Development and application of the WRFPLUS-Chem online chemistry adjoint and WRFDA-Chem assimilation system
Summary: WRFPLUS-Chem is a coupled meteorology-chemistry adjoint and tangent linear model, with applications in sensitivity analysis and four dimensional variational data assimilation. The linearized models are verified against finite difference approximations from the nonlinear forward model, WRF-Chem. A new checkpointing scheme enables data assimilation beyond six hours. New capabilities are demonstrated in an emission sensitivity study.
System for Automated Geoscientific Analyses (SAGA) v. 2.1.4
Summary: The System for Automated Geoscientific Analyses (SAGA) is a comprehensive and globally established open-source Geographic Information System (GIS) for scientific analysis and modeling. The current version 2.1.4 offers more than 700 tools which represent the broad scopes of SAGA in numerous fields of geoscientific endeavor. In this paper, we inform about the system’s architecture and functionality and highlight the wide spectrum of scientific applications of SAGA in a review of published studies.
O. Conrad, B. Bechtel, M. Bock, H. Dietrich, E. Fischer, L. Gerlitz, J. Wehberg, V. Wichmann, and J. Böhner Geosci. Model Dev. Discuss., 8, 2271-2312, 2015 AbstractDiscussion Paper (PDF, 1959 KB)Supplement (8333 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
27 Feb 2015
Improving the dynamics of northern vegetation in the ORCHIDEE ecosystem model
Summary: This study presents a new parameterization of vegetation dynamics module in the process-based ecosystem model ORCHIDEE for mid-to-high latitude regions, showing significant improvements in the modeling of the distribution of tree functional types north of 40°N. A new set of metrics is proposed to quantify the performance of ORCHIDEE, which integrates uncertainties in the observational datasets.
D. Zhu, S. S. Peng, P. Ciais, N. Viovy, A. Druel, M. Kageyama, G. Krinner, P. Peylin, C. Ottlé, S. L. Piao, B. Poulter, D. Schepaschenko, and A. Shvidenko Geosci. Model Dev. Discuss., 8, 2213-2270, 2015 AbstractDiscussion Paper (PDF, 10389 KB)Supplement (3203 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
27 Feb 2015
3-D visualization of ensemble weather forecasts – Part 2: Forecasting warm conveyor belt situations for aircraft-based field campaigns
Summary: This article presents the application of interactive 3D visualization of ensemble
weather predictions to forecasting warm conveyor belt situations during aircraft-based atmospheric research campaigns. A method to predict 3D probabilities of the spatial occurrence of WCBs is developed and integrated into the 3D visualization tool "Met.3D", introduced in the first part of this two-paper study. A case study demonstrates the use of 3D and uncertainty visualization for weather forecasting.
3-D visualization of ensemble weather forecasts – Part 1: The visualization tool Met.3D (version 1.0)
Summary: This article presents "Met.3D", a new open-source tool for the interactive 3D visualization of numerical ensemble weather predictions. Met.3D builds a bridge from proven 2D visualization methods commonly used in meteorology to 3D visualization and implements approaches to using the ensemble to allow the user to assess forecast uncertainty. The article is the first part of a two-paper study discussing how 3D and ensemble visualization can be used in a meaningful way suited to weather forecasting.
Impact of climate, vegetation, soil and crop management variables on multi-year ISBA-A-gs simulations of evapotranspiration over a Mediterranean crop site
Summary: This paper investigates the impacts of errors in climate, vegetation, soil and irrigation drivers on the simulation of evapotranspiration (ET) from the ISBA-A-gs land surface model over a 12-year Mediterranean crop succession. Vegetation dynamic and irrigation have the greatest impact on simulated evapotranspiration. Differences in climate datasets slightly influence simulated ET. Errors in the forcing variables generate smaller impact on simulated ET than errors in the soil parameters.
Representing life in the Earth system with soil microbial functional traits in the MIMICS model
Summary: Projecting biogeochemical responses to environmental change requires multi-scaled perspectives. However, microbes, the drivers of soil organic matter decomposition and stabilization, remain notably absent from models used to project carbon cycle – climate feedbacks. Here, we apply and evaluate representations of microbial functional diversity across scales and find that such representations may be critical to accurately project soil carbon dynamics in a changing world.
Multi-generational oxidation model to simulate secondary organic aerosol in a 3-D air quality model
Summary: Multi-generational oxidation of organic vapors can significantly alter the mass, chemical composition and properties of secondary organic aerosol (SOA). Here, we implement a semi-explicit, constrained multigenerational oxidation model of Cappa and Wilson (2012) in a 3D air quality model. When compared with results from a current generation SOA model, we predict similar mass concentrations of SOA but a different chemical composition. O:C ratios of SOA are in line with those measured globally.
AROME-WMED, a real-time mesoscale model designed for the HyMeX Special Observation Periods
Summary: To support the instrument deployment during HyMeX, aiming at studying the high precipitation in the Mediterranean area, a dedicated version of the operational convective-scale AROME-France model was developed: the AROME-WMED model. This paper presents the main features of this numerical weather prediction system in terms of data assimilation and forecast. The forecast skill of the model is then assessed during the HyMeX special observation periods and compared to the operational AROME-France.
N. Fourrié, É. Bresson, M. Nuret, C. Jany, P. Brousseau, A. Doerenbecher, M. Kreitz, O. Nuissier, E. Sevault, H. Bénichou, M. Amodei, and F. Pouponneau Geosci. Model Dev. Discuss., 8, 1801-1856, 2015 AbstractDiscussion Paper (PDF, 7150 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
20 Feb 2015
DYNAMICO, an icosahedral hydrostatic dynamical core designed for consistency and versatility
Summary: The design of the icosahedral atmospheric dynamical core DYNAMICO is presented. The key contribution is to combine a strict separatation of kinematics from dynamics to a Hamiltonian formulation of the equations of motion in a non-Eulerian vertical coordinate to achieve energetic consistency. This approach allows a unified treatment of various equations of motion, here multi-layer shallow-water equations and hydrostatic primitive equations.
Summary: This paper introduces and presents the Spatial Processes in HYdrology (SPHY) model (v2.0), its underlying concepts, and some typical applications. The main strengths of the SPHY model are: (i) it integrates most relevant hydrological processes, (ii) is setup modular, (iii) is easy adjustable and applicable, (iv) can easily be linked to remote sensing data, and (v) can be applied for operational as well as strategic decision support.
W. Terink, A. F. Lutz, G. W. H. Simons, W. W. Immerzeel, and P. Droogers Geosci. Model Dev. Discuss., 8, 1687-1748, 2015 AbstractDiscussion Paper (PDF, 4195 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
19 Feb 2015
Application of WRF/Chem version 3.4.1 over North America under the AQMEII Phase 2: evaluation of 2010 application and responses of air quality and meteorology–chemistry interactions to changes in emissions and meteorology from 2006 to 2010
Summary: The application of WRF/Chem to North America shows that it can reproduce most observations and their variation trends from 2006 to 2010. The inclusion of chemical feedbacks reduces biases in meteorological predictions in 2010 but increases errors comparing to WRF. The net changes in meteorology from 2006 to 2010 are mostly influenced by changes in meteorology and those of ozone and fine particles are influenced by changes in emissions and chemical BCONs, and to a lesser extent meteorology.
The Parallelized Large-Eddy Simulation Model (PALM) version 4.0 for atmospheric and oceanic flows: model formulation, recent developments, and future perspectives
Summary: The paper gives a detailed description of the PArallelized Large-eddy simulation Model (PALM) version 4.0 for the simulation of turbulent atmospheric and oceanic boundary layer flows. The model is optimized for use on massively parallel computer architectures and has been applied for various boundary-layer research studies over the last 15 years by various work groups all over the world. Beside the model description we outline past PALM applications and also discuss future perspectives.
B. Maronga, M. Gryschka, R. Heinze, F. Hoffmann, F. Kanani-Sühring, M. Keck, K. Ketelsen, M. O. Letzel, M. Sühring, and S. Raasch Geosci. Model Dev. Discuss., 8, 1539-1637, 2015 AbstractDiscussion Paper (PDF, 1407 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
19 Feb 2015
EwE-F 1.0: an implementation of Ecopath with Ecosim in Fortran 95/2003 for coupling
Summary: Marine ecosystem-based management requires integrating multiple models in one unified scheme. Being the most widely used food web model, Ecopath with Ecosim (EwE) is potentially a crucial component of such schemes. Written in Visual Basic for the .NET framework, integration of EwE with physical and/or biogeochemical oceanographic models, which are mostly in Fortran, is complicated. We release a re-coding of EwE in Fortran (EwE-F) so as to facilitate integrating EwE in coupled modelling schemes.
On the use of Schwarz–Christoffel conformal mappings to the grid generation for global ocean models
Summary: This article applies Schwarz-Christoffel (SC) conformal mappings, especially those for multiple-connected regions, to the grid generation for oceanic general circulation models. The generated grids could achieve: (1) removal of landmass & easier computational load balancing, (2) potentially better spatial resolution on continental boundaries, and alignment of these boundaries to grid lines. These grids could readily be utilized in current Bryan-Cox-Semtner type OGCMs.
GASAKe: forecasting landslide activations by a genetic-algorithms based hydrological model
Summary: A model for predicting the timing of activation of rainfall-induced landslides is presented. Calibration against real events is based on Genetic Algorithms, and provides a family of optimal solutions (kernels) that maximize the fitness function. Accordingly, a set of mobility functions is obtained through convolution with rainfall. Once properly validated, the model allows to estimating future landslide activations in the same study area, by employing either recorded or forecasted rainfall.
Experiences with distributed computing for meteorological applications: Grid computing and Cloud computing
Summary: Three practical meteorological applications with different characteristics highlight the core computer science aspects and applicability
of distributed computing to meteorology. Presenting Cloud and Grid computing this paper shows use case scenarios fitting a wide range of meteorological applications from operational to research studies. The paper concludes that distributed computing complements and extends existing high performance computing concepts.
Validation of reactive gases and aerosols in the MACC global analysis and forecast system
Summary: The MACC project is preparing the operational atmosphere service of the European Copernicus Programme, and uses data assimilation to combine atmospheric models with available observations. Our paper provides an overview of the aerosol and trace gas validation activity of MACC. Topics are the validation requirements, the measurement data, the assimilation systems, the upgrade procedure, operational aspects and the scoring methods. A summary is provided of recent results, including special events.
H. Eskes, V. Huijnen, A. Arola, A. Benedictow, A.-M. Blechschmidt, E. Botek, O. Boucher, I. Bouarar, S. Chabrillat, E. Cuevas, R. Engelen, H. Flentje, A. Gaudel, J. Griesfeller, L. Jones, J. Kapsomenakis, E. Katragkou, S. Kinne, B. Langerock, M. Razinger, A. Richter, M. Schultz, M. Schulz, N. Sudarchikova, V. Thouret, M. Vrekoussis, A. Wagner, and C. Zerefos Geosci. Model Dev. Discuss., 8, 1117-1169, 2015 AbstractDiscussion Paper (PDF, 3208 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMDSpecial Issue
05 Feb 2015
Evaluation of near surface ozone over Europe from the MACC reanalysis
Summary: This work is an extended evaluation of near surface ozone as part of the global reanalysis of atmospheric composition, produced within the European Funded project MACC (Monitoring Atmospheric Composition and Climate). It includes an evaluation over the period 2003-2012 and provides an overall assessment of the modelling system performance with respect to near surface ozone for specific European subregions.
E. Katragkou, P. Zanis, A. Tsikerdekis, J. Kapsomenakis, D. Melas, H. Eskes, J. Flemming, V. Huijnen, A. Inness, M. G. Schultz, O. Stein, and C. S. Zerefos Geosci. Model Dev. Discuss., 8, 1077-1115, 2015 AbstractDiscussion Paper (PDF, 8339 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMDSpecial Issue
05 Feb 2015
Evaluation of the high resolution WRF-Chem air quality forecast and its comparison with statistical ozone predictions
The Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM): a parsimonious, satellite data-driven model of high-latitude CO2 exchange
Summary: PolarVPRM uses a diagnostic, remote-sensing based approach optimized for polar regions to estimate net ecosystem CO2 exchange (NEE) between the high-latitude land surface and the atmosphere. PolarVPRM NEE shows close agreement with NEE observed from eddy covariance sites, relative to other models. Examination of per-pixel trends in PolarVPRM NEE and its drivers (North America north of 55 N, 2001-2012) indicate arctic greening and boreal browning in response to changing environmental conditions.
Analysis of the impact of inhomogeneous emissions in a semi-parameterized street canyon model
Summary: Semi-parameterized street canyon models are popular due to their speed and low input requirements. One often used assumption is that emissions are homogeneously distributed in the entire length and width of the street. It is thus the aim of the present study to analyse the impact of this assumption by implementing an inhomogeneous emission geometry scheme and validating it. The results show an improved performance, however confounded by challenges estimating the emissions accurately.
T.-B. Ottosen, K. E. Kakosimos, C. Johansson, O. Hertel, J. Brandt, H. Skov, R. Berkowicz, T. Ellermann, S. S. Jensen, and M. Ketzel Geosci. Model Dev. Discuss., 8, 935-977, 2015 AbstractDiscussion Paper (PDF, 2745 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
04 Feb 2015
Development of prognostic aerosol–cloud interactions combining a chemistry transport model and a regional climate model
Summary: We have showed that a coupled modelling system is beneficial in the sense that more complex processes can be included to better represent the aerosol processes starting from their formation, their interactions with clouds and provide better estimate of radiative forcing. Using this model set up, we estimated an annual mean 'indirect' radiative forcing of -0.64W/m2. This means that aerosols, solely by their capability of altering the microphysical properties of clouds can cool the Earth system.
M. A. Thomas, M. Kahnert, C. Andersson, H. Kokkola, U. Hansson, C. Jones, J. Langner, and A. Devasthale Geosci. Model Dev. Discuss., 8, 897-933, 2015 AbstractDiscussion Paper (PDF, 5632 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
03 Feb 2015
Finite-Element Sea Ice Model (FESIM), version 2
Summary: Unstructured meshes allow multi-resolution modelling of ocean dynamics. Sea-ice models formulated on unstructured meshes are a necessary component of ocean models intended for climate studies. This work present a description of finite-element sea ice model which is used as a component of finite-element sea ice ocean circulation model. The principles underlying its design can be of interest to other groups pursuing ocean modelling on unstructured meshes.
An updated interparcel mixing algorithm in the Lagrangian advection scheme with shape matrix (LASM) v0.2
Summary: The interparcel mixing algorithm in the Lagrangian advection scheme with shape matrix (LASM) is updated to make the scheme more robust. The new algorithm is more effective in controlling the shape of parcels, which is vital for long time simulation. LASM is inherently shape-preserving without any complicated filter or limiter, so it is linear. This fact contributes to the ability of LASM of preserving the sum of multiple tracers exactly.
An improved representation of physical permafrost dynamics in the JULES land surface model
Summary: Permafrost, ground that is frozen for 2 or more years, is found extensively in the Arctic. It stores large quantities of carbon, which may be released under climate warming, so it is important to include it in climate models. Here we improve the representation of permafrost in a climate model land-surface scheme, both in the numerical representation of soil and snow, and by adding the effects of organic soils and moss. Site simulations show significantly improved soil temperature and thaw depth.
S. Chadburn, E. Burke, R. Essery, J. Boike, M. Langer, M. Heikenfeld, P. Cox, and P. Friedlingstein Geosci. Model Dev. Discuss., 8, 715-759, 2015 AbstractDiscussion Paper (PDF, 2985 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMD
30 Jan 2015
S2P3-R (v1.0): a framework for efficient regional modelling of physical and biological structures and processes in shelf seas
Summary: Our relatively shallow shelf seas are warmed at the surface in spring and summer, while strong tidal currents act to mix away the surface warmth. These competing effects strongly influence the conditions for seasonal growth of the phytoplankton that support marine food webs. We have developed a versatile framework for fast computer modelling of shelf seas, to explore seasonal and year-to-year variations of warming and plankton productivity, tested against observations in different regions.
Development of PM2.5 source impact spatial fields using a hybrid source apportionment air quality model
Summary: An integral part of air quality management is knowledge of the impact of pollutant sources on ambient concentrations of particulate matter (PM). This work presents a novel spatiotemporal source apportionment method that generates source impacts for the continental U.S. Key sources presented include fossil fuel combustion, biomass burning, dust, sea salt, as well as agricultural activities, biogenics, and aircraft.
A generic approach to explicit simulation of uncertainty in the NEMO ocean model
Summary: In this paper, a simple and generic implementation approach is presented, with the aim of transforming a deterministic ocean model (like NEMO) into a probabilistic model. With this approach, several kinds of stochastic parameterizations are implemented to simulate the non-deterministic effect of unresolved processes, unresolved scales, unresolved diversity. The method is illustrated with three applications, showing that uncertainties can produce a major effect in the model simulations.
ICON-ART 1.0 – a new online-coupled model system from the global to regional scale
D. Rieger, M. Bangert, I. Bischoff-Gauss, J. Förstner, K. Lundgren, D. Reinert, J. Schröter, H. Vogel, G. Zängl, R. Ruhnke, and B. Vogel Geosci. Model Dev. Discuss., 8, 567-614, 2015 AbstractDiscussion Paper (PDF, 3978 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMDSpecial Issue
27 Jan 2015
The Met Office Global Coupled model 2.0 (GC2) configuration
K. D. Williams, C. M. Harris, A. Bodas-Salcedo, J. Camp, R. E. Comer, D. Copsey, D. Fereday, T. Graham, R. Hill, T. Hinton, P. Hyder, S. Ineson, G. Masato, S. F. Milton, M. J. Roberts, D. P. Rowell, C. Sanchez, A. Shelly, B. Sinha, D. N. Walters, A. West, T. Woollings, and P. K. Xavier Geosci. Model Dev. Discuss., 8, 521-565, 2015 AbstractDiscussion Paper (PDF, 4791 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMD
27 Jan 2015
Reaching the lower stratosphere: validating an extended vertical grid for COSMO
Summary: An extended vertical grid for the regional atmosperic model COSMO was developed which reaches the lower stratosphere. This extended vertical grid was used in model runs simulating almost a full year. The model output was then validated using temperature and relative humidity measurements taken from synoptic radio sondes. Using this extended vertical grid, the model was found to run stably and produce realistic values.
Plant functional type classification for Earth System Models: results from the European Space Agency's Land Cover Climate Change Initiative
Summary: Land cover is an essential variable in earth system models and determines conditions driving biogeochemical, energy, and water exchange between ecosystems and the atmosphere. A methodology is presented for mapping plant functional types used in global vegetation models from a updated land cover classification system and open-source conversion tool, resulting from a consultative process among map producers and modelers engaged in the European Space Agency’s Land Cover Climate Change Initiative.
B. Poulter, N. MacBean, A. Hartley, I. Khlystova, O. Arino, R. Betts, S. Bontemps, M. Boettcher, C. Brockmann, P. Defourny, S. Hagemann, M. Herold, G. Kirches, C. Lamarche, D. Lederer, C. Ottlé, M. Peters, and P. Peylin Geosci. Model Dev. Discuss., 8, 429-462, 2015 AbstractDiscussion Paper (PDF, 2172 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMD
21 Jan 2015
The integrated Earth System Model (iESM): formulation and functionality
Summary: The integrated Earth System Model (iESM) has been developed as a
new tool for projecting the joint human/climate system. The
iESM is based upon coupling an Integrated assessment model (IAM)
and an Earth system model (ESM) into a common modeling
infrastructure. By introducing heretofore-omitted
feedbacks between natural and societal drivers in iESM, we can improve
scientific understanding of the human-Earth system
W. D. Collins, A. P. Craig, J. E. Truesdale, A. V. Di Vittorio, A. D. Jones, B. Bond-Lamberty, K. V. Calvin, J. A. Edmonds, S. H. Kim, A. M. Thomson, P. Patel, Y. Zhou, J. Mao, X. Shi, P. E. Thornton, L. P. Chini, and G. C. Hurtt Geosci. Model Dev. Discuss., 8, 381-427, 2015 AbstractDiscussion Paper (PDF, 1447 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for GMD
21 Jan 2015
The software architecture of climate models: a graphical comparison of CMIP5 and EMICAR5 configurations
Summary: This paper describes an analysis of the software architecture of global climate models. The analysis provides a visualization of structure of these models, and reveals interesting differences between the models developed at different research labs.
ESP v2.0: enhanced method for exploring emission impacts of future scenarios in the United States – addressing spatial allocation
Summary: We present and demonstrate Version 2.0 of the Emission Scenario Projection (ESP) method. This method produces multi-decadal air pollutant emission projections suitable for air quality modeling. The method focuses on energy-related emissions, including those from the electric sector, buildings, industry and transportation. ESP v2.0 enhances ESP v1.0 by taking into population growth and migration and land use change into consideration.
A two-layer canopy with thermal inertia for an improved modelling of the sub-canopy snowpack energy-balance
Summary: We improve the canopy module of a very detailed snow model, Snowpack, with a view of a more consistant representation of the sub-canopy energy balance, of interest for the snowpack.
We show that adding a formulation of (i) the canopy heat capacity and (ii) a lowermost canopy layer (alike trunk + solar shaded leaves) yields significant improvement in the representation of sub-canopy incoming longwave radiations, especially at nighttime. This energy is a contributor to snowmelt.
CH4 parameter estimation in CLM4.5bgc using surrogate global optimization
Summary: We tune the CH4-related parameters of the Community Land Model (CLM) using surrogate global optimization in order to reduce the discrepancies between the CLM predictions and observed CH4 emissions. This is the first application of a surrogate optimization method to calibrate a global climate model. We found that the observation data drives the model to predict more CH4 emissions in the northern latitudes and less in the tropics.
J. Müller, R. Paudel, C. A. Shoemaker, J. Woodbury, Y. Wang, and N. Mahowald Geosci. Model Dev. Discuss., 8, 141-207, 2015 AbstractDiscussion Paper (PDF, 4264 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMD
06 Jan 2015
EMPOWER-1.0: an Efficient Model of Planktonic ecOsystems WrittEn in R
Summary: Ecosystem models provide a powerful tool for simulating ocean biology. Care must be exercised when selecting appropriate equations and parameter values to represent chosen marine ecosystems. Here, we present an efficient plankton model testbed, using simplified physics and coded in the freely available language R. Multiple runs can be undertaken for different ocean sites, permitting thorough evaluation of ecosystem model performance. The testbed also serves as an excellent resource for teaching.
A high-resolution ocean and sea-ice modelling system for the Arctic and North Atlantic Oceans
Summary: 1/12th degree resolution runs of Arctic-Atlantic were compared for the period 2003-2009. We found:
-accurate representation of sea surface height and of its statistics.
-model temperature and salinity in general agreement with in-situ measurements, but upper ocean properties in Beaufort Sea are challenging.
-distribution of concentration and volume of sea ice is improved when slowing down the ice.
-further improvements require better initial conditions and modifications to mixing.
On the wind stress formulation over shallow waters in atmospheric models
Summary: In spite of the substantial observational evidence supporting a higher drag over shallow waters than over the open ocean, regional and global models widely use a single formulation valid for the open ocean. Results of this work indicate that adding the extra drag is necessary to reconcile model results with long term observations of the wind profile within the first 100 m of the atmosphere, being the first modeling evidence supporting the reported added drag over shallow waters.
Development of efficient GPU parallelization of WRF Yonsei University planetary boundary layer scheme
Summary: To expedite weather research and prediction, we have put tremendous effort into developing an accelerated implementation of the entire WRF model using GPU massive parallel computing architecture. This paper presents our efficient GPU-based design on WRF YSU PBL scheme. Using one NVIDIA Tesla K40 GPU, the GPU-based YSU PBL scheme achieves a speedup of 193x with respect to its runtime on one CPU core. We can even boost the speedup to 360x with respect to one CPU core as two K40 GPUs are applied.
M. Huang, J. Mielikainen, B. Huang, H. Chen, H.-L. A. Huang, and M. D. Goldberg Geosci. Model Dev. Discuss., 7, 8031-8077, 2014 AbstractDiscussion Paper (PDF, 2612 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for GMD
21 Nov 2014
Verifications of the nonlinear numerical model and polarization relations of atmospheric acoustic-gravity waves
Summary: We performed high-resolution numerical simulations of nonlinear acoustic-gravity waves (AGWs) at altitudes 0 – 500 km and compared them with analytical polarization relations of linear AGW theory. After some transition time, t > te, the numbers of numerically simulated and analytical pairs of AGW parameters, which are equal with confidence 95%, are larger at altitudes 30 - 60 km and are smaller at t < te. The differences reveal circumstances, when numerical simulations of waves are required.
Summary: This paper provides a full GPU accelerated solution of mpiPOM. We design and implement several optimizing methods:
(i) computation optimization in a single GPU
(ii) communication optimization among multiple GPUs
(iii) I/O optimization between a hybrid GPU and CPU.
Our experimental results indicate that the performance of the gpuPOM on a workstation containing 4 GPUs is comparable to a powerful cluster with 408 CPU cores and it reduces the energy consumption by 6.8 times.
Thermo-hydro-mechanical processes in fractured rock formations during glacial advance
Summary: The paper examines the coupled thermo-hydro-mechanical (THM) processes that develop in a fractured rock region within a fluid-saturated rock mass due to loads imposed by an advancing glacier. This scenario needs to be examined in order to assess the suitability of potential sites for the location of deep geologic repositories for the storage of high-level nuclear waste. The THM processes are examined using a computational multiphysics approach.