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@comment{{Command line: /usr/bin/bib2bib --quiet -c 'not journal:"Discussions"' -c 'not journal:"Polymer Science"' -c year=2018 -c $type="ARTICLE" -oc lmd_EMC32018.txt -ob lmd_EMC32018.bib /home/WWW/LMD/public/Publis_LMDEMC3.link.bib}}
  author = {{Jouhaud}, J. and {Dufresne}, J.-L. and {Madeleine}, J.-B. and 
	{Hourdin}, F. and {Couvreux}, F. and {Villefranque}, N. and 
	{Jam}, A.},
  title = {{Accounting for Vertical Subgrid-Scale Heterogeneity in Low-Level Cloud Fraction Parameterizations}},
  journal = {Journal of Advances in Modeling Earth Systems},
  keywords = {cloud structure, subgrid scale, heterogeneity, GCM, LES},
  year = 2018,
  month = nov,
  volume = 10,
  pages = {2686-2705},
  abstract = {{Many general circulation models (GCMs) assume some heterogeneity of
water amounts in their grid boxes and use probability density functions
to parameterize cloud fractions CF and amounts of condensed water
q$_{c}$. Most GCM cloud schemes calculate the CF as the volume of
the grid box that contains clouds (CF$_{vol}$), whereas radiative
fluxes primarily depend on the CF by surface (CF$_{surf}$), that
is, the surface of the grid box covered by clouds when looking from
above. This discrepancy matters as previous findings suggest that CFsurf
is typically greater than CF$_{vol}$ by about 30\%. In this paper
we modify the single column model version of the LMDz GCM cloud scheme
by introducing the vertical subgrid-scale heterogeneity of water
content. This allows to distinctly compute the two fractions,
CF$_{vol}$ and CF$_{surf}$, as well as the amount of
condensed water q$_{c}$. This study is one of the first to take
into account such vertical subgrid-scale heterogeneity in a GCM cloud
scheme. Three large eddy simulation cases of cumuliform boundary layer
clouds are used to test and calibrate two different parameterizations.
These new developments increase cloud cover by about 10\% for the oceanic
cases RICO and Barbados Oceanographic Meteorological Experiment and by
up to 50\% for the continental case ARM. The change in condensed water
reduces the liquid water path by 10-20\% and therefore the cloud opacity
by 5-50\%. These results show the potential of the new scheme to reduce
the too few, too bright bias by increasing low-level CF and decreasing
cloud reflectance.
  doi = {10.1029/2018MS001379},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JAMES..10.2686J},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Vial}, J. and {Cassou}, C. and {Codron}, F. and {Bony}, S. and 
	{Ruprich-Robert}, Y.},
  title = {{Influence of the Atlantic Meridional Overturning Circulation on the Tropical Climate Response to CO$_{2}$ Forcing}},
  journal = {\grl},
  year = 2018,
  month = aug,
  volume = 45,
  pages = {8519-8528},
  abstract = {{The increase of atmospheric greenhouse gases is expected to affect the
hydrological cycle and large-scale precipitation patterns. In parallel,
unforced natural variability on decadal-to-multidecadal timescales can
also modulate forced changes at the regional scales. Based on
multimember ensembles from a coupled General Circulation Model, we
investigate the sensitivity of CO$_{2}$-forced changes in tropical
precipitation and atmospheric circulation to fluctuations of the
Atlantic Multidecadal Overturning Circulation (AMOC). We show that
contrasted AMOC states yield considerable differences in equatorial
Pacific precipitation forced changes, by impacting the direct (within a
year) CO$_{2}$-induced weakening of the Walker circulation. We use
global atmospheric energetics, as a theoretical backdrop, to explain the
relationship between the tropical atmospheric circulation and the AMOC
state. A physical mechanism is then proposed, relating the direct
CO$_{2}$-forced weakening of the atmospheric tropical circulation
to its climatological strength in unperturbed climate and indirectly to
the AMOC state.
  doi = {10.1029/2018GL078558},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..45.8519V},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Drobinski}, P. and {Silva}, N.~D. and {Panthou}, G. and {Bastin}, S. and 
	{Muller}, C. and {Ahrens}, B. and {Borga}, M. and {Conte}, D. and 
	{Fosser}, G. and {Giorgi}, F. and {G{\"u}ttler}, I. and {Kotroni}, V. and 
	{Li}, L. and {Morin}, E. and {{\"O}nol}, B. and {Quintana-Segui}, P. and 
	{Romera}, R. and {Torma}, C.~Z.},
  title = {{Scaling precipitation extremes with temperature in the Mediterranean: past climate assessment and projection in anthropogenic scenarios}},
  journal = {Climate Dynamics},
  keywords = {Precipitation extremes, Clausius-Clapeyron scaling , Regional climate, Europe, Mediterranean, HyMeX, MED-CORDEX},
  year = 2018,
  month = aug,
  volume = 51,
  pages = {1237-1257},
  abstract = {{In this study we investigate the scaling of precipitation extremes with
temperature in the Mediterranean region by assessing against
observations the present day and future regional climate simulations
performed in the frame of the HyMeX and MED-CORDEX programs. Over the
1979-2008 period, despite differences in quantitative precipitation
simulation across the various models, the change in precipitation
extremes with respect to temperature is robust and consistent. The
spatial variability of the temperature-precipitation extremes
relationship displays a hook shape across the Mediterranean, with
negative slope at high temperatures and a slope following
Clausius-Clapeyron (CC)-scaling at low temperatures. The temperature at
which the slope of the temperature-precipitation extreme relation
sharply changes (or temperature break), ranges from about 20 {\deg}C in
the western Mediterranean to $\lt$10 {\deg}C in Greece. In addition, this
slope is always negative in the arid regions of the Mediterranean. The
scaling of the simulated precipitation extremes is insensitive to
ocean-atmosphere coupling, while it depends very weakly on the
resolution at high temperatures for short precipitation accumulation
times. In future climate scenario simulations covering the 2070-2100
period, the temperature break shifts to higher temperatures by a value
which is on average the mean regional temperature change due to global
warming. The slope of the simulated future temperature-precipitation
extremes relationship is close to CC-scaling at temperatures below the
temperature break, while at high temperatures, the negative slope is
close, but somewhat flatter or steeper, than in the current climate
depending on the model. Overall, models predict more intense
precipitation extremes in the future. Adjusting the
temperature-precipitation extremes relationship in the present climate
using the CC law and the temperature shift in the future allows the
recovery of the temperature-precipitation extremes relationship in the
future climate. This implies negligible regional changes of relative
humidity in the future despite the large warming and drying over the
Mediterranean. This suggests that the Mediterranean Sea is the primary
source of moisture which counteracts the drying and warming impacts on
relative humidity in parts of the Mediterranean region.
  doi = {10.1007/s00382-016-3083-x},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ClDy...51.1237D},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Van Weverberg}, K. and {Morcrette}, C.~J. and {Petch}, J. and 
	{Klein}, S.~A. and {Ma}, H.-Y. and {Zhang}, C. and {Xie}, S. and 
	{Tang}, Q. and {Gustafson}, W.~I. and {Qian}, Y. and {Berg}, L.~K. and 
	{Liu}, Y. and {Huang}, M. and {Ahlgrimm}, M. and {Forbes}, R. and 
	{Bazile}, E. and {Roehrig}, R. and {Cole}, J. and {Merryfield}, W. and 
	{Lee}, W.-S. and {Cheruy}, F. and {Mellul}, L. and {Wang}, Y.-C. and 
	{Johnson}, K. and {Thieman}, M.~M.},
  title = {{CAUSES: Attribution of Surface Radiation Biases in NWP and Climate Models near the U.S. Southern Great Plains}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {warm bias, CAUSES, radiation, attribution, clouds},
  year = 2018,
  month = apr,
  volume = 123,
  pages = {3612-3644},
  abstract = {{Many Numerical Weather Prediction (NWP) and climate models exhibit too
warm lower tropospheres near the midlatitude continents. The warm bias
has been shown to coincide with important surface radiation biases that
likely play a critical role in the inception or the growth of the warm
bias. This paper presents an attribution study on the net radiation
biases in nine model simulations, performed in the framework of the
CAUSES project (Clouds Above the United States and Errors at the
Surface). Contributions from deficiencies in the surface properties,
clouds, water vapor, and aerosols are quantified, using an array of
radiation measurement stations near the Atmospheric Radiation
Measurement Southern Great Plains site. Furthermore, an in-depth
analysis is shown to attribute the radiation errors to specific cloud
regimes. The net surface shortwave radiation is overestimated in all
models throughout most of the simulation period. Cloud errors are shown
to contribute most to this overestimation, although nonnegligible
contributions from the surface albedo exist in most models. Missing deep
cloud events and/or simulating deep clouds with too weak cloud radiative
effects dominate in the cloud-related radiation errors. Some models have
compensating errors between excessive occurrence of deep cloud but
largely underestimating their radiative effect, while other models miss
deep cloud events altogether. Surprisingly, even the latter models tend
to produce too much and too frequent afternoon surface precipitation.
This suggests that rather than issues with the triggering of deep
convection, cloud radiative deficiencies are related to too weak
convective cloud detrainment and too large precipitation efficiencies.
  doi = {10.1002/2017JD027188},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JGRD..123.3612V},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Morcrette}, C.~J. and {Van Weverberg}, K. and {Ma}, H.-Y. and 
	{Ahlgrimm}, M. and {Bazile}, E. and {Berg}, L.~K. and {Cheng}, A. and 
	{Cheruy}, F. and {Cole}, J. and {Forbes}, R. and {Gustafson}, W.~I. and 
	{Huang}, M. and {Lee}, W.-S. and {Liu}, Y. and {Mellul}, L. and 
	{Merryfield}, W.~J. and {Qian}, Y. and {Roehrig}, R. and {Wang}, Y.-C. and 
	{Xie}, S. and {Xu}, K.-M. and {Zhang}, C. and {Klein}, S. and 
	{Petch}, J.},
  title = {{Introduction to CAUSES: Description of Weather and Climate Models and Their Near-Surface Temperature Errors in 5 day Hindcasts Near the Southern Great Plains}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {systematic errors, surface temperature bias, ARM, SGP},
  year = 2018,
  month = mar,
  volume = 123,
  pages = {2655-2683},
  abstract = {{We introduce the Clouds Above the United States and Errors at the
Surface (CAUSES) project with its aim of better understanding the
physical processes leading to warm screen temperature biases over the
American Midwest in many numerical models. In this first of four
companion papers, 11 different models, from nine institutes, perform a
series of 5 day hindcasts, each initialized from reanalyses. After
describing the common experimental protocol and detailing each model
configuration, a gridded temperature data set is derived from
observations and used to show that all the models have a warm bias over
parts of the Midwest. Additionally, a strong diurnal cycle in the screen
temperature bias is found in most models. In some models the bias is
largest around midday, while in others it is largest during the night.
At the Department of Energy Atmospheric Radiation Measurement Southern
Great Plains (SGP) site, the model biases are shown to extend several
kilometers into the atmosphere. Finally, to provide context for the
companion papers, in which observations from the SGP site are used to
evaluate the different processes contributing to errors there, it is
shown that there are numerous locations across the Midwest where the
diurnal cycle of the error is highly correlated with the diurnal cycle
of the error at SGP. This suggests that conclusions drawn from detailed
evaluation of models using instruments located at SGP will be
representative of errors that are prevalent over a larger spatial scale.
  doi = {10.1002/2017JD027199},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JGRD..123.2655M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Vignon}, E. and {Hourdin}, F. and {Genthon}, C. and {Van de Wiel}, B.~J.~H. and 
	{Gallée}, H. and {Madeleine}, J.-B. and {Beaumet}, J.},
  title = {{Modeling the Dynamics of the Atmospheric Boundary Layer Over the Antarctic Plateau With a General Circulation Model}},
  journal = {Journal of Advances in Modeling Earth Systems},
  keywords = {Antarctic Plateau, stable boundary-layer regimes, LMDZ, boundary-layer, general circulation model},
  year = 2018,
  month = jan,
  volume = 10,
  pages = {98-125},
  abstract = {{Observations evidence extremely stable boundary layers (SBL) over the
Antarctic Plateau and sharp regime transitions between weakly and very
stable conditions. Representing such features is a challenge for climate
models. This study assesses the modeling of the dynamics of the boundary
layer over the Antarctic Plateau in the LMDZ general circulation model.
It uses 1 year simulations with a stretched-grid over Dome C. The model
is nudged with reanalyses outside of the Dome C region such as
simulations can be directly compared to in situ observations. We
underline the critical role of the downward longwave radiation for
modeling the surface temperature. LMDZ reasonably represents the
near-surface seasonal profiles of wind and temperature but strong
temperature inversions are degraded by enhanced turbulent mixing
formulations. Unlike ERA-Interim reanalyses, LMDZ reproduces two SBL
regimes and the regime transition, with a sudden increase in the
near-surface inversion with decreasing wind speed. The sharpness of the
transition depends on the stability function used for calculating the
surface drag coefficient. Moreover, using a refined vertical grid leads
to a better reversed ``S-shaped'' relationship between the inversion and
the wind. Sudden warming events associated to synoptic advections of
warm and moist air are also well reproduced. Near-surface
supersaturation with respect to ice is not allowed in LMDZ but the
impact on the SBL structure is moderate. Finally, climate simulations
with the free model show that the recommended configuration leads to
stronger inversions and winds over the ice-sheet. However, the
near-surface wind remains underestimated over the slopes of
  doi = {10.1002/2017MS001184},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JAMES..10...98V},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Séférian}, R. and {Baek}, S. and {Boucher}, O. and 
	{Dufresne}, J.-L. and {Decharme}, B. and {Saint-Martin}, D. and 
	{Roehrig}, R.},
  title = {{An interactive ocean surface albedo scheme (OSAv1.0): formulation and evaluation in ARPEGE-Climat (V6.1) and LMDZ (V5A)}},
  journal = {Geoscientific Model Development},
  year = 2018,
  month = jan,
  volume = 11,
  pages = {321-338},
  abstract = {{Ocean surface represents roughly 70 \% of the Earth's surface, playing a
large role in the partitioning of the energy flow within the climate
system. The ocean surface albedo (OSA) is an important parameter in this
partitioning because it governs the amount of energy penetrating into
the ocean or reflected towards space. The old OSA schemes in the
ARPEGE-Climat and LMDZ models only resolve the latitudinal dependence in
an ad hoc way without an accurate representation of the solar zenith
angle dependence. Here, we propose a new interactive OSA scheme suited
for Earth system models, which enables coupling between Earth system
model components like surface ocean waves and marine biogeochemistry.
This scheme resolves spectrally the various contributions of the surface
for direct and diffuse solar radiation. The implementation of this
scheme in two Earth system models leads to substantial improvements in
simulated OSA. At the local scale, models using the interactive OSA
scheme better replicate the day-to-day distribution of OSA derived from
ground-based observations in contrast to old schemes. At global scale,
the improved representation of OSA for diffuse radiation reduces model
biases by up to 80 \% over the tropical oceans, reducing annual-mean
model-data error in surface upwelling shortwave radiation by up to 7 W
m$^{-2}$ over this domain. The spatial correlation coefficient
between modeled and observed OSA at monthly resolution has been
increased from 0.1 to 0.8. Despite its complexity, this interactive OSA
scheme is computationally efficient for enabling precise OSA calculation
without penalizing the elapsed model time.
  doi = {10.5194/gmd-11-321-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GMD....11..321S},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Richardson}, T.~B. and {Forster}, P.~M. and {Andrews}, T. and 
	{Boucher}, O. and {Faluvegi}, G. and {Fl{\"a}schner}, D. and 
	{Hodnebrog}, {\O}. and {Kasoar}, M. and {Kirkev{\aa}g}, A. and 
	{Lamarque}, J.-F. and {Myhre}, G. and {Olivié}, D. and {Samset}, B.~H. and 
	{Shawki}, D. and {Shindell}, D. and {Takemura}, T. and {Voulgarakis}, A.
  title = {{Drivers of Precipitation Change: An Energetic Understanding}},
  journal = {Journal of Climate},
  year = 2018,
  month = dec,
  volume = 31,
  pages = {9641-9657},
  doi = {10.1175/JCLI-D-17-0240.1},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JCli...31.9641R},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Dommo}, A. and {Philippon}, N. and {Vondou}, D.~A. and {Sèze}, G. and 
	{Eastman}, R.},
  title = {{The June-September Low Cloud Cover in Western Central Africa: Mean Spatial Distribution and Diurnal Evolution, and Associated Atmospheric Dynamics}},
  journal = {Journal of Climate},
  year = 2018,
  month = dec,
  volume = 31,
  pages = {9585-9603},
  doi = {10.1175/JCLI-D-17-0082.1},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JCli...31.9585D},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Fl{\"a}schner}, D. and {Mauritsen}, T. and {Stevens}, B. and 
	{Bony}, S.},
  title = {{The Signature of Shallow Circulations, Not Cloud Radiative Effects, in the Spatial Distribution of Tropical Precipitation}},
  journal = {Journal of Climate},
  year = 2018,
  month = dec,
  volume = 31,
  pages = {9489-9505},
  doi = {10.1175/JCLI-D-18-0230.1},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JCli...31.9489F},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Coppin}, D. and {Bony}, S.},
  title = {{On the Interplay Between Convective Aggregation, Surface Temperature Gradients, and Climate Sensitivity}},
  journal = {Journal of Advances in Modeling Earth Systems},
  keywords = {convective aggregation, climate sensitivity, radiative-convective equilibrium, ocean-atmosphere coupling, convection},
  year = 2018,
  month = dec,
  volume = 10,
  pages = {3123-3138},
  abstract = {{This study explores the extent to which convective aggregation interacts
with sea surface temperature (SST) and affects climate sensitivity. For
this purpose, radiative-convective equilibrium simulations are run with
a general circulation model coupled to an ocean mixed layer, and several
types of perturbations are imposed to the ocean-atmosphere system.
Convective aggregation turns out to be much more sensitive to
temperature in coupled experiments than in prescribed SST experiments.
But changes in convective aggregation induced by a doubling of the
CO$_{2}$ concentration are always smaller than changes associated
with the transition from a non-aggregated to an aggregated state. If
aggregation changes were acting alone, they would exert a strong
negative feedback on global mean surface temperature. However, in a
coupled framework, aggregation changes interact with the SST and
generate SST gradients that strengthen the positive low-cloud feedback
associated with changes in SST pattern. This overcompensates the
negative feedback due to aggregation changes and leads to a larger
equilibrium climate sensitivity than in the absence of SST gradients.
Although this effect might be model specific, interactions between
convective aggregation and the spatial distribution of SST appear
crucial to assess the impact of convective aggregation on climate
  doi = {10.1029/2018MS001406},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JAMES..10.3123C},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Li}, X. and {Balkanski}, Y. and {Wu}, Z. and {Gasser}, T. and 
	{Ciais}, P. and {Zhou}, F. and {Li}, L. and {Tao}, S. and {Peng}, S. and 
	{Piao}, S. and {Wang}, R. and {Wang}, T. and {Li}, B.},
  title = {{Analysis of slight precipitation in China during the past decades and its relationship with advanced very high radiometric resolution normalized difference vegetation index}},
  journal = {International Journal of Climatology},
  year = 2018,
  month = dec,
  volume = 38,
  pages = {5563-5575},
  doi = {10.1002/joc.5763},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018IJCli..38.5563L},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Krinner}, G. and {Derksen}, C. and {Essery}, R. and {Flanner}, M. and 
	{Hagemann}, S. and {Clark}, M. and {Hall}, A. and {Rott}, H. and 
	{Brutel-Vuilmet}, C. and {Kim}, H. and {Ménard}, C.~B. and 
	{Mudryk}, L. and {Thackeray}, C. and {Wang}, L. and {Arduini}, G. and 
	{Balsamo}, G. and {Bartlett}, P. and {Boike}, J. and {Boone}, A. and 
	{Chéruy}, F. and {Colin}, J. and {Cuntz}, M. and {Dai}, Y. and 
	{Decharme}, B. and {Derry}, J. and {Ducharne}, A. and {Dutra}, E. and 
	{Fang}, X. and {Fierz}, C. and {Ghattas}, J. and {Gusev}, Y. and 
	{Haverd}, V. and {Kontu}, A. and {Lafaysse}, M. and {Law}, R. and 
	{Lawrence}, D. and {Li}, W. and {Marke}, T. and {Marks}, D. and 
	{Ménégoz}, M. and {Nasonova}, O. and {Nitta}, T. and 
	{Niwano}, M. and {Pomeroy}, J. and {Raleigh}, M.~S. and {Schaedler}, G. and 
	{Semenov}, V. and {Smirnova}, T.~G. and {Stacke}, T. and {Strasser}, U. and 
	{Svenson}, S. and {Turkov}, D. and {Wang}, T. and {Wever}, N. and 
	{Yuan}, H. and {Zhou}, W. and {Zhu}, D.},
  title = {{ESM-SnowMIP: assessing snow models and quantifying snow-related climate feedbacks}},
  journal = {Geoscientific Model Development},
  year = 2018,
  month = dec,
  volume = 11,
  pages = {5027-5049},
  abstract = {{This paper describes ESM-SnowMIP, an international coordinated modelling
effort to evaluate current snow schemes, including snow schemes that are
included in Earth system models, in a wide variety of settings against
local and global observations. The project aims to identify crucial
processes and characteristics that need to be improved in snow models in
the context of local- and global-scale modelling. A further objective of
ESM-SnowMIP is to better quantify snow-related feedbacks in the Earth
system. Although it is not part of the sixth phase of the Coupled Model
Intercomparison Project (CMIP6), ESM-SnowMIP is tightly linked to the
CMIP6-endorsed Land Surface, Snow and Soil Moisture Model
Intercomparison (LS3MIP).
  doi = {10.5194/gmd-11-5027-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GMD....11.5027K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Bharath Kumar}, D. and {Verma}, S. and {Boucher}, O. and {Wang}, R.
  title = {{Constrained simulation of aerosol species and sources during pre-monsoon season over the Indian subcontinent}},
  journal = {Atmospheric Research},
  year = 2018,
  month = dec,
  volume = 214,
  pages = {91-108},
  abstract = {{This study was designed to deliver a better concurrence between model
estimates and observations, of atmospheric aerosol species, and predict
their spatial distribution as consistently as possible. A free running
aerosol simulation (freesimu) in a general circulation model (GCM) was
performed, and further the simulated aerosol optical depth (AOD) was
constrained with the observed AOD. The present study was carried out
during the pre-monsoon season and for the Tigerz experiment which was
conducted at stations over the Indo-Gangetic plain (IGP) and the
Himalayan foot-hills in northern India. Our formulation of the
constrained aerosol simulation (constrsimu) was based upon an
identification of the freesimu with the most consistent estimates of
aerosol characteristic among the three freesimu. The three freesimu
(differing in source of emissions and model horizontal resolution) were
carried out with the general circulation model (GCM) of Laboratoire de
Météorologie Dynamique (LMD-ZT GCM). Black carbon (BC),
organic carbon (OC), and sulfate-other water soluble (Sul-ows) estimated
from constrsimu amounted to 70\%-100\% compared to that from freesimu
being 20\%-50\% of their measured counterparts. Among the aerosol species,
the pre-monsoon mean concentration of dust was considerably high over
most part of the Indian subcontinent; the anthropogenic aerosol species
were, however, specifically predominant over the IGP (mostly 8-12 {$\mu$}g
m$^{-3}$ for Sul-ows, OC). The constrsimu estimated total
submicron aerosol mass concentration revealed its alarmingly high value
over the northern and north-western India ($\gt$ 100 {$\mu$}g m$^{-3}$
and as high as 300 {$\mu$}g m$^{-3}$). While the high value of
observed AOD was found being mainly due to dust (AOD due to dust greater
than 0.3) over the northern-northwestern IGP, it was due to Sul-ows (AOD
due to Sul-ows as high as 0.4) over the eastern IGP, eastern coastline,
and the Bay of Bengal. Temporal trend of fine (FM) and coarse mode (CM)
AOD from constrsimu estimates and that derived from Tigerz experiment
were in phase with each other for most of the days and exhibited a
strong positive correlation coefficient. Source of Tigerz aerosols was
mainly due to a predominant influence of dust from Africa/west Asia
followed by that from northwest India, and of anthropogenic emissions
originating in the IGP. A 200\% increase was inferred for potential black
carbon emissions (using India emission inventory implemented in a GCM)
to obtain a concurrence between observed and freesimu BC concentration.
  doi = {10.1016/j.atmosres.2018.07.001},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018AtmRe.214...91B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Smith}, C.~J. and {Kramer}, R.~J. and {Myhre}, G. and {Forster}, P.~M. and 
	{Soden}, B.~J. and {Andrews}, T. and {Boucher}, O. and {Faluvegi}, G. and 
	{Fl{\"a}schner}, D. and {Hodnebrog}, {\O}. and {Kasoar}, M. and 
	{Kharin}, V. and {Kirkev{\^a}g}, A. and {Lamarque}, J.-F. and 
	{M{\"u}lmenst{\"a}dt}, J. and {Olivié}, D. and {Richardson}, T. and 
	{Samset}, B.~H. and {Shindell}, D. and {Stier}, P. and {Takemura}, T. and 
	{Voulgarakis}, A. and {Watson-Parris}, D.},
  title = {{Understanding Rapid Adjustments to Diverse Forcing Agents}},
  journal = {\grl},
  keywords = {rapid adjustments, radiative forcing, PDRMIP, kernels},
  year = 2018,
  month = nov,
  volume = 45,
  pages = {12},
  abstract = {{Rapid adjustments are responses to forcing agents that cause a
perturbation to the top of atmosphere energy budget but are uncoupled to
changes in surface warming. Different mechanisms are responsible for
these adjustments for a variety of climate drivers. These remain to be
quantified in detail. It is shown that rapid adjustments reduce the
effective radiative forcing (ERF) of black carbon by half of the
instantaneous forcing, but for CO$_{2}$ forcing, rapid adjustments
increase ERF. Competing tropospheric adjustments for CO$_{2}$
forcing are individually significant but sum to zero, such that the ERF
equals the stratospherically adjusted radiative forcing, but this is not
true for other forcing agents. Additional experiments of increase in the
solar constant and increase in CH$_{4}$ are used to show that a
key factor of the rapid adjustment for an individual climate driver is
changes in temperature in the upper troposphere and lower stratosphere.
  doi = {10.1029/2018GL079826},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..4512023S},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Myhre}, G. and {Kramer}, R.~J. and {Smith}, C.~J. and {Hodnebrog}, {\O}. and 
	{Forster}, P. and {Soden}, B.~J. and {Samset}, B.~H. and {Stjern}, C.~W. and 
	{Andrews}, T. and {Boucher}, O. and {Faluvegi}, G. and {Fl{\"a}schner}, D. and 
	{Kasoar}, M. and {Kirkev{\^a}g}, A. and {Lamarque}, J.-F. and 
	{Olivié}, D. and {Richardson}, T. and {Shindell}, D. and 
	{Stier}, P. and {Takemura}, T. and {Voulgarakis}, A. and {Watson-Parris}, D.
  title = {{Quantifying the Importance of Rapid Adjustments for Global Precipitation Changes}},
  journal = {\grl},
  keywords = {precipitation changes, climate drivers, radiative kernels, PDRMIP},
  year = 2018,
  month = oct,
  volume = 45,
  pages = {11},
  abstract = {{Different climate drivers influence precipitation in different ways.
Here we use radiative kernels to understand the influence of rapid
adjustment processes on precipitation in climate models. Rapid
adjustments are generally triggered by the initial heating or cooling of
the atmosphere from an external climate driver. For precipitation
changes, rapid adjustments due to changes in temperature, water vapor,
and clouds are most important. In this study we have investigated five
climate drivers (CO$_{2}$, CH$_{4}$, solar irradiance, black
carbon, and sulfate aerosols). The fast precipitation responses to a
doubling of CO$_{2}$ and a 10-fold increase in black carbon are
found to be similar, despite very different instantaneous changes in the
radiative cooling, individual rapid adjustments, and sensible heating.
The model diversity in rapid adjustments is smaller for the experiment
involving an increase in the solar irradiance compared to the other
climate driver perturbations, and this is also seen in the precipitation
  doi = {10.1029/2018GL079474},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..4511399M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{G{\u a}inu{\c s}{\u a}-Bogdan}, A. and {Hourdin}, F. and {Traore}, A.~K. and 
	{Braconnot}, P.},
  title = {{Omens of coupled model biases in the CMIP5 AMIP simulations}},
  journal = {Climate Dynamics},
  keywords = {Climate model biases, AMIP simulations, Coupled simulations, Latent heat flux, Sea surface temperature, Sensitivity tests},
  year = 2018,
  month = oct,
  volume = 51,
  pages = {2927-2941},
  abstract = {{Despite decades of efforts and improvements in the representation of
processes as well as in model resolution, current global climate models
still suffer from a set of important, systematic biases in sea surface
temperature (SST), not much different from the previous generation of
climate models. Many studies have looked at errors in the wind field,
cloud representation or oceanic upwelling in coupled models to explain
the SST errors. In this paper we highlight the relationship between
latent heat flux (LH) biases in forced atmospheric simulations and the
SST biases models develop in coupled mode, at the scale of the entire
intertropical domain. By analyzing 22 pairs of forced atmospheric and
coupled ocean-atmosphere simulations from the CMIP5 database, we show a
systematic, negative correlation between the spatial patterns of these
two biases. This link between forced and coupled bias patterns is also
confirmed by two sets of dedicated sensitivity experiments with the
IPSL-CM5A-LR model. The analysis of the sources of the atmospheric LH
bias pattern reveals that the near-surface wind speed bias dominates the
zonal structure of the LH bias and that the near-surface relative
humidity dominates the east-west contrasts.
  doi = {10.1007/s00382-017-4057-3},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ClDy...51.2927G},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Richet}, O. and {Chomaz}, J.-M. and {Muller}, C.},
  title = {{Internal Tide Dissipation at Topography: Triadic Resonant Instability Equatorward and Evanescent Waves Poleward of the Critical Latitude}},
  journal = {Journal of Geophysical Research (Oceans)},
  keywords = {internal tide energy dissipation, triadic resonant instability, 2f-pump},
  year = 2018,
  month = sep,
  volume = 123,
  pages = {6136-6155},
  abstract = {{Several studies have shown the existence of a critical latitude where
the dissipation of internal tides is strongly enhanced. Internal tides
are internal waves generated by barotropic tidal currents impinging
rough topography at the seafloor. Their dissipation and concomitant
diapycnal mixing are believed to be important for water masses and the
large-scale ocean circulation. The purpose of this study is to clarify
the physical processes at the origin of this strong latitudinal
dependence of tidal energy dissipation. We find that different
mechanisms are involved equatorward and poleward of the critical
latitude. Triadic resonant instabilities are responsible for the
dissipation of internal tides equatorward of the critical latitude. In
particular, a dominant triad involving the primary internal tide and
near-inertial waves is key. At the critical latitude, the peak of energy
dissipation is explained by both increased instability growth rates, and
smaller scales of secondary waves thus more prone to break and dissipate
their energy. Surprisingly, poleward of the critical latitude, the
generation of evanescent waves appears to be crucial. Triadic
instabilities have been widely studied, but the transfer of energy to
evanescent waves has received comparatively little attention. Our work
suggests that the nonlinear transfer of energy from the internal tide to
evanescent waves (corresponding to the 2f-pump mechanism described by
Young et al., 2008, https://doi.org/10.1017/S0022112008001742)
is an efficient mechanism to dissipate internal tide energy near and
poleward of the critical latitude. The theoretical results are confirmed
in idealized high-resolution numerical simulations of a barotropic M2
tide impinging sinusoidal topography in a linearly stratified fluid.
  doi = {10.1029/2017JC013591},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JGRC..123.6136R},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Li}, W. and {Jiang}, Z. and {Zhang}, X. and {Li}, L.},
  title = {{On the Emergence of Anthropogenic Signal in Extreme Precipitation Change Over China}},
  journal = {\grl},
  keywords = {extreme precipitation, anthropogenic signal, detection, China},
  year = 2018,
  month = sep,
  volume = 45,
  pages = {9179-9185},
  abstract = {{The detection of anthropogenic influences on climate extremes at
regional scale is important for the development of national climate
change policy. Global climate simulations from phase 5 of the Coupled
Model Intercomparison Project under the Representative Concentration
Pathway 8.5 scenario are used to examine the time at which an
anthropogenic influence becomes detectable in extreme precipitation over
China and the change in probability of extreme precipitation with
certain magnitudes when the changes are detectable. Anthropogenic
influence is not significantly detected over China in the observational
record or simulations from 1961 to 2012 based on the test of field
significance. Simulations indicate that such change would become
detectable in the future by around 2035. Large changes would already
manifest by the time of signal detection; for example, extreme
precipitation events that occur on average once every 20, 50, and 100
years in current (1986-2005) climate would reduce to about 15, 34, and
63 years on average by the time of detection around 2035.
  doi = {10.1029/2018GL079133},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..45.9179L},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Zeng}, X. and {Klocke}, D. and {Shipway}, B.~J. and {Singh}, M.~S. and 
	{Sandu}, I. and {Hannah}, W. and {Bogenschutz}, P. and {Zhang}, Y. and 
	{Morrison}, H. and {Pritchard}, M. and {Rio}, C.},
  title = {{Future Community Efforts in Understanding and Modeling Atmospheric Processes}},
  journal = {Bulletin of the American Meteorological Society},
  year = 2018,
  month = sep,
  volume = 99,
  pages = {ES159-ES162},
  doi = {10.1175/BAMS-D-18-0139.1},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018BAMS...99S.159Z},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Kravitz}, B. and {Rasch}, P.~J. and {Wang}, H. and {Robock}, A. and 
	{Gabriel}, C. and {Boucher}, O. and {Cole}, J.~N.~S. and {Haywood}, J. and 
	{Ji}, D. and {Jones}, A. and {Lenton}, A. and {Moore}, J.~C. and 
	{Muri}, H. and {Niemeier}, U. and {Phipps}, S. and {Schmidt}, H. and 
	{Watanabe}, S. and {Yang}, S. and {Yoon}, J.-H.},
  title = {{The climate effects of increasing ocean albedo: an idealized representation of solar geoengineering}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2018,
  month = sep,
  volume = 18,
  pages = {13097-13113},
  abstract = {{Geoengineering, or climate intervention, describes methods of
deliberately altering the climate system to offset anthropogenic climate
change. As an idealized representation of near-surface solar
geoengineering over the ocean, such as marine cloud brightening, this
paper discusses experiment G1ocean-albedo of the Geoengineering Model
Intercomparison Project (GeoMIP), involving an abrupt quadrupling of the
CO$_{2}$ concentration and an instantaneous increase in ocean
albedo to maintain approximate net top-of-atmosphere radiative flux
balance. A total of 11 Earth system models are relatively consistent in
their temperature, radiative flux, and hydrological cycle responses to
this experiment. Due to the imposed forcing, air over the land surface
warms by a model average of 1.14 K, while air over most of the ocean
cools. Some parts of the near-surface air temperature over ocean warm
due to heat transport from land to ocean. These changes generally
resolve within a few years, indicating that changes in ocean heat
content play at most a small role in the warming over the oceans. The
hydrological cycle response is a general slowing down, with high
heterogeneity in the response, particularly in the tropics. While
idealized, these results have important implications for marine cloud
brightening, or other methods of geoengineering involving spatially
heterogeneous forcing, or other general forcings with a strong
land-ocean contrast. It also reinforces previous findings that keeping
top-of-atmosphere net radiative flux constant is not sufficient for
preventing changes in global mean temperature.
  doi = {10.5194/acp-18-13097-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ACP....1813097K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Genthon}, C. and {Forbes}, R. and {Vignon}, E. and {Gettelman}, A. and 
	{Madeleine}, J.-B.},
  title = {{Comment on ``Surface Air Relative Humidities Spuriously Exceeding 100\% in CMIP5 Model Output and Their Impact on Future Projections'' by K. Ruosteenoja et al. (2017)}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  year = 2018,
  month = aug,
  volume = 123,
  pages = {8724-8727},
  doi = {10.1029/2017JD028111},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JGRD..123.8724G},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Adloff}, F. and {Jord{\`a}}, G. and {Somot}, S. and {Sevault}, F. and 
	{Arsouze}, T. and {Meyssignac}, B. and {Li}, L. and {Planton}, S.
  title = {{Improving sea level simulation in Mediterranean regional climate models}},
  journal = {Climate Dynamics},
  keywords = {Mediterranean, Sea level, Regional climate model, Lateral boundary conditions, Atlantic forcing},
  year = 2018,
  month = aug,
  volume = 51,
  pages = {1167-1178},
  abstract = {{For now, the question about future sea level change in the Mediterranean
remains a challenge. Previous climate modelling attempts to estimate
future sea level change in the Mediterranean did not meet a consensus.
The low resolution of CMIP-type models prevents an accurate
representation of important small scales processes acting over the
Mediterranean region. For this reason among others, the use of high
resolution regional ocean modelling has been recommended in literature
to address the question of ongoing and future Mediterranean sea level
change in response to climate change or greenhouse gases emissions.
Also, it has been shown that east Atlantic sea level variability is the
dominant driver of the Mediterranean variability at interannual and
interdecadal scales. However, up to now, long-term regional simulations
of the Mediterranean Sea do not integrate the full sea level information
from the Atlantic, which is a substantial shortcoming when analysing
Mediterranean sea level response. In the present study we analyse
different approaches followed by state-of-the-art regional climate
models to simulate Mediterranean sea level variability. Additionally we
present a new simulation which incorporates improved information of
Atlantic sea level forcing at the lateral boundary. We evaluate the
skills of the different simulations in the frame of long-term hindcast
simulations spanning from 1980 to 2012 analysing sea level variability
from seasonal to multidecadal scales. Results from the new simulation
show a substantial improvement in the modelled Mediterranean sea level
signal. This confirms that Mediterranean mean sea level is strongly
influenced by the Atlantic conditions, and thus suggests that the
quality of the information in the lateral boundary conditions (LBCs) is
crucial for the good modelling of Mediterranean sea level. We also found
that the regional differences inside the basin, that are induced by
circulation changes, are model-dependent and thus not affected by the
LBCs. Finally, we argue that a correct configuration of LBCs in the
Atlantic should be used for future Mediterranean simulations, which
cover hindcast period, but also for scenarios.
  doi = {10.1007/s00382-017-3842-3},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ClDy...51.1167A},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Harzallah}, A. and {Jord{\`a}}, G. and {Dubois}, C. and {Sannino}, G. and 
	{Carillo}, A. and {Li}, L. and {Arsouze}, T. and {Cavicchia}, L. and 
	{Beuvier}, J. and {Akhtar}, N.},
  title = {{Long term evolution of heat budget in the Mediterranean Sea from Med-CORDEX forced and coupled simulations}},
  journal = {Climate Dynamics},
  keywords = {Mediterranean Sea, Heat budget, Heat content, Strait of Gibraltar, Regional climate models},
  year = 2018,
  month = aug,
  volume = 51,
  pages = {1145-1165},
  abstract = {{This study evaluates the Mediterranean Sea heat budget components from a
set of forced and coupled simulations performed in the frame of the
Med-CORDEX project. The simulations use regional climate system models
(RCSMs) dedicated to the Mediterranean area and driven by the
ERA40/ERA-Interim reanalyses. The study focuses on the period 1980-2010.
Interannual variations of the average net heat flux at the sea surface
are consistent among models but the spread in the mean values is large
(from -4.8 to +2.2 Wm$^{-2}$) with the coupled models showing the
lowest heat loss from the sea. For the heat flux at the Strait of
Gibraltar both interannual variations and mean values show a large
intermodel spread. The basin average temperature shows positive trends
with highest values in the coupled models; it also shows interannual
variations that are in good agreement with observations. The heat
content rate is calculated based on the derivative of the average
temperature and is found to be significantly correlated for most models
with the net heat flux at the sea surface (average correlation  0.5) but
not with the net heat flux through the Strait of Gibraltar (average
correlation  0.2), suggesting that in the considered RCSMs the
interannual variability of the heat content rate is mainly driven by the
surface heat fluxes. The resemblance between the simulated and observed
heat content rates is stronger in the forced models than in the coupled
ones. This is explained by the stronger constraint applied to the forced
models by the use of the surface temperature relaxation to observations.
The temperature of the outflowing water through the Strait of Gibraltar
shows positive and significant trends, also higher in the coupled
models. It is suggested that the Mediterranean Sea warming found in most
models and in particular in the coupled ones, induces a change of the
hydrographic conditions that affects the Strait of Gibraltar.
  doi = {10.1007/s00382-016-3363-5},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ClDy...51.1145H},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Obermann}, A. and {Bastin}, S. and {Belamari}, S. and {Conte}, D. and 
	{Gaertner}, M.~A. and {Li}, L. and {Ahrens}, B.},
  title = {{Mistral and Tramontane wind speed and wind direction patterns in regional climate simulations}},
  journal = {Climate Dynamics},
  keywords = {Regional climate models, Evaluation, Model intercomparison, Mistral, Tramontane, Bayesian network},
  year = 2018,
  month = aug,
  volume = 51,
  pages = {1059-1076},
  abstract = {{The Mistral and Tramontane are important wind phenomena that occur over
southern France and the northwestern Mediterranean Sea. Both winds
travel through constricting valleys before flowing out towards the
Mediterranean Sea. The Mistral and Tramontane are thus interesting
phenomena, and represent an opportunity to study channeling effects, as
well as the interactions between the atmosphere and land/ocean surfaces.
This study investigates Mistral and Tramontane simulations using five
regional climate models with grid spacing of about 50 km and smaller.
All simulations are driven by ERA-Interim reanalysis data. Spatial
patterns of surface wind, as well as wind development and error
propagation along the wind tracks from inland France to offshore during
Mistral and Tramontane events, are presented and discussed. To
disentangle the results from large-scale error sources in Mistral and
Tramontane simulations, only days with well simulated large-scale sea
level pressure field patterns are evaluated. Comparisons with the
observations show that the large-scale pressure patterns are well
simulated by the considered models, but the orographic modifications to
the wind systems are not well simulated by the coarse-grid simulations
(with a grid spacing of about 50 km), and are reproduced slightly better
by the higher resolution simulations. On days with Mistral and/or
Tramontane events, most simulations underestimate (by 13 \% on average)
the wind speed over the Mediterranean Sea. This effect is strongest at
the lateral borders of the main flow{\mdash}the flow width is
underestimated. All simulations of this study show a clockwise wind
direction bias over the sea during Mistral and Tramontane events.
Simulations with smaller grid spacing show smaller biases than their
coarse-grid counterparts.
  doi = {10.1007/s00382-016-3053-3},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ClDy...51.1059O},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Cavicchia}, L. and {Scoccimarro}, E. and {Gualdi}, S. and {Marson}, P. and 
	{Ahrens}, B. and {Berthou}, S. and {Conte}, D. and {Dell'Aquila}, A. and 
	{Drobinski}, P. and {Djurdjevic}, V. and {Dubois}, C. and {Gallardo}, C. and 
	{Li}, L. and {Oddo}, P. and {Sanna}, A. and {Torma}, C.},
  title = {{Mediterranean extreme precipitation: a multi-model assessment}},
  journal = {Climate Dynamics},
  keywords = {Extreme precipitation, Mediterranean climate, Regional climate modelling},
  year = 2018,
  month = aug,
  volume = 51,
  pages = {901-913},
  abstract = {{Exploiting the added value of the ensemble of high-resolution model
simulations provided by the Med-CORDEX coordinated initiative, an
updated assessment of Mediterranean extreme precipitation events as
represented in different observational, reanalysis and modelling
datasets is presented. A spatiotemporal characterisation of the
long-term statistics of extreme precipitation is performed, using a
number of different diagnostic indices. Employing a novel approach based
on the timing of extreme precipitation events a number of physically
consistent subregions are defined. The comparison of different
diagnostics over the Mediterranean domain and physically homogeneous
sub-domains is presented and discussed, focussing on the relative impact
of several model configuration features (resolution, coupling, physical
parameterisations) on the performance in reproducing extreme
precipitation events. It is found that the agreement between the
observed and modelled long-term statistics of extreme precipitation is
more sensitive to the model physics, in particular convective
parameterisation, than to other model configurations such as resolution
and coupling.
  doi = {10.1007/s00382-016-3245-x},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ClDy...51..901C},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Benedetti}, A. and {Reid}, J.~S. and {Knippertz}, P. and {Marsham}, J.~H. and 
	{Di Giuseppe}, F. and {Rémy}, S. and {Basart}, S. and {Boucher}, O. and 
	{Brooks}, I.~M. and {Menut}, L. and {Mona}, L. and {Laj}, P. and 
	{Pappalardo}, G. and {Wiedensohler}, A. and {Baklanov}, A. and 
	{Brooks}, M. and {Colarco}, P.~R. and {Cuevas}, E. and {da Silva}, A. and 
	{Escribano}, J. and {Flemming}, J. and {Huneeus}, N. and {Jorba}, O. and 
	{Kazadzis}, S. and {Kinne}, S. and {Popp}, T. and {Quinn}, P.~K. and 
	{Sekiyama}, T.~T. and {Tanaka}, T. and {Terradellas}, E.},
  title = {{Status and future of numerical atmospheric aerosol prediction with a focus on data requirements}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2018,
  month = jul,
  volume = 18,
  pages = {10615-10643},
  abstract = {{Numerical prediction of aerosol particle properties has become an
important activity at many research and operational weather centers.
This development is due to growing interest from a diverse set of
stakeholders, such as air quality regulatory bodies, aviation and
military authorities, solar energy plant managers, climate services
providers, and health professionals. Owing to the complexity of
atmospheric aerosol processes and their sensitivity to the underlying
meteorological conditions, the prediction of aerosol particle
concentrations and properties in the numerical weather prediction (NWP)
framework faces a number of challenges. The modeling of numerous
aerosol-related parameters increases computational expense. Errors in
aerosol prediction concern all processes involved in the aerosol life
cycle including (a) errors on the source terms (for both anthropogenic
and natural emissions), (b) errors directly dependent on the meteorology
(e.g., mixing, transport, scavenging by precipitation), and (c) errors
related to aerosol chemistry (e.g., nucleation, gas-aerosol
partitioning, chemical transformation and growth, hygroscopicity).
Finally, there are fundamental uncertainties and significant processing
overhead in the diverse observations used for verification and
assimilation within these systems. Indeed, a significant component of
aerosol forecast development consists in streamlining aerosol-related
observations and reducing the most important errors through model
development and data assimilation. Aerosol particle observations from
satellite- and ground-based platforms have been crucial to guide model
development of the recent years and have been made more readily
available for model evaluation and assimilation. However, for the
sustainability of the aerosol particle prediction activities around the
globe, it is crucial that quality aerosol observations continue to be
made available from different platforms (space, near surface, and
aircraft) and freely shared. This paper reviews current requirements for
aerosol observations in the context of the operational activities
carried out at various global and regional centers. While some of the
requirements are equally applicable to aerosol-climate, the focus here
is on global operational prediction of aerosol properties such as mass
concentrations and optical parameters. It is also recognized that the
term ``requirements'' is loosely used here given the diversity in global
aerosol observing systems and that utilized data are typically not from
operational sources. Most operational models are based on bulk schemes
that do not predict the size distribution of the aerosol particles.
Others are based on a mix of ``bin'' and bulk schemes with limited
capability of simulating the size information. However the next
generation of aerosol operational models will output both mass and
number density concentration to provide a more complete description of
the aerosol population. A brief overview of the state of the art is
provided with an introduction on the importance of aerosol prediction
activities. The criteria on which the requirements for aerosol
observations are based are also outlined. Assimilation and evaluation
aspects are discussed from the perspective of the user requirements.
  doi = {10.5194/acp-18-10615-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ACP....1810615B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Liu}, L. and {Shawki}, D. and {Voulgarakis}, A. and {Kasoar}, M. and 
	{Samset}, B.~H. and {Myhre}, G. and {Forster}, P.~M. and {Hodnebrog}, {\O}. and 
	{Sillmann}, J. and {Aalbergsj{\o}}, S.~G. and {Boucher}, O. and 
	{Faluvegi}, G. and {Iversen}, T. and {Kirkev{\aa}g}, A. and 
	{Lamarque}, J.-F. and {Olivié}, D. and {Richardson}, T. and 
	{Shindell}, D. and {Takemura}, T.},
  title = {{A PDRMIP Multimodel Study on the Impacts of Regional Aerosol Forcings on Global and Regional Precipitation}},
  journal = {Journal of Climate},
  year = 2018,
  month = jun,
  volume = 31,
  pages = {4429-4447},
  doi = {10.1175/JCLI-D-17-0439.1},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JCli...31.4429L},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Tang}, T. and {Shindell}, D. and {Samset}, B.~H. and {Boucher}, O. and 
	{Forster}, P.~M. and {Hodnebrog}, {\O}. and {Myhre}, G. and 
	{Sillmann}, J. and {Voulgarakis}, A. and {Andrews}, T. and {Faluvegi}, G. and 
	{Fl{\"a}schner}, D. and {Iversen}, T. and {Kasoar}, M. and {Kharin}, V. and 
	{Kirkev{\aa}g}, A. and {Lamarque}, J.-F. and {Olivié}, D. and 
	{Richardson}, T. and {Stjern}, C.~W. and {Takemura}, T.},
  title = {{Dynamical response of Mediterranean precipitation to greenhouse gases and aerosols}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2018,
  month = jun,
  volume = 18,
  pages = {8439-8452},
  abstract = {{Atmospheric aerosols and greenhouse gases affect cloud properties,
radiative balance and, thus, the hydrological cycle. Observations show
that precipitation has decreased in the Mediterranean since the
beginning of the 20th century, and many studies have investigated
possible mechanisms. So far, however, the effects of aerosol forcing on
Mediterranean precipitation remain largely unknown. Here we compare the
modeled dynamical response of Mediterranean precipitation to individual
forcing agents in a set of global climate models (GCMs). Our analyses
show that both greenhouse gases and aerosols can cause drying in the
Mediterranean and that precipitation is more sensitive to black carbon
(BC) forcing than to well-mixed greenhouse gases (WMGHGs) or sulfate
aerosol. In addition to local heating, BC appears to reduce
precipitation by causing an enhanced positive sea level pressure (SLP)
pattern similar to the North Atlantic Oscillation-Arctic Oscillation,
characterized by higher SLP at midlatitudes and lower SLP at high
latitudes. WMGHGs cause a similar SLP change, and both are associated
with a northward diversion of the jet stream and storm tracks, reducing
precipitation in the Mediterranean while increasing precipitation in
northern Europe. Though the applied forcings were much larger, if
forcings are scaled to those of the historical period of 1901-2010,
roughly one-third (31{\plusmn}17 \%) of the precipitation decrease would
be attributable to global BC forcing with the remainder largely
attributable to WMGHGs, whereas global scattering sulfate aerosols would
have negligible impacts. Aerosol-cloud interactions appear to have
minimal impacts on Mediterranean precipitation in these models, at least
in part because many simulations did not fully include such processes;
these merit further study. The findings from this study suggest that
future BC and WMGHG emissions may significantly affect regional water
resources, agricultural practices, ecosystems and the economy in the
Mediterranean region.
  doi = {10.5194/acp-18-8439-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ACP....18.8439T},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Fuglestvedt}, J. and {Rogelj}, J. and {Millar}, R.~J. and {Allen}, M. and 
	{Boucher}, O. and {Cain}, M. and {Forster}, P.~M. and {Kriegler}, E. and 
	{Shindell}, D.},
  title = {{Implications of possible interpretations of `greenhouse gas balance' in the Paris Agreement}},
  journal = {Philosophical Transactions of the Royal Society of London Series A},
  year = 2018,
  month = may,
  volume = 376,
  eid = {20160445},
  pages = {20160445},
  abstract = {{The main goal of the Paris Agreement as stated in Article 2 is `holding
the increase in the global average temperature to well below 2{\deg}C
above pre-industrial levels and pursuing efforts to limit the
temperature increase to 1.5{\deg}C'. Article 4 points to this long-term
goal and the need to achieve `balance between anthropogenic emissions by
sources and removals by sinks of greenhouse gases'. This statement on
`greenhouse gas balance' is subject to interpretation, and
clarifications are needed to make it operational for national and
international climate policies. We study possible interpretations from a
scientific perspective and analyse their climatic implications. We
clarify how the implications for individual gases depend on the metrics
used to relate them. We show that the way in which balance is
interpreted, achieved and maintained influences temperature outcomes.
Achieving and maintaining net-zero CO$_{2}$-equivalent emissions
conventionally calculated using GWP$_{100}$ (100-year global
warming potential) and including substantial positive contributions from
short-lived climate-forcing agents such as methane would result in a
sustained decline in global temperature. A modified approach to the use
of GWP$_{100}$ (that equates constant emissions of short-lived
climate forcers with zero sustained emission of CO$_{2}$) results
in global temperatures remaining approximately constant once net-zero
CO$_{2}$-equivalent emissions are achieved and maintained. Our
paper provides policymakers with an overview of issues and choices that
are important to determine which approach is most appropriate in the
context of the Paris Agreement.

This article is part of the theme issue `The Paris Agreement:
understanding the physical and social challenges for a warming world of
1.5{\deg}C above pre-industrial levels'.
  doi = {10.1098/rsta.2016.0445},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018RSPTA.37660445F},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Masunaga}, H. and {Bony}, S.},
  title = {{Radiative Invigoration of Tropical Convection by Preceding Cirrus Clouds}},
  journal = {Journal of Atmospheric Sciences},
  year = 2018,
  month = apr,
  volume = 75,
  pages = {1327-1342},
  doi = {10.1175/JAS-D-17-0355.1},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JAtS...75.1327M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Ma}, H.-Y. and {Klein}, S.~A. and {Xie}, S. and {Zhang}, C. and 
	{Tang}, S. and {Tang}, Q. and {Morcrette}, C.~J. and {Van Weverberg}, K. and 
	{Petch}, J. and {Ahlgrimm}, M. and {Berg}, L.~K. and {Cheruy}, F. and 
	{Cole}, J. and {Forbes}, R. and {Gustafson}, W.~I. and {Huang}, M. and 
	{Liu}, Y. and {Merryfield}, W. and {Qian}, Y. and {Roehrig}, R. and 
	{Wang}, Y.-C.},
  title = {{CAUSES: On the Role of Surface Energy Budget Errors to the Warm Surface Air Temperature Error Over the Central United States}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {surface air temperature, systematic errors, SGP, surface energy budget, radiation, evaporative fraction},
  year = 2018,
  month = mar,
  volume = 123,
  pages = {2888-2909},
  abstract = {{Many weather forecast and climate models simulate warm surface air
temperature (T$_{2m}$) biases over midlatitude continents during
the summertime, especially over the Great Plains. We present here one of
a series of papers from a multimodel intercomparison project (CAUSES:
Cloud Above the United States and Errors at the Surface), which aims to
evaluate the role of cloud, radiation, and precipitation biases in
contributing to the T$_{2m}$ bias using a short-term hindcast
approach during the spring and summer of 2011. Observations are mainly
from the Atmospheric Radiation Measurement Southern Great Plains sites.
The present study examines the contributions of surface energy budget
errors. All participating models simulate too much net shortwave and
longwave fluxes at the surface but with no consistent mean bias sign in
turbulent fluxes over the Central United States and Southern Great
Plains. Nevertheless, biases in the net shortwave and downward longwave
fluxes as well as surface evaporative fraction (EF) are contributors to
T$_{2m}$ bias. Radiation biases are largely affected by cloud
simulations, while EF bias is largely affected by soil moisture
modulated by seasonal accumulated precipitation and evaporation. An
approximate equation based upon the surface energy budget is derived to
further quantify the magnitudes of radiation and EF contributions to
T$_{2m}$ bias. Our analysis ascribes that a large EF underestimate
is the dominant source of error in all models with a large positive
temperature bias, whereas an EF overestimate compensates for an excess
of absorbed shortwave radiation in nearly all the models with the
smallest temperature bias.
  doi = {10.1002/2017JD027194},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JGRD..123.2888M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Behera}, A.~K. and {Rivière}, E.~D. and {Marécal}, V. and 
	{Rysman}, J.-F. and {Chantal}, C. and {Sèze}, G. and {Amarouche}, N. and 
	{Ghysels}, M. and {Khaykin}, S.~M. and {Pommereau}, J.-P. and 
	{Held}, G. and {Burgalat}, J. and {Durry}, G.},
  title = {{Modeling the TTL at Continental Scale for a Wet Season: An Evaluation of the BRAMS Mesoscale Model Using TRO-Pico Campaign, and Measurements From Airborne and Spaceborne Sensors}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {stratospheric overshooting convection, tropical tropopause layer, water vapor budget, mesoscale modeling, BRAMS, inertia-gravity waves},
  year = 2018,
  month = mar,
  volume = 123,
  pages = {2491-2508},
  abstract = {{In order to better understand the water vapor (WV) intrusion into the
tropical stratosphere, a mesoscale simulation of the tropical tropopause
layer using the BRAMS (Brazilian version of Regional Atmospheric
Modeling System (RAMS)) model is evaluated for a wet season. This
simulation with a horizontal grid point resolution of 20 km {\times} 20
km cannot resolve the stratospheric overshooting convection (SOC). Its
ability to reproduce other key parameters playing a role in the
stratospheric WV abundance is investigated using the balloon-borne
TRO-Pico campaign measurements, the upper-air soundings over Brazil, and
the satellite observations by Aura Microwave Limb Sounder, Microwave
Humidity Sounder, and Geostationary Operational Environmental Satellite
12. The BRAMS exhibits a good ability in simulating temperature,
cold-point, WV variability around the tropopause. However, the
simulation is typically observed to be warmer by {\tilde}2.0{\deg}C and
wetter by {\tilde}0.4 ppmv at the hygropause, which can be partly
affiliated with the grid boundary nudging of the model by European
Centre for Medium-Range Weather Forecasts operational analyses. The
modeled cloud tops show a good correlation (maximum cross-correlation of
{\tilde}0.7) with Geostationary Operational Environmental Satellite 12.
Furthermore, the overshooting cells detected by Microwave Humidity
Sounder are observed at the locations, where 75\% of the modeled cloud
tops are higher than 11 km. Finally, the modeled inertia-gravity wave
periodicity and wavelength are comparable with those deduced from the
radio sounding measurements during TRO-Pico campaign. The good behavior
of BRAMS confirms the SOC contribution in the WV abundance, and
variability is of lesser importance than the large-scale processes. This
simulation can be used as a reference run for upscaling the impact of
SOC at a continental scale for future studies.
  doi = {10.1002/2017JD027969},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018JGRD..123.2491B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Wing}, A.~A. and {Reed}, K.~A. and {Satoh}, M. and {Stevens}, B. and 
	{Bony}, S. and {Ohno}, T.},
  title = {{Radiative-convective equilibrium model intercomparison project}},
  journal = {Geoscientific Model Development},
  year = 2018,
  month = mar,
  volume = 11,
  pages = {793-813},
  abstract = {{RCEMIP, an intercomparison of multiple types of models configured in
radiative-convective equilibrium (RCE), is proposed. RCE is an
idealization of the climate system in which there is a balance between
radiative cooling of the atmosphere and heating by convection. The
scientific objectives of RCEMIP are three-fold. First, clouds and
climate sensitivity will be investigated in the RCE setting. This
includes determining how cloud fraction changes with warming and the
role of self-aggregation of convection in climate sensitivity. Second,
RCEMIP will quantify the dependence of the degree of convective
aggregation and tropical circulation regimes on temperature. Finally, by
providing a common baseline, RCEMIP will allow the robustness of the RCE
state across the spectrum of models to be assessed, which is essential
for interpreting the results found regarding clouds, climate
sensitivity, and aggregation, and more generally, determining which
features of tropical climate a RCE framework is useful for. A novel
aspect and major advantage of RCEMIP is the accessibility of the RCE
framework to a variety of models, including cloud-resolving models,
general circulation models, global cloud-resolving models, single-column
models, and large-eddy simulation models.
  doi = {10.5194/gmd-11-793-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GMD....11..793W},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Richardson}, T.~B. and {Forster}, P.~M. and {Andrews}, T. and 
	{Boucher}, O. and {Faluvegi}, G. and {Fl{\"a}schner}, D. and 
	{Kasoar}, M. and {Kirkev{\^a}g}, A. and {Lamarque}, J.-F. and 
	{Myhre}, G. and {Olivié}, D. and {Samset}, B.~H. and {Shawki}, D. and 
	{Shindell}, D. and {Takemura}, T. and {Voulgarakis}, A.},
  title = {{Carbon Dioxide Physiological Forcing Dominates Projected Eastern Amazonian Drying}},
  journal = {\grl},
  keywords = {precipitation, Amazon, physiological forcing, fast response, CO$_{2}$ forcing, stomatal response},
  year = 2018,
  month = mar,
  volume = 45,
  pages = {2815-2825},
  abstract = {{Future projections of east Amazonian precipitation indicate drying, but
they are uncertain and poorly understood. In this study we analyze the
Amazonian precipitation response to individual atmospheric forcings
using a number of global climate models. Black carbon is found to drive
reduced precipitation over the Amazon due to temperature-driven
circulation changes, but the magnitude is uncertain. CO$_{2}$
drives reductions in precipitation concentrated in the east, mainly due
to a robustly negative, but highly variable in magnitude, fast response.
We find that the physiological effect of CO$_{2}$ on plant stomata
is the dominant driver of the fast response due to reduced latent
heating and also contributes to the large model spread. Using a simple
model, we show that CO$_{2}$ physiological effects dominate future
multimodel mean precipitation projections over the Amazon. However, in
individual models temperature-driven changes can be large, but due to
little agreement, they largely cancel out in the model mean.
  doi = {10.1002/2017GL076520},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..45.2815R},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Benetti}, M. and {Lacour}, J.-L. and {Sveinbj{\"o}rnsd{\'o}ttir}, A.~E. and 
	{Aloisi}, G. and {Reverdin}, G. and {Risi}, C. and {Peters}, A.~J. and 
	{Steen-Larsen}, H.~C.},
  title = {{A Framework to Study Mixing Processes in the Marine Boundary Layer Using Water Vapor Isotope Measurements}},
  journal = {\grl},
  keywords = {mixing processes, marine boundary layer, water vapor isotopes, evaporation, model},
  year = 2018,
  month = mar,
  volume = 45,
  pages = {2524-2532},
  abstract = {{We propose a framework using water vapor isotopes to study mixing
processes in the marine boundary layer (MBL) during quiescent
conditions, where we expect evaporation to contribute to the moisture
budget. This framework complements the existing models, by taking into
account the changing isotopic composition of the evaporation flux
({$\delta$}$_{e}$), both directly in response to the mixing and
indirectly in response to mixing and surface conditions through
variations in MBL humidity. The robustness of the model is demonstrated
using measurements from the North Atlantic Ocean. This shows the
importance of considering the {$\delta$}$_{e}$ variability
simultaneous to the mixing of the lower free troposphere to the MBL, to
simulate the MBL water vapor, whereas a mixing model using a constant
{$\delta$}$_{e}$ fails to reproduce the data. The sensitivity of
isotope observations to evaporation and shallow mixing further
demonstrates how these observations can constrain uncertainties
associated with these key processes for climate feedback predictions.
  doi = {10.1002/2018GL077167},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..45.2524B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Wang}, R. and {Andrews}, E. and {Balkanski}, Y. and {Boucher}, O. and 
	{Myhre}, G. and {Samset}, B.~H. and {Schulz}, M. and {Schuster}, G.~L. and 
	{Valari}, M. and {Tao}, S.},
  title = {{Spatial Representativeness Error in the Ground-Level Observation Networks for Black Carbon Radiation Absorption}},
  journal = {\grl},
  keywords = {black carbon, representativeness error, AERONET, GAW, model resolution},
  year = 2018,
  month = feb,
  volume = 45,
  pages = {2106-2114},
  abstract = {{There is high uncertainty in the direct radiative forcing of black
carbon (BC), an aerosol that strongly absorbs solar radiation. The
observation-constrained estimate, which is several times larger than the
bottom-up estimate, is influenced by the spatial representativeness
error due to the mesoscale inhomogeneity of the aerosol fields and the
relatively low resolution of global chemistry-transport models. Here we
evaluated the spatial representativeness error for two widely used
observational networks (AErosol RObotic NETwork and Global Atmosphere
Watch) by downscaling the geospatial grid in a global model of BC
aerosol absorption optical depth to 0.1{\deg} {\times} 0.1{\deg}. Comparing
the models at a spatial resolution of 2{\deg} {\times} 2{\deg} with BC
aerosol absorption at AErosol RObotic NETwork sites (which are commonly
located near emission hot spots) tends to cause a global spatial
representativeness error of 30\%, as a positive bias for the current
top-down estimate of global BC direct radiative forcing. By contrast,
the global spatial representativeness error will be 7\% for the Global
Atmosphere Watch network, because the sites are located in such a way
that there are almost an equal number of sites with positive or negative
representativeness error.
  doi = {10.1002/2017GL076817},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018GeoRL..45.2106W},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Kleinschmitt}, C. and {Boucher}, O. and {Platt}, U.},
  title = {{Sensitivity of the radiative forcing by stratospheric sulfur geoengineering to the amount and strategy of the SO$_{2}$injection studied with the LMDZ-S3A model}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2018,
  month = feb,
  volume = 18,
  pages = {2769-2786},
  abstract = {{The enhancement of the stratospheric sulfate aerosol layer has been
proposed as a method of geoengineering to abate global warming. Previous
modelling studies found that stratospheric aerosol geoengineering (SAG)
could effectively compensate for the warming by greenhouse gases on the
global scale, but also that the achievable cooling effect per sulfur
mass unit, i.e. the forcing efficiency, decreases with increasing
injection rate. In this study we use the atmospheric general circulation
model LMDZ with the sectional aerosol module S3A to determine how the
forcing efficiency depends on the injected amount of SO$_{2}$, the
injection height, and the spatio-temporal pattern of injection. We find
that the forcing efficiency may decrease more drastically for larger
SO$_{2}$ injections than previously estimated. As a result, the
net instantaneous radiative forcing does not exceed the limit of -2 W
m$^{-2}$ for continuous equatorial SO$_{2}$ injections and
it decreases (in absolute value) for injection rates larger than 20 Tg S
yr$^{-1}$. In contrast to other studies, the net radiative forcing
in our experiments is fairly constant with injection height (in a range
17 to 23 km) for a given amount of SO$_{2}$ injected. Also,
spreading the SO$_{2}$ injections between 30$^{o}$ S and
30$^{o}$ N or injecting only seasonally from varying latitudes
does not result in a significantly larger (i.e. more negative) radiative
forcing. Other key characteristics of our simulations include a
consequent stratospheric heating, caused by the absorption of solar and
infrared radiation by the aerosol, and changes in stratospheric
dynamics, with a collapse of the quasi-biennial oscillation at larger
injection rates, which has impacts on the resulting spatial aerosol
distribution, size, and optical properties. But it has to be noted that
the complexity and uncertainty of stratospheric processes cause
considerable disagreement among different modelling studies of
stratospheric aerosol geoengineering. This may be addressed through
detailed model intercomparison activities, as observations to constrain
the simulations of stratospheric aerosol geoengineering are not
available and analogues (such as volcanic eruptions) are imperfect.
  doi = {10.5194/acp-18-2769-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ACP....18.2769K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Benveniste}, H. and {Boucher}, O. and {Guivarch}, C. and {Le Treut}, H. and 
	{Criqui}, P.},
  title = {{Impacts of nationally determined contributions on 2030 global greenhouse gas emissions: uncertainty analysis and distribution of emissions}},
  journal = {Environmental Research Letters},
  year = 2018,
  month = jan,
  volume = 13,
  number = 1,
  eid = {014022},
  pages = {014022},
  abstract = {{Nationally Determined Contributions (NDCs), submitted by Parties to the
United Nations Framework Convention on Climate Change before and after
the 21st Conference of Parties, summarize domestic objectives for
greenhouse gas (GHG) emissions reductions for the 2025-2030 time
horizon. In the absence, for now, of detailed guidelines for the format
of NDCs, ancillary data are needed to interpret some NDCs and project
GHG emissions in 2030. Here, we provide an analysis of uncertainty
sources and their impacts on 2030 global GHG emissions based on the sole
and full achievement of the NDCs. We estimate that NDCs project into
emissions in 2030 (90\% confidence interval), which is higher than
previous estimates, and with a larger uncertainty range. Despite these
uncertainties, NDCs robustly shift GHG emissions towards emerging and
developing countries and reduce international inequalities in per capita
GHG emissions. Finally, we stress that current NDCs imply larger
emissions reduction rates after 2030 than during the 2010-2030
period if long-term temperature goals are to be fulfilled. Our results
highlight four requirements for the forthcoming {\lsquo}climate
regime{\rsquo}: a clearer framework regarding future NDCs{\rsquo} design,
an increasing participation of emerging and developing countries in the
global mitigation effort, an ambitious update mechanism in order to
avoid hardly feasible decarbonization rates after 2030 and an
anticipation of steep decreases in global emissions after 2030.
  doi = {10.1088/1748-9326/aaa0b9},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ERL....13a4022B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Lacour}, J.-L. and {Risi}, C. and {Worden}, J. and {Clerbaux}, C. and 
	{Coheur}, P.-F.},
  title = {{Importance of depth and intensity of convection on the isotopic composition of water vapor as seen from IASI and TES {$\delta$}D observations}},
  journal = {Earth and Planetary Science Letters},
  keywords = {stable water isotopes, water vapor isotopologues, convection, water cycle, convective mixing, infrared remote sensing},
  year = 2018,
  month = jan,
  volume = 481,
  pages = {387-394},
  abstract = {{We use tropical observations of the water vapor isotopic composition,
derived from IASI and TES spaceborne measurements, to show that the
isotopic composition of water vapor in the free troposphere is sensitive
to both the depth and the intensity of convection. We find that for any
given precipitation intensity, vapor associated with deep convection is
isotopically depleted relative to vapor associated with shallow
convection. The intensity of precipitation also plays a role as for any
given depth of convection, the relative enrichment of water vapor
decreases as the intensity of precipitation increases. Shallow
convection, via the uplifting of enriched boundary layer air into the
free troposphere and the convective detrainment, enriches the free
troposphere. In contrast, deep convection is associated with processes
that deplete the water vapor in the free troposphere, such as rain
re-evaporation. The results of this study allow for a better
identification of the parameters controlling the isotopic composition of
the free troposphere and indicate that the isotopic composition of water
vapor can be used to evaluate the relative contributions of shallow and
deep convection in global models.
  doi = {10.1016/j.epsl.2017.10.048},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018E%26PSL.481..387L},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
  author = {{Stjern}, C.~W. and {Muri}, H. and {Ahlm}, L. and {Boucher}, O. and 
	{Cole}, J.~N.~S. and {Ji}, D. and {Jones}, A. and {Haywood}, J. and 
	{Kravitz}, B. and {Lenton}, A. and {Moore}, J.~C. and {Niemeier}, U. and 
	{Phipps}, S.~J. and {Schmidt}, H. and {Watanabe}, S. and {Egill Kristj{\'a}nsson}, J.
  title = {{Response to marine cloud brightening in a multi-model ensemble}},
  journal = {Atmospheric Chemistry \& Physics},
  year = 2018,
  month = jan,
  volume = 18,
  pages = {621-634},
  abstract = {{Here we show results from Earth system model simulations from the marine
cloud brightening experiment G4cdnc of the Geoengineering Model
Intercomparison Project (GeoMIP). The nine contributing models prescribe
a 50 \% increase in the cloud droplet number concentration (CDNC) of low
clouds over the global oceans in an experiment dubbed G4cdnc, with the
purpose of counteracting the radiative forcing due to anthropogenic
greenhouse gases under the RCP4.5 scenario. The model ensemble median
effective radiative forcing (ERF) amounts to -1.9 W m$^{-2}$, with
a substantial inter-model spread of -0.6 to -2.5 W m$^{-2}$. The
large spread is partly related to the considerable differences in clouds
and their representation between the models, with an underestimation of
low clouds in several of the models. All models predict a statistically
significant temperature decrease with a median of (for years 2020-2069)
-0.96 [-0.17 to -1.21] K relative to the RCP4.5 scenario, with
particularly strong cooling over low-latitude continents. Globally
averaged there is a weak but significant precipitation decrease of -2.35
[-0.57 to -2.96] \% due to a colder climate, but at low latitudes there
is a 1.19 \% increase over land. This increase is part of a circulation
change where a strong negative top-of-atmosphere (TOA) shortwave forcing
over subtropical oceans, caused by increased albedo associated with the
increasing CDNC, is compensated for by rising motion and positive TOA
longwave signals over adjacent land regions.
  doi = {10.5194/acp-18-621-2018},
  adsurl = {https://ui.adsabs.harvard.edu/abs/2018ACP....18..621S},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}