@article{17992, abstract = {Here we demonstrate for the first time that strained silanes couple directly to gold electrodes in break-junction conductance measurements. We find that strained silicon molecular wires terminated by alkyl sulfide aurophiles behave effectively as single-molecule parallel circuits with competing sulfur-to-sulfur (low G) and sulfur-to-silacycle (high G) pathways. We can switch off the high conducting sulfur-to-silacycle pathway by altering the environment of the electrode surface to disable the Au–silacycle coupling. Additionally, we can switch between conductive pathways in a single molecular junction by modulating the tip–substrate electrode distance. This study provides a new molecular design to control electronics in silicon-based single molecule wires.}, author = {Su, Timothy A. and Widawsky, Jonathan R. and Li, Haixing and Klausen, Rebekka S. and Leighton, James L. and Steigerwald, Michael L. and Venkataraman, Latha and Nuckolls, Colin}, issn = {1520-5126}, journal = {Journal of the American Chemical Society}, number = {49}, pages = {18331--18334}, publisher = {American Chemical Society}, title = {{Silicon ring strain creates high-conductance pathways in single-molecule circuits}}, doi = {10.1021/ja410656a}, volume = {135}, year = {2013}, } @article{17993, abstract = {We demonstrate a new method of achieving rectification in single molecule devices using the high-bias properties of gold–carbon bonds. Our design for molecular rectifiers uses a symmetric, conjugated molecular backbone with a single methylsulfide group linking one end to a gold electrode and a covalent gold–carbon bond at the other end. The gold–carbon bond results in a hybrid gold-molecule “gateway” state pinned close to the Fermi level of one electrode. Through nonequilibrium transport calculations, we show that the energy of this state shifts drastically with applied bias, resulting in rectification at surprisingly low voltages. We use this concept to design and synthesize a family of diodes and demonstrate through single-molecule current–voltage measurements that the rectification ratio can be predictably and efficiently tuned. This result constitutes the first experimental demonstration of a rationally tunable system of single-molecule rectifiers. More generally, the results demonstrate that the high-bias properties of “gateway” states can be used to provide additional functionality to molecular electronic systems.}, author = {Batra, Arunabh and Darancet, Pierre and Chen, Qishui and Meisner, Jeffrey S. and Widawsky, Jonathan R. and Neaton, Jeffrey B. and Nuckolls, Colin and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {12}, pages = {6233--6237}, publisher = {American Chemical Society}, title = {{Tuning rectification in single-molecular diodes}}, doi = {10.1021/nl403698m}, volume = {13}, year = {2013}, } @article{17994, abstract = {Charge transfer through noncovalent interactions is crucial to a variety of chemical phenomena. These interactions are often weak and nonspecific and can coexist, making it difficult to isolate the transfer efficiency of one type of bond versus another. Here, we show how core-hole clock spectroscopy can be used to measure charge transfer through noncovalent interactions. We study the model system 1,4-benzenediamine molecules bound on an Au surface through an Au–N donor–acceptor bond as these are known to provide a pathway for electronic conduction in molecular devices. We study different phases of the molecule/Au system and map charge delocalization times from carbon and nitrogen sites on the molecule. We show that charge delocalization across Au–N donor–acceptor bond occurs in less than 500 as. Furthermore, the Au–N bond also enhances delocalization times from neighboring carbon sites, demonstrating that fast charge transfer across a metal–organic interface does not require a covalently bonded system.}, author = {Kladnik, Gregor and Cvetko, Dean and Batra, Arunabh and Dell’Angela, Martina and Cossaro, Albano and Kamenetska, Maria and Venkataraman, Latha and Morgante, Alberto}, issn = {1932-7455}, journal = {The Journal of Physical Chemistry C}, number = {32}, pages = {16477--16482}, publisher = {American Chemical Society}, title = {{Ultrafast charge transfer through noncovalent Au–N interactions in molecular systems}}, doi = {10.1021/jp405229b}, volume = {117}, year = {2013}, } @article{17995, abstract = {We have measured the single-molecule conductance of a family of bithiophene derivatives terminated with methyl sulfide gold-binding linkers using a scanning tunneling microscope based break-junction technique. We find a broad distribution in the single-molecule conductance of bithiophene compared with that of a methyl sulfide terminated biphenyl. Using a combination of experiments and calculations, we show that this increased breadth in the conductance distribution is explained by the difference in 5-fold symmetry of thiophene rings as compared to the 6-fold symmetry of benzene rings. The reduced symmetry of thiophene rings results in a restriction on the torsion angle space available to these molecules when bound between two metal electrodes in a junction, causing each molecular junction to sample a different set of conformers in the conductance measurements. In contrast, the rotations of biphenyl are essentially unimpeded by junction binding, allowing each molecular junction to sample similar conformers. This work demonstrates that the conductance of bithiophene displays a strong dependence on the conformational fluctuations accessible within a given junction configuration, and that the symmetry of such small molecules can significantly influence their conductance behaviors.}, author = {Dell, Emma J. and Capozzi, Brian and DuBay, Kateri H. and Berkelbach, Timothy C. and Moreno, Jose Ricardo and Reichman, David R. and Venkataraman, Latha and Campos, Luis M.}, issn = {1520-5126}, journal = {Journal of the American Chemical Society}, number = {32}, pages = {11724--11727}, publisher = {American Chemical Society}, title = {{Impact of molecular symmetry on single-molecule conductance}}, doi = {10.1021/ja4055367}, volume = {135}, year = {2013}, } @article{17996, abstract = {We compare the conductance of a series of amine-terminated oligophenyl and alkane molecular junctions formed with Ag and Au electrodes using the scanning tunneling microscope based break-junction technique. For these molecules that conduct through the highest occupied molecular orbital, junctions formed with Au electrodes are more conductive than those formed with Ag electrodes, consistent with the lower work function for Ag. The measured conductance decays exponentially with molecular backbone length with a decay constant that is essentially the same for Ag and Au electrodes. However, the formation and evolution of molecular junctions upon elongation are very different for these two metals. Specifically, junctions formed with Ag electrodes sustain significantly longer elongation when compared with Au due to a difference in the initial gap opened up when the metal point-contact is broken. Using this observation and density functional theory calculations of junction structure and conductance we explain the trends observed in the single molecule junction conductance. Our work thus opens a new path to the conductance measurements of a single molecule junction in Ag electrodes.}, author = {Kim, Taekyeong and Vázquez, Héctor and Hybertsen, Mark S. and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {7}, pages = {3358--3364}, publisher = {American Chemical Society}, title = {{Conductance of molecular junctions formed with silver electrodes}}, doi = {10.1021/nl401654s}, volume = {13}, year = {2013}, } @article{17997, abstract = {We report the simultaneous measurement of conductance and thermopower of highly conducting single-molecule junctions using a scanning tunneling microscope-based break-junction setup. We start with molecular backbones (alkanes and oligophenyls) terminated with trimethyltin end groups that cleave off in situ to create junctions where terminal carbons are covalently bonded to the Au electrodes. We apply a thermal gradient across these junctions and measure their conductance and thermopower. Because of the electronic properties of the highly conducting Au–C links, the thermoelectric properties and power factor are very high. Our results show that the molecular thermopower increases nonlinearly with the molecular length while conductance decreases exponentially with increasing molecular length. Density functional theory calculations show that a gateway state representing the Au–C covalent bond plays a key role in the conductance. With this as input, we analyze a series of simplified models and show that a tight-binding model that explicitly includes the gateway states and the molecular backbone states accurately captures the experimentally measured conductance and thermopower trends.}, author = {Widawsky, J. R. and Chen, W. and Vázquez, H. and Kim, T. and Breslow, R. and Hybertsen, M. S. and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {6}, pages = {2889--2894}, publisher = {American Chemical Society}, title = {{Length-dependent thermopower of highly conducting Au–C bonded single molecule junctions}}, doi = {10.1021/nl4012276}, volume = {13}, year = {2013}, } @article{17998, abstract = {We measure simultaneously force and conductance of Ag metal point-contacts under ambient conditions at room temperature. We observe the formation of contacts with a conductance close to 1 G0, the quantum of conductance, which can be attributed to a single-atom contact, similar to those formed by Au. We also find two additional conductance features at ∼0.4 G0 and ∼1.3 G0, which have been previously ascribed to contacts with oxygen contaminations. Here, using a conductance cross-correlation technique, we distinguish three different atomic-scale structural motifs and analyze their rupture forces and stiffness. Our results allow us to assign the ∼0.4 G0 conductance feature to an Ag–O–Ag contact and the ∼1.3 G0 feature to an Ag–Ag single-atom contact with an oxygen atom in parallel. Utilizing complementary information from force and conductance, we thus demonstrate the correlation of conductance with the structural evolution at the atomic scale.}, author = {Aradhya, Sriharsha V. and Frei, Michael and Halbritter, András and Venkataraman, Latha}, issn = {1936-086X}, journal = {ACS Nano}, number = {4}, pages = {3706--3712}, publisher = {American Chemical Society}, title = {{Correlating structure, conductance, and mechanics of silver atomic-scale contacts}}, doi = {10.1021/nn4007187}, volume = {7}, year = {2013}, } @article{17999, abstract = {The idea of using individual molecules as active electronic components provided the impetus to develop a variety of experimental platforms to probe their electronic transport properties. Among these, single-molecule junctions in a metal–molecule–metal motif have contributed significantly to our fundamental understanding of the principles required to realize molecular-scale electronic components from resistive wires to reversible switches. The success of these techniques and the growing interest of other disciplines in single-molecule-level characterization are prompting new approaches to investigate metal–molecule–metal junctions with multiple probes. Going beyond electronic transport characterization, these new studies are highlighting both the fundamental and applied aspects of mechanical, optical and thermoelectric properties at the atomic and molecular scales. Furthermore, experimental demonstrations of quantum interference and manipulation of electronic and nuclear spins in single-molecule circuits are heralding new device concepts with no classical analogues. In this Review, we present the emerging methods being used to interrogate multiple properties in single molecule-based devices, detail how these measurements have advanced our understanding of the structure–function relationships in molecular junctions, and discuss the potential for future research and applications.}, author = {Aradhya, Sriharsha V. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {6}, pages = {399--410}, publisher = {Springer Nature}, title = {{Single-molecule junctions beyond electronic transport}}, doi = {10.1038/nnano.2013.91}, volume = {8}, year = {2013}, } @inbook{18351, abstract = {Motion-based segmentation is an important tool for the analysis of articulated shapes. As such, it plays an important role in mechanical engineering, computer graphics, and computer vision. In this chapter, we study motion-based segmentation of 3D articulated shapes. We formulate motion-based surface segmentation as a piecewise-smooth regularization problem for the transformations between several poses. Using Lie-group representation for the transformation at each surface point, we obtain a simple regularized fitting problem. An Ambrosio-Tortorelli scheme of a generalized Mumford-Shah model gives us the segmentation functional without assuming prior knowledge on the number of parts or even the articulated nature of the object. Experiments on several standard datasets compare the results of the proposed method to state-of-the-art algorithms.}, author = {Rosman, Guy and Bronstein, Michael M. and Bronstein, Alexander and Wolf, Alon and Kimmel, Ron}, booktitle = {Innovations for Shape Analysis}, editor = {Breuß, Michael and Bruckstein, Alfred and Maragos, Petros}, isbn = {9783642341403}, issn = {1612-3786}, pages = {263--281}, publisher = {Springer Nature}, title = {{Group-Valued Regularization for Motion Segmentation of Articulated Shapes}}, doi = {10.1007/978-3-642-34141-0_12}, year = {2013}, } @inbook{18352, abstract = {Feature-based analysis is becoming a very popular approach for geometric shape analysis. Following the success of this approach in image analysis, there is a growing interest in finding analogous methods in the 3D world. Maximally stable component detection is a low computation cost and high repeatability method for feature detection in images.In this study, a diffusion-geometry based framework for stable component detection is presented, which can be used for geometric feature detection in deformable shapes.The vast majority of studies of deformable 3D shapes models them as the two-dimensional boundary of the volume of the shape. Recent works have shown that a volumetric shape model is advantageous in numerous ways as it better captures the natural behavior of non-rigid deformations. We show that our framework easily adapts to this volumetric approach, and even demonstrates superior performance.A quantitative evaluation of our methods on the SHREC’10 and SHREC’11 feature detection benchmarks as well as qualitative tests on the SCAPE dataset show its potential as a source of high-quality features. Examples demonstrating the drawbacks of surface stable components and the advantage of their volumetric counterparts are also presented.}, author = {Litman, Roee and Bronstein, Alexander and Bronstein, Michael M.}, booktitle = {Innovations for Shape Analysis}, editor = {Breuß, Michael and Bruckstein, Alfred and Maragos, Petros}, isbn = {9783642341403}, issn = {1612-3786}, pages = {161 -- 189}, publisher = {Springer Nature}, title = {{Stable Semi-local Features for Non-rigid Shapes}}, doi = {10.1007/978-3-642-34141-0_8}, year = {2013}, } @inproceedings{18385, abstract = {In this paper we present a framework for real time enhancement of speech signals. Our method leverages a new process-centric approach for sparse and parsimonious models, where the representation pursuit is obtained applying a deterministic function or process rather than solving an optimization problem. We first propose a rank-regularized robust version of non-negative matrix factorization (NMF) for modeling time-frequency representations of speech signals in which the spectral frames are decomposed as sparse linear combinations of atoms of a low-rank dictionary. Then, a parametric family of pursuit processes is derived from the iteration of the proximal descent method for solving this model. We present several experiments showing successful results and the potential of the proposed framework. Incorporating discriminative learning makes the proposed method significantly outperform exact NMF algorithms, with fixed latency and at a fraction of it's computational complexity.}, author = {Sprechmann, Pablo and Bronstein, Alexander and Bronstein, Michael and Sapiro, Guillermo}, booktitle = {2013 IEEE International Conference on Acoustics, Speech and Signal Processing}, issn = {2379-190X}, location = {Vancouver, BC, Canada}, publisher = {IEEE}, title = {{Learnable low rank sparse models for speech denoising}}, doi = {10.1109/icassp.2013.6637624}, year = {2013}, } @inproceedings{18386, abstract = {A method for removing impulse noise from audio signals by fusing multiple copies of the same recording is introduced in this paper. The proposed algorithm exploits the fact that while in general multiple copies of a given recording are available, all sharing the same master, most degradations in audio signals are record-dependent. Our method first seeks for the optimal non-rigid alignment of the signals that is robust to the presence of sparse outliers with arbitrary magnitude. Unlike previous approaches, we simultaneously find the optimal alignment of the signals and impulsive degradation. This is obtained via continuous dynamic time warping computed solving an Eikonal equation. We propose to use our approach in the derivative domain, reconstructing the signal by solving an inverse problem that resembles the Poisson image editing technique. The proposed framework is here illustrated and tested in the restoration of old gramophone recordings showing promising results; however, it can be used in other applications where different copies of the signal of interest are available and the degradations are copy-dependent.}, author = {Sprechmann, Pablo and Bronstein, Alexander and Morel, Jean-Michel and Sapiro, Guillermo}, booktitle = {2013 IEEE International Conference on Acoustics, Speech and Signal Processing}, issn = {2379-190X}, location = {Vancouver, BC, Canada}, publisher = {IEEE}, title = {{Audio restoration from multiple copies}}, doi = {10.1109/icassp.2013.6637774}, year = {2013}, } @inproceedings{18395, abstract = {Dynamic Time Warping (DTW), is a simple but efficient technique for matching sequences with rigid deformation. Therefore, it is frequently used for matching shapes in general, and shapes of handwritten words in Document Image Analysis tasks. As DTW is computationally expensive, efficient algorithms for fast computation are crucial. Retrieving images from large scale datasets using DTW, suffers from the constraint of linear searching of all sample in the datasets. Fast approximation algorithms for image retrieval are mostly based on normed spaces where the triangle inequality holds, which is unfortunately not the case with the DTW metric. In this paper we present a novel approach for fast search of handwritten words within large datasets of shapes. The presented approach is based on the Boost-Map [1] algorithm, for embedding the feature space with the DTW measurement to an euclidean space and use the Local Sensitivity Hashing algorithm (LSH) to rank the k-nearest neighbors of a query image. The algorithm, first, processes and embeds objects of the large data sets to a normed space. Fast approximation of k-nearest neighbors using LSH on the embedding space, generates the top kranked samples which are examined using the real DTW distance to give final accurate results. We demonstrate our method on a database of 45; 800 images of word-parts extracted from the IFN/ENIT database [11] and images collected from 51 different writers. Our method achieves a speedup of 4 orders of magnitude over the exact method, at the cost of only a 2:2% reduction in accuracy.}, author = {Saabni, Raid and Bronstein, Alexander}, booktitle = {2012 International Conference on Frontiers in Handwriting Recognition}, isbn = {9781467322621}, location = {Bari, Italy}, publisher = {IEEE}, title = {{Fast key-word searching using 'BoostMap' based embedding}}, doi = {10.1109/icfhr.2012.204}, year = {2013}, } @article{18421, abstract = {The use of Laplacian eigenbases has been shown to be fruitful in many computer graphics applications. Today, state-of-the-art approaches to shape analysis, synthesis, and correspondence rely on these natural harmonic bases that allow using classical tools from harmonic analysis on manifolds. However, many applications involving multiple shapes are obstacled by the fact that Laplacian eigenbases computed independently on different shapes are often incompatible with each other. In this paper, we propose the construction of common approximate eigenbases for multiple shapes using approximate joint diagonalization algorithms, taking as input a set of corresponding functions (e.g. indicator functions of stable regions) on the two shapes. We illustrate the benefits of the proposed approach on tasks from shape editing, pose transfer, correspondence, and similarity.}, author = {Kovnatsky, A. and Bronstein, M. M. and Bronstein, Alexander and Glashoff, K. and Kimmel, R.}, issn = {1467-8659}, journal = {Computer Graphics Forum}, number = {2pt4}, pages = {439--448}, publisher = {Wiley}, title = {{Coupled quasi‐harmonic bases}}, doi = {10.1111/cgf.12064}, volume = {32}, year = {2013}, } @article{18422, abstract = {We present a novel sparse modeling approach to non-rigid shape matching using only the ability to detect repeatable regions. As the input to our algorithm, we are given only two sets of regions in two shapes; no descriptors are provided so the correspondence between the regions is not know, nor we know how many regions correspond in the two shapes. We show that even with such scarce information, it is possible to establish very accurate correspondence between the shapes by using methods from the field of sparse modeling, being this, the first non-trivial use of sparse models in shape correspondence. We formulate the problem of permuted sparse coding, in which we solve simultaneously for an unknown permutation ordering the regions on two shapes and for an unknown correspondence in functional representation. We also propose a robust variant capable of handling incomplete matches. Numerically, the problem is solved efficiently by alternating the solution of a linear assignment and a sparse coding problem. The proposed methods are evaluated qualitatively and quantitatively on standard benchmarks containing both synthetic and scanned objects.}, author = {Pokrass, J. and Bronstein, Alexander and Bronstein, M. M. and Sprechmann, P. and Sapiro, G.}, issn = {1467-8659}, journal = {Computer Graphics Forum}, number = {2pt4}, pages = {459--468}, publisher = {Wiley}, title = {{Sparse modeling of intrinsic correspondences}}, doi = {10.1111/cgf.12066}, volume = {32}, year = {2013}, } @article{18437, abstract = { Elg1 and Srs2 are two proteins involved in maintaining genome stability in yeast. After DNA damage, the homotrimeric clamp PCNA, which provides stability and processivity to DNA polymerases and serves as a docking platform for DNA repair enzymes, undergoes modification by the ubiquitin-like molecule SUMO. PCNA SUMOylation helps recruit Srs2 and Elg1 to the replication fork. In the absence of Elg1, both SUMOylated PCNA and Srs2 accumulate at the chromatin fraction, indicating that Elg1 is required for removing SUMOylated PCNA and Srs2 from DNA. Despite this interaction, which suggests that the two proteins work together, double mutants elg1Δ srs2Δ have severely impaired growth as haploids and exhibit synergistic sensitivity to DNA damage and a synergistic increase in gene conversion. In addition, diploid elg1Δ srs2Δ double mutants are dead, which implies that an essential function in the cell requires at least one of the two gene products for survival. To gain information about this essential function, we have carried out a high copy number suppressor screen to search for genes that, when overexpressed, suppress the synthetic lethality between elg1Δ and srs2Δ. We report the identification of 36 such genes, which are enriched for functions related to DNA- and chromatin-binding, chromatin packaging and modification, and mRNA export from the nucleus.}, author = {Gazy, Inbal and Liefshitz, Batia and Bronstein, Alexander and Parnas, Oren and Atias, Nir and Sharan, Roded and Kupiec, Martin}, issn = {2160-1836}, journal = { G3: Genes, Genomes, Genetics}, number = {5}, pages = {917--926}, publisher = {Oxford University Press}, title = {{A genetic screen for high copy number suppressors of the synthetic lethality between elg1Δ and srs2Δ in yeast}}, doi = {10.1534/g3.113.005561}, volume = {3}, year = {2013}, } @article{18440, abstract = {In this paper, we explore the use of the diffusion geometry framework for the fusion of geometric and photometric information in local and global shape descriptors. Our construction is based on the definition of a diffusion process on the shape manifold embedded into a high-dimensional space where the embedding coordinates represent the photometric information. Experimental results show that such data fusion is useful in coping with different challenges of shape analysis where pure geometric and pure photometric methods fail.}, author = {Bronstein, Alexander and Kovnatsky, Artiom and Raviv, Dan and Bronstein, Michael M. and Kimmel, Ron}, issn = {2079-7338}, journal = {Numerical Mathematics: Theory, Methods and Applications}, number = {1}, pages = {199--222}, publisher = {Global Science Press}, title = {{Geometric and photometric data fusion in non-rigid shape analysis}}, doi = {10.4208/nmtma.2013.mssvm11}, volume = {6}, year = {2013}, } @article{18441, abstract = {Partial similarity of shapes is a challenging problem arising in many important applications in computer vision, shape analysis, and graphics, e.g. when one has to deal with partial information and acquisition artifacts. The problem is especially hard when the underlying shapes are non-rigid and are given up to a deformation. Partial matching is usually approached by computing local descriptors on a pair of shapes and then establishing a point-wise non-bijective correspondence between the two, taking into account possibly different parts. In this paper, we introduce an alternative correspondence-less approach to matching fragments to an entire shape undergoing a non-rigid deformation. We use region-wise local descriptors and optimize over the integration domains on which the integral descriptors of the two parts match. The problem is regularized using the Mumford-Shah functional. We show an efficient discretization based on the Ambrosio-Tortorelli approximation generalized to triangular point clouds and meshes, and present experiments demonstrating the success of the proposed method.}, author = {Bronstein, Alexander and Pokrass, Jonathan and Bronstein, Michael M.}, issn = {2079-7338}, journal = {Numerical Mathematics: Theory, Methods and Applications}, number = {1}, pages = {223--244}, publisher = {Global Science Press}, title = {{Partial shape matching without point-wise correspondence}}, doi = {10.4208/nmtma.2013.mssvm12}, volume = {6}, year = {2013}, } @article{12633, abstract = {We use two hydrological models of varying complexity to study the Juncal River Basin in the Central Andes of Chile with the aim to understand the degree of conceptualization and the spatial structure that are needed to model present and future streamflows. We use a conceptual semi-distributed model based on elevation bands [Water Evaluation and Planning (WEAP)], frequently used for water management, and a physically oriented, fully distributed model [Topographic Kinematic Wave Approximation and Integration ETH Zurich (TOPKAPI-ETH)] developed for research purposes mainly. We evaluate the ability of the two models to reproduce the key hydrological processes in the basin with emphasis on snow accumulation and melt, streamflow and the relationships between internal processes. Both models are capable of reproducing observed runoff and the evolution of Moderate-resolution Imaging Spectroradiometer snow cover adequately. In spite of WEAP's simple and conceptual approach for modelling snowmelt and its lack of glacier representation and snow gravitational redistribution as well as a proper routing algorithm, this model can reproduce historical data with a similar goodness of fit as the more complex TOPKAPI-ETH. We show that the performance of both models can be improved by using measured precipitation gradients of higher temporal resolution. In contrast to the good performance of the conceptual model for the present climate, however, we demonstrate that the simplifications in WEAP lead to error compensation, which results in different predictions in simulated melt and runoff for a potentially warmer future climate. TOPKAPI-ETH, using a more physical representation of processes, depends less on calibration and thus is less subject to a compensation of errors through different model components. Our results show that data obtained locally in ad hoc short-term field campaigns are needed to complement data extrapolated from long-term records for simulating changes in the water cycle of high-elevation catchments but that these data can only be efficiently used by a model applying a spatially distributed physical representation of hydrological processes.}, author = {Ragettli, S. and Cortés, G. and McPhee, J. and Pellicciotti, Francesca}, issn = {0885-6087}, journal = {Hydrological Processes}, keywords = {Water Science and Technology}, number = {23}, pages = {5674--5695}, publisher = {Wiley}, title = {{An evaluation of approaches for modelling hydrological processes in high-elevation, glacierized Andean watersheds}}, doi = {10.1002/hyp.10055}, volume = {28}, year = {2013}, } @article{12638, abstract = {Central Asian water resources largely depend on melt water generated in the Pamir and Tien Shan mountain ranges. To estimate future water availability in this region, it is necessary to use climate projections to estimate the future glacier extent and volume. In this study, we evaluate the impact of uncertainty in climate change projections on the future glacier extent in the Amu and Syr Darya river basins. To this end we use the latest climate change projections generated for the upcoming IPCC report (CMIP5) and, for comparison, projections used in the fourth IPCC assessment (CMIP3). With these projections we force a regionalized glacier mass balance model, and estimate changes in the basins' glacier extent as a function of the glacier size distribution in the basins and projected temperature and precipitation. This glacier mass balance model is specifically developed for implementation in large scale hydrological models, where the spatial resolution does not allow for simulating individual glaciers and data scarcity is an issue. Although the CMIP5 ensemble results in greater regional warming than the CMIP3 ensemble and the range in projections for temperature as well as precipitation is wider for the CMIP5 than for the CMIP3, the spread in projections of future glacier extent in Central Asia is similar for both ensembles. This is because differences in temperature rise are small during periods of maximum melt (July–September) while differences in precipitation change are small during the period of maximum accumulation (October–February). However, the model uncertainty due to parameter uncertainty is high, and has roughly the same importance as uncertainty in the climate projections. Uncertainty about the size of the decline in glacier extent remains large, making estimates of future Central Asian glacier evolution and downstream water availability uncertain.}, author = {Lutz, A. F. and Immerzeel, W. W. and Gobiet, A. and Pellicciotti, Francesca and Bierkens, M. F. P.}, issn = {1607-7938}, journal = {Hydrology and Earth System Sciences}, keywords = {General Earth and Planetary Sciences, General Engineering, General Environmental Science}, number = {9}, pages = {3661--3677}, publisher = {Copernicus GmbH}, title = {{Comparison of climate change signals in CMIP3 and CMIP5 multi-model ensembles and implications for Central Asian glaciers}}, doi = {10.5194/hess-17-3661-2013}, volume = {17}, year = {2013}, }