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@comment{{Command line: /usr/bin/bib2bib --quiet -c 'not journal:"Discussions"' -c year=2017 -c $type="ARTICLE" -oc pub2017.txt -ob pub2017.bib}}
  author = {{Steele}, L.~J. and {Balme}, M.~R. and {Lewis}, S.~R. and {Spiga}, A.
  title = {{The water cycle and regolith-atmosphere interaction at Gale crater, Mars}},
  journal = {\icarus},
  keywords = {Mars, atmosphere, climate, surface},
  year = 2017,
  volume = 289,
  pages = {56-79},
  abstract = {{We perform mesoscale simulations of the water cycle in a region around
Gale crater, including the diffusion of water vapour in and out of the
regolith, and compare our results with measurements from the REMS
instrument on board the Curiosity rover. Simulations are performed at
three times of year, and show that diffusion in and out of the regolith
and adsorption/desorption needs to be taken into account in order to
match the diurnal variation of relative humidity measured by REMS.
During the evening and night, local downslope flows transport water
vapour down the walls of Gale crater. When including regolith-atmosphere
interaction, the amount of vapour reaching the crater floor is reduced
(by factors of 2-3 depending on season) due to vapour diffusing into the
regolith along the crater walls. The transport of vapour into Gale
crater is also affected by the regional katabatic flow over the
dichotomy boundary, with the largest flux of vapour into the regolith
initially occurring on the northern crater wall, and moving to the
southern wall by early morning. Upslope winds during the day transport
vapour desorbing and mixing out of the regolith up crater walls, where
it can then be transported a few hundred metres into the atmosphere at
convergence boundaries. Regolith-atmosphere interaction limits the
formation of surface ice by reducing water vapour abundances in the
lower atmosphere, though in some seasons ice can still form in the early
morning on eastern crater walls. Subsurface ice amounts are small in all
seasons, with ice only existing in the upper few millimetres of regolith
during the night. The results at Gale crater are representative of the
behaviour at other craters in the mesoscale domain.
  doi = {10.1016/j.icarus.2017.02.010},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Turbet}, M. and {Forget}, F. and {Head}, J.~W. and {Wordsworth}, R.
  title = {{3D modelling of the climatic impact of outflow channel formation events on early Mars}},
  journal = {\icarus},
  archiveprefix = {arXiv},
  eprint = {1701.07886},
  primaryclass = {astro-ph.EP},
  year = 2017,
  volume = 288,
  pages = {10-36},
  abstract = {{Mars was characterized by cataclysmic groundwater-sourced surface
flooding that formed large outflow channels and that may have altered
the climate for extensive periods during the Hesperian era. In
particular, it has been speculated that such events could have induced
significant rainfall and caused the formation of late-stage valley
networks. We present the results of 3-D Global Climate Model simulations
reproducing the short and long term climatic impact of a wide range of
outflow channel formation events under cold ancient Mars conditions. We
find that the most intense of these events (volumes of water up to
10$^{7}$ km$^{3}$ and released at temperatures up to 320 K)
cannot trigger long-term greenhouse global warming, regardless of how
favorable are the external conditions (e.g. obliquity and seasons).
Furthermore, the intensity of the response of the events is
significantly affected by the atmospheric pressure, a parameter not well
constrained for the Hesperian era. Thin atmospheres (P $\lt$ 80 mbar) can
be heated efficiently because of their low volumetric heat capacity,
triggering the formation of a convective plume that is very efficient in
transporting water vapor and ice at the global scale. Thick atmospheres
(P $\gt$ 0.5 bar) have difficulty in producing precipitation far from the
water flow area, and are more efficient in generating snowmelt. In any
case, outflow channel formation events at any atmospheric pressure are
unable to produce rainfall or significant snowmelt at latitudes below
40{\deg}N. As an example, for an outflow channel event (under a 0.2 bar
atmospheric pressure and 45{\deg} obliquity) releasing 10$^{6}$
km$^{3}$ of water heated at 300 K and at a discharge rate of
10$^{9}$ m$^{3}$ s-$^{1}$ , the flow of water reaches
the lowest point of the northern lowlands (around {\sim}70{\deg}N,
30{\deg}W) after {\sim}3 days and forms a 200 m deep lake of 4.2 {\times}
10$^{6}$ km$^{2}$ after {\sim}20 days; the lake becomes
entirely covered by an ice layer after {\sim}500 days. Over the short
term, such an event leaves 6.5 {\times} 10$^{3}$ km$^{3}$ of
ice deposits by precipitation (0.65\% of the initial outflow volume) and
can be responsible for the melting of {\sim}80 km$^{3}$ (0.008\% of
the initial outflow volume; 1\% of the deposited precipitation).
Furthermore, these quantities decrease drastically (faster than
linearly) for lower volumes of released water. Over the long term, we
find that the presence of the ice-covered lake has a climatic impact
similar to a simple body of water ice located in the Northern Plains.

For an obliquity of {\sim}45{\deg} and atmospheric pressures $\gt$ 80 mbar,
we find that the lake ice is transported progressively southward through
the mechanisms of sublimation and adiabatic cooling. At the same time,
and as long as the initial water reservoir is not entirely sublimated (a
lifetime of 10$^{5}$ martian years for the outflow channel event
described above), ice deposits remain in the West Echus Chasma Plateau
region where hints of hydrological activity contemporaneous with outflow
channel formation events have been observed. However, because the high
albedo of ice drives Mars to even colder temperatures, snowmelt produced
by seasonal solar forcing is difficult to attain.
  doi = {10.1016/j.icarus.2017.01.024},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Bertrand}, T. and {Forget}, F.},
  title = {{3D modeling of organic haze in Pluto's atmosphere}},
  journal = {\icarus},
  archiveprefix = {arXiv},
  eprint = {1702.03783},
  primaryclass = {astro-ph.EP},
  keywords = {Pluto, Atmosphere, Haze, Modeling, GCM},
  year = 2017,
  volume = 287,
  pages = {72-86},
  abstract = {{The New Horizons spacecraft, which flew by Pluto on July 14, 2015,
revealed the presence of haze in Pluto's atmosphere that were formed by
CH$_{4}$/N$_{2}$ photochemistry at high altitudes in Pluto's
atmosphere, as on Titan and Triton. In order to help the analysis of the
observations and further investigate the formation of organic haze and
its evolution at global scales, we have implemented a simple
parameterization of the formation of organic haze in our Pluto General
Circulation Model. The production of haze in our model is based on the
different steps of aerosol formation as understood on Titan and Triton:
photolysis of CH$_{4}$ in the upper atmosphere by Lyman-{$\alpha$} UV
radiation, production of various gaseous species, and conversion into
solid particles through accumulation and aggregation processes. The
simulations use properties of aerosols similar to those observed in the
detached haze layer on Titan. We compared two reference simulations ran
with a particle radius of 50  nm: with, and without South Pole
N$_{2}$ condensation. We discuss the impact of the particle radius
and the lifetime of the precursors on the haze distribution. We simulate
CH$_{4}$ photolysis and the haze formation up to 600  km above the
surface. Results show that CH$_{4}$ photolysis in Pluto's
atmosphere in 2015 occurred mostly in the sunlit summer hemisphere with
a peak at an altitude of 250  km, though the interplanetary source of
Lyman-{$\alpha$} flux can induce some photolysis even in the Winter
hemisphere. We obtained an extensive haze up to altitudes comparable
with the observations, and with non-negligible densities up to 500  km
altitude. In both reference simulations, the haze density is not
strongly impacted by the meridional circulation. With No South Pole
N$_{2}$ condensation, the maximum nadir opacity and haze extent is
obtained at the North Pole. With South Pole N$_{2}$ condensation,
the descending parcel of air above the South Pole leads to a
latitudinally more homogeneous haze density with a slight density peak
at the South Pole. The visible opacities obtained from the computed mass
of haze, which is about 2-4 {\times}10$^{-7}$ g cm-$^{2}$ in
the summer hemisphere, are similar for most of the simulation cases and
in the range of 0.001-0.01, which is consistent with recent observations
of Pluto and their interpretation.
  doi = {10.1016/j.icarus.2017.01.016},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Forget}, F. and {Bertrand}, T. and {Vangvichith}, M. and {Leconte}, J. and 
	{Millour}, E. and {Lellouch}, E.},
  title = {{A post-new horizons global climate model of Pluto including the N$_{2}$, CH$_{4}$ and CO cycles}},
  journal = {\icarus},
  keywords = {Pluto, atmosphere, Atmospheres, composition, dynamics},
  year = 2017,
  volume = 287,
  pages = {54-71},
  abstract = {{We have built a new 3D Global Climate Model (GCM) to simulate Pluto as
observed by New Horizons in 2015. All key processes are parametrized on
the basis of theoretical equations, including atmospheric dynamics and
transport, turbulence, radiative transfer, molecular conduction, as well
as phases changes for N$_{2}$, CH$_{2}$ and CO. Pluto's
climate and ice cycles are found to be very sensitive to model
parameters and initial states. Nevertheless, a reference simulation is
designed by running a fast, reduced version of the GCM with simplified
atmospheric transport for 40,000 Earth years to initialize the surface
ice distribution and sub-surface temperatures, from which a
28-Earth-year full GCM simulation is performed. Assuming a topographic
depression in a Sputnik-planum (SP)-like crater on the anti-Charon
hemisphere, a realistic Pluto is obtained, with most N$_{2}$ and
CO ices accumulated in the crater, methane frost covering both
hemispheres except for the equatorial regions, and a surface pressure
near 1.1 Pa in 2015 with an increase between 1988 and 2015, as reported
from stellar occultations. Temperature profiles are in qualitative
agreement with the observations. In particular, a cold atmospheric layer
is obtained in the lowest kilometers above Sputnik Planum, as observed
by New Horizons's REX experiment. It is shown to result from the
combined effect of the topographic depression and N$_{2}$ daytime
sublimation. In the reference simulation with surface N$_{2}$ ice
exclusively present in Sputnik Planum, the global circulation is only
forced by radiative heating gradients and remains relatively weak.
Surface winds are locally induced by topography slopes and by
N$_{2}$ condensation and sublimation around Sputnik Planum.
However, the circulation can be more intense depending on the exact
distribution of surface N$_{2}$ frost. This is illustrated in an
alternative simulation with N$_{2}$ condensing in the South Polar
regions and N$_{2}$ frost covering latitudes between 35{\deg}N and
48{\deg}N. A global condensation flow is then created, inducing strong
surface winds everywhere, a prograde jet in the southern high latitudes,
and an equatorial superrotation likely forced by barotropic
instabilities in the southern jet. Using realistic parameters, the GCM
predict atmospheric concentrations of CO and CH$_{4}$ in good
agreement with the observations. N$_{2}$ and CO do not condense in
the atmosphere, but CH$_{4}$ ice clouds can form during daytime at
low altitude near the regions covered by N$_{2}$ ice (assuming
that nucleation is efficient enough). This global climate model can be
used to study many aspects of the Pluto environment. For instance,
organic hazes are included in the GCM and analysed in a companion paper
(Bertrand and Forget, Icarus, this issue).
  doi = {10.1016/j.icarus.2016.11.038},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Lefèvre}, M. and {Spiga}, A. and {Lebonnois}, S.},
  title = {{Three-dimensional turbulence-resolving modeling of the Venusian cloud layer and induced gravity waves}},
  journal = {Journal of Geophysical Research (Planets)},
  keywords = {3-D mesoscale modeling, Venus, convective cloud layer, gravity waves},
  year = 2017,
  volume = 122,
  pages = {134-149},
  abstract = {{The impact of the cloud convective layer of the atmosphere of Venus on
the global circulation remains unclear. The recent observations of
gravity waves at the top of the cloud by the Venus Express mission
provided some answers. These waves are not resolved at the scale of
global circulation models (GCM); therefore, we developed an
unprecedented 3-D turbulence-resolving large-eddy simulations (LES)
Venusian model using the Weather Research and Forecast terrestrial
model. The forcing consists of three different heating rates: two
radiative ones for solar and infrared and one associated with the
adiabatic cooling/warming of the global circulation. The rates are
extracted from the Laboratoire de Météorlogie Dynamique
Venus GCM using two different cloud models. Thus, we are able to
characterize the convection and associated gravity waves in function of
latitude and local time. To assess the impact of the global circulation
on the convective layer, we used rates from a 1-D radiative-convective
model. The resolved layer, taking place between 1.0 {\times}
10$^{5}$ and 3.8 {\times} 10$^{4}$ Pa (48-53 km), is
organized as polygonal closed cells of about 10 km wide with vertical
wind of several meters per second. The convection emits gravity waves
both above and below the convective layer leading to temperature
perturbations of several tenths of kelvin with vertical wavelength
between 1 and 3 km and horizontal wavelength from 1 to 10 km. The
thickness of the convective layer and the amplitudes of waves are
consistent with observations, though slightly underestimated. The global
dynamics heating greatly modify the convective layer.
  doi = {10.1002/2016JE005146},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Gilli}, G. and {Lebonnois}, S. and {Gonz{\'a}lez-Galindo}, F. and 
	{L{\'o}pez-Valverde}, M.~A. and {Stolzenbach}, A. and {Lefèvre}, F. and 
	{Chaufray}, J.~Y. and {Lott}, F.},
  title = {{Thermal structure of the upper atmosphere of Venus simulated by a ground-to-thermosphere GCM}},
  journal = {\icarus},
  year = 2017,
  volume = 281,
  pages = {55-72},
  abstract = {{We present here the thermal structure of the upper atmosphere of Venus
predicted by a full self-consistent Venus General Circulation Model
(VGCM) developed at Laboratoire de Météorologie Dynamique
(LMD) and extended up to the thermosphere of the planet. Physical and
photochemical processes relevant at those altitudes, plus a
non-orographic GW parameterisation, have been added. All those
improvements make the LMD-VGCM the only existing ground-to-thermosphere
3D model for Venus: a unique tool to investigate the atmosphere of Venus
and to support the exploration of the planet by remote sounding. The aim
of this paper is to present the model reference results, to describe the
role of radiative, photochemical and dynamical effects in the observed
thermal structure in the upper mesosphere/lower thermosphere of the
planet. The predicted thermal structure shows a succession of warm and
cold layers, as recently observed. A cooling trend with increasing
latitudes is found during daytime at all altitudes, while at nighttime
the trend is inverse above about 110  km, with an atmosphere up to 15 K
warmer towards the pole. The latitudinal variation is even smaller at
the terminator, in agreement with observations. Below about 110  km, a
nighttime warm layer whose intensity decreases with increasing latitudes
is predicted by our GCM. A comparison of model results with a selection
of recent measurements shows an overall good agreement in terms of
trends and order of magnitude. Significant data-model discrepancies may
be also discerned. Among them, thermospheric temperatures are about
40-50 K colder and up to 30 K warmer than measured at terminator and at
nighttime, respectively. The altitude layer of the predicted mesospheric
local maximum (between 100 and 120  km) is also higher than observed.
Possible interpretations are discussed and several sensitivity tests
performed to understand the data-model discrepancies and to propose
future model improvements.
  doi = {10.1016/j.icarus.2016.09.016},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Genthon}, C. and {Piard}, L. and {Vignon}, E. and {Madeleine}, J.-B. and 
	{Casado}, M. and {Gallée}, H.},
  title = {{Atmospheric moisture supersaturation in the near-surface atmosphere at Dome C, Antarctic Plateau}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2017,
  volume = 17,
  pages = {691-704},
  abstract = {{Supersaturation often occurs at the top of the troposphere where cirrus
clouds form, but is comparatively unusual near the surface where the air
is generally warmer and laden with liquid and/or ice condensation
nuclei. One exception is the surface of the high Antarctic Plateau. One
year of atmospheric moisture measurement at the surface of Dome C on the
East Antarctic Plateau is presented. The measurements are obtained using
commercial hygrometry sensors modified to allow air sampling without
affecting the moisture content, even in the case of supersaturation.
Supersaturation is found to be very frequent. Common unadapted
hygrometry sensors generally fail to report supersaturation, and most
reports of atmospheric moisture on the Antarctic Plateau are thus likely
biased low. The measurements are compared with results from two models
implementing cold microphysics parameterizations: the European Center
for Medium-range Weather Forecasts through its operational analyses, and
the Model Atmosphérique Régional. As in the observations,
supersaturation is frequent in the models but the statistical
distribution differs both between models and observations and between
the two models, leaving much room for model improvement. This is
unlikely to strongly affect estimations of surface sublimation because
supersaturation is more frequent as temperature is lower, and moisture
quantities and thus water fluxes are small anyway. Ignoring
supersaturation may be a more serious issue when considering water
isotopes, a tracer of phase change and temperature, largely used to
reconstruct past climates and environments from ice cores. Because
observations are easier in the surface atmosphere, longer and more
continuous in situ observation series of atmospheric supersaturation can
be obtained than higher in the atmosphere to test parameterizations of
cold microphysics, such as those used in the formation of high-altitude
cirrus clouds in meteorological and climate models.
  doi = {10.5194/acp-17-691-2017},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}