MeteoIO 2.4.2: a preprocessing library for meteorological data
Summary: The open-source MeteoIO library has been designed to perform the data preprocessing required by numerical models using large meteorological data sets, with a strong emphasis on simplicity and modularity. It retrieves, filters and resamples the data if necessary as well as provides spatial interpolations and parameterizations. It presents a uniform interface to meteorological data in the models, hides the complexity of the preprocessing and guarantees a robust behaviour in case of data errors.
A simplified permafrost-carbon model for long-term climate studies with the CLIMBER-2 coupled earth system model
Summary: Permafrost is ground that remains frozen for two or more consecutive years. An estimated 50% of the global below-ground organic carbon is stored in soils of the permafrost zone. This study presents the development and validation of a simplified permafrost-carbon mechanism for the CLIMBER-2 model. Our model development allows, for the first time, the study of the role of permafrost soils in the global carbon cycle for long timescales and for coupled palaeoclimate Earth system modelling studies.
DYPTOP: a cost-efficient TOPMODEL implementation to simulate sub-grid spatio-temporal dynamics of global wetlands and peatlands
Summary: Simulating the spatio-temporal dynamics of inundation is key to understanding the role of wetlands under past and future climate change. Here, we describe and assess the DYPTOP model that predicts the extent of inundation and the global spatial distribution of peatlands. DYPTOP makes use of high-resolution topography information and uses ecosystem water balance and peatland soil C balance criteria to simulate peatland spatial dynamics and carbon accumulation.
Evaluation of North Eurasian snow-off dates in the ECHAM5.4 atmospheric general circulation model
Summary: Snowmelt influences greatly the climatic conditions in spring. This study evaluates the timing of springtime end of snowmelt in the ECHAM5 model. A key finding is that, in much of northern Eurasia, snow disappears too early in ECHAM5, in spite of a slight cold bias in spring. This points to the need for a more comprehensive treatment of the surface energy budget. In particular, the surface temperature for the snow-covered and snow-free parts of a climate model grid cell should be separated.
P. Räisänen, A. Luomaranta, H. Järvinen, M. Takala, K. Jylhä, O. N. Bulygina, K. Luojus, A. Riihelä, A. Laaksonen, J. Koskinen, and J. Pulliainen Geosci. Model Dev., 7, 3037-3057, 2014 AbstractFinal Revised Paper (PDF, 1516 KB)Discussion Paper (GMDD)
18 Dec 2014
A global finite-element shallow-water model supporting continuous and discontinuous elements
Summary: This paper compares continuous and discontinuous discretizations of the shallow-water equations on the sphere using the flux reconstruction formulation. The discontinuous framework comes at a cost, including a reduced time step size and higher computational expense, but has a number of desirable properties which may make it desirable for future use in atmospheric models.
A strategy for GIS-based 3-D slope stability modelling over large areas
Summary: The article deals with strategies to (i) reduce computation time and to (ii) appropriately account for uncertain input parameters when applying an open source GIS sliding surface model to estimate landslide susceptibility for a 90km² study area in central Italy. For (i), the area is split into a large number of tiles, enabling the exploitation of multi-processor computing environments. For (ii), the model is run with various parameter combinations to compute the slope failure probability.
A Lagrangian advection scheme with shape matrix (LASM) for solving advection problems
Summary: In this paper we have developed a new Lagrangian advection scheme that describes the shape of discrete parcels by linear deformation matrix. An adaptive interparcel mixing algorithm is also devised to reduce the possible aliasing errors. Several test cases are conducted to validate the new scheme.
Predicting the response of the Amazon rainforest to persistent drought conditions under current and future climates: a major challenge for global land surface models
E. Joetzjer, C. Delire, H. Douville, P. Ciais, B. Decharme, R. Fisher, B. Christoffersen, J. C. Calvet, A. C. L. da Costa, L. V. Ferreira, and P. Meir Geosci. Model Dev., 7, 2933-2950, 2014 AbstractFinal Revised Paper (PDF, 1499 KB)Discussion Paper (GMDD)
10 Dec 2014
Coupling the high-complexity land surface model ACASA to the mesoscale model WRF
Tropical troposphere to stratosphere transport of carbon monoxide and long-lived trace species in the Chemical Lagrangian Model of the Stratosphere (CLaMS)
Summary: A version of the chemical transport model CLaMS is presented, which features a simplified (numerically inexpensive) chemistry scheme. The model results using this version of CLaMS show a good representation of anomaly fields of CO, CH4, N2O, and CFC-11 in the lower stratosphere. CO measurements of three instruments (COLD, HAGAR, and Falcon-CO) in the lower tropical stratosphere (during the campaign TROCCINOX in 2005) have been compared and show a good agreement within the error bars.
R. Pommrich, R. Müller, J.-U. Grooß, P. Konopka, F. Ploeger, B. Vogel, M. Tao, C. M. Hoppe, G. Günther, N. Spelten, L. Hoffmann, H.-C. Pumphrey, S. Viciani, F. D'Amato, C. M. Volk, P. Hoor, H. Schlager, and M. Riese Geosci. Model Dev., 7, 2895-2916, 2014 AbstractFinal Revised Paper (PDF, 2844 KB)Supplement (1869 KB)Discussion Paper (GMDD)
08 Dec 2014
The North American Carbon Program Multi-scale Synthesis and Terrestrial Model Intercomparison Project – Part 2: Environmental driver data
Y. Wei, S. Liu, D. N. Huntzinger, A. M. Michalak, N. Viovy, W. M. Post, C. R. Schwalm, K. Schaefer, A. R. Jacobson, C. Lu, H. Tian, D. M. Ricciuto, R. B. Cook, J. Mao, and X. Shi Geosci. Model Dev., 7, 2875-2893, 2014 AbstractFinal Revised Paper (PDF, 1704 KB)Supplement (6017 KB)Discussion Paper (GMDD)
05 Dec 2014
Sensitivity of simulated CO2 concentration to regridding of global fossil fuel CO2 emissions
Evaluation of the ECHAM family radiation codes performance in the representation of the solar signal
Summary: The performance of the main generations of the ECHAM shortwave radiation schemes is analysed in terms of the representation of the solar signal in the heating rates. The way to correct missing or underrepresented spectral intervals in the solar signal in the heating rates is suggested using the example of ECHAM6 and six-band ECHAM5 schemes. The suggested method is computationally fast and suitable for any other radiation scheme.
GEOtop 2.0: simulating the combined energy and water balance at and below the land surface accounting for soil freezing, snow cover and terrain effects
Summary: GEOtop is a fine scale grid-based simulator that represents the heat and water budgets at and below the soil surface, reproduces the highly non-linear interactions between the water and energy balance during soil freezing and thawing and simulates snow cover. The core components of GEOtop 2.0. are described. Based on a synthetic simulation, it is shown that the interaction of processes represented in GEOtop 2.0. can result in phenomena that are relevant for applications involving frozen soils.
Uncertainty in Lagrangian pollutant transport simulations due to meteorological uncertainty from a mesoscale WRF ensemble
Summary: Uncertainty in Lagrangian particle dispersion model simulations was evaluated using an ensemble of WRF meteorological model runs. Uncertainty of tracer concentrations due solely to meteorological uncertainty is 30-40%. Spatial and temporal averaging reduces the uncertainty marginally. Tracer age uncertainty due solely to meteorological uncertainty is 15-20%. These are lower bounds on the uncertainty, because a number of processes are not accounted for in the analysis.