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@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 year=2005 -c $type="ARTICLE" -oc lmd_EMC32005.txt -ob lmd_EMC32005.bib /home/WWW/LMD/public/}}
  author = {{Haeffelin}, M. and {Barthès}, L. and {Bock}, O. and {Boitel}, C. and 
	{Bony}, S. and {Bouniol}, D. and {Chepfer}, H. and {Chiriaco}, M. and 
	{Cuesta}, J. and {Delanoë}, J. and {Drobinski}, P. and {Dufresne}, J.-L. and 
	{Flamant}, C. and {Grall}, M. and {Hodzic}, A. and {Hourdin}, F. and 
	{Lapouge}, F. and {Lema{\^i}tre}, Y. and {Mathieu}, A. and {Morille}, Y. and 
	{Naud}, C. and {Noël}, V. and {O'Hirok}, W. and {Pelon}, J. and 
	{Pietras}, C. and {Protat}, A. and {Romand}, B. and {Scialom}, G. and 
	{Vautard}, R.},
  title = {{SIRTA, a ground-based atmospheric observatory for cloud and aerosol research}},
  journal = {Annales Geophysicae},
  year = 2005,
  month = feb,
  volume = 23,
  pages = {253-275},
  abstract = {{Ground-based remote sensing observatories have a crucial role to play in
providing data to improve our understanding of atmospheric processes, to
test the performance of atmospheric models, and to develop new methods
for future space-borne observations. Institut Pierre Simon Laplace, a
French research institute in environmental sciences, created the Site
Instrumental de Recherche par Télédétection
Atmosphérique (SIRTA), an atmospheric observatory with these
goals in mind. Today SIRTA, located 20km south of Paris, operates a
suite a state-of-the-art active and passive remote sensing instruments
dedicated to routine monitoring of cloud and aerosol properties, and key
atmospheric parameters. Detailed description of the state of the
atmospheric column is progressively archived and made accessible to the
scientific community. This paper describes the SIRTA infrastructure and
database, and provides an overview of the scientific research associated
with the observatory. Researchers using SIRTA data conduct research on
atmospheric processes involving complex interactions between clouds,
aerosols and radiative and dynamic processes in the atmospheric column.
Atmospheric modellers working with SIRTA observations develop new
methods to test their models and innovative analyses to improve
parametric representations of sub-grid processes that must be accounted
for in the model. SIRTA provides the means to develop data
interpretation tools for future active remote sensing missions in space
(e.g. CloudSat and CALIPSO). SIRTA observation and research activities
take place in networks of atmospheric observatories that allow
scientists to access consistent data sets from diverse regions on the
  doi = {10.5194/angeo-23-253-2005},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Dufresne}, J.-L. and {Quaas}, J. and {Boucher}, O. and {Denvil}, S. and 
	{Fairhead}, L.},
  title = {{Contrasts in the effects on climate of anthropogenic sulfate aerosols between the 20th and the 21st century}},
  journal = {\grl},
  keywords = {Global Change: Atmosphere (0315, 0325), Global Change: Climate variability (1635, 3305, 3309, 4215, 4513), Global Change: Global climate models (3337, 4928), Atmospheric Processes: Clouds and aerosols, Atmospheric Processes: Radiative processes},
  year = 2005,
  month = nov,
  volume = 32,
  eid = {L21703},
  pages = {21703},
  abstract = {{In this study, we examine the time evolution of the relative
contribution of sulfate aerosols and greenhouse gases to anthropogenic
climate change. We use the new IPSL-CM4 coupled climate model for which
the first indirect effect of sulfate aerosols has been calibrated using
POLDER satellite data. For the recent historical period the sulfate
aerosols play a key role on the temperature increase with a cooling
effect of 0.5 K, to be compared to the 1.4 K warming due to greenhouse
gas increase. In contrast, the projected temperature change for the 21st
century is remarkably independent of the effects of anthropogenic
sulfate aerosols for the SRES-A2 scenario. Those results are interpreted
comparing the different radiative forcings, and can be extended to other
scenarios. We also highlight that the first indirect effect of aerosol
strongly depends on the land surface model by changing the cloud cover.
  doi = {10.1029/2005GL023619},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Bony}, S. and {Dufresne}, J.-L.},
  title = {{Marine boundary layer clouds at the heart of tropical cloud feedback uncertainties in climate models}},
  journal = {\grl},
  keywords = {Atmospheric Processes: Climate change and variability (1616, 1635, 3309, 4215, 4513), Atmospheric Processes: Boundary layer processes, Atmospheric Processes: Clouds and cloud feedbacks, Atmospheric Processes: Global climate models (1626, 4928), Atmospheric Processes: Tropical meteorology},
  year = 2005,
  month = oct,
  volume = 32,
  eid = {L20806},
  pages = {20806},
  abstract = {{The radiative response of tropical clouds to global warming exhibits a
large spread among climate models, and this constitutes a major source
of uncertainty for climate sensitivity estimates. To better interpret
the origin of that uncertainty, we analyze the sensitivity of the
tropical cloud radiative forcing to a change in sea surface temperature
that is simulated by 15 coupled models simulating climate change and
current interannual variability. We show that it is in regimes of
large-scale subsidence that the model results (1) differ the most in
climate change and (2) disagree the most with observations in the
current climate (most models underestimate the interannual sensitivity
of clouds albedo to a change in temperature). This suggests that the
simulation of the sensitivity of marine boundary layer clouds to
changing environmental conditions constitutes, currently, the main
source of uncertainty in tropical cloud feedbacks simulated by general
circulation models.
  doi = {10.1029/2005GL023851},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Dufresne}, J.-L. and {Fournier}, R. and {Hourdin}, C. and {Hourdin}, F.
  title = {{Net Exchange Reformulation of Radiative Transfer in the CO$_{2}$ 15-{$\mu$}m Band on Mars.}},
  journal = {Journal of Atmospheric Sciences},
  year = 2005,
  month = sep,
  volume = 62,
  pages = {3303-3319},
  abstract = {{The net exchange formulation (NEF) is an alternative to the usual
radiative transfer formulation. It was proposed by two authors in 1967,
but until now, this formulation has been used only in a very few cases
for atmospheric studies. The aim of this paper is to present the NEF and
its main advantages and to illustrate them in the case of planet Mars.In
the NEF, the radiative fluxes are no longer considered. The basic
variables are the net exchange rates between each pair of atmospheric
layers i, j. NEF offers a meaningful matrix representation of radiative
exchanges, allows qualification of the dominant contributions to the
local heating rates, and provides a general framework to develop
approximations satisfying reciprocity of radiative transfer as well as
the first and second principles of thermodynamics. This may be very
useful to develop fast radiative codes for GCMs.A radiative code
developed along those lines is presented for a GCM of Mars. It is shown
that computing the most important optical exchange factors at each time
step and the other exchange factors only a few times a day strongly
reduces the computation time without any significant precision lost.
With this solution, the computation time increases proportionally to the
number N of the vertical layers and no longer proportionally to its
square N$^{2}$. Some specific points, such as numerical
instabilities that may appear in the high atmosphere and errors that may
be introduced if inappropriate treatments are performed when reflection
at the surface occurs, are also investigated.
  doi = {10.1175/JAS3537.1},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Reddy}, M.~S. and {Boucher}, O. and {Bellouin}, N. and {Schulz}, M. and 
	{Balkanski}, Y. and {Dufresne}, J.-L. and {Pham}, M.},
  title = {{Estimates of global multicomponent aerosol optical depth and direct radiative perturbation in the Laboratoire de Météorologie Dynamique general circulation model}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), Atmospheric Composition and Structure: Troposphere: composition and chemistry, Atmospheric Composition and Structure: Pollution: urban and regional (0305, 0478, 4251), Atmospheric Composition and Structure: Radiation: transmission and scattering, aerosol absorption, model validation, sulfate, black carbon, organic matter},
  year = 2005,
  month = may,
  volume = 110,
  number = d9,
  eid = {D10S16},
  pages = {10},
  abstract = {{The global cycle of multicomponent aerosols including sulfate, black
carbon (BC), organic matter (OM), mineral dust, and sea salt is
simulated in the Laboratoire de Météorologie Dynamique
general circulation model (LMDZT GCM). The seasonal open biomass burning
emissions for simulation years 2000-2001 are scaled from climatological
emissions in proportion to satellite detected fire counts. The emissions
of dust and sea salt are parameterized online in the model. The
comparison of model-predicted monthly mean aerosol optical depth (AOD)
at 500 nm with Aerosol Robotic Network (AERONET) shows good agreement
with a correlation coefficient of 0.57(N = 1324) and 76\% of data points
falling within a factor of 2 deviation. The correlation coefficient for
daily mean values drops to 0.49 (N = 23,680). The absorption AOD
({$\tau$}$_{a}$ at 670 nm) estimated in the model is poorly
correlated with measurements (r = 0.27, N = 349). It is biased low by
24\% as compared to AERONET. The model reproduces the prominent features
in the monthly mean AOD retrievals from Moderate Resolution Imaging
Spectroradiometer (MODIS). The agreement between the model and MODIS is
better over source and outflow regions (i.e., within a factor of 2).
There is an underestimation of the model by up to a factor of 3 to 5
over some remote oceans. The largest contribution to global annual
average AOD (0.12 at 550 nm) is from sulfate (0.043 or 35\%), followed by
sea salt (0.027 or 23\%), dust (0.026 or 22\%), OM (0.021 or 17\%), and BC
(0.004 or 3\%). The atmospheric aerosol absorption is predominantly
contributed by BC and is about 3\% of the total AOD. The globally and
annually averaged shortwave (SW) direct aerosol radiative perturbation
(DARP) in clear-sky conditions is -2.17 Wm$^{-2}$ and is about a
factor of 2 larger than in all-sky conditions (-1.04 Wm$^{-2}$).
The net DARP (SW + LW) by all aerosols is -1.46 and -0.59
Wm$^{-2}$ in clear- and all-sky conditions, respectively. Use of
realistic, less absorbing in SW, optical properties for dust results in
negative forcing over the dust-dominated regions.
  doi = {10.1029/2004JD004757},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Bellouin}, N. and {Boucher}, O. and {Haywood}, J. and {Reddy}, M.~S.
  title = {{Global estimate of aerosol direct radiative forcing from satellite measurements}},
  journal = {\nat},
  year = 2005,
  month = dec,
  volume = 438,
  pages = {1138-1141},
  abstract = {{Atmospheric aerosols cause scattering and absorption of incoming solar
radiation. Additional anthropogenic aerosols released into the
atmosphere thus exert a direct radiative forcing on the climate system.
The degree of present-day aerosol forcing is estimated from global
models that incorporate a representation of the aerosol cycles. Although
the models are compared and validated against observations, these
estimates remain uncertain. Previous satellite measurements of the
direct effect of aerosols contained limited information about aerosol
type, and were confined to oceans only. Here we use state-of-the-art
satellite-based measurements of aerosols and surface wind speed to
estimate the clear-sky direct radiative forcing for 2002, incorporating
measurements over land and ocean. We use a Monte Carlo approach to
account for uncertainties in aerosol measurements and in the algorithm
used. Probability density functions obtained for the direct radiative
forcing at the top of the atmosphere give a clear-sky, global, annual
average of -1.9Wm$^{-2}$ with standard deviation, +/-
0.3Wm$^{-2}$. These results suggest that present-day direct
radiative forcing is stronger than present model estimates, implying
future atmospheric warming greater than is presently predicted, as
aerosol emissions continue to decline.
  doi = {10.1038/nature04348},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Vimeux}, F. and {Gallaire}, R. and {Bony}, S. and {Hoffmann}, G. and 
	{Chiang}, J.~C.~H.},
  title = {{What are the climate controls on @dD in precipitation in the Zongo Valley (Bolivia)? Implications for the Illimani ice core interpretation [rapid communication]}},
  journal = {Earth and Planetary Science Letters},
  year = 2005,
  month = dec,
  volume = 240,
  pages = {205-220},
  abstract = {{Controversy has surrounded the interpretation of the water isotopic
composition ( {$\delta$}D or {$\delta$}$^{18}$O) in tropical and
subtropical ice cores in South America. Although recent modeling studies
using AGCM have provided useful constraints at interannual time scales,
no direct calibration based on modern observations has been achieved. In
the context of the recent ice core drilling at Nevado Illimani
(16{\deg}39'S-67{\deg}47'W) in Bolivia, we examine the climatic controls
on the modern isotopic composition of precipitation in the Zongo Valley,
located on the northeast side of the Cordillera Real, at about 55 km
from Nevado Illimani. Monthly precipitation samples were collected from
September 1999 to August 2004 at various altitudes along this valley.
First we examine the local and regional controls on the common {$\delta$}D
signal measured along this valley. We show that (1) local temperature
has definitely no control on {$\delta$}D variations, and (2) local rainout
is a poor factor to explain {$\delta$}D variations. We thus seek regional
controls upstream the Valley potentially affecting air masses
distillation. Based on backtrajectory calculations and using satellite
data (TRMM precipitation, NOAA OLR) and direct observations of
precipitation (IAEA/GNIP), we show that moisture transport history and
the degree of rainout upstream are more important factors explaining
seasonal {$\delta$}D variations. Analysis of a 92-yr simulation from the
ECHAM-4 model (T30 version) implemented with water stable isotopes
confirms our observations at seasonal time scale and emphasize the role
of air masses distillation upstream as a prominent factor controlling
interannual {$\delta$}D variations. Lastly, we focus on the isotopic
depletion along the valley when air masses are lifted up. Our results
suggest that, if the temperature gradient between the base and the top
of the Andes was higher by a few degrees during the Last Glacial Maximum
(LGM), less than 10\% of the glacial to interglacial isotopic variation
recorded in the Illimani ice core could be accounted for by this
temperature change. It implies that the rest of the variation would
originate from wetter conditions along air masses trajectory during LGM.
  doi = {10.1016/j.epsl.2005.09.031},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Lott}, F. and {Fairhead}, L. and {Hourdin}, F. and {Levan}, P.
  title = {{The stratospheric version of LMDz: dynamical climatologies, arctic oscillation, and impact on the surface climate}},
  journal = {Climate Dynamics},
  year = 2005,
  month = dec,
  volume = 25,
  pages = {851-868},
  abstract = {{A climatology of the stratosphere is determined from a 20-year
integration with the stratospheric version of the Atmospheric General
Circulation Model LMDz. The model has an upper boundary at near 65 km,
uses a Doppler spread non-orographic gravity waves drag parameterization
and a subgrid-scale orography parameterization. It also has a Rayleigh
damping layer for resolved waves only (not the zonal mean flow) over the
top 5 km. This paper describes the basic features of the model and some
aspects of its radiative-dynamical climatology. Standard first order
diagnostics are presented but some emphasis is given to the
model{\rsquo}s ability to reproduce the low frequency variability of the
stratosphere in the winter northern hemisphere. In this model, the
stratospheric variability is dominated at each altitudes by patterns
which have some similarities with the arctic oscillation (AO). For those
patterns, the signal sometimes descends from the stratosphere to the
troposphere. In an experiment where the parameterized orographic gravity
waves that reach the stratosphere are exaggerated, the model
stratosphere in the NH presents much less variability. Although the
stratospheric variability is still dominated by patterns that resemble
to the AO, the downward influence of the stratosphere along these
patterns is near entirely lost. In the same time, the persistence of the
surface AO decreases, which is consistent with the picture that this
persistence is linked to the descent of the AO signal from the
stratosphere to the troposphere. A comparison between the stratospheric
version of the model, and its routinely used tropospheric version is
also done. It shows that the introduction of the stratosphere in a model
that already has a realistic AO persistence can lead to overestimate the
actual influence of the stratospheric dynamics onto the surface AO.
Although this result is certainly model dependent, it suggests that the
introduction of the stratosphere in a GCM also call for a new adjustment
of the model parameters that affect the tropospheric variability.
  doi = {10.1007/s00382-005-0064-x},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Anderson}, T.~L. and {Charlson}, R.~J. and {Bellouin}, N. and 
	{Boucher}, O. and {Chin}, M. and {Christopher}, S.~A. and {Haywood}, J. and 
	{Kaufman}, Y.~J. and {Kinne}, S. and {Ogren}, J.~A. and {Remer}, L.~A. and 
	{Takemura}, T. and {Tanré}, D. and {Torres}, O. and {Trepte}, C.~R. and 
	{Wielicki}, B.~A. and {Winker}, D.~M. and {Yu}, H.},
  title = {{An ''A-Train'' Strategy for Quantifying Direct Climate Forcing by Anthropogenic Aerosols.}},
  journal = {Bulletin of the American Meteorological Society},
  year = 2005,
  month = dec,
  volume = 86,
  pages = {1795-1809},
  abstract = {{This document outlines a practical strategy for achieving an
observationally based quantification of direct climate forcing by
anthropogenic aerosols. The strategy involves a four-step program for
shifting the current assumption-laden estimates to an increasingly
empirical basis using satellite observations coordinated with suborbital
remote and in situ measurements and with chemical transport models.
Conceptually, the problem is framed as a need for complete global
mapping of four parameters: clear-sky aerosol optical depth {$\delta$},
radiative efficiency per unit optical depth E, fine-mode fraction of
optical depth f$_{f}$, and the anthropogenic fraction of the fine
mode f$_{af}$. The first three parameters can be retrieved from
satellites, but correlative, suborbital measurements are required for
quantifying the aerosol properties that control E, for validating the
retrieval of f$_{f}$, and for partitioning fine-mode {$\delta$}
between natural and anthropogenic components. The satellite focus is on
the ''A-Train,'' a constellation of six spacecraft that will fly in
formation from about 2005 to 2008. Key satellite instruments for this
report are the Moderate Resolution Imaging Spectroradiometer (MODIS) and
Clouds and the Earth's Radiant Energy System (CERES) radiometers on
Aqua, the Ozone Monitoring Instrument (OMI) radiometer on Aura, the
Polarization and Directionality of Earth's Reflectances (POLDER)
polarimeter on the Polarization and Anistropy of Reflectances for
Atmospheric Sciences Coupled with Observations from a Lidar (PARASOL),
and the Cloud and Aerosol Lider with Orthogonal Polarization (CALIOP)
lidar on the Cloud Aerosol Lidar and Infrared Pathfinder Satellite
Observations (CALIPSO). This strategy is offered as an initial
framework{\mdash}subject to improvement over time{\mdash}for scientists
around the world to participate in the A-Train opportunity. It is a
specific implementation of the Progressive Aerosol Retrieval and
Assimilation Global Observing Network (PARAGON) program, presented
earlier in this journal, which identified the integration of diverse
data as the central challenge to progress in quantifying global-scale
aerosol effects. By designing a strategy around this need for
integration, we develop recommendations for both satellite data
interpretation and correlative suborbital activities that represent, in
many respects, departures from current practice.
  doi = {10.1175/BAMS-86-12-1795},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Peylin}, P. and {Rayner}, P.~J. and {Bousquet}, P. and {Carouge}, C. and 
	{Hourdin}, F. and {Heinrich}, P. and {Ciais}, P. and {Contributors}, A.
  title = {{Daily CO$_{2}$ flux estimates over Europe from continuous atmospheric measurements: 1, inverse methodology}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2005,
  month = nov,
  volume = 5,
  pages = {3173-3186},
  abstract = {{This paper presents an inverse method for inferring trace gas fluxes at
high temporal (daily) and spatial (model grid) resolution from
continuous atmospheric concentration measurements. The method is
designed for regional applications and for use in intensive campaigns.
We apply the method to a one month inversion of fluxes over Europe. We
show that the information added by the measurements depends critically
on the smoothness constraint assumed among the source components. We
show that the initial condition affects the inversion for 20 days,
provided one has enough observing sites to constrain regional fluxes. We
show that the impact of the far-field fluxes grows throughout the
inversion and hence a reasonable global flux field is a prerequisite for
a regional inversion.
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Brogniez}, H. and {Roca}, R. and {Picon}, L.},
  title = {{Evaluation of the distribution of subtropical free tropospheric humidity in AMIP-2 simulations using METEOSAT water vapor channel data}},
  journal = {\grl},
  keywords = {Global Change: Atmosphere (0315, 0325), Global Change: Global climate models (3337, 4928), Global Change: Remote sensing (1855)},
  year = 2005,
  month = oct,
  volume = 32,
  eid = {L19708},
  pages = {19708},
  abstract = {{In the framework of the Atmospheric Model Intercomparison Project (AMIP)
phase 2, we have established a diagnostic of the free tropospheric
humidity (FTH) distribution using METEOSAT data over the 1984-1995
period for 14 climate models. The methodology of evaluation follows a
two step ``model-to-satellite'' approach. First the raw METEOSAT ``Water
Vapor'' radiances are simulated from the model profiles of temperature
and humidity using the RTTOV-7 radiative transfer model. Second, the
radiances are converted into FTH using the same coefficients as in the
satellite product offering a direct comparison. The analysis is focused
on the dry subtropical areas observed by METEOSAT: the Eastern
Mediterranean and the tropical South Atlantic Ocean. Most of the models
reproduce the observed seasonal cycle both in terms of phasing and
magnitude, despite an overall moist bias. A few models are in close
agreement with the satellite data. The magnitude of the satellite
estimated inter-annual variability is also generally captured by models.
Again, a small subset of models shows close agreement with the
observations. This comparison suggests general improvements of the
models with respect to the AMIP-1 simulations.
  doi = {10.1029/2005GL024341},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Roca}, R. and {Louvet}, S. and {Picon}, L. and {Desbois}, M.
  title = {{A study of convective systems, water vapor and top of the atmosphere cloud radiative forcing over the Indian Ocean using INSAT-1B and ERBE data}},
  journal = {Meteorology and Atmospheric Physics},
  year = 2005,
  month = sep,
  volume = 90,
  pages = {49-65},
  abstract = {{The distribution of cloud radiative forcing (CRF) at the top of the
atmosphere over the Indian Ocean is investigated using satellite
observations. Two key regions are considered: The eastern Indian Ocean
and the Bay of Bengal which experience maximum upper-level cloudiness in
winter and summer respectively. It is found that longwave CRF in the Bay
of Bengal during summer is similar to that over the eastern Indian Ocean
during winter. On the other hand shortwave CRF magnitude is larger in
the Bay of Bengal. These differences explain the net CRF difference
between the two regions. The stronger shortwave forcing seems to be
related to the Upper-Level Cloudiness being larger over the Bay than
over the eastern Indian Ocean. The reasons for the longwave CRF
similarities are analysed in more details. Using the results from a
convective system classification method, it is first shown that the
longwave radiative properties of the individual systems do not vary much
from one region to another. The distribution of the different kind of
systems, a proxy for the vertical cloudiness structure, does not either
indicate strong difference between the regions. It is then proposed that
the substantial precipitable water vapour amount observed over the Bay
of Bengal damps the effects of the upper-level cloudiness on radiation
compared to the relatively dryer eastern Indian Ocean area; yielding to
similar LW CRF in both region despite more Upper-Level Cloudiness over
the Bay of Bengal. These observations are supported by idealised
radiative transfer computations. The distribution of cloudiness and
radiative forcing is then analysed over the whole tropical Indian Ocean
for each season. July is characterized by a low longwave CRF regime
(relative to January) over the most convectively active part of the
Ocean. The non linear damping effect of water vapor on longwave CRF is
also shown to contribute to this regime. Overall, this study reaffirms
the need for simultaneous documentation of the cloud systems properties
together with their moist environment in order to understand the overall
net radiative signature of tropical convection at the top of the
atmosphere (TOA).
  doi = {10.1007/s00703-004-0098-3},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Yoshioka}, M. and {Mahowald}, N. and {Dufresne}, J.-L. and 
	{Luo}, C.},
  title = {{Simulation of absorbing aerosol indices for African dust}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, Global Change: Land/atmosphere interactions (1218, 1843, 3322), Atmospheric Processes: Remote sensing, Geographic Location: Africa, African dust, TOMS},
  year = 2005,
  month = sep,
  volume = 110,
  number = d9,
  eid = {D18S17},
  pages = {18},
  abstract = {{It has been speculated that the vegetation change and human land use
have modulated the dust sources in North Africa and contributed to the
observed increase of desert dust since 1960s. However, the roles of
surface disturbances on dust generation are not well constrained because
of limitations in the available data and models. This study addresses
this issue by simulating the Total Ozone Mapping Spectrometer (TOMS)
Absorbing Aerosol Indices (AAIs) for model-predicted dust and comparing
them with the observations. Model simulations are conducted for natural
topographic depression sources with and without adding sources due to
vegetation change and cultivation over North Africa. The simulated AAIs
capture the previously reported properties of TOMS AAI as well as
observed magnitude and spatial distribution reasonably well, although
there are some important disagreements with observations. Statistical
analyses of spatial and temporal patterns of simulated AAI suggest that
simulations using only the natural topographic source capture the
observed patterns better than those using 50\% of surface disturbance
sources. The AAI gradients between Sahara (north) and Sahel (south)
suggest that the best mixture of surface disturbance sources is 20-25\%,
while spatial and temporal correlations suggest that the optimum mixture
is 0-15\% with the upper bound of 25-40\%. However, sensitivity studies
show that uncertainties associated with meteorology and source
parameterization are large and may undermine the findings derived from
the simulations. Additional uncertainties will arise because of model
errors in sources, transport, and deposition. Such uncertainties in the
model simulations need to be reduced in order to constrain the roles of
different types of dust sources better using AAI simulation.
  doi = {10.1029/2004JD005276},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Quaas}, J. and {Boucher}, O.},
  title = {{Constraining the first aerosol indirect radiative forcing in the LMDZ GCM using POLDER and MODIS satellite data}},
  journal = {\grl},
  keywords = {Atmospheric Processes: Climate change and variability (1616, 1635, 3309, 4215, 4513), Atmospheric Processes: Clouds and aerosols, Atmospheric Processes: Global climate models (1626, 4928), Atmospheric Processes: Remote sensing},
  year = 2005,
  month = sep,
  volume = 32,
  eid = {L17814},
  pages = {17814},
  abstract = {{The indirect effects of anthropogenic aerosols are expected to cause a
significant radiative forcing of the Earth's climate whose magnitude,
however, is still uncertain. Most climate models use parameterizations
for the aerosol indirect effects based on so-called ``empirical
relationships'' which link the cloud droplet number concentration to the
aerosol concentration. New satellite datasets such as those from the
POLDER and MODIS instruments are well suited to evaluate and improve
such parameterizations at a global scale. We derive statistical
relationships of cloud-top droplet radius and aerosol index (or aerosol
optical depth) from satellite retrievals and fit an empirical
parameterization in a general circulation model to match the
relationships. When applying the fitted parameterizations in the model,
the simulated radiative forcing by the first aerosol indirect effect is
reduced by 50\% as compared to our baseline simulation (down to -0.3 and
-0.4 Wm$^{-2}$ when using MODIS and POLDER satellite data,
  doi = {10.1029/2005GL023850},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Kaufman}, Y.~J. and {Boucher}, O. and {Tanré}, D. and {Chin}, M. and 
	{Remer}, L.~A. and {Takemura}, T.},
  title = {{Aerosol anthropogenic component estimated from satellite data}},
  journal = {\grl},
  keywords = {Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), Atmospheric Composition and Structure: Pollution: urban and regional (0305, 0478, 4251), Global Change: Atmosphere (0315, 0325)},
  year = 2005,
  month = sep,
  volume = 32,
  eid = {L17804},
  pages = {17804},
  abstract = {{Satellite instruments do not measure the aerosol chemical composition
needed to discriminate anthropogenic from natural aerosol components.
However the ability of new satellite instruments to distinguish fine
(submicron) from coarse (supermicron) aerosols over the oceans, serves
as a signature of the anthropogenic component and can be used to
estimate the fraction of anthropogenic aerosols with an uncertainty of
+/-30\%. Application to two years of global MODIS data shows that 21 +/-
7\% of the aerosol optical thickness over the oceans has an anthropogenic
origin. We found that three chemical transport models, used for global
estimates of the aerosol forcing of climate, calculate a global average
anthropogenic optical thickness over the ocean between 0.030 and 0.036,
in line with the present MODIS assessment of 0.033. This increases our
confidence in model assessments of the aerosol direct forcing of
climate. The MODIS estimated aerosol forcing over cloud free oceans is
therefore -1.4 +/- 0.4 W/m$^{2}$.
  doi = {10.1029/2005GL023125},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Zhang}, M.~H. and {Lin}, W.~Y. and {Klein}, S.~A. and {Bacmeister}, J.~T. and 
	{Bony}, S. and {Cederwall}, R.~T. and {Del Genio}, A.~D. and 
	{Hack}, J.~J. and {Loeb}, N.~G. and {Lohmann}, U. and {Minnis}, P. and 
	{Musat}, I. and {Pincus}, R. and {Stier}, P. and {Suarez}, M.~J. and 
	{Webb}, M.~J. and {Wu}, J.~B. and {Xie}, S.~C. and {Yao}, M.-S. and 
	{Zhang}, J.~H.},
  title = {{Comparing clouds and their seasonal variations in 10 atmospheric general circulation models with satellite measurements}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Processes: Clouds and cloud feedbacks, Atmospheric Processes: Global climate models (1626, 4928), Atmospheric Processes: Theoretical modeling, Global Change: Global climate models (3337, Global Change: Climate dynamics (0429, 3309), climate models, cloud modeling, seasonal variation of clouds},
  year = 2005,
  month = aug,
  volume = 110,
  number = d9,
  eid = {D15S02},
  pages = {15},
  abstract = {{To assess the current status of climate models in simulating clouds,
basic cloud climatologies from ten atmospheric general circulation
models are compared with satellite measurements from the International
Satellite Cloud Climatology Project (ISCCP) and the Clouds and Earth's
Radiant Energy System (CERES) program. An ISCCP simulator is employed in
all models to facilitate the comparison. Models simulated a four-fold
difference in high-top clouds. There are also, however, large
uncertainties in satellite high thin clouds to effectively constrain the
models. The majority of models only simulated 30-40\% of middle-top
clouds in the ISCCP and CERES data sets. Half of the models
underestimated low clouds, while none overestimated them at a
statistically significant level. When stratified in the optical
thickness ranges, the majority of the models simulated optically thick
clouds more than twice the satellite observations. Most models, however,
underestimated optically intermediate and thin clouds. Compensations of
these clouds biases are used to explain the simulated longwave and
shortwave cloud radiative forcing at the top of the atmosphere. Seasonal
sensitivities of clouds are also analyzed to compare with observations.
Models are shown to simulate seasonal variations better for high clouds
than for low clouds. Latitudinal distribution of the seasonal variations
correlate with satellite measurements at {\gt}0.9, 0.6-0.9, and -0.2-0.7
levels for high, middle, and low clouds, respectively. The seasonal
sensitivities of cloud types are found to strongly depend on the basic
cloud climatology in the models. Models that systematically
underestimate middle clouds also underestimate seasonal variations,
while those that overestimate optically thick clouds also overestimate
their seasonal sensitivities. Possible causes of the systematic cloud
biases in the models are discussed.
  doi = {10.1029/2004JD005021},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Bony}, S. and {Emanuel}, K.~A.},
  title = {{On the Role of Moist Processes in Tropical Intraseasonal Variability: Cloud-Radiation and Moisture-Convection Feedbacks.}},
  journal = {Journal of Atmospheric Sciences},
  year = 2005,
  month = aug,
  volume = 62,
  pages = {2770-2789},
  abstract = {{Recent observations of the tropical atmosphere reveal large variations
of water vapor and clouds at intraseasonal time scales. This study
investigates the role of these variations in the large-scale
organization of the tropical atmosphere, and in intraseasonal
variability in particular. For this purpose, the influence of feedbacks
between moisture (water vapor, clouds), radiation, and convection that
affect the growth rate and the phase speed of unstable modes of the
tropical atmosphere is investigated.Results from a simple linear model
suggest that interactions between moisture and tropospheric radiative
cooling, referred to as moist-radiative feedbacks, play a significant
role in tropical intraseasonal variability. Their primary effect is to
reduce the phase speed of large-scale tropical disturbances: by cooling
the atmosphere less efficiently during the rising phase of the
oscillations (when the atmosphere is moister) than during episodes of
large-scale subsidence (when the atmosphere is drier), the atmospheric
radiative heating reduces the effective stratification felt by
propagating waves and slows down their propagation. In the presence of
significant moist-radiative feedbacks, planetary disturbances are
characterized by an approximately constant frequency. In addition,
moist-radiative feedbacks excite small-scale disturbances advected by
the mean flow. The interactions between moisture and convection exert a
selective damping effect upon small-scale disturbances, thereby favoring
large-scale propagating waves at the expense of small-scale advective
disturbances. They also weaken the ability of radiative processes to
slow down the propagation of planetary-scale disturbances. This study
suggests that a deficient simulation of cloud radiative interactions or
of convection-moisture interactions may explain some of the difficulties
experienced by general circulation models in simulating tropical
intraseasonal oscillations.
  doi = {10.1175/JAS3506.1},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Halthore}, R.~N. and {Crisp}, D. and {Schwartz}, S.~E. and 
	{Anderson}, G.~P. and {Berk}, A. and {Bonnel}, B. and {Boucher}, O. and 
	{Chang}, F.-L. and {Chou}, M.-D. and {Clothiaux}, E.~E. and 
	{Dubuisson}, P. and {Fomin}, B. and {Fouquart}, Y. and {Freidenreich}, S. and 
	{Gautier}, C. and {Kato}, S. and {Laszlo}, I. and {Li}, Z. and 
	{Mather}, J.~H. and {Plana-Fattori}, A. and {Ramaswamy}, V. and 
	{Ricchiazzi}, P. and {Shiren}, Y. and {Trishchenko}, A. and 
	{Wiscombe}, W.},
  title = {{Intercomparison of shortwave radiative transfer codes and measurements}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Radiation: transmission and scattering, Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), Atmospheric Processes: Remote sensing, Atmospheric Composition and Structure: Cloud/radiation interaction, Atmospheric Processes: Clouds and aerosols, shortwave, model intercomparison, RT models},
  year = 2005,
  month = jun,
  volume = 110,
  number = d9,
  eid = {D11206},
  pages = {11206},
  abstract = {{Computation of components of shortwave (SW) or solar irradiance in the
surface-atmospheric system forms the basis of intercomparison between 16
radiative transfer models of varying spectral resolution ranging from
line-by-line models to broadband and general circulation models. In
order of increasing complexity the components are: direct solar
irradiance at the surface, diffuse irradiance at the surface, diffuse
upward flux at the surface, and diffuse upward flux at the top of the
atmosphere. These components allow computation of the atmospheric
absorptance. Four cases are considered from pure molecular atmospheres
to atmospheres with aerosols and atmosphere with a simple uniform cloud.
The molecular and aerosol cases allow comparison of aerosol forcing
calculation among models. A cloud-free case with measured atmospheric
and aerosol properties and measured shortwave radiation components
provides an absolute basis for evaluating the models. For the
aerosol-free and cloud-free dry atmospheres, models agree to within 1\%
(root mean square deviation as a percentage of mean) in broadband direct
solar irradiance at surface; the agreement is relatively poor at 5\% for
a humid atmosphere. A comparison of atmospheric absorptance, computed
from components of SW radiation, shows that agreement among models is
understandably much worse at 3\% and 10\% for dry and humid atmospheres,
respectively. Inclusion of aerosols generally makes the agreement among
models worse than when no aerosols are present, with some exceptions.
Modeled diffuse surface irradiance is higher than measurements for all
models for the same model inputs. Inclusion of an optically thick
low-cloud in a tropical atmosphere, a stringent test for multiple
scattering calculations, produces, in general, better agreement among
models for a low solar zenith angle (SZA = 30{\deg}) than for a high SZA
(75{\deg}). All models show about a 30\% increase in broadband absorptance
for 30{\deg} SZA relative to the clear-sky case and almost no enhancement
in absorptance for a higher SZA of 75{\deg}, possibly due to water vapor
line saturation in the atmosphere above the cloud.
  doi = {10.1029/2004JD005293},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Reddy}, M.~S. and {Boucher}, O. and {Balkanski}, Y. and {Schulz}, M.
  title = {{Aerosol optical depths and direct radiative perturbations by species and source type}},
  journal = {\grl},
  keywords = {Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), Atmospheric Composition and Structure: Radiation: transmission and scattering, Atmospheric Composition and Structure: Troposphere: composition and chemistry},
  year = 2005,
  month = jun,
  volume = 32,
  eid = {L12803},
  pages = {12803},
  abstract = {{We have used the Laboratoire de Météorologie Dynamique
General Circulation Model (LMDZT GCM) to estimate the relative
contributions of different aerosol source types (i.e., fossil fuels,
biomass burning, and ``natural'') and aerosol species to the aerosol
optical depth (AOD) and direct aerosol radiative perturbation (DARP) at
the top-of-atmosphere. The largest estimated contribution to the global
annual average AOD (0.12 at 550 nm) is from natural (58\%), followed by
fossil fuel (26\%), and biomass burning (16\%) sources. The global annual
mean all-sky DARP in the shortwave (SW) spectrum by sulfate, black
carbon (BC), organic matter (OM), dust, and sea salt are -0.62, +0.55,
-0.33, -0.28, and -0.30 Wm$^{-2}$, respectively. The all-sky DARP
in the longwave spectrum (LW) is not negligible and is a bit less than
half of the SW DARP. The net (i.e., SW+LW) DARP distribution is
predominantly negative with patches of positive values over the dust
source regions, and off the west coasts of Southern Africa and South and
North America. For dust aerosols the SW effect is partially offset by LW
greenhouse effect.
  doi = {10.1029/2004GL021743},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Ngo-Duc}, T. and {Laval}, K. and {Polcher}, J. and {Cazenave}, A.
  title = {{Contribution of continental water to sea level variations during the 1997-1998 El Ni{\~n}o-Southern Oscillation event: Comparison between Atmospheric Model Intercomparison Project simulations and TOPEX/Poseidon satellite data}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Global Change: Water cycles (1836), Global Change: Climate dynamics (0429, 3309), Hydrology: Groundwater hydrology, Hydrology: Reservoirs (surface), Hydrology: Soil moisture, continental water, sea level variations, TOPEX/Poseidon},
  year = 2005,
  month = may,
  volume = 110,
  eid = {D09103},
  pages = {9103},
  abstract = {{Satellite altimetry from TOPEX/Poseidon (T/P) is used to estimate the
variation of the global sea level. This signal, once corrected for
steric effects, reflects water mass exchange with the atmosphere and
land reservoirs (mainly ice caps, soils and snowpack). It can thus be
used to test the capacity of general circulations models (GCMs) to
estimate change in land water storage. In this study, we compare the
land hydrology contribution to global mean sea level variations during
the major 1997-1998 El Ni{\~n}o-Southern Oscillation event from two
data sets: (1) the results of the Organizing Carbon and Hydrology In
Dynamic Ecosystems (ORCHIDEE) land surface scheme, developed at the
Institute Pierre Simon Laplace, coupled to the Laboratoire de
Météorologie Dynamique Atmospheric General Circulation
Model (LMD AGCM) and (2) the T/P-based estimates. We show that the
seasonal variation of the continental water storage is well represented
in the model. The drastic amplitude change between the two contrasted
years, 1997 and 1998, observed from satellite altimetry, is also
simulated. We analyze the role of each component of simulated water
fluxes (precipitation, evaporation, and runoff) in determining the range
of annual continental water mass variation and its interannual
variability. The difference between the two years, 1997 and 1998, is,
for an essential part, due to land precipitation in the
20{\deg}N-20{\deg}S domain. This analysis emphasizes the important role of
tropical regions in interannual variability of climate.
  doi = {10.1029/2004JD004940},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Ngo-Duc}, T. and {Laval}, K. and {Polcher}, J. and {Lombard}, A. and 
	{Cazenave}, A.},
  title = {{Effects of land water storage on global mean sea level over the past half century}},
  journal = {\grl},
  keywords = {Global Change: Climate dynamics (0429, 3309), Global Change: Sea level change (1222, 1225, 4556), Global Change: Water cycles (1836)},
  year = 2005,
  month = may,
  volume = 32,
  eid = {L09704},
  pages = {9704},
  abstract = {{The output of the ORCHIDEE Land Surface Model, driven by a 53-yr
(1948-2000) atmospheric forcing data set, was used to estimate the
effects of land water storage on global mean sea level. Over the past
half century, no significant trend was detected but there is a strong
decadal variability in the land water storage, driven by precipitation
and originating principally in the tropics. The land water contribution
to sea level change over the past 50 yr appears highly anti-correlated
with thermal expansion of the oceans. This result suggests that change
in ocean heat content influences the global water cycle. It also shows
that, at decadal time scale, there is partial compensation in sea level
changes between thermal expansion and ocean water mass change due to
changes in land water storage.
  doi = {10.1029/2005GL022719},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Wang}, X.~B. and {Tuo}, J.~C. and {Li}, Z.~X. and {Yan}, H.
  title = {{Distribution of radioactive uranium and radon in sedimentary environments}},
  journal = {Geochimica et Cosmochimica Acta Supplement},
  year = 2005,
  month = may,
  volume = 69,
  pages = {480},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Fueglistaler}, S. and {Bonazzola}, M. and {Haynes}, P.~H. and 
	{Peter}, T.},
  title = {{Stratospheric water vapor predicted from the Lagrangian temperature history of air entering the stratosphere in the tropics}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Processes: Stratosphere/troposphere interactions, Atmospheric Composition and Structure: Middle atmosphere: constituent transport and chemistry (3334), Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), tropics, stratosphere, water},
  year = 2005,
  month = apr,
  volume = 110,
  eid = {D08107},
  pages = {8107},
  abstract = {{We present results of Lagrangian troposphere-to-stratosphere transport
(TST) in the tropics based on trajectory calculations for the period
1979-2001. The trajectories and corresponding temperature histories are
calculated from wind and temperature fields provided by the reanalysis
data ERA-40 of the European Centre for Medium-Range Weather Forecasts
(ECMWF). The water vapor mixing ratio of air entering the tropical
stratosphere is calculated from the minimum saturation mixing ratio over
ice encountered by each trajectory. We show that this Lagrangian
approach, which considers the global-scale to synoptic-scale dynamics of
tropical TST but neglects mesoscale dynamics and details of cloud
microphysics, substantially improves estimates of stratospheric humidity
compared to calculations based on Eulerian mean tropical tropopause
temperatures. For the period 1979-2001 we estimate from the Lagrangian
calculation that the mean water mixing ratio of air entering the
stratosphere is 3.5 ppmv, which is in good agreement with measurements
during the same period, ranging from 3.3 ppmv to 4 ppmv, whereas an
estimate based on an Eulerian mean calculation is about 6 ppmv. The
amplitude of the annual cycle in water vapor mixing ratio at a potential
temperature of 400 K in the tropics estimated from the Lagrangian
calculation is compared with measurements of water vapor from the
Halogen Occultation Experiment (HALOE). For the period 1992-2001, when
HALOE measurements and ERA-40 data overlap, we calculate a peak-to-peak
amplitude of {\tilde}1.7 ppmv, in good agreement with {\tilde}1.6 ppmv
seen in HALOE data. On average, the Lagrangian calculations have a moist
bias of {\tilde}0.2 ppmv, equivalent to a warm bias of the Lagrangian
cold point of about 0.5 K. We conclude that the Lagrangian calculation
based on synoptic-scale velocity and temperature fields yields estimates
for stratospheric water vapor in good agreement with observations and
that mesoscale and cloud microphysical processes need not be invoked, at
first order, to explain annual mean and seasonal variation of water
vapor mixing ratios in the tropical lower stratosphere.
  doi = {10.1029/2004JD005516},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Ngo-Duc}, T. and {Polcher}, J. and {Laval}, K.},
  title = {{A 53-year forcing data set for land surface models}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Biosphere/atmosphere interactions (0426, 1610), Global Change: Land/atmosphere interactions (1218, 1843, 3322), Global Change: Climate dynamics (0429, 3309), Hydrology: Streamflow, land surface model, forcing data set, Taylor diagram},
  year = 2005,
  month = mar,
  volume = 110,
  eid = {D06116},
  pages = {6116},
  abstract = {{As most variables describing the state of the surface are not directly
observable, we have to use land surface models in order to reconstruct
an estimate of their evolution. These large-scale land surface models
often require high-quality forcing data with a subdiurnal sampling.
Building these data sets is a major challenge but an essential step for
estimating the land surface water budget, which is a crucial part of
climate change prediction. To study the interannual variability of
surface conditions over the last half century, we have built a 53-year
forcing data set, named NCC. NCC has a 6-hourly time step from 1948 to
2000 and a spatial resolution of 1{\deg} {\times} 1{\deg}. It is based on
the National Centers for Environmental Prediction/National Center for
Atmospheric Research reanalysis project and a number of independent in
situ observations. In this study we show the adjustments which need to
be applied to the reanalysis and how they impact the simulated
continental water balance. The model outputs are validated with the
observed discharges of the world's 10 largest rivers to estimate the
combined errors of the forcing data and the land surface model. The
seasonal and interannual variations of these discharges are used for
this validation. Five numerical experiments have been carried out. They
used the forcing data sets obtained after each step of data adjustment
and the forcing of the Global Soil Wetness Project 2 as inputs for the
Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) land
surface model. The quality of forcing data is improved after each
adjustment. The precipitation correction gives the most important
improvement in the simulated river discharges, while the temperature
correction has a significant effect only at high latitudes. The
radiation correction also improves the forcing quality, especially in
term of discharge amplitude. The NCC forcing data set can be used to
study the water budget over many areas and catchment basins that have
not been yet analyzed in this study. With its period of 53 years, NCC
can also be used to evaluate the trends of terrestrial water storage in
particular regions.
  doi = {10.1029/2004JD005434},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Pham}, M. and {Boucher}, O. and {Hauglustaine}, D.},
  title = {{Changes in atmospheric sulfur burdens and concentrations and resulting radiative forcings under IPCC SRES emission scenarios for 1990-2100}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Evolution of the atmosphere (1610, 8125), Global Change: Atmosphere (0315, 0325), Global Change: Impacts of global change (1225), sulfur emission scenarios, atmospheric sulfur cycle, sulfate radiative forcing},
  year = 2005,
  month = mar,
  volume = 110,
  eid = {D06112},
  pages = {6112},
  abstract = {{Simulations of the global sulfur cycle under the IPCC SRES scenarios
have been performed. Sulfur dioxide and sulfate burdens, as well as the
direct and first indirect radiative forcing (RF) by sulfate aerosols
only, are presented for the period 1990 to 2100. By 2100, global sulfur
emission rates decline everywhere in all scenarios. At that time, the
anthropogenic sulfate burden ranges from 0.34 to 1.03 times the 1990
value of 0.47 Tg S. Direct and indirect global and annually mean RFs
relative to the year 1990 are near 0 or positive (range of -0.07 to 0.28
Wm$^{-2}$ and 0.01 to 0.38 Wm$^{-2}$ for the direct and
indirect effects, respectively). For reference these forcings amount
respectively to -0.42 and -0.79 Wm$^{-2}$ in 1990 relative to
preindustrial conditions (around 1750). Sulfur aerosols will therefore
induce a smaller cooling effect in 2100 than in 1990 relative to
preindustrial conditions. For the period 1990 to 2100, the forcing
efficiencies (computed relatively to 1990) are fairly constant for the
direct effect (around -160 W (g sulfate)$^{-1}$). The forcing
efficiencies for the indirect effect are around -200 and -100 W (g
sulfate)$^{-1}$ for negative and positive burden differences,
respectively. This is due to a shift in regional patterns of emissions
and a saturation in the indirect effect. The simulated annually averaged
SO$_{2}$ concentrations for A1B scenario in 2020 are close to air
quality objectives for public health in some parts of Africa and exceed
these objectives in some parts of China and Korea. Moreover, sulfate
deposition rates are estimated to increase by 200\% from the present
level in East and Southeast Asia. This shows that Asia may experience in
the future sulfur-related environmental and human health problems as
important as Europe and the United States did in the 1970s.
  doi = {10.1029/2004JD005125},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Stier}, P. and {Feichter}, J. and {Kinne}, S. and {Kloster}, S. and 
	{Vignati}, E. and {Wilson}, J. and {Ganzeveld}, L. and {Tegen}, I. and 
	{Werner}, M. and {Balkanski}, Y. and {Schulz}, M. and {Boucher}, O. and 
	{Minikin}, A. and {Petzold}, A.},
  title = {{The aerosol-climate model ECHAM5-HAM}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2005,
  month = mar,
  volume = 5,
  pages = {1125-1156},
  abstract = {{The aerosol-climate modelling system ECHAM5-HAM is introduced. It is
based on a flexible microphysical approach and, as the number of
externally imposed parameters is minimised, allows the application in a
wide range of climate regimes. ECHAM5-HAM predicts the evolution of an
ensemble of microphysically interacting internally- and externally-mixed
aerosol populations as well as their size-distribution and composition.
The size-distribution is represented by a superposition of log-normal
modes. In the current setup, the major global aerosol compounds sulfate
(SU), black carbon (BC), particulate organic matter (POM), sea salt
(SS), and mineral dust (DU) are included. The simulated global annual
mean aerosol burdens (lifetimes) for the year 2000 are for SU: 0.80
Tg(S) (3.9 days), for BC: 0.11 Tg (5.4 days), for POM: 0.99 Tg (5.4
days), for SS: 10.5 Tg (0.8 days), and for DU: 8.28 Tg (4.6 days). An
extensive evaluation with in-situ and remote sensing measurements
underscores that the model results are generally in good agreement with
observations of the global aerosol system. The simulated global annual
mean aerosol optical depth (AOD) is with 0.14 in excellent agreement
with an estimate derived from AERONET measurements (0.14) and a
composite derived from MODIS-MISR satellite retrievals (0.16).
Regionally, the deviations are not negligible. However, the main
patterns of AOD attributable to anthropogenic activity are reproduced.
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Cosme}, E. and {Hourdin}, F. and {Genthon}, C. and {Martinerie}, P.
  title = {{Origin of dimethylsulfide, non-sea-salt sulfate, and methanesulfonic acid in eastern Antarctica}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, Atmospheric Composition and Structure: Air/sea constituent fluxes (3339, 4504), Atmospheric Processes: Global climate models (1626, 4928), Mathematical Geophysics: Inverse theory, Geographic Location: Antarctica (4207), Antarctica, sulfur cycle, adjoint methods, backtracking},
  year = 2005,
  month = feb,
  volume = 110,
  eid = {D03302},
  pages = {3302},
  abstract = {{Ignoring the origin of atmospheric chemicals is often a strong
limitation to the full interpretation of their measurement. In this
article, this question is addressed in the case of the sulfur species in
Antarctica, with an original method of retrotransport of tracers. The
retrotransport model is derived from the Laboratoire de
Météorologie Dynamique Zoom-Tracers (LMD-ZT) atmospheric
general circulation model, optimized for polar climate and expanded to
simulate atmospheric sulfur chemistry. For two East Antarctic scientific
stations (Dumont d'Urville and Vostok) the effects of transport and
chemistry and the influence of oceanic, volcanic, and anthropogenic
sources on dimethylsulfide (DMS), non-sea-salt (nss) sulfate, and
methanesulfonic acid (MSA) concentrations are evaluated in summer and
winter. The oceanic source largely dominates, but other sources can
episodically be significant. The meridional origin and the age of DMS,
MSA, and biogenic nss sulfate are also estimated. The latitudes of
origin of MSA and nss sulfate are similar in summer, but they differ
markedly in winter. This is a signature of their different chemical
production scheme. Also, the interannual variability of the origin of
the sulfur species at Vostok is weak compared to that at Dumont
d'Urville. Acknowledging that the DMS concentrations in the ocean have
no interannual variability in the model, this result suggests
unsurprisingly that inland Antarctic stations may be better observation
sites to monitor large-scale DMS bioproductivity variability than
coastal sites are. The combination of slower chemistry and more intense
atmospheric circulation in winter leads to unexpected results, such as a
younger DMS in winter than in summer at Vostok.
  doi = {10.1029/2004JD004881},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Codron}, F.},
  title = {{Relation between Annular Modes and the Mean State: Southern Hemisphere Summer.}},
  journal = {Journal of Climate},
  year = 2005,
  month = jan,
  volume = 18,
  pages = {320-330},
  abstract = {{The annular modes emerge as the leading mode of extratropical
month-to-month climate variability in both hemispheres. Here the
influence of the background state on the structure and dynamics of the
Southern Hemisphere annular mode (SAM) during the austral summer when
the climatology is characterized by a single, well-defined, eddy-driven
jet is studied. Subsets of the climatology are constructed for early and
late summer, and for contrasting polarities of the ENSO cycle. The
analysis is based both on observations and on perpetual-state GCM
experiments. The main differences between the subsets involve variations
of the latitude of the mean jet.It is found that in all the cases, the
SAM is characterized by latitudinal shifts of the jet about its mean
position, reinforced by a positive momentum flux feedback from
baroclinic waves. This result is consistent with previous studies of the
dynamics of the zonally averaged circulation but is found here to hold
over all longitudes and for different positions of the mean jet. The low
frequency eddies exert a weaker negative feedback upon the mean flow,
with a less zonally symmetric structure.The strong differences in the
amplitude of the SAM among the various climatologies seem to be
determined by a combination of 1) the variance of the ''random'' forcing
by transient eddies and 2) the strength of the positive feedback
component of this forcing. The latter mechanism increases the variance
at low frequencies only and lengthens the decorrelation time of
zonal-mean zonal wind anomalies. It tends to become stronger when the
mean jet moves equatorward.
  doi = {10.1175/JCLI-3255.1},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Rannou}, P. and {Lebonnois}, S. and {Hourdin}, F. and {Luz}, D.
  title = {{Titan atmosphere database}},
  journal = {Advances in Space Research},
  year = 2005,
  volume = 36,
  pages = {2194-2198},
  abstract = {{We have developed in the last decade a two-dimensional version of the
Titan global circulation model LMDZ. This model accounts for multiple
coupling occuring on Titan between dynamics, haze, chemistry and
radiative transfer. It was successful at explaining many observed
features related to atmosphere state (wind, temperature), haze structure
and chemical species distributions, recently, an important step in our
knowledge about Titan has been done with Cassini and Huygens visits to
Titan. In this context, we want to make the results of our model
available for the scientific community which is involved in the study of
Titan. Such a tool should be useful to give a global frame (spatial and
time behaviour of physical quantities) for interpreting ground based
telescope observations.
  doi = {10.1016/j.asr.2005.09.041},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Bertaux}, J.-L. and {Korablev}, O. and {Fonteyn}, D. and {Guibert}, S. and 
	{Chassefière}, E. and {Lefèvre}, F. and {Dimarellis}, E. and 
	{Dubois}, J.~P. and {Hauchecorne}, A. and {Cabane}, M. and {Rannou}, P. and 
	{Levasseur-Regourd}, A.~C. and {Cernogora}, G. and {Quémerais}, E. and 
	{Hermans}, C. and {Kockarts}, G. and {Lippens}, C. and {de Maziere}, M. and 
	{Moreau}, D. and {Muller}, C. and {Neefs}, E. and {Simon}, P.~C. and 
	{Forget}, F. and {Hourdin}, F. and {Talagrand}, O. and {Moroz}, V.~I. and 
	{Rodin}, A. and {Sandel}, B. and {Stern}, A.},
  title = {{Global structure and composition of the martian atmosphere with SPICAM on Mars express}},
  journal = {Advances in Space Research},
  year = 2005,
  volume = 35,
  pages = {31-36},
  abstract = {{SPectroscopy for the Investigation of the Characteristics of the
Atmosphere of Mars (SPICAM) Light, a light-weight (4.7 kg) UV-IR
instrument to be flown on Mars Express orbiter, is dedicated to the
study of the atmosphere and ionosphere of Mars. A UV spectrometer
(118-320 nm, resolution 0.8 nm) is dedicated to nadir viewing, limb
viewing and vertical profiling by stellar and solar occultation (3.8
kg). It addresses key issues about ozone, its coupling with
H$_{2}$O, aerosols, atmospheric vertical temperature structure and
ionospheric studies. UV observations of the upper atmosphere will allow
studies of the ionosphere through the emissions of CO, CO$^{+}$,
and CO2+, and its direct interaction with the solar wind. An IR
spectrometer (1.0-1.7 {$\mu$}m, resolution 0.5-1.2 nm) is dedicated
primarily to nadir measurements of H$_{2}$O abundances
simultaneously with ozone measured in the UV, and to vertical profiling
during solar occultation of H$_{2}$O, CO$_{2}$, and
aerosols. The SPICAM Light near-IR sensor employs a pioneering
technology acousto-optical tunable filter (AOTF), leading to a compact
and light design. Overall, SPICAM Light is an ideal candidate for future
orbiter studies of Mars, after Mars Express, in order to study the
interannual variability of martian atmospheric processes. The potential
contribution to a Mars International Reference Atmosphere is clear.
  doi = {10.1016/j.asr.2003.09.055},
  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

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