Articles | Volume 20, issue 3
https://doi.org/10.5194/npg-20-343-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/npg-20-343-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
24 May 2013
Research article |
| 24 May 2013
Development and analysis of a simple model to represent the zero rainfall in a universal multifractal framework
Université Paris Est, Ecole des Ponts ParisTech, LEESU, Marne-la-Vallée, France
Invited contribution by A. Gires, recipient of the EGU Outstanding Student Poster (OSP) Awards 2012
I. Tchiguirinskaia
Université Paris Est, Ecole des Ponts ParisTech, LEESU, Marne-la-Vallée, France
D. Schertzer
Université Paris Est, Ecole des Ponts ParisTech, LEESU, Marne-la-Vallée, France
S. Lovejoy
McGill University, Physics department, Montreal, QC, Canada
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Wind energy exhibits extreme variability in space and time. However, it also shows scaling properties (properties that remain similar across different times and spaces of measurement). This can be quantified using appropriate statistical tools. In this way, the scaling properties of power from a wind farm are analysed here. Since every turbine is manufactured by design for a rated power, this acts as an upper limit on the data. This bias is identified here using data and numerical simulations.
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This paper proposes a two-step investigation to illustrate the extent of scale effects in urban hydrology. First, fractal tools are used to highlight the scale dependency observed within GIS data inputted in urban hydrological models. Then an intensive multi-scale modelling work was carried out to confirm effects on model performances. The model was implemented at 17 spatial resolutions ranging from 100 to 5 m. Results allow the understanding of scale challenges in hydrology modelling.
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Precipitation intensities simulated by the COSMO weather prediction model are compared to radar observations over a range of spatial and temporal scales using the universal multifractal framework. Our results highlight the strong influence of meteorological and topographical features on the multifractal characteristics of precipitation. Moreover, the influence of the subgrid parameterizations of COSMO is clearly visible by a break in the scaling properties that is absent from the radar data.
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Auguste Gires, Catherine L. Muller, Marie-Agathe le Gueut, and Daniel Schertzer
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In the present study, we investigate the scaling properties of the topography of Mars. Planetary topographic fields are well known to exhibit (mono)fractal behavior. Indeed, fractal formalism is efficient in reproducing the variability observed in topography. Our results suggest a multifractal behavior from the planetary scale down to 10 km. From 10 km to 300 m, the topography seems to be simple monofractal.
S. Lovejoy, L. del Rio Amador, and R. Hébert
Earth Syst. Dynam., 6, 637–658, https://doi.org/10.5194/esd-6-637-2015, https://doi.org/10.5194/esd-6-637-2015, 2015
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Numerical climate models forecast the weather well beyond the deterministic limit. In this “macroweather” regime, they are random number generators. Stochastic models can have more realistic noises and can be forced to converge to the real-world climate. Existing stochastic models do not exploit the very long atmospheric and oceanic memories. With skill up to decades, our new ScaLIng Macroweather Model (SLIMM) exploits this to make forecasts more accurate than GCMs.
C. A. Varotsos, S. Lovejoy, N. V. Sarlis, C. G. Tzanis, and M. N. Efstathiou
Atmos. Chem. Phys., 15, 7301–7306, https://doi.org/10.5194/acp-15-7301-2015, https://doi.org/10.5194/acp-15-7301-2015, 2015
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Varotsos et al. (Theor. Appl. Climatol., 114, 725–727, 2013) found that the solar ultraviolet (UV) wavelengths exhibit 1/f-type power-law correlations. In this study, we show that the residues of the spectral solar incident flux with respect to the Planck law over a wider range of wavelengths (i.e. UV-visible) have a scaling regime too.
J. Pinel and S. Lovejoy
Atmos. Chem. Phys., 14, 3195–3210, https://doi.org/10.5194/acp-14-3195-2014, https://doi.org/10.5194/acp-14-3195-2014, 2014
G. A. Schmidt, J. D. Annan, P. J. Bartlein, B. I. Cook, E. Guilyardi, J. C. Hargreaves, S. P. Harrison, M. Kageyama, A. N. LeGrande, B. Konecky, S. Lovejoy, M. E. Mann, V. Masson-Delmotte, C. Risi, D. Thompson, A. Timmermann, L.-B. Tremblay, and P. Yiou
Clim. Past, 10, 221–250, https://doi.org/10.5194/cp-10-221-2014, https://doi.org/10.5194/cp-10-221-2014, 2014
S. Lovejoy, D. Schertzer, and D. Varon
Earth Syst. Dynam., 4, 439–454, https://doi.org/10.5194/esd-4-439-2013, https://doi.org/10.5194/esd-4-439-2013, 2013
