lmd_Li2006.bib
@comment{{This file has been generated by bib2bib 1.95}}
@comment{{Command line: /usr/bin/bib2bib --quiet -c 'not journal:"Discussions"' -c 'not journal:"Polymer Science"' -c ' author:"Li" ' -c year=2006 -c $type="ARTICLE" -oc lmd_Li2006.txt -ob lmd_Li2006.bib /home/WWW/LMD/public/Publis_LMDEMC3.link.bib}}
@article{2006ClDy...27..787H,
author = {{Hourdin}, F. and {Musat}, I. and {Bony}, S. and {Braconnot}, P. and
{Codron}, F. and {Dufresne}, J.-L. and {Fairhead}, L. and {Filiberti}, M.-A. and
{Friedlingstein}, P. and {Grandpeix}, J.-Y. and {Krinner}, G. and
{Levan}, P. and {Li}, Z.-X. and {Lott}, F.},
title = {{The LMDZ4 general circulation model: climate performance and sensitivity to parametrized physics with emphasis on tropical convection}},
journal = {Climate Dynamics},
year = 2006,
month = dec,
volume = 27,
pages = {787-813},
abstract = {{The LMDZ4 general circulation model is the atmospheric component of the
IPSL CM4 coupled model which has been used to perform climate change
simulations for the 4th IPCC assessment report. The main aspects of the
model climatology (forced by observed sea surface temperature) are
documented here, as well as the major improvements with respect to the
previous versions, which mainly come form the parametrization of
tropical convection. A methodology is proposed to help analyse the
sensitivity of the tropical Hadley Walker circulation to the
parametrization of cumulus convection and clouds. The tropical
circulation is characterized using scalar potentials associated with the
horizontal wind and horizontal transport of geopotential (the Laplacian
of which is proportional to the total vertical momentum in the
atmospheric column). The effect of parametrized physics is analysed in a
regime sorted framework using the vertical velocity at 500 hPa as a
proxy for large scale vertical motion. Compared to Tiedtke{\rsquo}s
convection scheme, used in previous versions, the Emanuel{\rsquo}s scheme
improves the representation of the Hadley Walker circulation, with a
relatively stronger and deeper large scale vertical ascent over tropical
continents, and suppresses the marked patterns of concentrated rainfall
over oceans. Thanks to the regime sorted analyses, these differences are
attributed to intrinsic differences in the vertical distribution of
convective heating, and to the lack of self-inhibition by precipitating
downdraughts in Tiedtke{\rsquo}s parametrization. Both the convection and
cloud schemes are shown to control the relative importance of large
scale convection over land and ocean, an important point for the
behaviour of the coupled model.
}},
doi = {10.1007/s00382-006-0158-0},
adsurl = {http://adsabs.harvard.edu/abs/2006ClDy...27..787H},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ClDy...26..145W,
author = {{Williams}, K.~D. and {Ringer}, M.~A. and {Senior}, C.~A. and
{Webb}, M.~J. and {McAvaney}, B.~J. and {Andronova}, N. and
{Bony}, S. and {Dufresne}, J.-L. and {Emori}, S. and {Gudgel}, R. and
{Knutson}, T. and {Li}, B. and {Lo}, K. and {Musat}, I. and
{Wegner}, J. and {Slingo}, A. and {Mitchell}, J.~F.~B.},
title = {{Evaluation of a component of the cloud response to climate change in an intercomparison of climate models}},
journal = {Climate Dynamics},
year = 2006,
month = feb,
volume = 26,
pages = {145-165},
abstract = {{Most of the uncertainty in the climate sensitivity of contemporary
general circulation models (GCMs) is believed to be connected with
differences in the simulated radiative feedback from clouds. Traditional
methods of evaluating clouds in GCMs compare time-mean geographical
cloud fields or aspects of present-day cloud variability, with
observational data. In both cases a hypothetical assumption is made that
the quantity evaluated is relevant for the mean climate change response.
Nine GCMs (atmosphere models coupled to mixed-layer ocean models) from
the CFMIP and CMIP model comparison projects are used in this study to
demonstrate a common relationship between the mean cloud response to
climate change and present-day variability. Although
atmosphere-mixed-layer ocean models are used here, the results are found
to be equally applicable to transient coupled model simulations. When
changes in cloud radiative forcing (CRF) are composited by changes in
vertical velocity and saturated lower tropospheric stability, a
component of the local mean climate change response can be related to
present-day variability in all of the GCMs. This suggests that the
relationship is not model specific and might be relevant in the real
world. In this case, evaluation within the proposed compositing
framework is a direct evaluation of a component of the cloud response to
climate change. None of the models studied are found to be clearly
superior or deficient when evaluated, but a couple appear to perform
well on several relevant metrics. Whilst some broad similarities can be
identified between the 60{\deg}N-60{\deg}S mean change in CRF to increased
CO$_{2}$ and that predicted from present-day variability, the two
cannot be quantitatively constrained based on changes in vertical
velocity and stability alone. Hence other processes also contribute to
the global mean cloud response to climate change.
}},
doi = {10.1007/s00382-005-0067-7},
adsurl = {http://adsabs.harvard.edu/abs/2006ClDy...26..145W},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006JCli...19.3445B,
author = {{Bony}, S. and {Colman}, R. and {Kattsov}, V.~M. and {Allan}, R.~P. and
{Bretherton}, C.~S. and {Dufresne}, J.-L. and {Hall}, A. and
{Hallegatte}, S. and {Holland}, M.~M. and {Ingram}, W. and {Randall}, D.~A. and
{Soden}, B.~J. and {Tselioudis}, G. and {Webb}, M.~J.},
title = {{How Well Do We Understand and Evaluate Climate Change Feedback Processes?}},
journal = {Journal of Climate},
year = 2006,
volume = 19,
pages = {3445},
doi = {10.1175/JCLI3819.1},
adsurl = {http://adsabs.harvard.edu/abs/2006JCli...19.3445B},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006AtmRe..82..276L,
author = {{Liberti}, G.~L. and {Chéruy}, F.},
title = {{Tropospheric dryness and clouds over tropical Indian Ocean}},
journal = {Atmospheric Research},
year = 2006,
month = nov,
volume = 82,
pages = {276-293},
abstract = {{Dry layers in the free troposphere over Tropical Oceans have been
studied for their role in convective activity and for their effects in
the radiation budget. Previous studies concentrated, mostly, on the
Western Pacific region because of the abundance of observations during
the TOGA-COARE. This study aims to document the occurrence of dry layers
over the Indian Ocean and to investigate the cloudiness observed, but
poorly documented, during such events. One month (March 1999, during
INDOEX) of combined Visible/Infrared and Microwave data from the TRMM
radiometers had been processed to classify observations in terms of
total precipitable water vapour (TPWV), cloud occurrence and type.
Soundings (1978-2004) from the Seychelles station have been analysed to
validate the capability, through the analysis of TPWV, to detect dry
layers. The study area (40{\deg}E-80{\deg}E, 30{\deg}S-30{\deg}N) had been
portioned into 2.5{\deg} {\times} 2.5{\deg} boxes to investigate the
spatial distribution of occurrence of dry events with associated
cloudiness. South of the ITCZ cloudiness associated with low TPWV is due
to low-level clouds: probably generated by shallow convection trapped by
the trade inversion. North of the ITCZ cirrus are mostly observed during
relatively dry events. Further analyses, concentrating on possible links
between occurrence of cirrus and TPWV, suggest, in addition to the
obvious mechanism (i.e. the higher the moisture, the higher the
convective activity and as a consequence the higher the occurrence of
cirrus), a second one that would be responsible of relatively high
occurrence of cirrus for low TPWV. A case (14th-15th March 1999) is
studied in detail with TRMM observations, sounding data and METEOSAT
imagery. The observed cirrus, generated by convection, migrate over
relatively dry air of extra-tropical origin. Cirrus extend as filaments
for more than 1000 km in length and about 50 to 100 km in width, and
they last for 2-3 days. A retrieval method is designed and applied to
the data giving as cirrus top pressure approximately 250 hPa while the
retrieved effective radius value is consistent with what expected, from
literature, for dissipating cirrus at that pressure. The vertical
structure of the atmosphere, observed during such event suggests the
hypothesis that a combination of presented radiative and dynamical
mechanisms could be responsible, through the supply of moisture from
lower levels, of increasing the cirrus lifetime and, as a consequence,
increasing the occurrence of cirrus over relatively dry air columns. A
larger data set is investigated to confirm the results based on the
March 1999 data set analysis. The average vertical structure of the
atmosphere, during such events, as obtained from the Seychelles sounding
data set ({\gt} 7000 soundings) analysis confirms the occurrence of the
features observed in the study case. Similarly, the analysis of 105 days
of TRMM orbits over the box containing the Seychelles station, confirms
the statistical features that indicate a possible relationship between
the occurrence of dry air and associated cirrus. However, possible
interaction between dry layer and cirrus occurrence should be
investigated in a detailed modelling framework (beyond the scope of this
study) such as the one offered by the cloud resolving models.
}},
doi = {10.1016/j.atmosres.2005.10.013},
adsurl = {http://adsabs.harvard.edu/abs/2006AtmRe..82..276L},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ACP.....6.5225S,
author = {{Schulz}, M. and {Textor}, C. and {Kinne}, S. and {Balkanski}, Y. and
{Bauer}, S. and {Berntsen}, T. and {Berglen}, T. and {Boucher}, O. and
{Dentener}, F. and {Guibert}, S. and {Isaksen}, I.~S.~A. and
{Iversen}, T. and {Koch}, D. and {Kirkev{\aa}g}, A. and {Liu}, X. and
{Montanaro}, V. and {Myhre}, G. and {Penner}, J.~E. and {Pitari}, G. and
{Reddy}, S. and {Seland}, {\O}. and {Stier}, P. and {Takemura}, T.
},
title = {{Radiative forcing by aerosols as derived from the AeroCom present-day and pre-industrial simulations}},
journal = {Atmospheric Chemistry \& Physics},
year = 2006,
month = nov,
volume = 6,
pages = {5225-5246},
abstract = {{Nine different global models with detailed aerosol modules have
independently produced instantaneous direct radiative forcing due to
anthropogenic aerosols. The anthropogenic impact is derived from the
difference of two model simulations with prescribed aerosol emissions,
one for present-day and one for pre-industrial conditions. The
difference in the solar energy budget at the top of the atmosphere (ToA)
yields a new harmonized estimate for the aerosol direct radiative
forcing (RF) under all-sky conditions. On a global annual basis RF is
-0.22 Wm$^{-2}$, ranging from +0.04 to -0.41
Wm$^{-2}$, with a standard deviation of {\plusmn}0.16
Wm$^{-2}$. Anthropogenic nitrate and dust are not included
in this estimate. No model shows a significant positive all-sky RF. The
corresponding clear-sky RF is -0.68 Wm$^{-2}$. The
cloud-sky RF was derived based on all-sky and clear-sky RF and modelled
cloud cover. It was significantly different from zero and ranged between
-0.16 and +0.34 Wm$^{-2}$. A sensitivity analysis
shows that the total aerosol RF is influenced by considerable diversity
in simulated residence times, mass extinction coefficients and most
importantly forcing efficiencies (forcing per unit optical depth). The
clear-sky forcing efficiency (forcing per unit optical depth) has
diversity comparable to that for the all-sky/ clear-sky forcing ratio.
While the diversity in clear-sky forcing efficiency is impacted by
factors such as aerosol absorption, size, and surface albedo, we can
show that the all-sky/clear-sky forcing ratio is important because
all-sky forcing estimates require proper representation of cloud fields
and the correct relative altitude placement between absorbing aerosol
and clouds. The analysis of the sulphate RF shows that long sulphate
residence times are compensated by low mass extinction coefficients and
vice versa. This is explained by more sulphate particle humidity growth
and thus higher extinction in those models where short-lived sulphate is
present at lower altitude and vice versa. Solar atmospheric forcing
within the atmospheric column is estimated at +0.82{\plusmn}0.17
Wm$^{-2}$. The local annual average maxima of atmospheric
forcing exceed +5 Wm$^{-2}$ confirming the regional
character of aerosol impacts on climate. The annual average surface
forcing is -1.02{\plusmn}0.23 Wm$^{-2}$. With the
current uncertainties in the modelling of the radiative forcing due to
the direct aerosol effect we show here that an estimate from one model
is not sufficient but a combination of several model estimates is
necessary to provide a mean and to explore the uncertainty.
}},
adsurl = {http://adsabs.harvard.edu/abs/2006ACP.....6.5225S},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006WRR....4210403R,
author = {{Ramillien}, G. and {Frappart}, F. and {G{\"u}ntner}, A. and
{Ngo-Duc}, T. and {Cazenave}, A. and {Laval}, K.},
title = {{Time variations of the regional evapotranspiration rate from Gravity Recovery and Climate Experiment (GRACE) satellite gravimetry}},
journal = {Water Resources Research},
keywords = {Geodesy and Gravity: Time variable gravity (7223, 7230), Hydrology: Evapotranspiration, Geodesy and Gravity: Mass balance (0762, 1223, 1631, 1836, 1843, 3010, 3322, 4532), evapotranspiration, global hydrology, GRACE satellite mission, water mass balance},
year = 2006,
month = oct,
volume = 42,
eid = {W10403},
pages = {10403},
abstract = {{Since its launch in March 2002, the Gravity Recovery and Climate
Experiment (GRACE) mission has been measuring the global time variations
of the Earth's gravity field with a current resolution of {\tilde}500 km.
Especially over the continents, these measurements represent the
integrated land water mass, including surface waters (lakes, wetlands
and rivers), soil moisture, groundwater, and snow cover. In this study,
we use the GRACE land water solutions computed by Ramillien et al.
(2005a) through an iterative inversion of monthly geoids from April 2002
to May 2004 to estimate time series of basin-scale regional
evapotranspiration rate and associated uncertainties. Evapotranspiration
is determined by integrating and solving the water mass balance
equation, which relates land water storage (from GRACE), precipitation
data (from the Global Precipitation Climatology Centre), runoff (from a
global land surface model), and evapotranspiration (the unknown). We
further examine the sensibility of the computation when using different
model runoff. Evapotranspiration results are compared to outputs of four
different global land surface models. The overall satisfactory agreement
between GRACE-derived and model-based evapotranspiration prove the
ability of GRACE to provide realistic estimates of this parameter.
}},
doi = {10.1029/2005WR004331},
adsurl = {http://adsabs.harvard.edu/abs/2006WRR....4210403R},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ACP.....6.4321D,
author = {{Dentener}, F. and {Kinne}, S. and {Bond}, T. and {Boucher}, O. and
{Cofala}, J. and {Generoso}, S. and {Ginoux}, P. and {Gong}, S. and
{Hoelzemann}, J.~J. and {Ito}, A. and {Marelli}, L. and {Penner}, J.~E. and
{Putaud}, J.-P. and {Textor}, C. and {Schulz}, M. and {van der Werf}, G.~R. and
{Wilson}, J.},
title = {{Emissions of primary aerosol and precursor gases in the years 2000 and 1750 prescribed data-sets for AeroCom}},
journal = {Atmospheric Chemistry \& Physics},
year = 2006,
month = sep,
volume = 6,
pages = {4321-4344},
abstract = {{Inventories for global aerosol and aerosol precursor emissions have been
collected (based on published inventories and published simulations),
assessed and prepared for the year 2000 (present-day conditions) and for
the year 1750 (pre-industrial conditions). These global datasets
establish a comprehensive source for emission input to global modeling,
when simulating the aerosol impact on climate with state-of-the-art
aerosol component modules. As these modules stratify aerosol into dust,
sea-salt, sulfate, organic matter and soot, for all these aerosol types
global fields on emission strength and recommendations for injection
altitude and particulate size are provided. Temporal resolution varies
between daily (dust and sea-salt), monthly (wild-land fires) and annual
(all other emissions). These datasets benchmark aerosol emissions
according to the knowledge in the year 2004. They are intended to serve
as systematic constraints in sensitivity studies of the AeroCom
initiative, which seeks to quantify (actual) uncertainties in aerosol
global modeling.
}},
adsurl = {http://adsabs.harvard.edu/abs/2006ACP.....6.4321D},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006JGRD..11114317C,
author = {{Collins}, W.~D. and {Ramaswamy}, V. and {Schwarzkopf}, M.~D. and
{Sun}, Y. and {Portmann}, R.~W. and {Fu}, Q. and {Casanova}, S.~E.~B. and
{Dufresne}, J.-L. and {Fillmore}, D.~W. and {Forster}, P.~M.~D. and
{Galin}, V.~Y. and {Gohar}, L.~K. and {Ingram}, W.~J. and {Kratz}, D.~P. and
{Lefebvre}, M.-P. and {Li}, J. and {Marquet}, P. and {Oinas}, V. and
{Tsushima}, Y. and {Uchiyama}, T. and {Zhong}, W.~Y.},
title = {{Radiative forcing by well-mixed greenhouse gases: Estimates from climate models in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4)}},
journal = {Journal of Geophysical Research (Atmospheres)},
keywords = {Atmospheric Processes: Global climate models (1626, 4928), Atmospheric Processes: Radiative processes, Global Change: Global climate models (3337, Global Change: Impacts of global change (1225), radiation, models, greenhouse gas},
year = 2006,
month = jul,
volume = 111,
number = d10,
eid = {D14317},
pages = {14317},
abstract = {{The radiative effects from increased concentrations of well-mixed
greenhouse gases (WMGHGs) represent the most significant and best
understood anthropogenic forcing of the climate system. The most
comprehensive tools for simulating past and future climates influenced
by WMGHGs are fully coupled atmosphere-ocean general circulation models
(AOGCMs). Because of the importance of WMGHGs as forcing agents it is
essential that AOGCMs compute the radiative forcing by these gases as
accurately as possible. We present the results of a radiative transfer
model intercomparison between the forcings computed by the radiative
parameterizations of AOGCMs and by benchmark line-by-line (LBL) codes.
The comparison is focused on forcing by CO$_{2}$, CH$_{4}$,
N$_{2}$O, CFC-11, CFC-12, and the increased H$_{2}$O
expected in warmer climates. The models included in the intercomparison
include several LBL codes and most of the global models submitted to the
Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment
Report (AR4). In general, the LBL models are in excellent agreement with
each other. However, in many cases, there are substantial discrepancies
among the AOGCMs and between the AOGCMs and LBL codes. In some cases
this is because the AOGCMs neglect particular absorbers, in particular
the near-infrared effects of CH$_{4}$ and N$_{2}$O, while in
others it is due to the methods for modeling the radiative processes.
The biases in the AOGCM forcings are generally largest at the surface
level. We quantify these differences and discuss the implications for
interpreting variations in forcing and response across the multimodel
ensemble of AOGCM simulations assembled for the IPCC AR4.
}},
doi = {10.1029/2005JD006713},
adsurl = {http://adsabs.harvard.edu/abs/2006JGRD..11114317C},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ClDy...27...17W,
author = {{Webb}, M.~J. and {Senior}, C.~A. and {Sexton}, D.~M.~H. and
{Ingram}, W.~J. and {Williams}, K.~D. and {Ringer}, M.~A. and
{McAvaney}, B.~J. and {Colman}, R. and {Soden}, B.~J. and {Gudgel}, R. and
{Knutson}, T. and {Emori}, S. and {Ogura}, T. and {Tsushima}, Y. and
{Andronova}, N. and {Li}, B. and {Musat}, I. and {Bony}, S. and
{Taylor}, K.~E.},
title = {{On the contribution of local feedback mechanisms to the range of climate sensitivity in two GCM ensembles}},
journal = {Climate Dynamics},
year = 2006,
month = jul,
volume = 27,
pages = {17-38},
abstract = {{Global and local feedback analysis techniques have been applied to two
ensembles of mixed layer equilibrium CO$_{2}$ doubling climate
change experiments, from the CFMIP (Cloud Feedback Model Intercomparison
Project) and QUMP (Quantifying Uncertainty in Model Predictions)
projects. Neither of these new ensembles shows evidence of a
statistically significant change in the ensemble mean or variance in
global mean climate sensitivity when compared with the results from the
mixed layer models quoted in the Third Assessment Report of the IPCC.
Global mean feedback analysis of these two ensembles confirms the large
contribution made by inter-model differences in cloud feedbacks to those
in climate sensitivity in earlier studies; net cloud feedbacks are
responsible for 66\% of the inter-model variance in the total feedback in
the CFMIP ensemble and 85\% in the QUMP ensemble. The ensemble mean
global feedback components are all statistically indistinguishable
between the two ensembles, except for the clear-sky shortwave feedback
which is stronger in the CFMIP ensemble. While ensemble variances of the
shortwave cloud feedback and both clear-sky feedback terms are larger in
CFMIP, there is considerable overlap in the cloud feedback ranges; QUMP
spans 80\% or more of the CFMIP ranges in longwave and shortwave cloud
feedback. We introduce a local cloud feedback classification system
which distinguishes different types of cloud feedbacks on the basis of
the relative strengths of their longwave and shortwave components, and
interpret these in terms of responses of different cloud types diagnosed
by the International Satellite Cloud Climatology Project simulator. In
the CFMIP ensemble, areas where low-top cloud changes constitute the
largest cloud response are responsible for 59\% of the contribution from
cloud feedback to the variance in the total feedback. A similar figure
is found for the QUMP ensemble. Areas of positive low cloud feedback
(associated with reductions in low level cloud amount) contribute most
to this figure in the CFMIP ensemble, while areas of negative cloud
feedback (associated with increases in low level cloud amount and
optical thickness) contribute most in QUMP. Classes associated with
high-top cloud feedbacks are responsible for 33 and 20\% of the cloud
feedback contribution in CFMIP and QUMP, respectively, while classes
where no particular cloud type stands out are responsible for 8 and 21\%.
}},
doi = {10.1007/s00382-006-0111-2},
adsurl = {http://adsabs.harvard.edu/abs/2006ClDy...27...17W},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ACP.....6.1815K,
author = {{Kinne}, S. and {Schulz}, M. and {Textor}, C. and {Guibert}, S. and
{Balkanski}, Y. and {Bauer}, S.~E. and {Berntsen}, T. and {Berglen}, T.~F. and
{Boucher}, O. and {Chin}, M. and {Collins}, W. and {Dentener}, F. and
{Diehl}, T. and {Easter}, R. and {Feichter}, J. and {Fillmore}, D. and
{Ghan}, S. and {Ginoux}, P. and {Gong}, S. and {Grini}, A. and
{Hendricks}, J. and {Herzog}, M. and {Horowitz}, L. and {Isaksen}, I. and
{Iversen}, T. and {Kirkev{\aa}g}, A. and {Kloster}, S. and {Koch}, D. and
{Kristjansson}, J.~E. and {Krol}, M. and {Lauer}, A. and {Lamarque}, J.~F. and
{Lesins}, G. and {Liu}, X. and {Lohmann}, U. and {Montanaro}, V. and
{Myhre}, G. and {Penner}, J. and {Pitari}, G. and {Reddy}, S. and
{Seland}, O. and {Stier}, P. and {Takemura}, T. and {Tie}, X.
},
title = {{An AeroCom initial assessment - optical properties in aerosol component modules of global models}},
journal = {Atmospheric Chemistry \& Physics},
year = 2006,
month = may,
volume = 6,
pages = {1815-1834},
abstract = {{The AeroCom exercise diagnoses multi-component aerosol modules in global
modeling. In an initial assessment simulated global distributions for
mass and mid-visible aerosol optical thickness (aot) were compared among
20 different modules. Model diversity was also explored in the context
of previous comparisons. For the component combined aot general
agreement has improved for the annual global mean. At 0.11 to 0.14,
simulated aot values are at the lower end of global averages suggested
by remote sensing from ground (AERONET ca. 0.135) and space (satellite
composite ca. 0.15). More detailed comparisons, however, reveal that
larger differences in regional distribution and significant differences
in compositional mixture remain. Of particular concern are large model
diversities for contributions by dust and carbonaceous aerosol, because
they lead to significant uncertainty in aerosol absorption (aab). Since
aot and aab, both, influence the aerosol impact on the radiative
energy-balance, the aerosol (direct) forcing uncertainty in modeling is
larger than differences in aot might suggest. New diagnostic approaches
are proposed to trace model differences in terms of aerosol processing
and transport: These include the prescription of common input (e.g.
amount, size and injection of aerosol component emissions) and the use
of observational capabilities from ground (e.g. measurements networks)
or space (e.g. correlations between aerosol and clouds).
}},
adsurl = {http://adsabs.harvard.edu/abs/2006ACP.....6.1815K},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ACP.....6.1777T,
author = {{Textor}, C. and {Schulz}, M. and {Guibert}, S. and {Kinne}, S. and
{Balkanski}, Y. and {Bauer}, S. and {Berntsen}, T. and {Berglen}, T. and
{Boucher}, O. and {Chin}, M. and {Dentener}, F. and {Diehl}, T. and
{Easter}, R. and {Feichter}, H. and {Fillmore}, D. and {Ghan}, S. and
{Ginoux}, P. and {Gong}, S. and {Grini}, A. and {Hendricks}, J. and
{Horowitz}, L. and {Huang}, P. and {Isaksen}, I. and {Iversen}, I. and
{Kloster}, S. and {Koch}, D. and {Kirkev{\aa}g}, A. and {Kristjansson}, J.~E. and
{Krol}, M. and {Lauer}, A. and {Lamarque}, J.~F. and {Liu}, X. and
{Montanaro}, V. and {Myhre}, G. and {Penner}, J. and {Pitari}, G. and
{Reddy}, S. and {Seland}, {\O}. and {Stier}, P. and {Takemura}, T. and
{Tie}, X.},
title = {{Analysis and quantification of the diversities of aerosol life cycles within AeroCom}},
journal = {Atmospheric Chemistry \& Physics},
year = 2006,
month = may,
volume = 6,
pages = {1777-1813},
abstract = {{Simulation results of global aerosol models have been assembled in the
framework of the AeroCom intercomparison exercise. In this paper, we
analyze the life cycles of dust, sea salt, sulfate, black carbon and
particulate organic matter as simulated by sixteen global aerosol
models. The differences among the results (model diversities) for
sources and sinks, burdens, particle sizes, water uptakes, and spatial
dispersals have been established. These diversities have large
consequences for the calculated radiative forcing and the aerosol
concentrations at the surface. Processes and parameters are identified
which deserve further research. {\lt}P style=''line-height: 20px;''{\gt} The
AeroCom all-models-average emissions are dominated by the mass of sea
salt (SS), followed by dust (DU), sulfate (SO$_{4}$), particulate
organic matter (POM), and finally black carbon (BC). Interactive
parameterizations of the emissions and contrasting particles sizes of SS
and DU lead generally to higher diversities of these species, and for
total aerosol. The lower diversity of the emissions of the fine
aerosols, BC, POM, and SO$_{4}$, is due to the use of similar
emission inventories, and does therefore not necessarily indicate a
better understanding of their sources. The diversity of
SO$_{4}$-sources is mainly caused by the disagreement on
depositional loss of precursor gases and on chemical production. The
diversities of the emissions are passed on to the burdens, but the
latter are also strongly affected by the model-specific treatments of
transport and aerosol processes. The burdens of dry masses decrease from
largest to smallest: DU, SS, SO$_{4}$, POM, and BC. {\lt}P
style=''line-height: 20px;''{\gt} The all-models-average residence time is
shortest for SS with about half a day, followed by SO$_{4}$ and DU
with four days, and POM and BC with six and seven days, respectively.
The wet deposition rate is controlled by the solubility and increases
from DU, BC, POM to SO$_{4}$ and SS. It is the dominant sink for
SO$_{4}$, BC, and POM, and contributes about one third to the
total removal of SS and DU species. For SS and DU we find high
diversities for the removal rate coefficients and deposition pathways.
Models do neither agree on the split between wet and dry deposition, nor
on that between sedimentation and other dry deposition processes. We
diagnose an extremely high diversity for the uptake of ambient water
vapor that influences the particle size and thus the sink rate
coefficients. Furthermore, we find little agreement among the model
results for the partitioning of wet removal into scavenging by
convective and stratiform rain. {\lt}P style=''line-height: 20px;''{\gt}
Large differences exist for aerosol dispersal both in the vertical and
in the horizontal direction. In some models, a minimum of total aerosol
concentration is simulated at the surface. Aerosol dispersal is most
pronounced for SO$_{4}$ and BC and lowest for SS. Diversities are
higher for meridional than for vertical dispersal, they are similar for
the individual species and highest for SS and DU. For these two
components we do not find a correlation between vertical and meridional
aerosol dispersal. In addition the degree of dispersals of SS and DU is
not related to their residence times. SO$_{4}$, BC, and POM,
however, show increased meridional dispersal in models with larger
vertical dispersal, and dispersal is larger for longer simulated
residence times.
}},
adsurl = {http://adsabs.harvard.edu/abs/2006ACP.....6.1777T},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006ACP.....6.1657B,
author = {{Bates}, T.~S. and {Anderson}, T.~L. and {Baynard}, T. and {Bond}, T. and
{Boucher}, O. and {Carmichael}, G. and {Clarke}, A. and {Erlick}, C. and
{Guo}, H. and {Horowitz}, L. and {Howell}, S. and {Kulkarni}, S. and
{Maring}, H. and {McComiskey}, A. and {Middlebrook}, A. and
{Noone}, K. and {O'Dowd}, C.~D. and {Ogren}, J. and {Penner}, J. and
{Quinn}, P.~K. and {Ravishankara}, A.~R. and {Savoie}, D.~L. and
{Schwartz}, S.~E. and {Shinozuka}, Y. and {Tang}, Y. and {Weber}, R.~J. and
{Wu}, Y.},
title = {{Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling}},
journal = {Atmospheric Chemistry \& Physics},
year = 2006,
month = may,
volume = 6,
pages = {1657-1732},
abstract = {{The largest uncertainty in the radiative forcing of climate change over
the industrial era is that due to aerosols, a substantial fraction of
which is the uncertainty associated with scattering and absorption of
shortwave (solar) radiation by anthropogenic aerosols in cloud-free
conditions (IPCC, 2001). Quantifying and reducing the uncertainty in
aerosol influences on climate is critical to understanding climate
change over the industrial period and to improving predictions of future
climate change for assumed emission scenarios. Measurements of aerosol
properties during major field campaigns in several regions of the globe
during the past decade are contributing to an enhanced understanding of
atmospheric aerosols and their effects on light scattering and climate.
The present study, which focuses on three regions downwind of major
urban/population centers (North Indian Ocean (NIO) during INDOEX, the
Northwest Pacific Ocean (NWP) during ACE-Asia, and the Northwest
Atlantic Ocean (NWA) during ICARTT), incorporates understanding gained
from field observations of aerosol distributions and properties into
calculations of perturbations in radiative fluxes due to these aerosols.
This study evaluates the current state of observations and of two
chemical transport models (STEM and MOZART). Measurements of burdens,
extinction optical depth (AOD), and direct radiative effect of aerosols
(DRE - change in radiative flux due to total aerosols) are used as
measurement-model check points to assess uncertainties. In-situ measured
and remotely sensed aerosol properties for each region (mixing state,
mass scattering efficiency, single scattering albedo, and angular
scattering properties and their dependences on relative humidity) are
used as input parameters to two radiative transfer models (GFDL and
University of Michigan) to constrain estimates of aerosol radiative
effects, with uncertainties in each step propagated through the
analysis. Constraining the radiative transfer calculations by
observational inputs increases the clear-sky, 24-h averaged AOD
(34{\plusmn}8\%), top of atmosphere (TOA) DRE (32{\plusmn}12\%), and TOA
direct climate forcing of aerosols (DCF - change in radiative flux due
to anthropogenic aerosols) (37{\plusmn}7\%) relative to values obtained
with ''a priori'' parameterizations of aerosol loadings and properties
(GFDL RTM). The resulting constrained clear-sky TOA DCF is
-3.3{\plusmn}0.47, -14{\plusmn}2.6, -6.4{\plusmn}2.1
Wm$^{-2}$ for the NIO, NWP, and NWA, respectively. With the
use of constrained quantities (extensive and intensive parameters) the
calculated uncertainty in DCF was 25\% less than the ''structural
uncertainties'' used in the IPCC-2001 global estimates of direct aerosol
climate forcing. Such comparisons with observations and resultant
reductions in uncertainties are essential for improving and developing
confidence in climate model calculations incorporating aerosol forcing.
}},
adsurl = {http://adsabs.harvard.edu/abs/2006ACP.....6.1657B},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2006JCli...19.2665L,
author = {{Lin}, J.-L. and {Kiladis}, G.~N. and {Mapes}, B.~E. and {Weickmann}, K.~M. and
{Sperber}, K.~R. and {Lin}, W. and {Wheeler}, M.~C. and {Schubert}, S.~D. and
{Del Genio}, A. and {Donner}, L.~J. and {Emori}, S. and {Gueremy}, J.-F. and
{Hourdin}, F. and {Rasch}, P.~J. and {Roeckner}, E. and {Scinocca}, J.~F.
},
title = {{Tropical Intraseasonal Variability in 14 IPCC AR4 Climate Models. Part I: Convective Signals}},
journal = {Journal of Climate},
year = 2006,
volume = 19,
pages = {2665},
doi = {10.1175/JCLI3735.1},
adsurl = {http://adsabs.harvard.edu/abs/2006JCli...19.2665L},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
