The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Pascal Yiou - One of the best experts on this subject based on the ideXlab platform.
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control of recent european surface climate change by Atmospheric Flow
Geophysical Research Letters, 2009Co-Authors: Robert Vautard, Pascal YiouAbstract:[1] Many changes in European surface climate have occurred over the past decades, but most of the processes driving them are not identified. In particular, the role of Atmospheric Flow in driving surface trends needs to be evaluated to better predict future regional climate. We compare observed surface climate trends with those constructed from daily Flow analogues. We find that during the last 60 years Atmospheric circulation changes are the main drivers of surface weather trends in winter, but not in summer where temperature strongly interacts with the water cycle. For instance, increasing anticyclonic conditions control the decreasing summer rainfall frequency, but rainfall amount and cloud cover have not decreased accordingly, because individual rainfall events bring more rain now than decades ago. Over the past three decades the control by Atmospheric Flow changes has weakened, indicating evolutions in the processes steering European surface climate change.
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Inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006/2007 fall/winter and recent warming in Europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
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inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006 2007 fall winter and recent warming in europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
Christophe Cassou - One of the best experts on this subject based on the ideXlab platform.
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Inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006/2007 fall/winter and recent warming in Europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
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inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006 2007 fall winter and recent warming in europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
Robert Vautard - One of the best experts on this subject based on the ideXlab platform.
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control of recent european surface climate change by Atmospheric Flow
Geophysical Research Letters, 2009Co-Authors: Robert Vautard, Pascal YiouAbstract:[1] Many changes in European surface climate have occurred over the past decades, but most of the processes driving them are not identified. In particular, the role of Atmospheric Flow in driving surface trends needs to be evaluated to better predict future regional climate. We compare observed surface climate trends with those constructed from daily Flow analogues. We find that during the last 60 years Atmospheric circulation changes are the main drivers of surface weather trends in winter, but not in summer where temperature strongly interacts with the water cycle. For instance, increasing anticyclonic conditions control the decreasing summer rainfall frequency, but rainfall amount and cloud cover have not decreased accordingly, because individual rainfall events bring more rain now than decades ago. Over the past three decades the control by Atmospheric Flow changes has weakened, indicating evolutions in the processes steering European surface climate change.
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Inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006/2007 fall/winter and recent warming in Europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
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inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006 2007 fall winter and recent warming in europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
Umberto Giostra - One of the best experts on this subject based on the ideXlab platform.
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A PDF micromixing model of dispersion for Atmospheric Flow. Part II: application to convective boundary layer
Atmospheric Environment, 2005Co-Authors: Massimo Cassiani, Pasquale Franzese, Umberto GiostraAbstract:The Lagrangian stochastic probability density function (PDF) model developed by Cassiani et al. [Atmos. Environ. (2005) Part 1] is extended to the Atmospheric convective boundary layer. The model is applied to simulate concentration statistics and PDF generated by passive releases from point and line sources in the convective boundary layer. A dynamical time-expandable grid is implemented, which optimises the computational resources required for dispersion simulations in Atmospheric Flow. A parameterised formulation for the micromixing time scale in convective conditions is derived. Model concentration statistics including mean field, fluctuations and concentration PDF are tested with four water tank experiments.
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a pdf micromixing model of dispersion for Atmospheric Flow part i development of the model application to homogeneous turbulence and to neutral boundary layer
Atmospheric Environment, 2005Co-Authors: Massimo Cassiani, Pasquale Franzese, Umberto GiostraAbstract:A Lagrangian stochastic (LS) probability density function (PDF) model has been developed to study statistics and PDF of concentration generated by continuous releases of passive substances from point and line sources in Atmospheric Flow. The model simulates the combined effect of turbulent mixing (macromixing) and molecular diffusivity (micromixing) on dispersion of tracers. Turbulent dispersion is modelled using an LS model; molecular diffusivity is simulated by an interaction by exchange with the conditional mean (IECM) model. A dynamical computational grid, which expands with time around the plume, has been developed to optimise computational time and memory requirements. The model has been tested with the results of a two-particle LS model in homogeneous turbulence and with wind tunnel observations in a neutral boundary layer. The proposed model can account for chemical reactions in a direct way with no closure assumptions.
Philippe Naveau - One of the best experts on this subject based on the ideXlab platform.
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Inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006/2007 fall/winter and recent warming in Europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.
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inconsistency between Atmospheric dynamics and temperatures during the exceptional 2006 2007 fall winter and recent warming in europe
Geophysical Research Letters, 2007Co-Authors: Pascal Yiou, Robert Vautard, Philippe Naveau, Christophe CassouAbstract:[1] Europe witnessed unprecedented warmth persisting throughout fall and winter 2006–2007, with only a few cold breaks. Whether this anomaly and recent warming in Europe can be linked to changes in Atmospheric dynamics is a key question in the climate change prospective. We show that despite the fall/winter Atmospheric Flow was favorable to warmth, it cannot explain alone such an exceptional anomaly. Observed temperatures remained well above those found for analogue Atmospheric circulations in other fall and winter seasons. Such an offset is also found during the last decade and culminates in 2006/2007. These observational results suggest that the main drivers of recent European warming are not changes in regional Atmospheric Flow and weather regimes frequencies, contrasting with observed changes before 1994.