Skip to content. | Skip to navigation

Personal tools

You are here: Home / Publications / Peer-reviewed papers / lmd_Dufresne2013_bib.html



@comment{{This file has been generated by bib2bib 1.95}}
@comment{{Command line: /usr/bin/bib2bib --quiet -c 'not journal:"Discussions"' -c 'not journal:"Polymer Science"' -c '  author:"Dufresne"  ' -c year=2013 -c $type="ARTICLE" -oc lmd_Dufresne2013.txt -ob lmd_Dufresne2013.bib /home/WWW/LMD/public/}}
  author = {{Dufresne}, J.-L. and {Foujols}, M.-A. and {Denvil}, S. and 
	{Caubel}, A. and {Marti}, O. and {Aumont}, O. and {Balkanski}, Y. and 
	{Bekki}, S. and {Bellenger}, H. and {Benshila}, R. and {Bony}, S. and 
	{Bopp}, L. and {Braconnot}, P. and {Brockmann}, P. and {Cadule}, P. and 
	{Cheruy}, F. and {Codron}, F. and {Cozic}, A. and {Cugnet}, D. and 
	{de Noblet}, N. and {Duvel}, J.-P. and {Ethé}, C. and {Fairhead}, L. and 
	{Fichefet}, T. and {Flavoni}, S. and {Friedlingstein}, P. and 
	{Grandpeix}, J.-Y. and {Guez}, L. and {Guilyardi}, E. and {Hauglustaine}, D. and 
	{Hourdin}, F. and {Idelkadi}, A. and {Ghattas}, J. and {Joussaume}, S. and 
	{Kageyama}, M. and {Krinner}, G. and {Labetoulle}, S. and {Lahellec}, A. and 
	{Lefebvre}, M.-P. and {Lefevre}, F. and {Levy}, C. and {Li}, Z.~X. and 
	{Lloyd}, J. and {Lott}, F. and {Madec}, G. and {Mancip}, M. and 
	{Marchand}, M. and {Masson}, S. and {Meurdesoif}, Y. and {Mignot}, J. and 
	{Musat}, I. and {Parouty}, S. and {Polcher}, J. and {Rio}, C. and 
	{Schulz}, M. and {Swingedouw}, D. and {Szopa}, S. and {Talandier}, C. and 
	{Terray}, P. and {Viovy}, N. and {Vuichard}, N.},
  title = {{Climate change projections using the IPSL-CM5 Earth System Model: from CMIP3 to CMIP5}},
  journal = {Climate Dynamics},
  keywords = {Climate, Climate change, Climate projections, Earth System Model, CMIP5, CMIP3, Greenhouse gases, Aerosols, Carbon cycle, Allowable emissions, RCP scenarios, Land use changes},
  year = 2013,
  month = may,
  volume = 40,
  pages = {2123-2165},
  abstract = {{We present the global general circulation model IPSL-CM5 developed to
study the long-term response of the climate system to natural and
anthropogenic forcings as part of the 5th Phase of the Coupled Model
Intercomparison Project (CMIP5). This model includes an interactive
carbon cycle, a representation of tropospheric and stratospheric
chemistry, and a comprehensive representation of aerosols. As it
represents the principal dynamical, physical, and bio-geochemical
processes relevant to the climate system, it may be referred to as an
Earth System Model. However, the IPSL-CM5 model may be used in a
multitude of configurations associated with different boundary
conditions and with a range of complexities in terms of processes and
interactions. This paper presents an overview of the different model
components and explains how they were coupled and used to simulate
historical climate changes over the past 150 years and different
scenarios of future climate change. A single version of the IPSL-CM5
model (IPSL-CM5A-LR) was used to provide climate projections associated
with different socio-economic scenarios, including the different
Representative Concentration Pathways considered by CMIP5 and several
scenarios from the Special Report on Emission Scenarios considered by
CMIP3. Results suggest that the magnitude of global warming projections
primarily depends on the socio-economic scenario considered, that there
is potential for an aggressive mitigation policy to limit global warming
to about two degrees, and that the behavior of some components of the
climate system such as the Arctic sea ice and the Atlantic Meridional
Overturning Circulation may change drastically by the end of the
twenty-first century in the case of a no climate policy scenario.
Although the magnitude of regional temperature and precipitation changes
depends fairly linearly on the magnitude of the projected global warming
(and thus on the scenario considered), the geographical pattern of these
changes is strikingly similar for the different scenarios. The
representation of atmospheric physical processes in the model is shown
to strongly influence the simulated climate variability and both the
magnitude and pattern of the projected climate changes.
  doi = {10.1007/s00382-012-1636-1},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Hourdin}, F. and {Grandpeix}, J.-Y. and {Rio}, C. and {Bony}, S. and 
	{Jam}, A. and {Cheruy}, F. and {Rochetin}, N. and {Fairhead}, L. and 
	{Idelkadi}, A. and {Musat}, I. and {Dufresne}, J.-L. and {Lahellec}, A. and 
	{Lefebvre}, M.-P. and {Roehrig}, R.},
  title = {{LMDZ5B: the atmospheric component of the IPSL climate model with revisited parameterizations for clouds and convection}},
  journal = {Climate Dynamics},
  keywords = {Climate modeling, Physical parameterizations, Shallow convection, Deep convection, Climate change projections},
  year = 2013,
  month = may,
  volume = 40,
  pages = {2193-2222},
  abstract = {{Based on a decade of research on cloud processes, a new version of the
LMDZ atmospheric general circulation model has been developed that
corresponds to a complete recasting of the parameterization of
turbulence, convection and clouds. This LMDZ5B version includes a
mass-flux representation of the thermal plumes or rolls of the
convective boundary layer, coupled to a bi-Gaussian statistical cloud
scheme, as well as a parameterization of the cold pools generated below
cumulonimbus by re-evaporation of convective precipitation. The
triggering and closure of deep convection are now controlled by lifting
processes in the sub-cloud layer. An available lifting energy and
lifting power are provided both by the thermal plumes and by the spread
of cold pools. The individual parameterizations were carefully validated
against the results of explicit high resolution simulations. Here we
present the work done to go from those new concepts and developments to
a full 3D atmospheric model, used in particular for climate change
projections with the IPSL-CM5B coupled model. Based on a series of
sensitivity experiments, we document the differences with the previous
LMDZ5A version distinguishing the role of parameterization changes from
that of model tuning. Improvements found previously in single-column
simulations of case studies are confirmed in the 3D model: (1) the
convective boundary layer and cumulus clouds are better represented and
(2) the diurnal cycle of convective rainfall over continents is delayed
by several hours, solving a longstanding problem in climate modeling.
The variability of tropical rainfall is also larger in LMDZ5B at
intraseasonal time-scales. Significant biases of the LMDZ5A model
however remain, or are even sometimes amplified. The paper emphasizes
the importance of parameterization improvements and model tuning in the
frame of climate change studies as well as the new paradigm that
represents the improvement of 3D climate models under the control of
single-column case studies simulations.
  doi = {10.1007/s00382-012-1343-y},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Hourdin}, F. and {Foujols}, M.-A. and {Codron}, F. and {Guemas}, V. and 
	{Dufresne}, J.-L. and {Bony}, S. and {Denvil}, S. and {Guez}, L. and 
	{Lott}, F. and {Ghattas}, J. and {Braconnot}, P. and {Marti}, O. and 
	{Meurdesoif}, Y. and {Bopp}, L.},
  title = {{Impact of the LMDZ atmospheric grid configuration on the climate and sensitivity of the IPSL-CM5A coupled model}},
  journal = {Climate Dynamics},
  keywords = {Climate modeling, Grid resolution, Climate change projections},
  year = 2013,
  month = may,
  volume = 40,
  pages = {2167-2192},
  abstract = {{The IPSL-CM5A climate model was used to perform a large number of
control, historical and climate change simulations in the frame of
CMIP5. The refined horizontal and vertical grid of the atmospheric
component, LMDZ, constitutes a major difference compared to the previous
IPSL-CM4 version used for CMIP3. From imposed-SST (Sea Surface
Temperature) and coupled numerical experiments, we systematically
analyze the impact of the horizontal and vertical grid resolution on the
simulated climate. The refinement of the horizontal grid results in a
systematic reduction of major biases in the mean tropospheric structures
and SST. The mid-latitude jets, located too close to the equator with
the coarsest grids, move poleward. This robust feature, is accompanied
by a drying at mid-latitudes and a reduction of cold biases in
mid-latitudes relative to the equator. The model was also extended to
the stratosphere by increasing the number of layers on the vertical from
19 to 39 (15 in the stratosphere) and adding relevant parameterizations.
The 39-layer version captures the dominant modes of the stratospheric
variability and exhibits stratospheric sudden warmings. Changing either
the vertical or horizontal resolution modifies the global energy balance
in imposed-SST simulations by typically several W/m$^{2}$ which
translates in the coupled atmosphere-ocean simulations into a different
global-mean SST. The sensitivity is of about 1.2 K per 1 W/m$^{2}$
when varying the horizontal grid. A re-tuning of model parameters was
thus required to restore this energy balance in the imposed-SST
simulations and reduce the biases in the simulated mean surface
temperature and, to some extent, latitudinal SST variations in the
coupled experiments for the modern climate. The tuning hardly
compensates, however, for robust biases of the coupled model. Despite
the wide range of grid configurations explored and their significant
impact on the present-day climate, the climate sensitivity remains
essentially unchanged.
  doi = {10.1007/s00382-012-1411-3},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Zhang}, M. and {Bretherton}, C.~S. and {Blossey}, P.~N. and 
	{Austin}, P.~H. and {Bacmeister}, J.~T. and {Bony}, S. and {Brient}, F. and 
	{Cheedela}, S.~K. and {Cheng}, A. and {Genio}, A.~D. and {Roode}, S.~R. and 
	{Endo}, S. and {Franklin}, C.~N. and {Golaz}, J.-C. and {Hannay}, C. and 
	{Heus}, T. and {Isotta}, F.~A. and {Dufresne}, J.-L. and {Kang}, I.-S. and 
	{Kawai}, H. and {K{\"o}hler}, M. and {Larson}, V.~E. and {Liu}, Y. and 
	{Lock}, A.~P. and {Lohmann}, U. and {Khairoutdinov}, M.~F. and 
	{Molod}, A.~M. and {Neggers}, R.~A.~J. and {Rasch}, P. and {Sandu}, I. and 
	{Senkbeil}, R. and {Siebesma}, A.~P. and {Siegenthaler-Le Drian}, C. and 
	{Stevens}, B. and {Suarez}, M.~J. and {Xu}, K.-M. and {Salzen}, K. and 
	{Webb}, M.~J. and {Wolf}, A. and {Zhao}, M.},
  title = {{CGILS: Results from the first phase of an international project to understand the physical mechanisms of low cloud feedbacks in single column models}},
  journal = {Journal of Advances in Modeling Earth Systems},
  keywords = {low cloud feedbacks, CGILS, single column models, large eddy models},
  year = 2013,
  month = dec,
  volume = 5,
  pages = {826-842},
  abstract = {{CGILS{\mdash}the CFMIP-GASS Intercomparison of Large Eddy Models (LESs)
and single column models (SCMs){\mdash}investigates the mechanisms of
cloud feedback in SCMs and LESs under idealized climate change
perturbation. This paper describes the CGILS results from 15 SCMs and 8
LES models. Three cloud regimes over the subtropical oceans are studied:
shallow cumulus, cumulus under stratocumulus, and well-mixed coastal
stratus/stratocumulus. In the stratocumulus and coastal stratus regimes,
SCMs without activated shallow convection generally simulated negative
cloud feedbacks, while models with active shallow convection generally
simulated positive cloud feedbacks. In the shallow cumulus alone regime,
this relationship is less clear, likely due to the changes in cloud
depth, lateral mixing, and precipitation or a combination of them. The
majority of LES models simulated negative cloud feedback in the
well-mixed coastal stratus/stratocumulus regime, and positive feedback
in the shallow cumulus and stratocumulus regime. A general framework is
provided to interpret SCM results: in a warmer climate, the moistening
rate of the cloudy layer associated with the surface-based turbulence
parameterization is enhanced; together with weaker large-scale
subsidence, it causes negative cloud feedback. In contrast, in the
warmer climate, the drying rate associated with the shallow convection
scheme is enhanced. This causes positive cloud feedback. These
mechanisms are summarized as the ''NESTS'' negative cloud feedback and the
''SCOPE'' positive cloud feedback (Negative feedback from Surface
Turbulence under weaker Subsidence{\mdash}Shallow Convection PositivE
feedback) with the net cloud feedback depending on how the two opposing
effects counteract each other. The LES results are consistent with these
  doi = {10.1002/2013MS000246},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Vial}, J. and {Dufresne}, J.-L. and {Bony}, S.},
  title = {{On the interpretation of inter-model spread in CMIP5 climate sensitivity estimates}},
  journal = {Climate Dynamics},
  keywords = {Climate sensitivity, Feedback, Radiative forcing, Fast adjustment, Radiative kernel, CMIP5 climate model simulations, Climate change, Inter-model spread},
  year = 2013,
  month = dec,
  volume = 41,
  pages = {3339-3362},
  abstract = {{This study diagnoses the climate sensitivity, radiative forcing and
climate feedback estimates from eleven general circulation models
participating in the Fifth Phase of the Coupled Model Intercomparison
Project (CMIP5), and analyzes inter-model differences. This is done by
taking into account the fact that the climate response to increased
carbon dioxide (CO$_{2}$) is not necessarily only mediated by
surface temperature changes, but can also result from fast land warming
and tropospheric adjustments to the CO$_{2}$ radiative forcing. By
considering tropospheric adjustments to CO$_{2}$ as part of the
forcing rather than as feedbacks, and by using the radiative kernels
approach, we decompose climate sensitivity estimates in terms of
feedbacks and adjustments associated with water vapor, temperature lapse
rate, surface albedo and clouds. Cloud adjustment to CO$_{2}$ is,
with one exception, generally positive, and is associated with a reduced
strength of the cloud feedback; the multi-model mean cloud feedback is
about 33 \% weaker. Non-cloud adjustments associated with temperature,
water vapor and albedo seem, however, to be better understood as
responses to land surface warming. Separating out the tropospheric
adjustments does not significantly affect the spread in climate
sensitivity estimates, which primarily results from differing climate
feedbacks. About 70 \% of the spread stems from the cloud feedback, which
remains the major source of inter-model spread in climate sensitivity,
with a large contribution from the tropics. Differences in tropical
cloud feedbacks between low-sensitivity and high-sensitivity models
occur over a large range of dynamical regimes, but primarily arise from
the regimes associated with a predominance of shallow cumulus and
stratocumulus clouds. The combined water vapor plus lapse rate feedback
also contributes to the spread of climate sensitivity estimates, with
inter-model differences arising primarily from the relative humidity
responses throughout the troposphere. Finally, this study points to a
substantial role of nonlinearities in the calculation of adjustments and
feedbacks for the interpretation of inter-model spread in climate
sensitivity estimates. We show that in climate model simulations with
large forcing (e.g., 4 {\times} CO$_{2}$), nonlinearities cannot be
assumed minor nor neglected. Having said that, most results presented
here are consistent with a number of previous feedback studies, despite
the very different nature of the methodologies and all the uncertainties
associated with them.
  doi = {10.1007/s00382-013-1725-9},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Seneviratne}, S.~I. and {Wilhelm}, M. and {Stanelle}, T. and 
	{Hurk}, B. and {Hagemann}, S. and {Berg}, A. and {Cheruy}, F. and 
	{Higgins}, M.~E. and {Meier}, A. and {Brovkin}, V. and {Claussen}, M. and 
	{Ducharne}, A. and {Dufresne}, J.-L. and {Findell}, K.~L. and 
	{Ghattas}, J. and {Lawrence}, D.~M. and {Malyshev}, S. and {Rummukainen}, M. and 
	{Smith}, B.},
  title = {{Impact of soil moisture-climate feedbacks on CMIP5 projections: First results from the GLACE-CMIP5 experiment}},
  journal = {\grl},
  keywords = {CMIP5, soil moisture, feedbacks, climate extremes, land-atmosphere interactions, projections},
  year = 2013,
  month = oct,
  volume = 40,
  pages = {5212-5217},
  abstract = {{Global Land-Atmosphere Climate Experiment-Coupled Model Intercomparison
Project phase 5 (GLACE-CMIP5) is a multimodel experiment investigating
the impact of soil moisture-climate feedbacks in CMIP5 projections. We
present here first GLACE-CMIP5 results based on five Earth System
Models, focusing on impacts of projected changes in regional soil
moisture dryness (mostly increases) on late 21st century climate.
Projected soil moisture changes substantially impact climate in several
regions in both boreal and austral summer. Strong and consistent effects
are found on temperature, especially for extremes (about 1-1.5 K for
mean temperature and 2-2.5 K for extreme daytime temperature). In the
Northern Hemisphere, effects on mean and heavy precipitation are also
found in most models, but the results are less consistent than for
temperature. A direct scaling between soil moisture-induced changes in
evaporative cooling and resulting changes in temperature mean and
extremes is found in the simulations. In the Mediterranean region, the
projected soil moisture changes affect about 25\% of the projected
changes in extreme temperature.
  doi = {10.1002/grl.50956},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{P Sabin}, T. and {Krishnan}, R. and {Ghattas}, J. and {Denvil}, S. and 
	{Dufresne}, J.-L. and {Hourdin}, F. and {Pascal}, T.},
  title = {{High resolution simulation of the South Asian monsoon using a variable resolution global climate model}},
  journal = {Climate Dynamics},
  keywords = {High-resolution variable-grid LMDZ model, South Asian monsoon, Moist-convective processes, Scale interactions},
  year = 2013,
  month = jul,
  volume = 41,
  pages = {173-194},
  abstract = {{This study examines the feasibility of using a variable resolution
global general circulation model (GCM), with telescopic zooming and
enhanced resolution (\~{}35 km) over South Asia, to better understand
regional aspects of the South Asian monsoon rainfall distribution and
the interactions between monsoon circulation and precipitation. For this
purpose, two sets of ten member realizations are produced with and
without zooming using the LMDZ (Laboratoire Meteorologie Dynamique and Z
stands for zoom) GCM. The simulations without zoom correspond to a
uniform 1{\deg} {\times} 1{\deg} grid with the same total number of grid
points as in the zoom version. So the grid of the zoomed simulations is
finer inside the region of interest but coarser outside. The use of
these finer and coarser resolution ensemble members allows us to examine
the impact of resolution on the overall quality of the simulated
regional monsoon fields. It is found that the monsoon simulation with
high-resolution zooming greatly improves the representation of the
southwesterly monsoon flow and the heavy precipitation along the narrow
orography of the Western Ghats, the northeastern mountain slopes and
northern Bay of Bengal (BOB). A realistic Monsoon Trough (MT) is also
noticed in the zoomed simulation, together with remarkable improvements
in representing the associated precipitation and circulation features,
as well as the large-scale organization of meso-scale convective systems
over the MT region. Additionally, a more reasonable simulation of the
monsoon synoptic disturbances (lows and disturbances) along the MT is
noted in the high-resolution zoomed simulation. On the other hand, the
no-zoom version has limitations in capturing the depressions and their
movement, so that the MT zone is relatively dry in this case. Overall,
the results from this work demonstrate the usefulness of the
high-resolution variable resolution LMDZ model in realistically
capturing the interactions among the monsoon large-scale dynamics, the
synoptic systems and the meso-scale convective systems, which are
essential elements of the South Asian monsoon system.
  doi = {10.1007/s00382-012-1658-8},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Lahellec}, A. and {Dufresne}, J.-L.},
  title = {{A Formal Analysis of the Feedback Concept in Climate Models. Part I: Exclusive and Inclusive Feedback Analyses}},
  journal = {Journal of Atmospheric Sciences},
  year = 2013,
  month = dec,
  volume = 70,
  pages = {3940-3958},
  abstract = {{Climate sensitivity and feedback are key concepts if the complex
behavior of climate response to perturbation is to be interpreted in a
simple way. They have also become an essential tool for comparing global
circulation models and assessing the reason for the spread in their
results. The authors introduce a formal basic model to analyze the
practical methods used to infer climate feedbacks and sensitivity from
GCMs. The tangent linear model is used first to critically review the
standard methods of feedback analyses that have been used in the GCM
community for 40 years now. This leads the authors to distinguish
between exclusive feedback analyses as in the partial radiative
perturbation approach and inclusive analyses as in the ''feedback
suppression'' methods. This review explains the hypotheses needed to
apply these methods with confidence. Attention is paid to the more
recent regression technique applied to the abrupt 2-CO2
experiment. A numerical evaluation of it is given, related to the
Lyapunov analysis of the dynamical feature of the regression. It is
applied to the Planck response, determined in its most strict definition
within the GCM. In this approach, the Planck feedback becomes a
dynamical feedback among others and, as such, also has a fast response
differing from its steady-state profile.
  doi = {10.1175/JAS-D-12-0218.1},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Tomassini}, L. and {Geoffroy}, O. and {Dufresne}, J.-L. and 
	{Idelkadi}, A. and {Cagnazzo}, C. and {Block}, K. and {Mauritsen}, T. and 
	{Giorgetta}, M. and {Quaas}, J.},
  title = {{The respective roles of surface temperature driven feedbacks and tropospheric adjustment to CO$_{2}$ in CMIP5 transient climate simulations}},
  journal = {Climate Dynamics},
  keywords = {Climate feedbacks, Tropospheric adjustment, Transient climate response},
  year = 2013,
  month = dec,
  volume = 41,
  pages = {3103-3126},
  abstract = {{An overview of radiative climate feedbacks and ocean heat uptake
efficiency diagnosed from idealized transient climate change experiments
of 14 CMIP5 models is presented. Feedbacks explain about two times more
variance in transient climate response across the models than ocean heat
uptake efficiency. Cloud feedbacks can clearly be identified as the main
source of inter-model spread. Models with strong longwave feedbacks in
the tropics feature substantial increases in cloud ice around the
tropopause suggestive of changes in cloud-top heights. The lifting of
the tropical tropopause goes together with a general weakening of the
tropical circulation. Distinctive inter-model differences in cloud
shortwave feedbacks occur in the subtropics including the equatorward
flanks of the storm-tracks. Related cloud fraction changes are not
confined to low clouds but comprise middle level clouds as well. A
reduction in relative humidity through the lower and mid troposphere can
be identified as being the main associated large-scale feature.
Experiments with prescribed sea surface temperatures are analyzed in
order to investigate whether the diagnosed feedbacks from the transient
climate simulations contain a tropospheric adjustment component that is
not conveyed through the surface temperature response. The strengths of
the climate feedbacks computed from atmosphere-only experiments with
prescribed increases in sea surface temperatures, but fixed
CO$_{2}$ concentrations, are close to the ones derived from the
transient experiment. Only the cloud shortwave feedback exhibits
discernible differences which, however, can not unequivocally be
attributed to tropospheric adjustment to CO$_{2}$. Although for
some models a tropospheric adjustment component is present in the global
mean shortwave cloud feedback, an analysis of spatial patterns does not
lend support to the view that cloud feedbacks are dominated by their
tropospheric adjustment part. Nevertheless, there is positive
correlation between the strength of tropospheric adjustment processes
and cloud feedbacks across different climate models.
  doi = {10.1007/s00382-013-1682-3},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Szopa}, S. and {Balkanski}, Y. and {Schulz}, M. and {Bekki}, S. and 
	{Cugnet}, D. and {Fortems-Cheiney}, A. and {Turquety}, S. and 
	{Cozic}, A. and {Déandreis}, C. and {Hauglustaine}, D. and 
	{Idelkadi}, A. and {Lathière}, J. and {Lefevre}, F. and 
	{Marchand}, M. and {Vuolo}, R. and {Yan}, N. and {Dufresne}, J.-L.
  title = {{Aerosol and ozone changes as forcing for climate evolution between 1850 and 2100}},
  journal = {Climate Dynamics},
  keywords = {Ozone, Aerosols, Radiative forcing, Climate-chemistry, Modeling, Future projections},
  year = 2013,
  month = may,
  volume = 40,
  pages = {2223-2250},
  abstract = {{Global aerosol and ozone distributions and their associated radiative
forcings were simulated between 1850 and 2100 following a recent
historical emission dataset and under the representative concentration
pathways (RCP) for the future. These simulations were used in an Earth
System Model to account for the changes in both radiatively and
chemically active compounds, when simulating the climate evolution. The
past negative stratospheric ozone trends result in a negative climate
forcing culminating at -0.15 W m$^{-2}$ in the 1990s. In the
meantime, the tropospheric ozone burden increase generates a positive
climate forcing peaking at 0.41 W m$^{-2}$. The future evolution
of ozone strongly depends on the RCP scenario considered. In RCP4.5 and
RCP6.0, the evolution of both stratospheric and tropospheric ozone
generate relatively weak radiative forcing changes until 2060-2070
followed by a relative 30 \% decrease in radiative forcing by 2100. In
contrast, RCP8.5 and RCP2.6 model projections exhibit strongly different
ozone radiative forcing trajectories. In the RCP2.6 scenario, both
effects (stratospheric ozone, a negative forcing, and tropospheric
ozone, a positive forcing) decline towards 1950s values while they both
get stronger in the RCP8.5 scenario. Over the twentieth century, the
evolution of the total aerosol burden is characterized by a strong
increase after World War II until the middle of the 1980s followed by a
stabilization during the last decade due to the strong decrease in
sulfates in OECD countries since the 1970s. The cooling effects reach
their maximal values in 1980, with -0.34 and -0.28 W m$^{-2}$
respectively for direct and indirect total radiative forcings. According
to the RCP scenarios, the aerosol content, after peaking around 2010, is
projected to decline strongly and monotonically during the twenty-first
century for the RCP8.5, 4.5 and 2.6 scenarios. While for RCP6.0 the
decline occurs later, after peaking around 2050. As a consequence the
relative importance of the total cooling effect of aerosols becomes
weaker throughout the twenty-first century compared with the positive
forcing of greenhouse gases. Nevertheless, both surface ozone and
aerosol content show very different regional features depending on the
future scenario considered. Hence, in 2050, surface ozone changes vary
between -12 and +12 ppbv over Asia depending on the RCP projection,
whereas the regional direct aerosol radiative forcing can locally exceed
-3 W m$^{-2}$.
  doi = {10.1007/s00382-012-1408-y},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Su}, H. and {Jiang}, J.~H. and {Zhai}, C. and {Perun}, V.~S. and 
	{Shen}, J.~T. and {Del Genio}, A. and {Nazarenko}, L.~S. and 
	{Donner}, L.~J. and {Horowitz}, L. and {Seman}, C. and {Morcrette}, C. and 
	{Petch}, J. and {Ringer}, M. and {Cole}, J. and {von Salzen}, K. and 
	{Mesquita}, M.~S. and {Iversen}, T. and {Kristjansson}, J.~E. and 
	{Gettelman}, A. and {Rotstayn}, L. and {Jeffrey}, S. and {Dufresne}, J.-L. and 
	{Watanabe}, M. and {Kawai}, H. and {Koshiro}, T. and {Wu}, T. and 
	{Volodin}, E.~M. and {L'Ecuyer}, T. and {Teixeira}, J. and {Stephens}, G.~L.
  title = {{Diagnosis of regime-dependent cloud simulation errors in CMIP5 models using ''A-Train'' satellite observations and reanalysis data}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Clouds, Climate Model, Satellite Observation, CMIP5, A-Train, large-scale regimes, conditional sampling, model error diagnosis},
  year = 2013,
  month = apr,
  volume = 118,
  pages = {2762-2780},
  abstract = {{The vertical distributions of cloud water content (CWC) and cloud
fraction (CF) over the tropical oceans, produced by 13 coupled
atmosphere-ocean models submitted to the Phase 5 of Coupled Model
Intercomparison Project (CMIP5), are evaluated against CloudSat/CALIPSO
observations as a function of large-scale parameters. Available CALIPSO
simulator CF outputs are also examined. A diagnostic framework is
developed to decompose the cloud simulation errors into large-scale
errors, cloud parameterization errors and covariation errors. We find
that the cloud parameterization errors contribute predominantly to the
total errors for all models. The errors associated with large-scale
temperature and moisture structures are relatively greater than those
associated with large-scale midtropospheric vertical velocity and
lower-level divergence. All models capture the separation of deep and
shallow clouds in distinct large-scale regimes; however, the vertical
structures of high/low clouds and their variations with large-scale
parameters differ significantly from the observations. The CWCs
associated with deep convective clouds simulated in most models do not
reach as high in altitude as observed, and their magnitudes are
generally weaker than CloudSat total CWC, which includes the
contribution of precipitating condensates, but are close to CloudSat
nonprecipitating CWC. All models reproduce maximum CF associated with
convective detrainment, but CALIPSO simulator CFs generally agree better
with CloudSat/CALIPSO combined retrieval than the model CFs, especially
in the midtroposphere. Model simulated low clouds tend to have little
variation with large-scale parameters except lower-troposphere
stability, while the observed low cloud CWC, CF, and cloud top height
vary consistently in all large-scale regimes.
  doi = {10.1029/2012JD018575},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{K{\"o}rper}, J. and {H{\"o}schel}, I. and {Lowe}, J.~A. and 
	{Hewitt}, C.~D. and {Salas y Melia}, D. and {Roeckner}, E. and 
	{Huebener}, H. and {Royer}, J.-F. and {Dufresne}, J.-L. and 
	{Pardaens}, A. and {Giorgetta}, M.~A. and {Sanderson}, M.~G. and 
	{Otter{\aa}}, O.~H. and {Tjiputra}, J. and {Denvil}, S.},
  title = {{The effects of aggressive mitigation on steric sea level rise and sea ice changes}},
  journal = {Climate Dynamics},
  keywords = {Climate, Projections, Stabilization, Sea level rise, Sea ice, Multi-model, ENSEMBLES, CMIP5, Mitigation},
  year = 2013,
  month = feb,
  volume = 40,
  pages = {531-550},
  abstract = {{With an increasing political focus on limiting global warming to less
than 2 {\deg}C above pre-industrial levels it is vital to understand the
consequences of these targets on key parts of the climate system. Here,
we focus on changes in sea level and sea ice, comparing twenty-first
century projections with increased greenhouse gas concentrations (using
the mid-range IPCC A1B emissions scenario) with those under a mitigation
scenario with large reductions in emissions (the E1 scenario). At the
end of the twenty-first century, the global mean steric sea level rise
is reduced by about a third in the mitigation scenario compared with the
A1B scenario. Changes in surface air temperature are found to be poorly
correlated with steric sea level changes. While the projected decreases
in sea ice extent during the first half of the twenty-first century are
independent of the season or scenario, especially in the Arctic, the
seasonal cycle of sea ice extent is amplified. By the end of the century
the Arctic becomes sea ice free in September in the A1B scenario in most
models. In the mitigation scenario the ice does not disappear in the
majority of models, but is reduced by 42 \% of the present September
extent. Results for Antarctic sea ice changes reveal large initial
biases in the models and a significant correlation between projected
changes and the initial extent. This latter result highlights the
necessity for further refinements in Antarctic sea ice modelling for
more reliable projections of future sea ice.
  doi = {10.1007/s00382-012-1612-9},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
Contact information

EMC3 group

Case 99
Tour 45-55, 3ème étage
4 Place Jussieu
75252 Paris Cedex 05
Tel: 33 + 1 44 27 27 99
      33 + 6 16 27 34 18 (Dr F. Cheruy)
Tel: 33 + 1 44 27 35 25 (Secretary)
Fax: 33 + 1 44 27 62 72
email: emc3 at

Map of our location

Real time LMDZ simulations

Today's LMDZ meteogram for the SIRTA site

Intranet EMC3

Intranet EMC3