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4. DRIFTSONDES : Providing In Situ Long-Duration Dropsonde Observations over Remote Regions

Author

Cohn, Stephen A., Hock, Terry, Cocquerez, Philippe, Wang, Junhong, Rabier, Florence, Parsons, David, Harr, Patrick, Wu, Chun-Chieh, Drobinski, Philippe, Karbou, Fatima, Vénel, Stéphanie, Vargas, André, Fourrié, Nadia, Saint-Ramond, Nathalie, Guidard, Vincent, Doerenbecher, Alexis, Hsu, Huang-Hsiung, Lin, Po-Hsiung, Chou, Ming-Dah, Redelsperger, Jean-Luc, Martin, Charlie, Fox, Jack, Potts, Nick, Young, Kathryn, and Cole, Hal

Published
2013

7. Relative current effect on short wave growth

Author

Veras Guimarães, Pedro, Ardhuin, Fabrice, Perignon, Yves, Benetazzo, Alvise, Bouin, Marie-noëlle, Garnier, Valerie, Redelsperger, Jean-luc, Accensi, Mickael, Thomson, Jim, Veras Guimarães, Pedro, Ardhuin, Fabrice, Perignon, Yves, Benetazzo, Alvise, Bouin, Marie-noëlle, Garnier, Valerie, Redelsperger, Jean-luc, Accensi, Mickael, and Thomson, Jim

Abstract

Short waves growth is characterized by nonlinear and dynamic processes that couple ocean and atmosphere. Ocean surface currents can have a strong impact on short wave steepness and breaking, modifying the surface roughness, and consequently their growth. However, this interplay is poorly understood and observations are scarce. This work uses in situ measurements of near-surface winds, surface current, and waves under strong tidal current conditions to investigate the relative wind speed effect on the local short waves growth. Those observations were extensive compared with numerical modeling using WAVEWACHIII, where the simulations repeatedly fail to reproduce the observed wind sea energy under strong current conditions. Our field observations and coupled ocean-atmosphere numerical simulations suggest that surface currents can strongly modulate surface winds. That is a local process, better observed closer to the boundary layer than at 10 m height. Yet, it can cause a significant impact on the local wind shear estimation and consequently on the local waves’ growth source term. The results presented here show that the relative wind effect is not well solved inside spectral waves models, causing a significant bias around the peak of wind sea energy.

Published
2022
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8. Parallelization of the French Meteorological Mesoscale Model MésoNH

Author

Jabouille, Patrick, Guivarch, Ronan, Kloos, Philippe, Gazen, Didier, Gicquel, Nicolas, Giraud, Luc, Asencio, Nicole, Ducrocq, Veronique, Escobar, Juan, Redelsperger, Jean-Luc, Stein, Joël, Pinty, Jean-Pierre, Amestoy, Patrick, editor, Berger, Philippe, editor, Daydé, Michel, editor, Ruiz, Daniel, editor, Duff, Iain, editor, Frayssé, Valérie, editor, and Giraud, Luc, editor

Published
1999
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9. AMMA-MODEL INTERCOMPARISON PROJECT

Author

Hourdin, Frédéric, Musat, Ionela, Guichard, Françoise, Ruti, Paolo Michele, Favot, Florence, Filiberti, Marie-Angèle, Pham, Maï, Grandpeix, Jean-Yves, Polcher, Jan, Marquet, Pascal, Boone, Aaron, Lafore, Jean-Philippe, Redelsperger, Jean-Luc, Dell’aquila, Alessandro, Doval, Teresa Losada, Traore, Abdoul Khadre, and Gallée, Hubert

Published
2010

16. A simplified atmospheric boundary layer model for an improved representation of air–sea interactions in eddying oceanic models: implementation and first evaluation in NEMO (4.0)

Author

Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-luc, Giordani, Hervé, Brivoal, Théo, Madec, Gurvan, Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-luc, Giordani, Hervé, Brivoal, Théo, and Madec, Gurvan

Abstract

A simplified model of the atmospheric boundary layer (ABL) of intermediate complexity between a bulk parameterization and a three-dimensional atmospheric model is developed and integrated to the Nucleus for European Modelling of the Ocean (NEMO) general circulation model. An objective in the derivation of such a simplified model, called ABL1d, is to reach an apt representation in ocean-only numerical simulations of some of the key processes associated with air–sea interactions at the characteristic scales of the oceanic mesoscale. In this paper we describe the formulation of the ABL1d model and the strategy to constrain this model with large-scale atmospheric data available from reanalysis or real-time forecasts. A particular emphasis is on the appropriate choice and calibration of a turbulent closure scheme for the atmospheric boundary layer. This is a key ingredient to properly represent the air–sea interaction processes of interest. We also provide a detailed description of the NEMO-ABL1d coupling infrastructure and its computational efficiency. The resulting simplified model is then tested for several boundary-layer regimes relevant to either ocean–atmosphere or sea-ice–atmosphere coupling. The coupled system is also tested with a realistic 0.25∘ resolution global configuration. The numerical results are evaluated using standard metrics from the literature to quantify the wind–sea-surface-temperature (a.k.a. thermal feedback effect), wind–current (a.k.a. current feedback effect), and ABL–sea-ice couplings. With respect to these metrics, our results show very good agreement with observations and fully coupled ocean–atmosphere models for a computational overhead of about 9 % in terms of elapsed time compared to standard uncoupled simulations. This moderate overhead, largely due to I/O operations, leaves room for further improvement to relax the assumption of horizontal homogeneity behind ABL1d and thus to further improve the realism of the coupling while keeping t

Published
2021
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17. Two‐sided turbulent surface‐layer parameterizations for computing air–sea fluxes

Author

UCL - SST/ELI/ELIC - Earth & Climate, Pelletier, Charles, Lemarié, Florian, Blayo, Eric, Bouin, Marie‐Noëlle, Redelsperger, Jean‐Luc, UCL - SST/ELI/ELIC - Earth & Climate, Pelletier, Charles, Lemarié, Florian, Blayo, Eric, Bouin, Marie‐Noëlle, and Redelsperger, Jean‐Luc

Abstract

Standard methods for determining air–sea fluxes typically rely on bulk algorithms set in the frame of Monin–Obukhov similarity theory (MOST), using ocean surface fields and atmosphere near-surface fields. In the context of coupled ocean–atmosphere simulations, the shallowest ocean vertical level is usually used as bulk input and, by default, the turbulent closure is one-sided: it extrapolates atmosphere near-surface solution profiles (for wind speed, temperature, and humidity) to the prescribed ocean surface values. Using near-surface ocean fields as surface ones is equivalent to considering that, in the ocean surface layer, solution profiles are constant instead of also being determined by turbulent closure. Here we introduce a method for extending existing turbulent parameterizations to a two-sided framework by explicitly including the ocean surface layer within the aforementioned parameterizations. The formalism we use for this method is derived from that of classical turbulent closures, so that our novelties can easily be implemented within existing formulations. Special care is taken to ensure the smoothness of the resulting solution profiles. Other physical phenomena, such as the penetration of radiative fluxes in the ocean and the formation of waves, are then included within our formalism, and their effects are assessed. We also investigate the impact of such two-sided bulk formulations on air–sea fluxes evaluated from a setting similar to those of coupled ocean–atmosphere simulations.

Published
2021

18. A Case Study of the Coupled Ocean‐Atmosphere Response to an Oceanic Diurnal Warm Layer

Author

Brilouet, Pierre Etienne, Redelsperger, Jean-luc, Bouin, Marie‐noëlle, Couvreux, Fleur, Brossier, Cindy Lebeaupin, Brilouet, Pierre Etienne, Redelsperger, Jean-luc, Bouin, Marie‐noëlle, Couvreux, Fleur, and Brossier, Cindy Lebeaupin

Abstract

A modelling case study based on observations from the Dynamics of the Madden‐Julian Oscillation field campaign is presented and discussed. It aims at investigating the ocean‐atmosphere coupling and the marine atmospheric boundary layer structure over an oceanic diurnal warm layer. This case corresponds to the development of a diurnal warm layer characterized by a sea surface temperature diurnal cycle of _ 2°C. A 1‐D oceanic model with high vertical resolution is used to investigate the mechanisms responsible for the establishment and decay of the diurnal warm layer highlighting competing impact of the absorption of the solar radiation, the turbulent transport and the surface heat loss. An atmospheric large‐eddy simulation coupled to the 1‐D oceanic model is then presented and extensively evaluated against the numerous observations available for this case. The simulation is able to reproduce the surface fluxes and the main boundary layer structures. This study thus provides a case to investigate the ability of parametrizations to handle the ocean‐atmosphere coupling and its impact on the atmospheric boundary layer.

Published
2021
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19. Two‐sided turbulent surface layer parameterizations for computing air‐sea fluxes

Author

Pelletier, Charles, Lemarie, Florian, Blayo, Eric, Bouin, Marie-noelle, Redelsperger, Jean-luc, Pelletier, Charles, Lemarie, Florian, Blayo, Eric, Bouin, Marie-noelle, and Redelsperger, Jean-luc

Abstract

Standard methods for determining air ‐ sea fluxes typically rely on bulk algorithms set in the frame of Monin‐Obukhov stability theory (MOST), using ocean surface fields and atmosphere near‐surface fields. In the context of coupled ocean ‐ atmosphere simulations, the shallowest ocean vertical level is usually used as bulk input and by default, the turbulent closure is one‐sided: it extrapolates atmosphere near‐surface solution profiles (for wind speed, temperature and humidity) to the prescribed ocean surface values. Using near‐surface ocean fields as surface ones is equivalent to considering that in the ocean surface layer, solution profiles are constant instead of also being determined by a turbulent closure. Here we introduce a method for extending existing turbulent parameterizations to a two‐sided framework by explicitely including the ocean surface layer within the aforementioned parameterizations. The formalism we use for this method is derived from that of classical turbulent closures, so that our novelties can easily be implemented within existing formulations. Special care is taken to ensure the smoothness of resulting solution profiles. Other physical phenomena, such as the penetration of radiative fluxes in the ocean and the formation of waves, are then included within our formalism, and their effects are assessed. We also investigate the impact of such two‐sided bulk formulations on air ‐ sea fluxes evaluated from a setting similar to those of coupled ocean ‐ atmosphere simulations.

Published
2021
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21. An approach for convective parameterization with memory: separating microphysics and transport in grid-scale equations

Author

Piriou, Jean-Marcel, Redelsperger, Jean-Luc, Geleyn, Jean-Francois, Lafore, Jean-Philippe, and Guichard, Francoise

Subjects
Atmospheric physics -- Research, Molecular dynamics -- Research, Parameter estimation -- Methods, Convection (Meteorology) -- Observations, Earth sciences, Science and technology
Abstract

An approach for convective parameterization is presented here, in which grid-scale budget equations of parameterization use separate microphysics and transport terms. This separation is used both as a way to introduce into the parameterization a more explicit causal link between all involved processes and as a vehicle for an easier representation of the memory of convective cells. The equations of parameterization become closer to those of convection-resolving models [cloud-system-resolving models (CSRMs) and largeeddy simulations (LESs)], facilitating parameterization development and validation processes versus a detailed budget of these high-resolution models. The new Microphysics and Transport Convective Scheme (MTCS) equations are presented and discussed. A first version of a convective scheme based on these equations is tested within a single-column framework. The results obtained with the new scheme are close to those of traditional ones in very moist convective cases [like the Global Atmospheric Research Programme (GARP) Atlantic Tropical Experiment (GATE) Phase III, 1974]. The simulation of more difficult drier situations [European Cloud Systems Study/Global Energy and Water Cycle Experiment (GEWEX) Cloud System Studies (EUROCS/GCSS)] is improved through more memory due to higher sensitivity of simulated convection to dry midtropospheric layers; a prognostic relation between cloudy entrainment and precipitation evaporation dramatically improves the prediction of the phase lag of the convective diurnal cycle over land with respect to surface heat forcing. The present proposal contains both a relatively general equation set, which can deal continuously with dry, moist, and deep precipitating convection, and separate--and still crude--explicit moist microphysics. In the future, when increasing the complexity of microphysical computations, such an approach may help to unity dry, moist, and deep precipitating convection inside a single parameterization, as well as facilitate global climate model (GCM) and limited-area model (LAM) parameterizations in sharing the same formulation of explicit microphysics with CSRMs.

Published
2007

22. An idealized two-dimensional framework to study the West African monsoon. Part I: validation and key controlling factors

Author

Peyrille, Philippe, Lafore, Jean-Philippe, and Redelsperger, Jean-Luc

Subjects
West Africa -- Environmental aspects, Monsoons -- Observations, Eddies -- Models, Earth sciences, Science and technology
Abstract

An idealized vertical-meridional zonally symmetric model is developed in order to recover a July typical monsoon regime over West Africa in response to surface conditions. The model includes a parameterization to account for heal and momentum fluxes associated with eddies. The sensitivity of the simulated West African monsoon equilibrium regime to some major processes is explored. It allows confirmation of the important role played by the sun's latitudinal position, the aerosols, the albedo, and the SST's magnitude in the Gulf of Guinea and in the Mediterranean Sea. The important role of aerosols in warming the Saharan lower layers and their effect on the whole monsoon is underlined. Model results also stress the importance of the Mediterranean Sea, which is needed to obtain the extreme dryness of the Sahara. The use of this idealized model is finally discussed for studying the scale interactions and coupling involved in the West African monsoon as explored in a companion paper.

Published
2007

23. Numerical and experimental investigation of the neutral atmospheric surface layer

Author

Drobinski, Philippe, Carlotti, Pierre, Redelsperger, Jean-Luc, Banta, Robert M., Masson, Valery, and Newsom, Rob K.

Subjects
Eddies -- Research, Atmospheric turbulence -- Research, Winds -- Speed, Winds -- Spectra, Winds -- Research, Earth sciences, Science and technology
Abstract

This study combines the experimental measurements with large-eddy simulation (LES) data of a neutral planetary boundary layer (PBL) documented by a 60-m lower instrumented with eight sonic anemometers, and a high-resolution Doppler lidar during the 1999 Cooperative Atmospheric and Surface Exchange Study (CASES-99) experiment. The target of the paper is (i) to investigate the multiscale nature of the turbulent eddies in the surface layer (SL), (ii) to explain the existence of a -1 power law in the velocity fluctuation spectra, and (iii) to investigate the different nature of turbulence in the two sublayers within the SL, which are the eddy surface layer (ESL; lower sublayer of the SL lying between the surface and about 20-m height) and the shear surface layer (SSL; lying between the ESL top and the SL top). The sonic anemometers and Doppler lidar prove to be proper instruments for LES validation, and in particular, the Doppler lidar because of its ability to map near-surface eddies. This study shows the different nature of turbulence in the ESL and the SSL in terms of organized eddies, velocity fluctuation spectra, and second-order moment statistics. If quantitative agreement is found in the SSL between the LES and the measurements, only qualitative similarity is found in the ESL due to the subgrid-scale model, indicating that the LES captures part of the physics of the ESL. The LES helps explain the origin of the -1 power-law spectral subrange evidence in the velocity fluctuation spectra computed in the SL using the CASES-99 dataset: strong interaction between the mean flow and the fluctuating vorticities is found in the SL, and turbulent production is found to be larger than turbulent energy transfer for [k.sub.1]z> 1 ([k.sub.1] being the longitudinal wavenumber and z the height), which is the condition of the -1 power-law existence.

Published
2007

24. Development of a two-way-coupled ocean–wave model: assessment on a global NEMO(v3.6)–WW3(v6.02) coupled configuration

Author

Couvelard, Xavier, Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-luc, Ardhuin, Fabrice, Benshila, Rachid, Madec, Gurvan, Couvelard, Xavier, Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-luc, Ardhuin, Fabrice, Benshila, Rachid, and Madec, Gurvan

Abstract

This paper describes the implementation of a coupling between a three-dimensional ocean general circulation model (NEMO) and a wave model (WW3) to represent the interactions of the upper oceanic flow dynamics with surface waves. The focus is on the impact of such coupling on upper-ocean properties (temperature and currents) and mixed-layer depths (MLD) at global eddying scales. A generic coupling interface has been developed and the NEMO governing equations and boundary conditions have been adapted to include wave-induced terms following the approach of McWilliams et al. (2004) and Ardhuin et al. (2008). In particular, the contributions of Stokes-Coriolis, Vortex and surface pressure forces have been implemented on top of the necessary modifications of the tracer/continuity equation and turbulent closure scheme (a 1-equation TKE closure here). To assess the new developments, we perform a set of sensitivity experiments with a global oceanic configuration at 1/4° resolution coupled with a wave model configured at 1/2° resolution. Numerical simulations show a global increase of wind-stress due to the interaction with waves (via the Charnock coefficient) particularly at high latitudes. The modifications brought to the TKE closure scheme and the inclusion of a parameterization for Langmuir turbulence lead to a significant increase of the mixing thus helping to deepen the MLD. This deepening is mainly located in the Southern Hemisphere and results in reduced sea-surface currents and temperatures.

Published
2020
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25. Impacts of surface gravity waves on a tidal front: A coupled model perspective

Author

Brumer, Sophia, Garnier, Valerie, Redelsperger, Jean-luc, Bouin, Marie-noelle, Ardhuin, Fabrice, Accensi, Mickael, Brumer, Sophia, Garnier, Valerie, Redelsperger, Jean-luc, Bouin, Marie-noelle, Ardhuin, Fabrice, and Accensi, Mickael

Abstract

A set of realistic coastal coupled ocean-wave numerical simulations is used to study the impact of surface gravity waves on a tidal temperature front and surface currents. The processes at play are elucidated through analyses of the budgets of the horizontal momentum, the temperature, and the turbulence closure equations. The numerical system consists of a 3D coastal hydrodynamic circulation model (Model for Applications at Regional Scale, MARS3D) and the third generation wave model WAVEWATCH III (WW3) coupled with OASIS-MCT at horizontal resolutions of 500 and 1500 m, respectively. The models were run for a period of low to moderate southwesterly winds as observed during the Front de Marée Variable (FroMVar) field campaign in the Iroise Sea where a seasonal small-scale tidal sea surface temperature front is present. Over the 2 day period considered, long fetch waves grow gradually propagating north east and east. Contrasting a stand-alone ocean run with a coupled ocean-wave run shows that waves move the Ushant front offshore by up to 4 kilometres and cool the offshore stratified side of the front by up to 1.5°C. The analysis of the temperature budget shows that the change in advection is the dominant factor contributing to the frontal shift while the contribution of wave enhanced vertical temperature diffusion is secondary. Temperature, considered to be a tracer, is advected in the coupled run by the Lagrangian current resulting from the quasi-Eulerian and Stokes drift. Although the Stokes drift is directed shorewards, changes in the quasi-Eulerian current lead to a more offshore advection in the coupled than the stand-alone run. The quasi-Eulerian current is reduced (enhanced) during the ebb (flood) flow which correspond to periods of wave-following (-opposing) currents. This is due to wave breaking enhanced vertical mixing acting on the positive vertical gradient present in the quasi-Eulerian current during both ebb and flood tides. Partially coupled runs reveal

Published
2020
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26. Scalewise Return‐to‐Isotropy in Stratified Boundary Layer Flows

Author

Ayet, Alex, Katul, G. G., Bragg, A. D., Redelsperger, Jean-luc, Ayet, Alex, Katul, G. G., Bragg, A. D., and Redelsperger, Jean-luc

Abstract

Anisotropic turbulence is ubiquitous in atmospheric and oceanic boundary layers due to differences in energy injection mechanisms. Unlike mechanical production that injects energy in the streamwise velocity component, buoyancy affects only the vertical velocity component. This anisotropy in energy sources, quantified by the flux Richardson number Ri f , is compensated by a `return to isotropy' (RTI) tendency of turbulent flows. Describing RTI in Reynolds‐averaged models and across scales continues to be a challenge in stratified turbulent flows. Using phenomenological models for spectral energy transfers, the necessary conditions for which the widely used Rotta model captures RTI across various Ri f and eddy sizes is discussed for the first time. This work unravels adjustments to the Rotta constant, with Ri f and scale, necessary to obtain consistency between RTI models and the measured properties of the atmospheric surface layer for planar‐homogeneous and stationary flows in the absence of subsidence. A range of Ri f and eddy sizes where the usage of a conventional Rotta model is prohibited is also found. Those adjustments lay the groundwork for new closure schemes. Plain Language Summary In the atmosphere and in oceans, turbulence dominates much of the exchanges of momentum, heat, water vapor, and scalars such as carbon dioxide, ozone, or methane. Representing turbulence in numerical models of the Earth and climate system remains a first‐order problem, requiring the development of simplified approaches to describe the energetics of the flow. One such representation is based on the universal tendency of all turbulent flows to attain an isotropic state, where kinetic energy is equi‐partitioned among its three velocity components, labelled `return‐to‐isotropy'. However, the presence of buoyancy forces and mechanical generation of turbulence causes the flow to be anisotropic at a wide range of eddy sizes. To what degree this additional layer of complexity invalidates

Published
2020
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27. On the Impact of Long Wind-Waves on Near-Surface Turbulence and Momentum Fluxes

Author

Ayet, Alex, Chapron, Bertrand, Redelsperger, Jean-luc, Lapeyre, Guillaume, Marié, Louis, Ayet, Alex, Chapron, Bertrand, Redelsperger, Jean-luc, Lapeyre, Guillaume, and Marié, Louis

Abstract

We propose a new phenomenological model to represent the impact of wind-waves on the dissipation of turbulence kinetic energy near the sea surface. In this model, the momentum flux at a given height results from the averaged contribution of eddies attached to the sea surface whose sizes are related to the surface geometry. This yields a coupling between long wind-waves and turbulence at heights of about 10 m. This new wind-and-waves coupling is thus not exclusively confined to the short wave range and heights below 5 m, where most of the momentum transfer to the waves is known to occur. The proposed framework clarifies the impact of wind-waves on Monin–Obukhov similarity theory, and the role of long wind-waves on the observed wind-wave variability of momentum fluxes. This work reveals which state variables related to the wind-wave coupling require more accurate measurements to further improve wind-over-waves models and parametrizations.

Published
2020
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33. Extratropical dry-air intrusions into the West African monsoon midtroposphere: an important factor for the convective activity over the Sahel

Author

Roca, Remy, Lafore, Jean-Philippe, Piriou, Catherine, and Redelsperger, Jean-Luc

Subjects
Monsoons -- Research, Atmosphere -- Research, Earth -- Atmosphere, Earth -- Research, Earth sciences, Science and technology
Abstract

This paper investigates the relationship between large-scale dynamics, water vapor, and organized convection over West Africa. Making use of a simplified condensation hypothesis, a back-trajectory model fed by NCEP-analyzed winds is used to reconstruct the midtropospheric humidity field over Africa during July to August 1992. The approach documents both the moisture content and the origin of the air masses. Meteosat satellite infrared imagery is used to characterize the convective systems. A case study analysis reveals that very dry air patches (RH < 5%) are located in the immediate midtropospheric environment of a typical squall line. Such dry-air structures are shown to originate in the upper levels (200-250 hPa) on the anticyclonic side of the polar jet stream at 50[degrees]N. Focusing on the Sahel region, dry events are isolated using the time series of the 500-hPa relative humidity distribution during the monsoon period. These dry events are shown to be composed of extratropical air. Composite analysis of the convective activity indicator exhibits a strong positive association between dry intrusions and convection on the eastern side of the Sahelian region. Organized convective systems that are fast moving and long lasting are more likely over this region when a dry intrusion is present. This coincides with the well-established theory that midtropospheric dry air, when combined with sufficient wind shear, can maintain and intensify previously triggered deep convection through rain evaporation that feeds the cold pools, especially within squall lines. This paper suggests that the extratropical dry-air intrusions modulate the occurrence and duration of convective systems and, therefore, the mode of variability of rainfall over West Africa during the monsoon.

Published
2005

34. Estimations of mass fluxes for cumulus parameterizations from high-resolution spatial data

Author

Yano, Jun-Ichi, Guichard, Francoise, Lafore, Jean-Philippe, Redelsperger, Jean-Luc, and Bechtold, Peter

Subjects
Atmosphere -- Research, Earth sciences, Science and technology
Abstract

The core of the mass flux formulation, on which the majority of the current cumulus parameterizations are based, is to transport physical variables by the so-called mass flux for individual physical components, such as convective updrafts, downdrafts, and environment. These parameterizations use horizontal means over the subdomains occupied by these physical components to define the mass fluxes and transported variables. However, evaluations of the mass flux formulation against high-resolution spatial data obtained from explicit numerical models reveal that it substantially underestimates vertical transport of heat, moisture, and momentum by deep convection. The present paper proposes an alternative approach, in which the effective values weighted toward extreme values are used both for the mass flux and the transported variable to obtain an accurate estimate of vertical transport. Statistically, the distribution of convective variables is so widely distributed within individual subdomains that the vertical transports are controlled by extreme values, rather than by simple means. Evaluation for these effective values are facilitated by considering four categories depending on the sign of both the vertical velocity and the transported variable, instead of the conventional convective-type classifications. A best estimate of the effective value is obtained empirically by weighting the variable by a power of one-quarter during the averaging. A major consequence of this alternative approach is that the mass fluxes must be defined differently for the individual variables. Thus, chemical species would not be transported by the same mass flux as that for temperature or moisture. With this extra elaboration, the proposed formulation provides more robust estimation of the subgrid-scale convective transports.

Published
2004

35. The structure of the near-neutral atmospheric surface layer

Author

Drobinski, Philippe, Carlotti, Pierre, Newsom, Rob K., Banta, Robert M., Foster, Ralph C., and Redelsperger, Jean-Luc

Subjects
Earth sciences, Science and technology
Abstract

Recent observational data (turbulence variables by sonic anemometers and three-dimensional flow pattern by Doppler lidar), obtained during the Cooperative Atmosphere Surface Exchange Study field campaign in October 1999 (CASES-99), show evidence of a layered structure of the near-neutral surface layer: (i) the eddy surface layer (ESL), which is the lower sublayer where blocking of impinging eddies is the dominating mechanism; and (ii) the shear surface layer (SSL), which is an intermediate sublayer, where shear affects the isotropy of turbulence. The origin of the eddies impinging from aloft (probably from the SSL) down to the ESL is preliminarily addressed in this study, since the Doppler lidar data show evidence of linearly organized eddies embedded in the surface layer (i.e., about 100-m vertical extent) and horizontally spaced by about 300 m. This is consistent with theories predicting that the primary mechanism of eddy motion in high Reynolds number wall layers is 'top-down.' The layered structure of the surface layer also has a visible effect on vertical profiles of vertical velocity variance (bar.[w.sup.2]) and momentum transport. In the ESL, (bar.[w.sup.2]) scales as [z.sup.2/3] while it is constant or slightly decreases within the SSL. Concerning momentum transport, ejections contribute identically to the momentum flux as do sweeps in the ESL, whereas in the SSL, ejections give about 50% higher relative contribution.

Published
2004

36. 'Renormalization' approach for subgrid-scale representations

Author

Yano, Jun-Ichi, Bechtold, Peter, and Redelsperger, Jean-Luc

Subjects
Atmosphere -- Research, Earth sciences, Science and technology
Abstract

Physical processes in numerical modeling are currently handled by a dichotomy of either an explicit or a parameterization approach. Herein, an alternative approach is proposed, in which degrading explicit physics with decreasing resolutions are compensated by a 'renormalization.' More specifically, a 'renormalization' factor depending on the model resolution is multiplied on explicit evaluations so that the subgrid-scale contributions to a given grid scale are approximately recovered without a parameterization. The approach is analogous to the renormalization approach in statistical physics, but without rigorously relying on its mathematical basis. For this reason, this name is evoked with a quotation. In order to demonstrate this idea, the domain-mean vertical fluxes of heat, moisture, and momentum from cloud-resolving model experiments, corresponding to the grid-box averages in the large-scale modeling, are examined. In order to mimic the effects of degrading horizontal resolution, data are filtered in wavelet space. The 'renormalization' factors that recover the full vertical fluxes are found to be relatively stable with time, and the associated errors by 'renormalization' are overall less than the order of the vertical variance of the fluxes, indicating a potential usefulness of this approach. An analogous approach is found to work more effectively using data compression by wavelets.

Published
2003

42. Toward an improved representation of air-sea interactions in high-resolution global oceanic forecasting systems

Author

Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-Luc, Madec, Gurvan, Giordani, Hervé, Bourdallé-Badie, Romain, Mathematics and computing applied to oceanic and atmospheric flows (AIRSEA), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Laboratoire Jean Kuntzmann (LJK ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Nucleus for European Modeling of the Ocean (NEMO R&D ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Lemarié, Florian

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

43. An analytical study of the atmospheric boundary layer flow and divergence over a SST front

Author

Ayet, Alex, Redelsperger, Jean-luc, Ayet, Alex, and Redelsperger, Jean-luc

Abstract

We present an analytical model reproducing literature‐based numerical simulations of the Marine Atmospheric Boundary Layer (MABL) over a SST front, with wind blowing from the cold to the warm side. Turbulence is parameterised through a varying diffusion coefficient with two critical features: it is parabolic on the vertical and its mean value is decoupled from the MABL height (unlike an Ekman layer model). These two novel features are found essential to recover the internal structure of the MABL from numerical simulations. Different dynamical regimes are obtained and interpreted in terms of non‐dimensional numbers characterising the relative importance of terms driving the momentum equation. A closed‐form expression of the vertically integrated wind divergence in the MABL is then obtained. The resulting divergence is linearly linked to the SST Laplacian and to the downwind SST gradient. This shows that the response of the MABL wind divergence to a SST front is highly dependent on its spatial scale. The coupling coefficients vary with the ratio of MABL height to turbulence strength, i.e. the inverse Ekman number. We further show different regimes in the rate of variation of the coupling coefficients, depending on the Ekman number value. This can result in qualitatively different vertical winds, having potential implications for the coupling of the MABL with the free troposphere.

Published
2019
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44. Parallelization of the French Meteorological Mesoscale Model MésoNH

Author

Jabouille, Patrick, primary, Guivarch, Ronan, additional, Kloos, Philippe, additional, Gazen, Didier, additional, Gicquel, Nicolas, additional, Giraud, Luc, additional, Asencio, Nicole, additional, Ducrocq, Veronique, additional, Escobar, Juan, additional, Redelsperger, Jean-Luc, additional, Stein, Joël, additional, and Pinty, Jean-Pierre, additional

Published
1999
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45. Overview of the Meso-NH model version 5.4 and its applications

Author

Lac, Christine, Chaboureau, Jean-Pierre, Masson, Valéry, Pinty, Jean-Pierre, Tulet, Pierre, Escobar, Juan, Leriche, Maud, Barthe, Christelle, Aouizerats, Benjamin, Augros, Clotilde, Aumond, Pierre, Auguste, Franck, Bechtold, Peter, Berthet, Sarah, Bielli, Soline, Bosseur, Frédéric, Caumont, Olivier, Cohard, Jean-Martial, Colin, Jeanne, Couvreux, Fleur, Cuxart, Joan, Delautier, Gaëlle, Dauhut, Thibaut, Ducrocq, Véronique, Filippi, Jean-Baptiste, Gazen, Didier, Geoffroy, Olivier, Gheusi, François, Honnert, Rachel, Lafore, Jean-Philippe, Lebeaupin Brossier, Cindy, Libois, Quentin, Lunet, Thibaut, Mari, Céline, Maric, Tomislav, Mascart, Patrick, Mogé, Maxime, Molinié, Gilles, Nuissier, Olivier, Pantillon, Florian, Peyrillé, Philippe, Pergaud, Julien, Perraud, Emilie, Pianezze, Joris, Redelsperger, Jean-Luc, Ricard, Didier, Richard, Evelyne, Riette, Sébastien, Rodier, Quentin, Schoetter, Robert, Seyfried, Léo, Stein, Joël, Suhre, Karsten, Taufour, Marie, Thouron, Odile, Turner, Sandra, Verrelle, Antoine, Vié, Benoît, Visentin, Florian, Vionnet, Vincent, Wautelet, Philippe, Centre national de recherches météorologiques (CNRM), Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), CERFACS, European Centre for Medium-Range Weather Forecasts (ECMWF), Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of the Balearic Islands (UIB), CERFACS [Toulouse], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Météo-France [Paris], Météo France, Institute of Bioinformatics and Systems Biology [München], Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Weill Cornell Medicine [Qatar], Revenue Canada Agency, Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LA), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), VU University Amsterdam, Météo France-Centre National de la Recherche Scientifique (CNRS), Département Infrastructures et Mobilité (IFSTTAR/IM), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM), Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Feux de Forêt, Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génie Electrique de Grenoble (G2ELab), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Associé de Météorologie Physique, Aubière, Compilation pour les Architectures MUlti-coeurS (CAMUS), Inria Nancy - Grand Est, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Biogéosciences [Dijon] (BGS), Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), Information génomique et structurale (IGS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques ( CNRM ), Météo France-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'aérologie - LA ( LA ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de l'Atmosphère et des Cyclones ( LACy ), Météo France-Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique ( CERFACS ), European Centre for Medium-Range Weather Forecasts ( ECMWF ), Sciences pour l'environnement ( SPE ), Université Pascal Paoli ( UPP ) -Centre National de la Recherche Scientifique ( CNRS ), Institut des Géosciences de l’Environnement ( IGE ), Institut de Recherche pour le Développement ( IRD ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), University of the Balearic Islands ( UIB ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Océanographie Physique et Spatiale ( LOPS ), Institut de Recherche pour le Développement ( IRD ) -Institut Français de Recherche pour l'Exploitation de la Mer ( IFREMER ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ), Technische Universität München [München] ( TUM ), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), and Météo-France

Subjects
[ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Physics::Atmospheric and Oceanic Physics, ComputingMilieux_MISCELLANEOUS
Abstract

This paper presents the Meso-NH model version 5.4. Meso-NH is an atmospheric non hydrostatic research model that is applied to a broad range of resolutions, from synoptic to turbulent scales, and is designed for studies of physics and chemistry. It is a limited-area model employing advanced numerical techniques, including monotonic advection schemes for scalar transport and fourth-order centered or odd-order WENO advection schemes for momentum. The model includes state-of-the-art physics parameterization schemes that are important to represent convective-scale phenomena and turbulent eddies, as well as flows at larger scales. In addition, Meso-NH has been expanded to provide capabilities for a range of Earth system prediction applications such as chemistry and aerosols, electricity and lightning, hydrology, wildland fires, volcanic eruptions, and cyclones with ocean coupling. Here, we present the main innovations to the dynamics and physics of the code since the pioneer paper of Lafore et al. (1998) and provide an overview of recent applications and couplings.

Published
2018
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46. PPR SIMBAD: en quête d’une nouvelle méthodologie de représentation des échanges air-mer dans les modèles opérationnels globaux d’océan à haute-résolution

Author

Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-Luc, Madec, Gurvan, Giordani, Hervé, Bourdalle-Badie, Romain, Drillet, Yann, Mathematics and computing applied to oceanic and atmospheric flows (AIRSEA), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Laboratoire Jean Kuntzmann (LJK ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Nucleus for European Modeling of the Ocean (NEMO R&D ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Université Grenoble Alpes (UGA)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Météo France-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU]Sciences of the Universe [physics], [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [MATH]Mathematics [math], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2018

49. Strong winds in a coupled wave-atmosphere model during a North Atlantic storm event: evaluation against observations

Author

Pineau-guillou, Lucia, Ardhuin, Fabrice, Bouin, Marie-noelle, Redelsperger, Jean-luc, Chapron, Bertrand, Bidlot, Jean-raymond, Quilfen, Yves, Pineau-guillou, Lucia, Ardhuin, Fabrice, Bouin, Marie-noelle, Redelsperger, Jean-luc, Chapron, Bertrand, Bidlot, Jean-raymond, and Quilfen, Yves

Abstract

Strong winds may be biased in atmospheric models. Here the ECMWF coupled wave-atmosphere model is used (1) to evaluate strong winds against observations, (2) to test how alternative wind stress parameterizations could lead to a more accurate model. For the period of storms Kaat and Lilli (23 to 27 January 2014), we compared simulated winds with in-situ – moored buoys and platforms - and satellite observations available from the North Atlantic. Five wind stress parameterizations were evaluated. The first result is that moderate simulated winds (5-20 m s-1) match with all observations. However, for strong winds (above 20 m s-1), mean differences appear, as much as -7 m s-1 at 30 m s-1. Significant differences also exist between observations, with buoys and ASCAT-KNMI generally showing lower wind speeds than the platforms and other remote sensing data used in this study (AMSR2, ASCAT-RSS, WindSat, SMOS and JASON-2). It is difficult to conclude which dataset should be used as a reference. Even so, buoy and ASCAT-KNMI winds are likely to underestimate the real wind speed. The second result is that common wave-age dependent parameterizations produce unrealistic drags and are not appropriate for coupling, whereas a newly empirically-adjusted Charnock parameterization leads to higher winds compared to the default ECMWF parameterization. This proposed new parameterization may lead to more accurate results in an operational context.

Published
2018
Full Text
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50. Toward an improved representation of air-sea interactions in high-resolution global oceanic forecasting systems

Author

Lemarié, Florian, Samson, Guillaume, Redelsperger, Jean-Luc, Madec, Gurvan, Giordani, Hervé, Mathematics and computing applied to oceanic and atmospheric flows (AIRSEA), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Laboratoire Jean Kuntzmann (LJK ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Nucleus for European Modeling of the Ocean (NEMO R&D ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, [MATH]Mathematics [math], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

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