A test of an optimal stomatal conductance scheme within the CABLE land surface model
Summary: Stomatal conductance affects the fluxes of carbon, energy and water between the vegetated land surface and the atmosphere. We test an implementation of an optimal stomatal conductance model within the CABLE land surface model (LSM). The new implementation resulted in a large reduction in the annual fluxes of transpiration across evergreen needleleaf, tundra and C4 grass regions. We conclude that optimisation theory can yield a tractable approach to predicting stomatal conductance in LSMs.
M. G. De Kauwe, J. Kala, Y.-S. Lin, A. J. Pitman, B. E. Medlyn, R. A. Duursma, G. Abramowitz, Y.-P. Wang, and D. G. Miralles Geosci. Model Dev., 8, 431-452, doi:10.5194/gmd-8-431-2015, 2015 AbstractFinal Revised Paper (PDF, 5055 KB)Discussion Paper (GMDD)
24 Feb 2015
A new WRF-Chem treatment for studying regional-scale impacts of cloud processes on aerosol and trace gases in parameterized cumuli
Summary: This work presents a new methodology for representing regional-scale impacts of cloud processing on both aerosol and trace gases in sub-grid-scale convective clouds. Using the new methodology, we can better simulate the aerosol lifecycle over large areas. The results presented in this work highlight the potential change in column-integrated amounts of black carbon, organic aerosol, and sulfate aerosol, which were found to range from -50% for black carbon to +40% for sulfate.
Modelling of primary aerosols in the chemical transport model MOCAGE: development and evaluation of aerosol physical parameterizations
B. Sič, L. El Amraoui, V. Marécal, B. Josse, J. Arteta, J. Guth, M. Joly, and P. D. Hamer Geosci. Model Dev., 8, 381-408, doi:10.5194/gmd-8-381-2015, 2015 AbstractFinal Revised Paper (PDF, 3186 KB)Discussion Paper (GMDD)
23 Feb 2015
MetUM-GOML1: a near-globally coupled atmosphere–ocean-mixed-layer model
Summary: Atmosphere-ocean interactions are best isolated in models rather than observations, but state-of-the-art models are expensive and often simulate these interactions poorly. We present a less expensive modelling framework that resolves air-sea interactions well, and permits a more rigorous identification of these interactions' effects than previously possible. In our model, air-sea interactions improve tropical rainfall variations but have limited effects on midlatitude jet streams.
Testing the performance of state-of-the-art dust emission schemes using DO4Models field data
Summary: In this paper, the performance of three commonly used dust emissions schemes is investigated using a box model environment and observational data obtained in Botswana (Sua Pan). The results suggest that all schemes fail to reproduce the observed horizontal dust flux properly. They overestimate its magnitude by several orders of magnitude. The key parameter for this mismatch is the surface crusting which limits the availability of erosive material, even at higher wind speeds.
ASAM v2.7: a compressible atmospheric model with a Cartesian cut cell approach
Summary: A detailed description of the All Scale Atmospheric Model (ASAM) is presented. To include obstacles or orographical structures within the Cartesian grid, the cut cell method is used. Discretization is realized by a mixture of finite differences and finite volumes together with a linear-implicit Rosenbrock time integration scheme. Results of idealized test cases are shown, which include conservation tests as well as convergence studies with respect to model accuracy.
The Global Gridded Crop Model Intercomparison: data and modeling protocols for Phase 1 (v1.0)
Summary: We present and describe the Global Gridded Crop Model Intercomparison (GGCMI) project, an ongoing international effort to 1) validate global models of crop productivity, 2) improve models through detailed analysis of processes, and 3) assess the impacts of climate change on agriculture and food security. We present analysis of data inputs for the project, detailed protocols for conducting and evaluating simulation outputs, and example results.
J. Elliott, C. Müller, D. Deryng, J. Chryssanthacopoulos, K. J. Boote, M. Büchner, I. Foster, M. Glotter, J. Heinke, T. Iizumi, R. C. Izaurralde, N. D. Mueller, D. K. Ray, C. Rosenzweig, A. C. Ruane, and J. Sheffield Geosci. Model Dev., 8, 261-277, doi:10.5194/gmd-8-261-2015, 2015 AbstractFinal Revised Paper (PDF, 784 KB)Discussion Paper (GMDD)
11 Feb 2015
Application of a global nonhydrostatic model with a stretched-grid system to regional aerosol simulations around Japan
Summary: An aerosol-coupled global non-hydrostatic model with a stretched-grid system has been developed to simulate aerosols on a region scale of 10 km grids. The regional simulation does require either a nesting technique or lateral boundary conditions, as opposed to general regional models. It generally reproduces monthly mean distributions of the observed sulfate and SO2 over East Asia as well as the diurnal and synoptic variations of the observed ones around the main target region, Tokyo/Japan.
D. Goto, T. Dai, M. Satoh, H. Tomita, J. Uchida, S. Misawa, T. Inoue, H. Tsuruta, K. Ueda, C. F. S. Ng, A. Takami, N. Sugimoto, A. Shimizu, T. Ohara, and T. Nakajima Geosci. Model Dev., 8, 235-259, doi:10.5194/gmd-8-235-2015, 2015 AbstractFinal Revised Paper (PDF, 17897 KB)Discussion Paper (GMDD)
11 Feb 2015
A high-order conservative collocation scheme and its application to global shallow-water equations
MATCH-SALSA – Multi-scale Atmospheric Transport and CHemistry model coupled to the SALSA aerosol microphysics model – Part 1: Model description and evaluation
Summary: We have integrated the sectional aerosol dynamics model SALSA into the European scale chemistry-transport model MATCH. The combined model reproduces observed higher particle number concentration (PNCs) in central Europe and lower concentrations in remote regions; however, the total PNC is underestimated. The low nucleation rate coefficient used in this study is an important reason for the underestimation.
Implementation and comparison of a suite of heat stress metrics within the Community Land Model version 4.5
Summary: We implemented the HumanIndexMod, which calculates 13 diagnostic heat stress metrics, into the Community Land Model (CLM4.5). The goal of this module is to have a common predictive framework for measuring heat stress globally. These metrics are in operational use by weather forecasters, industry, and agriculture. We show metric-dependent results of regional partitioning of extreme moisture and temperature levels in a 1901-2010 simulation.
Atmospheric transport and chemistry of trace gases in LMDz5B: evaluation and implications for inverse modelling
R. Locatelli, P. Bousquet, F. Hourdin, M. Saunois, A. Cozic, F. Couvreux, J.-Y. Grandpeix, M.-P. Lefebvre, C. Rio, P. Bergamaschi, S. D. Chambers, U. Karstens, V. Kazan, S. van der Laan, H. A. J. Meijer, J. Moncrieff, M. Ramonet, H. A. Scheeren, C. Schlosser, M. Schmidt, A. Vermeulen, and A. G. Williams Geosci. Model Dev., 8, 129-150, doi:10.5194/gmd-8-129-2015, 2015 AbstractFinal Revised Paper (PDF, 1711 KB)Supplement (167 KB)Discussion Paper (GMDD)
03 Feb 2015
Assessing the nonlinear response of fine particles to precursor emissions: development and application of an extended response surface modeling technique v1.0
B. Zhao, S. X. Wang, J. Xing, K. Fu, J. S. Fu, C. Jang, Y. Zhu, X. Y. Dong, Y. Gao, W. J. Wu, J. D. Wang, and J. M. Hao Geosci. Model Dev., 8, 115-128, doi:10.5194/gmd-8-115-2015, 2015 AbstractFinal Revised Paper (PDF, 2813 KB)Supplement (1843 KB)Discussion Paper (GMDD)
30 Jan 2015
Photochemical grid model implementation and application of VOC, NOx, and O3 source apportionment
Summary: The implementation and application of the Integrated Source Apportionment Method (ISAM) for O3 and its precursors for the Community Multiscale Air Quality (CMAQ) model are described. CMAQ-ISAM is a hybrid of source apportionment and source sensitivity in that O3 production is attributed to precursor sources based on the O3 formation regime. CMAQ-ISAM offers a source attribution tool for the purposes of quantifying and understanding sources and impacts of regional air pollution.
The impact of periodization methods on the kinetic energy spectra for limited-area numerical weather prediction models
Summary: The paper deals with the comparison of the common periodization methods used to obtain spectral fields of limited-area models for numerical weather prediction. The focus is on the impact the methods have on the spectra of the fields. The results show that detrending and DCT have little impact on the spectra, as does the Boyd method for extension zone. For the ALADIN and HIRLAM methods, the impact depends on the width of the extension zone - the wider the zone, the larger impact on the spectra.