Skip to content. | Skip to navigation

Personal tools

You are here: Home / Publications / Peer-reviewed papers / lmd_Hourdin2004_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:"Hourdin"  ' -c year=2004 -c $type="ARTICLE" -oc lmd_Hourdin2004.txt -ob lmd_Hourdin2004.bib /home/WWW/LMD/public/}}
  author = {{Hourdin}, F. and {Lebonnois}, S. and {Luz}, D. and {Rannou}, P.
  title = {{Titan's stratospheric composition driven by condensation and dynamics}},
  journal = {Journal of Geophysical Research (Planets)},
  keywords = {Planetology: Fluid Planets: Atmospheres-structure and dynamics, Planetology: Fluid Planets: Atmospheres-composition and chemistry, Planetology: Solar System Objects: Saturnian satellites},
  year = 2004,
  month = dec,
  volume = 109,
  number = e18,
  eid = {E12005},
  pages = {12005},
  abstract = {{Atmospheric transport of chemical compounds and organic haze in the
stratosphere of Titan is investigated with an axisymmetric general
circulation model. It has been shown previously that the meridional
circulation, dominated by global Hadley cells, is responsible both for
the creation of an intense stratospheric zonal flow and for the
accumulation of chemical compounds and haze in high latitudes. The
modified composition in turn intensifies the meridional circulation and
equator-to-pole thermal contrasts. This paper analyzes in detail the
transport processes responsible for the observed vertical and
latitudinal variations of atmospheric composition. It is shown that the
competition between rapid sinking of air from the upper stratosphere in
the winter polar vortex and latitudinal mixing by barotropic planetary
waves (parameterized in the model) controls the vertical gradient of
chemical compounds. The magnitude of polar enrichment (of a factor 1.4
to 20 depending on the particular species) with respect to low latitudes
is mostly controlled by the way the meridional advection increases the
concentrations of chemical compounds in the clean air which is rising
from the troposphere, where most of the chemical compounds are removed
by condensation (the temperature at the tropopause being close to 70 K).
The agreement between the observed and simulated contrasts provides an
indirect but strong validation of the simulated dynamics, thus
confirming the explanation put forward for atmospheric superrotation. It
is shown also that by measuring the atmospheric composition, the
Cassini-Huygens mission will provide a strong constraint about Titan's
atmospheric circulation.
  doi = {10.1029/2004JE002282},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Rannou}, P. and {Hourdin}, F. and {McKay}, C.~P. and {Luz}, D.
  title = {{A coupled dynamics-microphysics model of Titan's atmosphere}},
  journal = {\icarus},
  year = 2004,
  month = aug,
  volume = 170,
  pages = {443-462},
  abstract = {{We have developed a coupled general circulation model of Titan's
atmosphere in which the aerosol haze is treated with a microphysical
model and is advected by the winds. The radiative transfer accounts for
the non uniform haze distribution and, in turn, drives the dynamics. We
analyze the GCM results, especially focusing on the difference between a
uniform haze layer and a haze layer coupled to the dynamics. In the
coupled simulation the aerosols tend to accumulate at the poles, at
latitudes higher than {\plusmn}60{\deg}. During winter, aerosols strongly
radiate at thermal infrared wavelengths enhancing the cooling rate near
the pole. Since this tends to increase the latitudinal gradients of
temperature the direct effect of this cooling excess, in contrast to the
uncoupled haze case, is to increase the strength of the meridional cells
as well as the strength of the zonal winds and profile. This is a
positive feedback of the haze on dynamics. The coupled model reproduces
observations about the state of the atmosphere better than the uniform
haze model, and in addition, the northern polar hood and the detached
haze are qualitatively reproduced.
  doi = {10.1016/j.icarus.2004.03.007},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Hauglustaine}, D.~A. and {Hourdin}, F. and {Jourdain}, L. and 
	{Filiberti}, M.-A. and {Walters}, S. and {Lamarque}, J.-F. and 
	{Holland}, E.~A.},
  title = {{Interactive chemistry in the Laboratoire de Météorologie Dynamique general circulation model: Description and background tropospheric chemistry evaluation}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Constituent sources and sinks, Atmospheric Composition and Structure: Troposphere-composition and chemistry, Atmospheric Composition and Structure: Troposphere-constituent transport and chemistry, global modeling, tropospheric ozone budget, climate-chemistry interactions},
  year = 2004,
  month = feb,
  volume = 109,
  eid = {D04314},
  pages = {4314},
  abstract = {{We provide a description and evaluation of LMDz-INCA, which couples the
Laboratoire de Météorologie Dynamique general circulation
model (LMDz) and the Interaction with Chemistry and Aerosols (INCA)
model. In this first version of the model a
CH$_{4}$-NO$_{x}$-CO-O$_{3}$ chemical scheme
representative of the background chemistry of the troposphere is
considered. We derive rapid interhemispheric exchange times of 1.13-1.38
years and 0.70-0.82 years, based on surface and pressure-weighted mixing
ratios of inert tracers, respectively. The general patterns of the
nitrogen deposition are correctly reproduced by the model. However,
scavenging processes remain a major source of uncertainty in current
models, with convective precipitation playing a key role in the global
distribution of soluble species. The global and annual mean methane (7.9
years) and methylchloroform (4.6 years) chemical lifetimes suggest that
OH is too high by about 19-25\% in the model. This disagreement with
previous estimates is attributed to the missing nonmethane hydrocarbons
in this version of the model. The model simulates quite satisfactorily
the distribution and seasonal cycle of CO at most stations. At several
tropical sites and in the Northern Hemisphere during summer, the OH
overestimate leads, however, to a too intense CO chemical destruction.
LMDz-INCA reproduces fairly well the distribution of ozone throughout
most of the troposphere. A main disagreement appears in the Northern
Hemisphere upper troposphere during summer, due to a too high tropopause
in the GCM. When the GCM winds are relaxed toward assimilated
meteorology, a much higher variability is obtained for ozone in the
upper troposphere, reflecting more frequent stratospheric intrusions.
The stratospheric influx of ozone increases from 523 Tg/yr in the base
case simulation to 783 Tg/yr in the nudged version.
  doi = {10.1029/2003JD003957},
  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