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Your search keyword '"Christensen, O. B."' showing total 8 results
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8 results on '"Christensen, O. B."'

2. Adjusting climate model bias for agricultural impact assessment : How to cut the mustard

Author

Galmarini, S., Cannon, Aj, Ceglar, A., Christensen, O. B., de Noblet-Ducoudre, N., Dentener, F., Doblas-Reyes, F. J., Dosio, A., Gutierrez, J. M., Iturbide, M., Jury, M., Lange, S., Loukos, H., Maiorano, A., Maraun, D., McGinnis, S., Nikulin, Grigory, Riccio, A., Sanchez, E., Solazzo, E., Toreti, A., Vrac, M., Zampieri, M., Galmarini, S., Cannon, Aj, Ceglar, A., Christensen, O. B., de Noblet-Ducoudre, N., Dentener, F., Doblas-Reyes, F. J., Dosio, A., Gutierrez, J. M., Iturbide, M., Jury, M., Lange, S., Loukos, H., Maiorano, A., Maraun, D., McGinnis, S., Nikulin, Grigory, Riccio, A., Sanchez, E., Solazzo, E., Toreti, A., Vrac, M., and Zampieri, M.

Published
2019
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3. Daily precipitation statistics in a EURO-CORDEX RCM ensemble: added value of raw and bias-corrected high-resolution simulations

Author

Casanueva, A., primary, Kotlarski, S., additional, Herrera, S., additional, Fernández, J., additional, Gutiérrez, J. M., additional, Boberg, F., additional, Colette, A., additional, Christensen, O. B., additional, Goergen, K., additional, Jacob, D., additional, Keuler, K., additional, Nikulin, G., additional, Teichmann, C., additional, and Vautard, R., additional

Published
2015
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6. Downscaling future precipitation extremes to urban hydrology scales using a spatio-temporal Neyman--Scott weather generator.

Author

Sørup, H. J. D., Christensen, O. B., Arnbjerg-Nielsen, K., and Mikkelsen, P. S.

Abstract

Spatio-temporal precipitation is modelled for urban application at 1 h temporal resolution on a 2 km grid using a Spatio-Temporal Neyman--Scott Rectangular Pulses weather generator (WG). Precipitation time series for fitting the model are obtained from a network of 60 tipping-bucket rain gauges irregularly placed in a 40 by 60 km model domain. The model simulates precipitation time series that are comparable to the observations with respect to extreme precipitation statistics. The WG is used for downscaling climate change signals from Regional Climate Models (RCMs) with spatial resolutions of 25 and 8 km respectively. Six diferent RCM simulations are used to perturb the WG with climate change signals resulting in six very different perturbation schemes. All perturbed WGs result in more extreme precipitation at the sub-daily to multi-daily level and these extremes exhibit a much more realistic spatial pattern than what is observed in RCM precipitation output. The WG seems to correlate increased extreme intensities with an increased spatial extent of the extremes meaning that the climate-change-perturbed extremes have a larger spatial extent than those of the present climate. Overall, the WG produces robust results and is seen as a reliable procedure for downscaling RCM precipitation output for use in urban hydrology. [ABSTRACT FROM AUTHOR]

Published
2015
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7. How warmer and drier will the Mediterranean region be at the end of the twenty-first century?

Author

Nicolas Da Silva, Ole Bøssing Christensen, Philippe Drobinski, Bodo Ahrens, Sylvain Mailler, Piero Lionello, Sophie Bastin, Caroline Muller, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut für Atmosphäre und Umwelt [Frankfurt/Main] (IAU), Goethe-Universität Frankfurt am Main, Danish Meteorological Institute (DMI), Euro-Mediterranean Center on Climate Change (CMCC), Drobinski, P., Da Silva, N., Bastin, S., Mailler, S., Muller, C., Ahrens, B., Christensen, O. B., and Lionello, P.

Subjects
Mediterranean climate, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Climate change, 010501 environmental sciences, Mediterranean, 01 natural sciences, Regional climate change, Mediterranean sea, Peninsula, Heat low, 0105 earth and related environmental sciences, Global and Planetary Change, geography, geography.geographical_feature_category, Advection, Human health, Dryness, Humidity, Clausius-Clapeyron law, 15. Life on land, Heat lows, Arid, Europe, 13. Climate action, Aridification, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Environmental science, MED-CORDEX, HyMeX, Dryne, Warming, Water cycle
Abstract

International audience; Nearly all regions in the world are projected to become dryer in a warming climate. Here, we investigate the Mediterranean region, often referred to as a climate change “hot spot”. From regional climate simulations, it is shown that although enhanced warming and drying over land is projected, the spatial pattern displays high variability. Indeed, drying is largely caused by enhanced warming over land. However, in Northern Europe, soil moisture alleviates warming induced drying by up to 50% due to humidity uptake from land. In already arid regions, the Mediterranean Sea is generally the only humidity source, and drying is only due to land warming. However, over Sahara and the Iberian Peninsula, enhanced warming over land is insufficient to explain the extreme drying. These regions are also isolated from humidity advection by heat lows, which are cyclonic circulation anomalies associated with surface heating over land. The cyclonic circulation scales with the temperature gradient between land and ocean which increases with climate change, reinforcing the cyclonic circulation over Sahara and the Iberian Peninsula, both diverting the zonal advection of humidity to the south of the Iberian Peninsula. The dynamics are therefore key in the warming and drying of the Mediterranean region, with extreme aridification over the Sahara and Iberian Peninsula. In these regions, the risk for human health due to the thermal load which accounts for air temperature and humidity is therefore projected to increase significantly with climate change at a level of extreme danger.

Published
2020
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