The Experts below are selected from a list of 8238 Experts worldwide ranked by ideXlab platform
Edriss S. Titi - One of the best experts on this subject based on the ideXlab platform.
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Global Existence of Weak Solutions to the Compressible Primitive Equations of Atmospheric Dynamics with Degenerate Viscosities
Siam Journal on Mathematical Analysis, 2020Co-Authors: Edriss S. TitiAbstract:We show the existence of global weak solutions to the three-dimensional compressible primitive equations of Atmospheric Dynamics with degenerate viscosities. In analogy with the case of the compres...
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Global Existence of Weak Solutions to the Compressible Primitive Equations of Atmospheric Dynamics with Degenerate Viscosities
arXiv: Analysis of PDEs, 2018Co-Authors: Edriss S. TitiAbstract:We show the existence of global weak solutions to the three-dimensional compressible primitive equations of Atmospheric Dynamics with degenerate viscosities. In analogy with the case of the compressible Navier-Stokes equations, the weak solutions satisfy the basic energy inequality, the Bresh-Desjardins entropy inequality and the Mellet-Vasseur estimate. These estimates play an important role in establishing the compactness of the vertical velocity of the approximating solutions, and therefore are essential to recover the vertical velocity in the weak solutions.
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Finite-Time Blowup for the Inviscid Primitive Equations of Oceanic and Atmospheric Dynamics
Communications in Mathematical Physics, 2015Co-Authors: Slim Ibrahim, Kenji Nakanishi, Edriss S. TitiAbstract:In an earlier work we have shown the global (for all initial data and all time) well-posedness of strong solutions to the three-dimensional viscous primitive equations of large scale oceanic and Atmospheric Dynamics. In this paper we show that for certain class of initial data the corresponding smooth solutions of the inviscid (non-viscous) primitive equations, if they exist, they blow up in finite time. Specifically, we consider the three-dimensional inviscid primitive equations in a three-dimensional infinite horizontal channel, subject to periodic boundary conditions in the horizontal directions, and with no-normal flow boundary conditions on the solid, top and bottom boundaries. For certain class of initial data we reduce this system into the two-dimensional system of primitive equations in an infinite horizontal strip with the same type of boundary conditions; and then we show that for specific sub-class of initial data the corresponding smooth solutions of the reduced inviscid two-dimensional system develop singularities in finite time.
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finite time blowup for the inviscid primitive equations of oceanic and Atmospheric Dynamics
arXiv: Analysis of PDEs, 2012Co-Authors: Slim Ibrahim, Kenji Nakanishi, Edriss S. TitiAbstract:In an earlier work we have shown the global (for all initial data and all time) well-posedness of strong solutions to the three-dimensional viscous primitive equations of large scale oceanic and Atmospheric Dynamics. In this paper we show that for certain class of initial data the corresponding smooth solutions of the inviscid (non-viscous) primitive equations blow up in finite time. Specifically, we consider the three-dimensional inviscid primitive equations in a three-dimensional infinite horizontal channel, subject to periodic boundary conditions in the horizontal directions, and with no-normal flow boundary conditions on the solid, top and bottom, boundaries. For certain class of initial data we reduce this system into the two-dimensional system of primitive equations in an infinite horizontal strip with the same type of boundary conditions; and then show that for specific sub-class of initial data the corresponding smooth solutions of the reduced inviscid two-dimensional system develop singularities in finite time.
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.
Slim Ibrahim - One of the best experts on this subject based on the ideXlab platform.
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Finite-Time Blowup for the Inviscid Primitive Equations of Oceanic and Atmospheric Dynamics
Communications in Mathematical Physics, 2015Co-Authors: Slim Ibrahim, Kenji Nakanishi, Edriss S. TitiAbstract:In an earlier work we have shown the global (for all initial data and all time) well-posedness of strong solutions to the three-dimensional viscous primitive equations of large scale oceanic and Atmospheric Dynamics. In this paper we show that for certain class of initial data the corresponding smooth solutions of the inviscid (non-viscous) primitive equations, if they exist, they blow up in finite time. Specifically, we consider the three-dimensional inviscid primitive equations in a three-dimensional infinite horizontal channel, subject to periodic boundary conditions in the horizontal directions, and with no-normal flow boundary conditions on the solid, top and bottom boundaries. For certain class of initial data we reduce this system into the two-dimensional system of primitive equations in an infinite horizontal strip with the same type of boundary conditions; and then we show that for specific sub-class of initial data the corresponding smooth solutions of the reduced inviscid two-dimensional system develop singularities in finite time.
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finite time blowup for the inviscid primitive equations of oceanic and Atmospheric Dynamics
arXiv: Analysis of PDEs, 2012Co-Authors: Slim Ibrahim, Kenji Nakanishi, Edriss S. TitiAbstract:In an earlier work we have shown the global (for all initial data and all time) well-posedness of strong solutions to the three-dimensional viscous primitive equations of large scale oceanic and Atmospheric Dynamics. In this paper we show that for certain class of initial data the corresponding smooth solutions of the inviscid (non-viscous) primitive equations blow up in finite time. Specifically, we consider the three-dimensional inviscid primitive equations in a three-dimensional infinite horizontal channel, subject to periodic boundary conditions in the horizontal directions, and with no-normal flow boundary conditions on the solid, top and bottom, boundaries. For certain class of initial data we reduce this system into the two-dimensional system of primitive equations in an infinite horizontal strip with the same type of boundary conditions; and then show that for specific sub-class of initial data the corresponding smooth solutions of the reduced inviscid two-dimensional system develop singularities in finite time.
Pascal Yiou - 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.
N. B. Crosby - One of the best experts on this subject based on the ideXlab platform.
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Toward an Improved Representation of Middle Atmospheric Dynamics Thanks to the ARISE Project
Surveys in Geophysics, 2018Co-Authors: E. Blanc, L. Ceranna, A. Charlton-perez, E. Marchetti, L. G. Evers, T. Kvaerna, J. Lastovicka, Lars Eliasson, Alain Hauchecorne, N. B. CrosbyAbstract:This paper reviews recent progress toward understanding the Dynamics of the middle atmosphere in the framework of the Atmospheric Dynamics Research InfraStructure in Europe (ARISE) initiative. The middle atmosphere, integrating the stratosphere and mesosphere, is a crucial region which influences tropospheric weather and climate. Enhancing the understanding of middle atmosphere Dynamics requires improved measurement of the propagation and breaking of planetary and gravity waves originating in the lowest levels of the atmosphere. Inter-comparison studies have shown large discrepancies between observations and models, especially during unresolved disturbances such as sudden stratospheric warmings for which model accuracy is poorer due to a lack of observational constraints. Correctly predicting the variability of the middle atmosphere can lead to improvements in tropospheric weather forecasts on timescales of weeks to season. The ARISE project integrates different station networks providing observations from ground to the lower thermosphere, including the infrasound system developed for the Comprehensive Nuclear-Test-Ban Treaty verification, the Lidar Network for the Detection of Atmospheric Composition Change, complementary meteor radars, wind radiometers, ionospheric sounders and satellites. This paper presents several examples which show how multi-instrument observations can provide a better description of the vertical Dynamics structure of the middle atmosphere, especially during large disturbances such as gravity waves activity and stratospheric warming events. The paper then demonstrates the interest of ARISE data in data assimilation for weather forecasting and re-analyzes the determination of Dynamics evolution with climate change and the monitoring of Atmospheric extreme events which have an Atmospheric signature, such as thunderstorms or volcanic eruptions.
