@comment{{This file has been generated by bib2bib 1.97}}
@comment{{Command line: bib2bib --quiet -c year=2012 -c $type="ARTICLE" -oc pub2012.txt -ob pub2012.bib}}
  author = {{Lebonnois}, S. and {Covey}, C. and {Grossman}, A. and {Parish}, H. and 
	{Schubert}, G. and {Walterscheid}, R. and {Lauritzen}, P. and 
	{Jablonowski}, C.},
  title = {{Angular momentum budget in General Circulation Models of superrotating atmospheres: A critical diagnostic}},
  journal = {Journal of Geophysical Research (Planets)},
  keywords = {Atmospheric Composition and Structure: Planetary atmospheres (5210, 5405, 5704), Atmospheric Processes: General circulation (1223), Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 1060), Planetary Sciences: Solar System Objects: Venus},
  year = 2012,
  volume = 117,
  number = e16,
  eid = {E12004},
  pages = {12004},
  abstract = {{To help understand the large disparity in the results of circulation
modeling for the atmospheres of Titan and Venus, where the whole
atmosphere rotates faster than the surface (superrotation), the
atmospheric angular momentum budget is detailed for two General
Circulation Models (GCMs). The LMD GCM is tested for both Venus (with
simplified and with more realistic physical forcings) and Titan
(realistic physical forcings). The Community Atmosphere Model is tested
for both Earth and Venus with simplified physical forcings. These
analyses demonstrate that errors related to atmospheric angular momentum
conservation are significant, especially for Venus when the physical
forcings are simplified. Unphysical residuals that have to be balanced
by surface friction and mountain torques therefore affect the overall
circulation. The presence of topography increases exchanges of angular
momentum between surface and atmosphere, reducing the impact of these
numerical errors. The behavior of GCM dynamical cores with regard to
angular momentum conservation under Venus conditions provides an
explanation of why recent GCMs predict dissimilar results despite
identical thermal forcing. The present study illustrates the need for
careful and detailed analysis of the angular momentum budget for any GCM
used to simulate superrotating atmospheres.
  doi = {10.1029/2012JE004223},
  adsurl = {},
  localpdf = {REF/2012JGRE..11712004L.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Lorenz}, R.~D. and {Newman}, C.~E. and {Tokano}, T. and {Mitchell}, J.~L. and 
	{Charnay}, B. and {Lebonnois}, S. and {Achterberg}, R.~K.},
  title = {{Formulation of a wind specification for Titan late polar summer exploration}},
  journal = {\planss},
  year = 2012,
  volume = 70,
  pages = {73-83},
  abstract = {{Titan's polar regions, and its hydrocarbon lakes in particular, are of
interest for future exploration. The polar conditions have considerable
seasonal variation and are distinct from the equatorial environment
experienced by Huygens. Thus specific environmental models are required
for these regions. This paper, informed by Cassini and groundbased
observations and four independent Global Circulation Models (GCMs),
summarizes northern summer polar conditions (specifically, regions north
of 65{\deg}N, during the 2023-2024 period, or solar longitude
L$_{s}${\tilde}150$^{o}$-170{\deg}) and presents a simple
analytical formulation of expected, minimum and maximum winds as a
function of altitude to aid spacecraft and instrument design for future
exploration, with particular reference to the descent dispersions of the
Titan Mare Explorer (TiME) mission concept presently under development.
We also consider winds on the surface, noting that these (of relevance
for impact conditions, for waves, and for wind-driven drift of a
floating capsule) are weaker than those in the lowest cell in most GCMs:
some previously-reported estimates of 'surface' wind speeds (actually at
90-500 m altitude) should be reduced by 20-35\% to refer to the standard
10 m 'anemometer height' applicable for surface phenomena. A Weibull
distribution with scale speed C=0.4 m/s and shape parameter k=2.0
embraces the GCM-predicted surface wind speeds.
  doi = {10.1016/j.pss.2012.05.015},
  adsurl = {},
  localpdf = {REF/2012P_26SS...70...73L.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Wilson}, C.~F. and {Chassefière}, E. and {Hinglais}, E. and 
	{Baines}, K.~H. and {Balint}, T.~S. and {Berthelier}, J.-J. and 
	{Blamont}, J. and {Durry}, G. and {Ferencz}, C.~S. and {Grimm}, R.~E. and 
	{Imamura}, T. and {Josset}, J.-L. and {Leblanc}, F. and {Lebonnois}, S. and 
	{Leitner}, J.~J. and {Limaye}, S.~S. and {Marty}, B. and {Palomba}, E. and 
	{Pogrebenko}, S.~V. and {Rafkin}, S.~C.~R. and {Talboys}, D.~L. and 
	{Wieler}, R. and {Zasova}, L.~V. and {Szopa}, C.},
  title = {{The 2010 European Venus Explorer (EVE) mission proposal}},
  journal = {Experimental Astronomy},
  keywords = {Venus, Planetary mission, Cosmic vision, Superpressure balloon, Geochemistry, Dynamics},
  year = 2012,
  volume = 33,
  pages = {305-335},
  abstract = {{The European Venus Explorer (EVE) mission described in this paper was
proposed in December 2010 to ESA as an `M-class' mission under the
Cosmic Vision programme. It consists of a single balloon platform
floating in the middle of the main convective cloud layer of Venus at an
altitude of 55 km, where temperatures and pressures are benign
({\tilde}25{\deg}C and {\tilde}0.5 bar). The balloon float lifetime would
be at least 10 Earth days, long enough to guarantee at least one full
circumnavigation of the planet. This offers an ideal platform for the
two main science goals of the mission: study of the current climate
through detailed characterization of cloud-level atmosphere, and
investigation of the formation and evolution of Venus, through careful
measurement of noble gas isotopic abundances. These investigations would
provide key data for comparative planetology of terrestrial planets in
our solar system and beyond.
  doi = {10.1007/s10686-011-9259-9},
  adsurl = {},
  localpdf = {REF/2012ExA....33..305W.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Lebonnois}, S. and {Burgalat}, J. and {Rannou}, P. and {Charnay}, B.
  title = {{Titan global climate model: A new 3-dimensional version of the IPSL Titan GCM}},
  journal = {\icarus},
  year = 2012,
  volume = 218,
  pages = {707-722},
  abstract = {{We have developed a new 3-dimensional climate model for Titan's
atmosphere, using the physics of the IPSL Titan 2-dimensional climate
model with the current version of the LMDZ General Circulation Model
dynamical core. Microphysics and photochemistry are still computed as
zonal averages. This GCM covers altitudes from surface to 500 km
altitude, with barotropic waves now being resolved and the diurnal cycle
included. The boundary layer scheme has been changed, yielding a strong
improvement in the tropospheric zonal wind profile modeled at Huygens
descent position and season. The potential temperature profile is fairly
consistent with Huygens observations in the lowest 10 km. The
latitudinal profile of the near-surface temperature is close to observed
values. The minimum of zonal wind observed by the Huygens probe just
above the tropopause is also present in these simulations, and its
origin is discussed by comparing solar heating and dynamical transport
of energy. The stratospheric temperature and wind fields are consistent
with our previous works. Compared to observations, the zonal wind peak
is too weak (around 120 m/s) and too low (around 200 km). The
temperature structures appear to be compressed in altitude, and depart
strongly from observations in the upper stratosphere. These
discrepancies are correlated, and most probably related to the altitude
of the haze production. The model produces a detached haze layer located
more than 150 km lower than observed by the Cassini instruments. This
low production altitude is due to the current position of the GCM upper
boundary. However, the temporal behaviour of the detached haze layer in
the model may explain the seasonal differences observed between Cassini
and Voyager 1. The waves present in the GCM are analyzed, together with
their respective roles in the angular momentum budget. Though the role
of the mean meridional circulation in momentum transport is similar to
previous work, and the transport by barotropic waves is clearly seen in
the stratosphere, a significant part of the transport at high latitudes
is done all year long through low-frequency tropospheric waves that may
be baroclinic waves.
  doi = {10.1016/j.icarus.2011.11.032},
  adsurl = {},
  localpdf = {REF/2012Icar..218..707L.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Cordier}, D. and {Mousis}, O. and {Lunine}, J.~I. and {Lebonnois}, S. and 
	{Rannou}, P. and {Lavvas}, P. and {Lobo}, L.~Q. and {Ferreira}, A.~G.~M.
  title = {{Titan's lakes chemical composition: Sources of uncertainties and variability}},
  journal = {\planss},
  archiveprefix = {arXiv},
  eprint = {1104.2131},
  primaryclass = {astro-ph.EP},
  year = 2012,
  volume = 61,
  pages = {99-107},
  abstract = {{Between 2004 and 2007 the instruments of the Cassini spacecraft,
orbiting within the Saturn system, discovered dark patches in the polar
regions of Titan. These features are interpreted as hydrocarbon lakes
and seas with ethane and methane identified as the main compounds. In
this context, we have developed a lake-atmosphere equilibrium model
allowing the determination of the chemical composition of these liquid
areas present on Titan. The model is based on uncertain thermodynamic
data and precipitation rates of organic species predicted to be present
in the lakes and seas that are subject to spatial and temporal
variations. Here we explore and discuss the influence of these
uncertainties and variations. The errors and uncertainties relevant to
thermodynamic data are simulated via Monte Carlo simulations. Global
circulation models (GCM) are also employed in order to investigate the
possibility of chemical asymmetry between the south and the north poles,
due to differences in precipitation rates. We find that mole fractions
of compounds in the liquid phase have a high sensitivity to
thermodynamic data used as inputs, in particular molar volumes and
enthalpies of vaporization. When we combine all considered
uncertainties, the ranges of obtained mole fractions are rather large
(up to {\tilde}8500\%) but the distributions of values are narrow. The
relative standard deviations remain between 10\% and {\tilde}300\%
depending on the compound considered. Compared to other sources of
uncertainties and variability, deviation caused by surface pressure
variations are clearly negligible, remaining of the order of a few
percent up to {\tilde}20\%. Moreover, no significant difference is found
between the composition of lakes located in north and south poles.
Because the theory of regular solutions employed here is sensitive to
thermodynamic data and is not suitable for polar molecules such as HCN
and CH$_{3}$CN, our work strongly underlines the need for
experimental simulations and the improvement of Titan's atmospheric
  doi = {10.1016/j.pss.2011.05.009},
  adsurl = {},
  localpdf = {REF/2012P_26SS...61...99C.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Charnay}, B. and {Lebonnois}, S.},
  title = {{Two boundary layers in Titan's lower troposphere inferred from a climate model}},
  journal = {Nature Geoscience},
  year = 2012,
  volume = 5,
  pages = {106-109},
  abstract = {{Saturn's moon Titan has a dense atmosphere, but its thermal structure is
poorly known. Conflicting information has been gathered on the nature,
extent and evolution of Titan's planetary boundary layer--the layer of
the atmosphere that is influenced by the surface--from radio-occultation
observations by the Voyager 1 spacecraft and the Cassini orbiter,
measurements by the Huygens probe and by dune-spacing analyses.
Specifically, initial analyses of the Huygens data suggested a boundary
layer of 300m depth with no diurnal evolution, incompatible with
alternative estimates of 2-3km (refs , , ). Here we use a
three-dimensional general circulation model, albeit not explicitly
simulating the methane cycle, to analyse the dynamics leading to the
thermal profile of Titan's lowermost atmosphere. In our simulations, a
convective boundary layer develops in the course of the day, rising to
an altitude of 800m. In addition, a seasonal boundary of 2km depth is
produced by the reversal of the Hadley cell at the equinox, with a
dramatic impact on atmospheric circulation. We interpret fog that had
been discovered at Titan's south pole earlier as boundary layer clouds.
We conclude that Titan's troposphere is well structured, featuring two
boundary layers that control wind patterns, dune spacing and cloud
formation at low altitudes.
  doi = {10.1038/ngeo1374},
  adsurl = {},
  localpdf = {REF/2012NatGe...5..106C.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Migliorini}, A. and {Grassi}, D. and {Montabone}, L. and {Lebonnois}, S. and 
	{Drossart}, P. and {Piccioni}, G.},
  title = {{Investigation of air temperature on the nightside of Venus derived from VIRTIS-H on board Venus-Express}},
  journal = {\icarus},
  year = 2012,
  volume = 217,
  pages = {640-647},
  abstract = {{We present the spatial distribution of air temperature on Venus' night
side, as observed by the high spectral resolution channel of VIRTIS
(Visible and Infrared Thermal Imaging Spectrometer), or VIRTIS-H, on
board the ESA mission Venus Express. The present work extends the
investigation of the average thermal fields in the northern hemisphere
of Venus, by including the VIRTIS-H data. We show results in the
pressure range of 100-4 mbar, which corresponds to the altitude range of
65-80 km. With these new retrievals, we are able to compare the thermal
structure of the Venus' mesosphere in both hemispheres. The major
thermal features reported in previous investigations, i.e. the cold
collar at about 65-70{\deg}S latitude, 100 mbar pressure level, and the
asymmetry between the evening and morning sides, are confirmed here. By
comparing the temperatures retrieved by the VIRTIS spectrometer in the
North and South we find that similarities exist between the two
hemispheres. Solar thermal tides are clearly visible in the average
temperature fields. To interpret the thermal tide signals (otherwise
impossible without day site observations), we apply model simulations
using the Venus global circulation model Venus GCM (Lebonnois, S.,
Hourdin, F., Forget, F., Eymet, V., Fournier, R. [2010b]. International
Venus Conference, Aussois, 20-26 June 2010) of the Laboratoire de
Météorologie Dynamique (LMD). We suggest that the signal
detected at about 60-70{\deg} latitude and pressure of 100 mbar is a
diurnal component, while those located at equatorial latitudes are
semi-diurnal. Other tide-related features are clearly identified in the
upper levels of the atmosphere.
  doi = {10.1016/j.icarus.2011.07.013},
  adsurl = {},
  localpdf = {REF/2012Icar..217..640M.pdf},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}