Yves Balkanski | Université Versailles Saint-Quentin en Yvelines (original) (raw)
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CSIC (Consejo Superior de Investigaciones Científicas-Spanish National Research Council)
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Papers by Yves Balkanski
Journal of Environmental Radioactivity, 2015
In this study we conduct a detailed comparison of the modelling response of the Fukushima Dai-ich... more In this study we conduct a detailed comparison of the modelling response of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident with global and local observations. We use five different model versions characterized by different horizontal and vertical resolutions of the same General Circulation Model (GCM). Transport efficiencies of (137)Cs across the world are presented as an indication of the expected radioactive impact. Activity concentrations were well represented showing lower Normalized Mean Biases (NMBs) when the better resolved versions of the GCM were used. About 95% of the results using the zoom configuration over Europe (zEur) remained within a factor of 10 from the observations. Close to Japan, the model reproduced well (137)Cs concentrations using the zoom version over Asia (zAsia) showing high correlations, while more than 64% of the modelling results were found within a factor of two from the observations and more than 92% within a factor of 10. Labile and refractory rare radionuclides calculated indirectly showed larger deviations, with about 60% of the simulated concentrations within a factor of 10 from the observations. We estimate that around 23% of the released (137)Cs remained into Japan, while 76% deposited in the oceans. Around 163 TBq deposited over North America, among which 95 TBq over USA, 40 TBq over Canada and 5 TBq over Greenland). About 14 TBq deposited over Europe (mostly in the European part of Russia, Sweden and Norway) and 47 TBq over Asia (mostly in the Asian part of Russia, Philippines and South Korea), while traces were observed over Africa, Oceania and Antarctica. Since the radioactive plume followed a northward direction before its arrival to USA and then to Europe, a significant amount of about 69 TBq deposited in the Arctic, as well. These patterns of deposition are fully consistent with the most recent reports for the accident.
Climate Dynamics
During the Last Glacial Maximum (LGM, 21 kyr BP), no large ice sheets were present in northern As... more During the Last Glacial Maximum (LGM, 21 kyr BP), no large ice sheets were present in northern Asia, while northern Europe and North America (except Alaska) were heavily glaciated. We use a general circulation model with high regional resolution and a new parameterization of snow albedo to show that the ice-free conditions in northern Asia during the LGM are favoured by strong glacial dust deposition on the seasonal snow cover. Our climate model simulations indicate that mineral dust deposition on the snow surface leads to low snow albedo during the melt season. This, in turn, caused enhanced snow melt and therefore favoured snow-free peak summer conditions over almost the entire Asian continent during the LGM, whereas perennial snow cover is simulated over a large part of eastern Siberia when glacial dust deposition is not taken into account.
Geophysical Research Letters, Mar 1, 2008
... xi Page 21. XII The conference was structured so that the impact of Saharan dust on the Medit... more ... xi Page 21. XII The conference was structured so that the impact of Saharan dust on the Mediterranean Sea could be evaluated within a multi-disciplinary framework in relation to several individual themes, each of which was addressed by a number of experts. ...
ATMOSPHERIC CHEMISTRY AND PHYSICS
Atmospheric and Oceanic Optics, 2012
... [9] report an example (for ozone forcing from the transport sectors) where the efficacy is (q... more ... [9] report an example (for ozone forcing from the transport sectors) where the efficacy is (quadratically) extrapolated back to small values Page 5. 448 Shine KP, Highwood EJ, Rädel G., et al. of forcing, to infer a value that is appropriate for the actual values of the forcing. ...
Atmospheric Chemistry and Physics Discussions, 2011
... RANGE TRANSPORT; RADON 210; AEROSOLS; AFRICA; ATLANTIC ... CONVECTION; GENERAL CIRCULATION MO... more ... RANGE TRANSPORT; RADON 210; AEROSOLS; AFRICA; ATLANTIC ... CONVECTION; GENERAL CIRCULATION MODELS; INDIAN OCEAN; RADIATION MONITORING ... RADIOISOTOPES; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; LEAD ISOTOPES; MASS TRANSFER ...
Journal of Environmental Radioactivity, 2015
In this study we conduct a detailed comparison of the modelling response of the Fukushima Dai-ich... more In this study we conduct a detailed comparison of the modelling response of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident with global and local observations. We use five different model versions characterized by different horizontal and vertical resolutions of the same General Circulation Model (GCM). Transport efficiencies of (137)Cs across the world are presented as an indication of the expected radioactive impact. Activity concentrations were well represented showing lower Normalized Mean Biases (NMBs) when the better resolved versions of the GCM were used. About 95% of the results using the zoom configuration over Europe (zEur) remained within a factor of 10 from the observations. Close to Japan, the model reproduced well (137)Cs concentrations using the zoom version over Asia (zAsia) showing high correlations, while more than 64% of the modelling results were found within a factor of two from the observations and more than 92% within a factor of 10. Labile and refractory rare radionuclides calculated indirectly showed larger deviations, with about 60% of the simulated concentrations within a factor of 10 from the observations. We estimate that around 23% of the released (137)Cs remained into Japan, while 76% deposited in the oceans. Around 163 TBq deposited over North America, among which 95 TBq over USA, 40 TBq over Canada and 5 TBq over Greenland). About 14 TBq deposited over Europe (mostly in the European part of Russia, Sweden and Norway) and 47 TBq over Asia (mostly in the Asian part of Russia, Philippines and South Korea), while traces were observed over Africa, Oceania and Antarctica. Since the radioactive plume followed a northward direction before its arrival to USA and then to Europe, a significant amount of about 69 TBq deposited in the Arctic, as well. These patterns of deposition are fully consistent with the most recent reports for the accident.
Climate Dynamics
During the Last Glacial Maximum (LGM, 21 kyr BP), no large ice sheets were present in northern As... more During the Last Glacial Maximum (LGM, 21 kyr BP), no large ice sheets were present in northern Asia, while northern Europe and North America (except Alaska) were heavily glaciated. We use a general circulation model with high regional resolution and a new parameterization of snow albedo to show that the ice-free conditions in northern Asia during the LGM are favoured by strong glacial dust deposition on the seasonal snow cover. Our climate model simulations indicate that mineral dust deposition on the snow surface leads to low snow albedo during the melt season. This, in turn, caused enhanced snow melt and therefore favoured snow-free peak summer conditions over almost the entire Asian continent during the LGM, whereas perennial snow cover is simulated over a large part of eastern Siberia when glacial dust deposition is not taken into account.
Geophysical Research Letters, Mar 1, 2008
... xi Page 21. XII The conference was structured so that the impact of Saharan dust on the Medit... more ... xi Page 21. XII The conference was structured so that the impact of Saharan dust on the Mediterranean Sea could be evaluated within a multi-disciplinary framework in relation to several individual themes, each of which was addressed by a number of experts. ...
ATMOSPHERIC CHEMISTRY AND PHYSICS
Atmospheric and Oceanic Optics, 2012
... [9] report an example (for ozone forcing from the transport sectors) where the efficacy is (q... more ... [9] report an example (for ozone forcing from the transport sectors) where the efficacy is (quadratically) extrapolated back to small values Page 5. 448 Shine KP, Highwood EJ, Rädel G., et al. of forcing, to infer a value that is appropriate for the actual values of the forcing. ...
Atmospheric Chemistry and Physics Discussions, 2011
... RANGE TRANSPORT; RADON 210; AEROSOLS; AFRICA; ATLANTIC ... CONVECTION; GENERAL CIRCULATION MO... more ... RANGE TRANSPORT; RADON 210; AEROSOLS; AFRICA; ATLANTIC ... CONVECTION; GENERAL CIRCULATION MODELS; INDIAN OCEAN; RADIATION MONITORING ... RADIOISOTOPES; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; LEAD ISOTOPES; MASS TRANSFER ...