a clear seasonal and diurnal variation was observed on the extensive parameters (scattering, absorption). Scattering and absorption coefficients were highest during the warm season and daytime, in concordance with the seasonality and diurnal variation of the PBL height reaching the site. Intensive parameters (single scattering albedo, asymmetry factor, refractive index) did not show such a strong diurnal variability, but still indicated different values depending on the season. Both extensive and intensive optical parameters were sensitive to the air mass origin. A strong impact of hygroscopicity on aerosol optical properties was calculated, mainly on aerosol scattering, with a dependence on the aerosol type. At 90% humidity, the scattering factor enhancement ( f σ sca ) was more than 4.4 for oceanic aerosol that have mixed with a pollution plume. Consequently, the aerosol radiative forcing was estimated to be 2.8 times higher at RH = 90% and 1.75 times higher at ambient RH when hygroscopic growth of the aerosol was considered. The hygroscopicity enhancement factor of the scattering coefficient was parameterized as a function of humidity and air mass type.

Description: Fluxes of carbon and nutrients to the Iceland Sea surface layer and inferred primary productivity and stoichiometry Biogeosciences Discussions, 11, 15399-15433, 2014 Author(s): E. Jeansson, R. G. J. Bellerby, I. Skjelvan, H. Frigstad, S. R. Ólafsdóttir, and J. Ólafsson Fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea are evaluated. The study utilises hydro-chemical data from the Iceland Sea time-series station (68.00° N, 12.67° W), for the years between 1993 and 2006. By comparing data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper 100 m), and a sub-surface layer (100–200 m), we calculate monthly deficits in the surface, and use these to deduce the surface layer fluxes that affect the deficits: vertical mixing, horizontal advection, air–sea exchange, and biological activity. The deficits show a clear seasonality with a minimum in winter, when the mixed layer is at the deepest, and a maximum in early autumn, when biological uptake has removed much of the nutrients. The annual vertical fluxes of DIC and nitrate amounts to 1.7 ± 0.3 and 0.23 ± 0.07 mol m −2 yr −1 , respectively, and the annual air–sea uptake of atmospheric CO 2 is 4.4 ± 1.1 mol m −2 yr −1 . The biologically driven changes in DIC during the year relates to net community production (NCP), and the net annual NCP corresponds to export production, and is here calculated to 6.1 ± 0.9 mol C m −2 yr −1 . The typical, median C : N ratio during the period of net community uptake is 11, and thus clearly higher than Redfield, but is varying during the season.

Description: Efficient performance of the Met Office Unified Model v8.2 on Intel Xeon partially used nodes Geoscientific Model Development Discussions, 7, 7395-7425, 2014 Author(s): I. Bermous The atmospheric Unified Model (UM) developed at the UK Met Office is used for weather and climate prediction by forecast teams at a number of international meteorological centres and research institutes on a wide variety of hardware and software environments. Over its 25 year history the UM sources have been optimised for a better application performance on a number of HPC systems including NEC SX vector architecture systems and recently the IBM Power6/Power7 platforms. Understanding the influence of the compiler flags, MPI libraries and run configurations is crucial to achieving the shortest elapsed times for a UM application on any particular HPC system. These aspects are very important for applications that must run within operational time frames. Driving the current study is the HPC industry trend since 1980 for processor arithmetic performance to increase at a faster rate than memory bandwidth. This gap has been growing especially fast for multicore processors in the past 10 years and it can have significant implication for the performance and performance scaling of memory bandwidth intensive applications, such as the UM. Analysis of partially used nodes on Intel Xeon clusters is provided in this paper for short and medium range weather forecasting systems using global and limited-area configurations. It is shown that on the Intel Xeon based clusters the fastest elapsed times and the most efficient system usage can be achieved using partially committed nodes.

Description: Mechanism for potential strengthening of Atlantic overturning prior to collapse Earth System Dynamics, 5, 383-397, 2014 Author(s): D. Ehlert and A. Levermann The Atlantic meridional overturning circulation (AMOC) carries large amounts of heat into the North Atlantic influencing climate regionally as well as globally. Palaeo-records and simulations with comprehensive climate models suggest that the positive salt-advection feedback may yield a threshold behaviour of the system. That is to say that beyond a certain amount of freshwater flux into the North Atlantic, no meridional overturning circulation can be sustained. Concepts of monitoring the AMOC and identifying its vicinity to the threshold rely on the fact that the volume flux defining the AMOC will be reduced when approaching the threshold. Here we advance conceptual models that have been used in a paradigmatic way to understand the AMOC, by introducing a density-dependent parameterization for the Southern Ocean eddies. This additional degree of freedom uncovers a mechanism by which the AMOC can increase with additional freshwater flux into the North Atlantic, before it reaches the threshold and collapses: an AMOC that is mainly wind-driven will have a constant upwelling as long as the Southern Ocean winds do not change significantly. The downward transport of tracers occurs either in the northern sinking regions or through Southern Ocean eddies. If freshwater is transported, either atmospherically or via horizontal gyres, from the low to high latitudes, this would reduce the eddy transport and by continuity increase the northern sinking which defines the AMOC until a threshold is reached at which the AMOC cannot be sustained. If dominant in the real ocean this mechanism would have significant consequences for monitoring the AMOC.

Description: A high-frequency atmospheric and seawater p CO 2 data set from 14 open-ocean sites using a moored autonomous system Earth System Science Data, 6, 353-366, 2014 Author(s): A. J. Sutton, C. L. Sabine, S. Maenner-Jones, N. Lawrence-Slavas, C. Meinig, R. A. Feely, J. T. Mathis, S. Musielewicz, R. Bott, P. D. McLain, H. J. Fought, and A. Kozyr In an intensifying effort to track ocean change and distinguish between natural and anthropogenic drivers, sustained ocean time series measurements are becoming increasingly important. Advancements in the ocean carbon observation network over the last decade, such as the development and deployment of Moored Autonomous p CO 2 (MAPCO 2 ) systems, have dramatically improved our ability to characterize ocean climate, sea–air gas exchange, and biogeochemical processes. The MAPCO 2 system provides high-resolution data that can measure interannual, seasonal, and sub-seasonal dynamics and constrain the impact of short-term biogeochemical variability on carbon dioxide (CO 2 ) flux. Overall uncertainty of the MAPCO 2 using in situ calibrations with certified gas standards and post-deployment standard operating procedures is 〈 2 μatm for seawater partial pressure of CO 2 ( p CO 2 ) and 〈 1 μatm for air p CO 2 . The MAPCO 2 maintains this level of uncertainty for over 400 days of autonomous operation. MAPCO 2 measurements are consistent with shipboard seawater p CO 2 measurements and GLOBALVIEW-CO2 boundary layer atmospheric values. Here we provide an open-ocean MAPCO 2 data set including over 100 000 individual atmospheric and seawater p CO 2 measurements on 14 surface buoys from 2004 through 2011 and a description of the methods and data quality control involved. The climate-quality data provided by the MAPCO 2 have allowed for the establishment of open-ocean observatories to track surface ocean p CO 2 changes around the globe. Data are available at doi:10.3334/CDIAC/OTG.TSM_NDP092 and http://cdiac.ornl.gov/oceans/Moorings/ndp092 .

Description: Hydrogeology of an Alpine rockfall aquifer system and its role in flood attenuation and maintaining baseflow Hydrology and Earth System Sciences, 18, 4437-4452, 2014 Author(s): U. Lauber, P. Kotyla, D. Morche, and N. Goldscheider The frequency and intensity of extreme hydrological events in Alpine regions is projected to increase with climate change. The goal of this study is to better understand the functioning of aquifers composed of complex alluvial and rockfall deposits in Alpine valleys and to quantify the role of these natural storage spaces in flood attenuation and baseflow maintenance. Geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements were conducted in the Reintal (German Alps), where runoff from a karst spring infiltrates a series of postglacial alluvial/rockfall aquifers. During high-flow conditions, groundwater velocities of 30 m h −1 were determined along 500 m; hydrograph analyses revealed short lag times (5 h) between discharge peaks upstream and downstream from the aquifer series; the maximum discharge ratio downstream (22) and the peak recession coefficient (0.196 d −1 ) are low compared with other Alpine catchments. During low-flow conditions, the underground flow path length increased to 2 km and groundwater velocities decreased to 13 m h −1 . Downstream hydrographs revealed a delayed discharge response after 101 h and peaks damped by a factor of 1.5. These results indicate that alluvial/rockfall aquifers might play an important role in the flow regime and attenuation of floods in Alpine regions.

Description: Observed groundwater temperature response to recent climate change Hydrology and Earth System Sciences, 18, 4453-4466, 2014 Author(s): K. Menberg, P. Blum, B. L. Kurylyk, and P. Bayer Climate change is known to have a considerable influence on many components of the hydrological cycle. Yet, the implications for groundwater temperature, as an important driver for groundwater quality, thermal use and storage, are not yet comprehensively understood. Furthermore, few studies have examined the implications of climate-change-induced groundwater temperature rise for groundwater-dependent ecosystems. Here, we examine the coupling of atmospheric and groundwater warming by employing stochastic and deterministic models. Firstly, several decades of temperature time series are statistically analyzed with regard to climate regime shifts (CRSs) in the long-term mean. The observed increases in shallow groundwater temperatures can be associated with preceding positive shifts in regional surface air temperatures, which are in turn linked to global air temperature changes. The temperature data are also analyzed with an analytical solution to the conduction–advection heat transfer equation to investigate how subsurface heat transfer processes control the propagation of the surface temperature signals into the subsurface. In three of the four monitoring wells, the predicted groundwater temperature increases driven by the regime shifts at the surface boundary condition generally concur with the observed groundwater temperature trends. Due to complex interactions at the ground surface and the heat capacity of the unsaturated zone, the thermal signals from distinct changes in air temperature are damped and delayed in the subsurface, causing a more gradual increase in groundwater temperatures. These signals can have a significant impact on large-scale groundwater temperatures in shallow and economically important aquifers. These findings demonstrate that shallow groundwater temperatures have responded rapidly to recent climate change and thus provide insight into the vulnerability of aquifers and groundwater-dependent ecosystems to future climate change.

Description: Snow mass decrease in the Northern Hemisphere (1979/80–2010/11) The Cryosphere Discussions, 8, 5623-5644, 2014 Author(s): Z. Li, J. Liu, L. Huang, N. Wang, B. Tian, J. Zhou, Q. Chen, and P. Zhang Snow cover has a key effect on climate change and hydrological cycling, as well as water supply to a sixth of the world's population across the Northern Hemisphere. However, reliable data on trends in snow cover in the Northern Hemisphere is lacking. Snow water equivalent (SWE) is a common measure of the amount of equivalent water of the snow pack. Here we verify the accuracy of three existing global SWE products and merge the most accurate aspects of them to generate a new SWE product covering the last 32 years (1979/80–2010/11). Using this new SWE product, we show that there has been a significant decreasing trend in the total mass of snow in the Northern Hemisphere. The most notable changes in total snow mass are −16.45 ± 6.68 and −13.55 ± 7.80 Gt year −1 in January and February, respectively. These are followed by March and December, which have trends of −12.58 ± 6.88 and −10.70 ± 5.62 Gt year −1 , respectively, from 1979/80 to 2010/11. During the same period, the temperature in the study area raised 0.17 °C decade −1 , which is thought to be the main reason of SWE decline.

Description: Factors controlling Slope Environmental Lapse Rate (SELR) of temperature in the monsoon and cold-arid glacio-hydrological regimes of the Himalaya The Cryosphere Discussions, 8, 5645-5686, 2014 Author(s): R. J. Thayyen and A. P. Dimri Moisture, temperature and precipitation interplay forced through the orographic processes sustains the Himalayan cryospheric system. However, factors controlling the Slope Environmental Lapse Rate (SELR) of temperature along the higher Himalayan mountain slopes across various glacio-hydrologic regimes remain as a key knowledge gap. Present study dwells on the orographic processes driving the moisture–temperature interplay in the monsoon and cold-arid glacio-hydrological regimes of the Himalaya. Systematic data collection at three altitudes between 2540 and 3763 m a.s.l. in the Garhwal Himalaya (hereafter called monsoon regime) and between 3500 and 5600 m a.s.l. in the Ladakh Himalaya (herefater called cold-arid regime) revealed moistrue control on temperature distribution at temporal and spatial scales. Observed daily SELR of temperature ranges between 9.0 to 1.9 °C km −1 and 17.0 to 2.8 °C km −1 in the monsoon and cold-arid regimes respectively highlighting strong regional variability. Moisture influx to the region, either from Indian summer monsoon (ISM) or from Indian winter monsoon (IWM) forced lowering of SELR. This phenophena of "monsoon lowering" of SELR is due to the release latent heat of condensation from orographically focred lifted air parcel. Seasonal response of SELR in the monsoon regime is found to be closly linked with the variations in the local lifting condensation levels (LCL). Contrary to this, cold-arid system is characterised by the extremely high values of daily SELR upto 17 °C km −1 signifying the extremely arid conditions prevailing in summer. Distinctly lower SELR devoid of monsoon lowering at higher altitude sections of monsoon and cold-arid regimes suggests sustained wetter high altitude regimes. We have proposed a SELR model for both glacio-hydrological regimes demostrating with two sections each using a derivative of the Clausius–Clapeyron relationship by deriving monthly SELR indices. It has been proposed that the manifestations of presence or absence of moisture is the single most important factor determining the temperature distribution along the higher Himalayan slopes driven by the orographic forcings. This work also suggests that the arbitary use of temperature lapse rate to extrapolate temperature to the higher Himalaya is extremely untenable.

Description: Author(s): Jian Wang, Ding Zhong, Liangzhu Mu, and Heng Fan We investigate the fidelity of measurement-based quantum computation (MBQC) when it is coupled with a boson environment, by measuring the cluster-state fidelity and gate fidelity. Two schemes of cluster-state preparation are studied. In the controlled-Z (CZ) creation scheme, cluster states are prepa... [Phys. Rev. A 90, 052306] Published Thu Nov 06, 2014

Description: Author(s): Soumyajit Saha, Ankur Mandal, Jobin Jose, Hari R. Varma, P. C. Deshmukh, A. S. Kheifets, V. K. Dolmatov, and S. T. Manson The time delay of photoemission from noble-gas atoms is analyzed in the vicinity of a Cooper minimum, showing that the presence of the Cooper minimum in one channel has a strong effect on the time delay in other channels. [Phys. Rev. A 90, 053406] Published Thu Nov 06, 2014

Description: Author(s): ShengLi Zhang, XuBo Zou, JianHong Shi, JianSheng Guo, and GuangCan Guo Quantum illumination can be used to detect the low-reflectivity target hidden in strong background noise. All known results are based on the assumption of ideal photon transmission and reception. In this paper, we investigate the impact of photon loss on the performance of quantum illumination in tw... [Phys. Rev. A 90, 052308] Published Thu Nov 06, 2014

Description: Author(s): Gaetana Spedalieri and Samuel L. Braunstein We consider the asymmetric formulation of quantum hypothesis testing, where two quantum hypotheses have different associated costs. In this problem, the aim is to minimize the probability of false negatives and the optimal performance is provided by the quantum Hoeffding bound. After a brief review ... [Phys. Rev. A 90, 052307] Published Thu Nov 06, 2014

Description: Author(s): M. Palmero, R. Bowler, J. P. Gaebler, D. Leibfried, and J. G. Muga We investigate the dynamics of mixed-species ion crystals during transport between spatially distinct locations in a linear Paul trap in the diabatic regime. In a general mixed-species crystal, all degrees of freedom along the direction of transport are excited by an accelerating well, so unlike the... [Phys. Rev. A 90, 053408] Published Thu Nov 06, 2014

Description: Author(s): E. B. Linscott and P. B. Blakie An analytical model that quantifies the energy barrier to local collapse of a flattened dipolar condensate is developed, and a stochastic Gross-Pitaevskii theory is used to perform finite-temperature simulations verifying the local collapse scenario. [Phys. Rev. A 90, 053605] Published Thu Nov 06, 2014

Description: Author(s): M. McAneny and J. K. Freericks The Coulomb repulsion between ions in a linear Paul trap gives rise to anharmonic terms in the potential energy when expanded about the equilibrium positions. We examine the effect of these anharmonic terms on the accuracy of a quantum simulator made from trapped ions. To be concrete, we consider a ... [Phys. Rev. A 90, 053405] Published Thu Nov 06, 2014

Description: Author(s): D. Pinna, D. L. Stein, and A. D. Kent We study the magnetization dynamics of spin-torque oscillators in the presence of thermal noise and as a function of the spin-polarization angle in a macrospin model. The macrospin has biaxial magnetic anisotropy, typical of thin film magnetic elements, with an easy axis in the film plane and a hard... [Phys. Rev. B 90, 174405] Published Thu Nov 06, 2014

Description: Author(s): Y. Fang, Federico Duque-Gomez, and J. E. Sipe The dynamics of wave packets in periodic potentials and subject to a sudden external force is studied, and it is shown that the usual semiclassical description in terms of effective mass and anomalous velocity requires corrections in such a case. [Phys. Rev. A 90, 053407] Published Thu Nov 06, 2014

Description: Author(s): Dale R. Harshman and Anthony T. Fiory In their article, Zhang et al. [Phys. Rev. B 86 , 024516 (2012)PRBMDO10.1103/PhysRevB.86.024516] present a remarkable result for Ax(S)yTiNCl compounds (α-phase TiNCl partially intercalated with alkali A and optionally co-intercalated molecular species S), finding the superconducting transition temper... [Phys. Rev. B 90, 186501] Published Thu Nov 06, 2014

Description: Author(s): S. Zhang, Masashi Tanaka, and Shoji Yamanaka We have studied the electron-doped α-form TiNCl (FeOCl orthorhombic type) in detail and have found the transition temperature Tc of 18.0 K decreases monotonically with increasing the interlayer spacing d upon co-intercalation of various kinds of organic solvent molecules with alkali atoms. We conclu... [Phys. Rev. B 90, 186502] Published Thu Nov 06, 2014

Description: Author(s): Tsung-Wei Chen, Jian-Huang Li, and Chong-Der Hu The Berry phase on the Fermi surface and its influence on the conserved spin current in a two-dimensional system with generic k-linear spin-orbit interaction are investigated. We calculate the response of the effective conserved spin current to the applied electric field, which is composed of conven... [Phys. Rev. B 90, 195202] Published Thu Nov 06, 2014

Description: Author(s): P. K. Pyatkovskiy and V. A. Miransky Edge excitations of the ν=0 quantum Hall state in monolayer graphene are studied within the mean-field theory with different symmetry-breaking terms. The analytical expressions for the continuum (Dirac) model wave functions are obtained for the charge density wave, Kekulé distortion, ferromagnetic, ... [Phys. Rev. B 90, 195407] Published Thu Nov 06, 2014

Description: Author(s): M. Grüning and C. Attaccalite [Phys. Rev. B 90, 199901] Published Thu Nov 06, 2014

Description: Author(s): Sanjeev Kumar, Kalarikad J. Thomas, Luke W. Smith, Michael Pepper, Graham L. Creeth, Ian Farrer, David Ritchie, Geraint Jones, and Jonathan Griffiths We have investigated electron transport in a quasi-one dimensional (quasi-1D) electron gas as a function of the confinement potential. At a particular potential configuration, and electron concentration, the ground state of a 1D quantum wire splits into two rows to form an incipient Wigner lattice. ... [Phys. Rev. B 90, 201304] Published Thu Nov 06, 2014

Description: Author(s): S. S. Dimitrova, A. A. Cowley, E. V. Zemlyanaya, and K. V. Lukyanov The reaction mechanism of pre-equilibrium proton-induced α-particle emission from Nb93 at an incident energy of 100 MeV was investigated with polarized projectiles. A formalism based on the statistical multistep direct emission model of Feshbach, Kerman, and Koonin was found to give a reasonably goo... [Phys. Rev. C 90, 054604] Published Thu Nov 06, 2014

Description: Author(s): Shao-Liang Zhang and Qi Zhou The realization of band structures with nontrivial topological properties in an optical lattice is an exciting topic in current studies of ultracold atoms. Here we point out that this lofty goal can be achieved by using a simple scheme of shaking an optical lattice, which is directly applicable in c... [Phys. Rev. A 90, 051601] Published Thu Nov 06, 2014

Description: Author(s): P. Lampen, M. H. Phan, H. Srikanth, K. Kovnir, P. Chai, and M. Shatruk The critical behavior near the continuous paramagnetic to ferromagnetic transition in a single crystal of La0.75Pr0.25Co2P2 has been determined based on high-resolution bulk magnetization data near TC ∼ 167 K, where long-range order is established in the Co sublattice. Scaling equation of state anal... [Phys. Rev. B 90, 174404] Published Thu Nov 06, 2014

Description: Author(s): Neil J. Robinson, Fabian H. L. Essler, Ivelisse Cabrera, and Radu Coldea We present experimental and theoretical evidence that an interesting quantum many-body effect—quasiparticle breakdown—occurs in the quasi-one-dimensional spin-12 Ising-like ferromagnet CoNb2O6 in its paramagnetic phase at high transverse field as a result of explicit breaking of spin inversion symme... [Phys. Rev. B 90, 174406] Published Thu Nov 06, 2014

Description: Author(s): Hyungwon Kim, Tatsuhiko N. Ikeda, and David A. Huse We ask whether the eigenstate thermalization hypothesis (ETH) is valid in a strong sense: in the limit of an infinite system, every eigenstate is thermal. We examine expectation values of few-body operators in highly excited many-body eigenstates and search for “outliers,” the eigenstates that devia... [Phys. Rev. E 90, 052105] Published Thu Nov 06, 2014

Description: Author(s): Maksym Serbyn, Z. Papić, and D. A. Abanin Many-body localized (MBL) systems are characterized by the absence of transport and thermalization and, therefore, cannot be described by conventional statistical mechanics. In this paper, using analytic arguments and numerical simulations, we study the behavior of local observables in an isolated M... [Phys. Rev. B 90, 174302] Published Thu Nov 06, 2014

Description: Author(s): Onkar Parrikar, Taylor L. Hughes, and Robert G. Leigh We study the response of a class of topological systems to electromagnetic and gravitational sources, including torsion and curvature. By using the technology of anomaly polynomials, we derive the parity-odd response of a massive Dirac fermion in d=2+1 and d=4+1, which provides a simple model for a ... [Phys. Rev. D 90, 105004] Published Thu Nov 06, 2014

Description: Author(s): Michi-To Suzuki and Hiroaki Ikeda On the basis of group theory and first-principles calculations, we investigate high-rank multipole orderings in URu2Si2, which have been proposed as a genuine primary order parameter in the hidden-order phase below 17.5 K. We apply Shubnikov group theory to the multipole ordered states characterized... [Phys. Rev. B 90, 184407] Published Thu Nov 06, 2014

Description: Author(s): Rami M. Amro and Alexander B. Neiman Sensory hair cells of amphibians exhibit spontaneous activity in their hair bundles and membrane potentials, reflecting two distinct active amplification mechanisms employed in these peripheral mechanosensors. We use a two-compartment model of the bullfrog's saccular hair cell to study how the inter... [Phys. Rev. E 90, 052704] Published Thu Nov 06, 2014

Description: Author(s): Thibault Damour and Philippe Spindel We study the quantum dynamics of a supersymmetric squashed three-sphere by dimensionally reducing (to one timelike dimension) the action of D=4 simple supergravity for a SU(2)-homogeneous (Bianchi IX) cosmological model. The quantization of the homogeneous gravitino field leads to a 64-dimensional f... [Phys. Rev. D 90, 103509] Published Thu Nov 06, 2014

Description: Author(s): Alma X. Gonzalez-Morales, Stefano Profumo, and Farinaldo S. Queiroz Recent discoveries of optical signatures of black holes in dwarf galaxies indicates that low-mass galaxies can indeed host intermediate massive black holes. This motivates the assessment of the resulting effect on the host dark matter density profile, and the consequences for the constraints on the ... [Phys. Rev. D 90, 103508] Published Thu Nov 06, 2014

Description: Author(s): Yan-Lin Tang, Hua-Lei Yin, Si-Jing Chen, Yang Liu, Wei-Jun Zhang, Xiao Jiang, Lu Zhang, Jian Wang, Li-Xing You, Jian-Yu Guan, Dong-Xu Yang, Zhen Wang, Hao Liang, Zhen Zhang, Nan Zhou, Xiongfeng Ma, Teng-Yun Chen, Qiang Zhang, and Jian-Wei Pan Using stable, high-efficiency single photon detectors, a quantum key distribution protocol is demonstrated and shown to be secure over a distance of 200 km. [Phys. Rev. Lett. 113, 190501] Published Thu Nov 06, 2014

Description: Author(s): Marc Kamionkowski and Ely D. Kovetz Ongoing searches for primordial gravitational waves have a new way to identify possible contaminations from cosmic dust. [Phys. Rev. Lett. 113, 191303] Published Thu Nov 06, 2014

Description: Author(s): James Healy, Carlos O. Lousto, and Yosef Zlochower We perform a set of 36 nonprecessing black-hole binary simulations with spins either aligned or counteraligned with the orbital angular momentum in order to model the final mass, spin, and recoil of the merged black hole as a function of the individual black-hole spin magnitudes and the mass ratio o... [Phys. Rev. D 90, 104004] Published Thu Nov 06, 2014

Description: Author(s): S. S. Melnik and O. V. Usatenko We study the N-step binary stationary ergodic Markov chain and analyze its differential entropy. Supposing that the correlations are weak we express the conditional probability function of the chain through the pair correlation function and represent the entropy as a functional of the pair correlato... [Phys. Rev. E 90, 052106] Published Thu Nov 06, 2014

Description: Author(s): Gilles Pütz, Denis Rosset, Tomer Jack Barnea, Yeong-Cherng Liang, and Nicolas Gisin The use of Bell’s theorem in any application or experiment relies on the assumption of free choice or, more precisely, measurement independence, meaning that the measurements can be chosen freely. Here, we prove that even in the simplest Bell test—one involving 2 parties each performing 2 binary-out... [Phys. Rev. Lett. 113, 190402] Published Thu Nov 06, 2014

Description: Author(s): Hui Zhang, Fangfei Ming, Hyun-Jung Kim, Hongbin Zhu, Qiang Zhang, Hanno H. Weitering, Xudong Xiao, Changgan Zeng, Jun-Hyung Cho, and Zhenyu Zhang Exploration and manipulation of electronic states in low-dimensional systems are of great importance in the fundamental and practical aspects of nanomaterial and nanotechnology. Here, we demonstrate that the incorporation of vacancy defects into monatomic indium wires on n-type Si(111) can stabilize... [Phys. Rev. Lett. 113, 196802] Published Thu Nov 06, 2014

Description: Author(s): O. V. Usatenko, S. S. Melnik, S. S. Apostolov, N. M. Makarov, and A. A. Krokhin We propose an efficient iterative method for generating random correlated binary sequences with a prescribed correlation function. The method is based on consecutive linear modulations of an initially uncorrelated sequence into a correlated one. Each step of modulation increases the correlations unt... [Phys. Rev. E 90, 053305] Published Thu Nov 06, 2014

Description: Author(s): A. Biffin, R. D. Johnson, I. Kimchi, R. Morris, A. Bombardi, J. G. Analytis, A. Vishwanath, and R. Coldea Materials that realize Kitaev spin models with bond-dependent anisotropic interactions have long been searched for, as the resulting frustration effects are predicted to stabilize novel forms of magnetic order or quantum spin liquids. Here, we explore the magnetism of γ-Li2IrO3, which has the topolo... [Phys. Rev. Lett. 113, 197201] Published Thu Nov 06, 2014

Description: Author(s): Hannah M. Price, Tomoki Ozawa, and Iacopo Carusotto The Berry curvature is a geometrical property of an energy band which acts as a momentum space magnetic field in the effective Hamiltonian describing single-particle quantum dynamics. We show how this perspective may be exploited to study systems directly relevant to ultracold gases and photonics. G... [Phys. Rev. Lett. 113, 190403] Published Thu Nov 06, 2014

Description: Author(s): Stéphane Fartoukh A novel collision scheme, known as “crab kissing,” opens up new possibilities for controlling quantity and quality of physics data at the high-luminosity LHC. [Phys. Rev. ST Accel. Beams 17, 111001] Published Thu Nov 06, 2014

Description: Author(s): Lin Ding and Marcos D. Caballero Evaluating curricula using stratum-specific analysis to compare performance of students with equal mastery levels as measured by the Force Concept Inventory. [Phys. Rev. ST Phys. Educ. Res. 10, 020125] Published Thu Nov 06, 2014

Description: Author(s): Shu-Ping Lee, Karen Michaeli, Jason Alicea, and Amir Yacoby Quantum spin Hall–superconductor hybrids are promising sources of topological superconductivity and Majorana modes, particularly given recent progress on HgTe and InAs/GaSb. We propose a new method of revealing topological superconductivity in extended quantum spin Hall Josephson junctions supportin... [Phys. Rev. Lett. 113, 197001] Published Thu Nov 06, 2014

Description: Author(s): D. Kamburov, Yang Liu, M. A. Mueed, M. Shayegan, L. N. Pfeiffer, K. W. West, and K. W. Baldwin Composite fermions (CFs), exotic particles formed by pairing an even number of flux quanta to each electron, provide a fascinating description of phenomena exhibited by interacting two-dimensional electrons at high magnetic fields. At and near Landau level filling ν=1/2, CFs occupy a Fermi sea and e... [Phys. Rev. Lett. 113, 196801] Published Thu Nov 06, 2014

Description: Technical Note: Artificial coral reef mesocosms for ocean acidification investigations Biogeosciences Discussions, 11, 15463-15505, 2014 Author(s): J. Leblud, L. Moulin, A. Batigny, P. Dubois, and P. Grosjean The design and evaluation of replicated artificial mesocosms are presented in the context of a thirteen month experiment on the effects of ocean acidification on tropical coral reefs. They are defined here as (semi)-closed (i.e. with or without water change from the reef) mesocosms in the laboratory with a more realistic physico-chemical environment than microcosms. Important physico-chemical parameters (i.e. pH, p O 2 , p CO 2 , total alkalinity, temperature, salinity, total alkaline earth metals and nutrients availability) were successfully monitored and controlled. Daily variations of irradiance and pH were applied to approach field conditions. Results highlighted that it was possible to maintain realistic physico-chemical parameters, including daily changes, into artificial mesocosms. On the other hand, the two identical artificial mesocosms evolved differently in terms of global community oxygen budgets although the initial biological communities and physico-chemical parameters were comparable. Artificial reef mesocosms seem to leave enough degrees of freedom to the enclosed community of living organisms to organize and change along possibly diverging pathways.

Description: Phytoplankton community structure in the North Sea: coupling between remote sensing and automated in situ analysis at the single cell level Biogeosciences Discussions, 11, 15621-15662, 2014 Author(s): M. Thyssen, S. Alvain, A. Lefèbvre, D. Dessailly, M. Rijkeboer, N. Guiselin, V. Creach, and L.-F. Artigas Phytoplankton observation in the ocean can be a challenge in oceanography. Accurate estimations of their biomass and dynamics will help to understand ocean ecosystems and refine global climate models. This requires relevant datasets of phytoplankton at a functional level and on a daily and sub meso scale. In order to achieve this, an automated, high frequency, dedicated scanning flow cytometer (SFC, Cytobuoy, NL), has been developed to cover the entire size range of phytoplankton cells whilst simultaneously taking pictures of the largest of them. This cytometer was directly connected to the water inlet of a~pocket Ferry Box during a cruise in the North Sea, 8–12 May 2011 (DYMAPHY project, INTERREG IV A "2 Seas"), in order to identify the phytoplankton community structure of near surface waters (6 m) with a high resolution spacial basis (2.2 ± 1.8 km). Ten groups of cells, distinguished on the basis of their optical pulse shapes, were described (abundance, size estimate, red fluorescence per unit volume). Abundances varied depending on the hydrological status of the traversed waters, reflecting different stages of the North Sea blooming period. Comparisons between several techniques analyzing chlorophyll a and the scanning flow cytometer, using the integrated red fluorescence emitted by each counted cell, showed significant correlations. The community structure observed from the automated flow cytometry was compared with the PHYSAT reflectance anomalies over a daily scale. The number of matchups observed between the SFC automated high frequency in situ sampling and the remote sensing was found to be two to three times better than when using traditional water sampling strategies. Significant differences in the phytoplankton community structure within the two days for which matchups were available, suggest that it is possible to label PHYSAT anomalies not only with dominant groups, but at the level of the community structure.

Description: Long term effects on regional European boreal climate due to structural vegetation changes Biogeosciences Discussions, 11, 15507-15547, 2014 Author(s): J. H. Rydsaa, F. Stordal, and L. M. Tallaksen Amplified warming at high latitudes over the past decades has led to changes in the boreal and arctic climate system, such as structural changes in high latitude ecosystems and soil moisture properties. These changes trigger land-atmosphere feedbacks, through altered energy partitioning in response to changes in albedo and surface water fluxes. Local scale changes in the arctic and boreal zone may propagate to affect large scale climatic features. In this study, MODIS land surface data are used with the Weather Research and Forecasting model (WRF V3.5.1) and Noah LSM, in a series of experiments to simulate the influence of structural vegetation changes over a Northern European boreal ecosystem. Emphasis is placed on surface energy partitioning and near surface atmospheric variables, in order to investigate changes in atmospheric response due to observed and anticipated structural vegetation changes. We find that a northward migration of evergreen needle leaf forest into tundra regions causes an increase in latent rather than sensible heat fluxes, increased near surface temperatures and boundary layer height. Shrub expansion in tundra areas has only small effects on surface fluxes. However, it influences near surface wind speeds and boundary layer height. Northward migration of mixed forest across the present southern border of the boreal forest has largely opposite effects on surface fluxes and the near surface atmosphere, and acts to moderate the overall mean regional effects of boreal forest migration on the near surface atmosphere.

Description: Evaluation of the satellite-based Global Flood Detection System for measuring river discharge: influence of local factors Hydrology and Earth System Sciences, 18, 4467-4484, 2014 Author(s): B. Revilla-Romero, J. Thielen, P. Salamon, T. De Groeve, and G. R. Brakenridge One of the main challenges for global hydrological modelling is the limited availability of observational data for calibration and model verification. This is particularly the case for real-time applications. This problem could potentially be overcome if discharge measurements based on satellite data were sufficiently accurate to substitute for ground-based measurements. The aim of this study is to test the potentials and constraints of the remote sensing signal of the Global Flood Detection System for converting the flood detection signal into river discharge values. The study uses data for 322 river measurement locations in Africa, Asia, Europe, North America and South America. Satellite discharge measurements were calibrated for these sites and a validation analysis with in situ discharge was performed. The locations with very good performance will be used in a future project where satellite discharge measurements are obtained on a daily basis to fill the gaps where real-time ground observations are not available. These include several international river locations in Africa: the Niger, Volta and Zambezi rivers. Analysis of the potential factors affecting the satellite signal was based on a classification decision tree (random forest) and showed that mean discharge, climatic region, land cover and upstream catchment area are the dominant variables which determine good or poor performance of the measure\-ment sites. In general terms, higher skill scores were obtained for locations with one or more of the following characteristics: a river width higher than 1km; a large floodplain area and in flooded forest, a potential flooded area greater than 40%; sparse vegetation, croplands or grasslands and closed to open and open forest; leaf area index 〉 2; tropical climatic area; and without hydraulic infrastructures. Also, locations where river ice cover is seasonally present obtained higher skill scores. This work provides guidance on the best locations and limitations for estimating discharge values from these daily satellite signals.

Description: Sampling frequency trade-offs in the assessment of mean transit times of tropical montane catchment waters under semi-steady-state conditions Hydrology and Earth System Sciences Discussions, 11, 12443-12488, 2014 Author(s): E. Timbe, D. Windhorst, R. Celleri, L. Timbe, P. Crespo, H.-G. Frede, J. Feyen, and L. Breuer Stream and soil waters were collected on a weekly basis in a tropical montane cloud forest catchment for two years and analyzed for stable water isotopes in order to infer transit time distribution functions and to define the mean transit times. Depending on the water type (stream or soil water), lumped distribution functions such as Exponential-Piston flow, Linear-Piston flow and Gamma models using temporal isotopic variations of precipitation event samples as input, were fitted. Samples were aggregated to daily, weekly, biweekly, monthly and bimonthly time scales in order to check the sensitivity of temporal sampling on model predictions. The study reveals that the effect of decreasing sampling frequency depends on the water type. For soil waters with transit times in the order of weeks to months, there was a clear trend of over prediction. In contrast, the trend of prediction for stream waters, with a dampened isotopic signal and mean transit times in the order of 2 to 4 years, was less clear and depending on the type of model used. The trade-off to coarse data resolutions could potentially lead to misleading conclusions on how water actually moves through the catchment, while at the same time predictions can reach better fitting efficiencies, lesser uncertainties, errors and biases. For both water types an optimal sampling frequency seems to be one or at most two weeks. The results of our analyses provide information for the planning (in particular in terms of cost-benefit and time requirements) of future fieldwork in similar Andean or other catchments.

Description: Gaseous chemistry and aerosol mechanism developments for version 3.5.1 of the online regional model, WRF-Chem Geoscientific Model Development, 7, 2557-2579, 2014 Author(s): S. Archer-Nicholls, D. Lowe, S. Utembe, J. Allan, R. A. Zaveri, J. D. Fast, Ø. Hodnebrog, H. Denier van der Gon, and G. McFiggans We have made a number of developments to the Weather, Research and Forecasting model coupled with Chemistry (WRF-Chem), with the aim of improving model prediction of trace atmospheric gas-phase chemical and aerosol composition, and of interactions between air quality and weather. A reduced form of the Common Reactive Intermediates gas-phase chemical mechanism (CRIv2-R5) has been added, using the Kinetic Pre-Processor (KPP) interface, to enable more explicit simulation of VOC degradation. N 2 O 5 heterogeneous chemistry has been added to the existing sectional MOSAIC aerosol module, and coupled to both the CRIv2-R5 and existing CBM-Z gas-phase schemes. Modifications have also been made to the sea-spray aerosol emission representation, allowing the inclusion of primary organic material in sea-spray aerosol. We have worked on the European domain, with a particular focus on making the model suitable for the study of nighttime chemistry and oxidation by the nitrate radical in the UK atmosphere. Driven by appropriate emissions, wind fields and chemical boundary conditions, implementation of the different developments are illustrated, using a modified version of WRF-Chem 3.4.1, in order to demonstrate the impact that these changes have in the Northwest European domain. These developments are publicly available in WRF-Chem from version 3.5.1 onwards.

Description: Author(s): A. Mandilara, T. Coudreau, A. Keller, and P. Milman We give explicit expressions for canonical states labeling the vast majority of entanglement equivalent classes of symmetric states of qubits and efficient algorithms for reducing a given state to the representative of the class it belongs. This way, we achieve an almost complete classification unde... [Phys. Rev. A 90, 050302] Published Fri Nov 07, 2014

Description: Changes in extreme regional sea surface height due to an abrupt weakening of the Atlantic meridional overturning circulation Ocean Science, 10, 881-891, 2014 Author(s): S.-E. Brunnabend, H. A. Dijkstra, M. A. Kliphuis, B. van Werkhoven, H. E. Bal, F. Seinstra, J. Maassen, and M. van Meersbergen As an extreme scenario of dynamical sea level changes, regional sea surface height (SSH) changes that occur in the North Atlantic due to an abrupt weakening of the Atlantic meridional overturning circulation (AMOC) are simulated. Two versions of the same ocean-only model are used to study the effect of ocean model resolution on these SSH changes: a high-resolution (HR) strongly eddying version and a low-resolution (LR) version in which the effect of eddies is parameterised. The weakening of the AMOC is induced in both model versions by applying strong freshwater perturbations around Greenland. A rapid decrease of the AMOC in the HR version induces much shorter return times of several specific regional and coastal extremes in North Atlantic SSH than in the LR version. This effect is caused by a change in main eddy pathways associated with a change in separation latitude of the Gulf Stream.

Description: Author(s): Swathi S. Hegde, Hemant Katiyar, T. S. Mahesh, and Arnab Das We experimentally demonstrate the phenomenon of dynamical many-body freezing in a periodically driven Ising chain. Theoretically [A. Das, Phys. Rev. B 82 , 172402 (2010)PRBMDO10.1103/PhysRevB.82.172402], for certain values of the drive parameters all fundamental degrees of freedom contributing to the... [Phys. Rev. B 90, 174407] Published Fri Nov 07, 2014