Marion Marchand

Polytech Paris-UPMC, Lutetia Parisorum, Île-de-France, France

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Publications (68)

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    Full-text Dataset · Jun 2016
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    [Show abstract] [Hide abstract] ABSTRACT: The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of 14 limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20 and 40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5–12 % and the drifts are at most ±5 % decade−1 (or even ±3 % decade−1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10 % and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY) and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses.
    Full-text Article · Jun 2016 · Atmospheric Measurement Techniques
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    [Show abstract] [Hide abstract] ABSTRACT: The enhancement of the stratospheric aerosol layer by volcanic eruptions induces a complex set of responses causing global and regional climate effects on a broad range of timescales. Uncertainties exist regarding the climatic response to strong volcanic forcing identified in coupled climate simulations that contributed to the fifth phase of the Climate Model Intercomparison Project (CMIP5). In order to better understand the sources of these model diversities, the model intercomparison project on the climate response to volcanic forcing (VolMIP) has defined a coordinated set of idealized volcanic perturbation experiments to be carried out in alignment with the CMIP6 protocol. VolMIP provides a common stratospheric aerosol dataset for each experiment to eliminate differences in the applied volcanic forcing, and defines a set of initial conditions to determine how internal climate variability contributes to determining the response. VolMIP will assess to what extent volcanically-forced responses of the coupled ocean-atmosphere system are robustly simulated by state-of-the-art coupled climate models and identify the causes that limit robust simulated behavior, especially differences in the treatment of physical processes. This paper illustrates the design of the idealized volcanic perturbation experiments in the VolMIP protocol and describes the common aerosol forcing input datasets to be used.
    Full-text Article · Apr 2016 · Geoscientific Model Development Discussions
  • Article · Jun 2015
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    Sébastien Bossay · Slimane Bekki · Marion Marchand · [...] · Ralf Toumi
    [Show abstract] [Hide abstract] ABSTRACT: The correlation between tropical stratospheric ozone and UV radiation on solar rotational time scales is investigated using daily satellite ozone observations and reconstructed solar spectra. We consider two 3-year periods falling within the descending phases of two 11-year solar cycles 22 (1991-1994) and 23 (2004-2007). The UV rotational cycle is highly irregular and even disappears for half a year during cycle 23. For the 1991-1994 period, ozone and 205 nm UV flux are found to be correlated between about 10 and 1 hPa with a maximum of 0.29 at ~5 hPa; ozone sensitivity (percentage change in ozone for 1 percent change in UV) peaks at ~0.4. Correlation during cycle 23 is weaker with a peak ozone sensitivity of 0.2. The correlation is found to vary widely, not only with altitude, but also from one year to the next with a rotational signal in ozone appearing almost intermittent. Unexpectedly, the correlation is not found to bear any relation with the solar rotational forcing. For instance, solar rotational fluctuations are by far the strongest during 1991-1992 whereas the correlation peaks at the end of 1993, a rotationally quiescent period. When calculated over sliding intervals of 1-year, the sensitivity is found to vary very strongly within both 3-year periods; it is almost negligible over the entire vertical profile during some 1-year intervals or reaches close to 1 around 2–5 mb for other intervals. Other sources of variability, presumably of dynamical origin, operate on the rotational spectral range and determine to a large extent the estimated solar rotational signal. Even considering 3 years of observations (corresponding to about 40 solar cycles), the extraction of the rotational solar signal does not appear to be robust during declining phases of 11-year solar cycles. As observational studies cover at best three 11-year solar cycles, it must be challenging to produce a reliable estimation of the 11-year solar cycle signal in stratospheric ozone, especially in the presence of decadal climate variability.
    Full-text Article · May 2015 · Journal of Atmospheric and Solar-Terrestrial Physics
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    [Show abstract] [Hide abstract] ABSTRACT: Traditional validation of atmospheric profiles is based on the intercomparison of two or more data sets in predefined ranges or classes of a given observational characteristic such as latitude or solar zenith angle. In this study we trained a self-organising map (SOM) with a full time series of relative difference profiles of SCIAMACHY limb v5.02 and lidar ozone profiles from seven observation sites. Each individual observation characteristic was then mapped to the obtained SOM to investigate to which degree variation in this characteristic is explanatory for the variation seen in the SOM map. For the studied data sets, altitude-dependent relations for the global data set were found between the difference profiles and studied variables. From the lowest altitude studied (18 km) ascending, the most influencing factors were found to be longitude, followed by solar zenith angle and latitude, sensor age and again solar zenith angle together with the day of the year at the highest altitudes studied here (up to 45 km). After accounting for both latitude and longitude, residual partial correlations with a reduced magnitude are seen for various factors. However, (partial) correlations cannot point out which (combination) of the factors drives the observed differences between the ground-based and satellite ozone profiles as most of the factors are inter-related. Clustering into three classes showed that there are also some local dependencies, with for instance one cluster having a much stronger correlation with the sensor age (days since launch) between 36 and 42 km. The proposed SOM-based approach provides a powerful tool for the exploration of differences between data sets without being limited to a priori defined data subsets.
    Full-text Article · May 2015 · Atmospheric Measurement Techniques
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    Sébastien Bossay · Marion Marchand · Slimane Bekki
    Full-text Article · Mar 2015
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    [Show abstract] [Hide abstract] ABSTRACT: Traditional validation of atmospheric profiles is based on the intercomparison of two or more data sets in predefined ranges or classes of a given observational characteristic such as latitude or solar zenith angle. In this study we trained a self-organising map (SOM) with a full time series of relative difference profiles of SCIAMACHY limb v5.02 and lidar ozone profiles from seven observation sites. Each individual observation characteristic was then mapped to the obtained SOM to investigate to which degree variation in this characteristic is explanatory for the variation seen in the SOM map. For the studied data sets, altitude-dependent relations for the global data set were found between the difference profiles and studied variables. From the lowest altitude studied (18 km) ascending, the most influencing factors were found to be longitude, followed by solar zenith angle and latitude, sensor age and again solar zenith angle together with the day of the year at the highest altitudes studied here (up to 45 km). After accounting for both latitude and longitude, residual partial correlations with a reduced magnitude are seen for various factors. However, (partial) correlations cannot point out which (combination) of the factors drives the observed differences between the ground-based and satellite ozone profiles as most of the factors are inter-related. Clustering into three classes showed that there are also some local dependencies, with for instance one cluster having a much stronger correlation with the sensor age (days since launch) between 36 and 42 km. The proposed SOM-based approach provides a powerful tool for the exploration of differences between data sets without being limited to a priori defined data subsets.
    Full-text Article · Apr 2014
  • [Show abstract] [Hide abstract] ABSTRACT: [1] We have diagnosed the lifetimes of long-lived source gases emitted at the surface and removed in the stratosphere using six three-dimensional chemistry-climate models (CCMs) and a two-dimensional model. The models all used the same standard photochemical data. We investigate the effect of different definitions of lifetimes, including running the models with both mixing ratio (MBC) and flux (FBC) boundary conditions. Within the same model, the lifetimes diagnosed by different methods agree very well. Using FBCs versus MBCs leads to a different tracer burden as the implied lifetime contained in the MBC value does not necessarily match a model's own calculated lifetime. In general, there are much larger differences in the lifetimes calculated by different models, the main causes of which are variations in the modelled rates of ascent and horizontal mixing in the tropical mid-lower stratosphere. The model runs have been used to compute instantaneous and steady-state lifetimes. For chlorofluorocarbons (CFCs) their atmospheric distribution was far from steady state in their growth phase through to the 1980s and the diagnosed instantaneous lifetime is accordingly much longer. Following the cessation of emissions, the resulting decay of CFCs is much closer to steady-state. For 2100 conditions the model circulation speeds generally increase, but a thicker ozone layer due to recovery and climate change reduces photolysis rates. These effects compensate so the net impact on modelled lifetimes is small. For future assessments of stratospheric ozone use of FBCs would allow a consistent balance between rate of CFC removal and model circulation rate.
    Article · Mar 2014
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    Full-text Dataset · Mar 2014
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    [Show abstract] [Hide abstract] ABSTRACT: The international research project RECONCILE has addressed central questions regarding polar ozone depletion, with the objective to quantify some of the most relevant yet still uncertain physical and chemical processes and thereby improve prognostic modelling capabilities to realistically predict the response of the ozone layer to climate change. This overview paper outlines the scope and the general approach of RECONCILE, and it provides a summary of observations and modelling in 2010 and 2011 that have generated an in many respects unprecedented dataset to study processes in the Arctic winter stratosphere. Principally, it summarises important outcomes of RECONCILE including (i) better constraints and enhanced consistency on the set of parameters governing catalytic ozone destruction cycles, (ii) a better understanding of the role of cold binary aerosols in heterogeneous chlorine activation, (iii) an improved scheme of polar stratospheric cloud (PSC) processes that includes heterogeneous nucleation of nitric acid trihydrate (NAT) and ice on non-volatile background aerosol leading to better model parameterisations with respect to denitrification, and (iv) long transient simulations with a chemistry-climate model (CCM) updated based on the results of RECONCILE that better reproduce past ozone trends in Antarctica and are deemed to produce more reliable predictions of future ozone trends. The process studies and the global simulations conducted in RECONCILE show that in the Arctic, ozone depletion uncertainties in the chemical and microphysical processes are now clearly smaller than the sensitivity to dynamic variability.
    Full-text Article · Sep 2013 · ATMOSPHERIC CHEMISTRY AND PHYSICS
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    [Show abstract] [Hide abstract] ABSTRACT: We present a summary of the scientific objectives, payload and mission profile of the Space Weather & Ultraviolet Solar Variability Microsatellite Mission (SWUSV) proposed to CNES and ESA (small mission).
    Full-text Conference Paper · Jun 2013
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    [Show abstract] [Hide abstract] ABSTRACT: We present a statistical analysis of total column ozone records obtained from satellite measurements and from two global climate chemistry models on global scale. Firstly, a spectral weight analysis is performed where the relative strength of semiannual, annual and quasi-biennial oscillations are determined with respect to the integrated power spectra. The comparison reveals some anomalies in the model representations at each spectral component. The tails of the spectra demonstrate that both models underestimate high frequency (daily) ozone variability, which might have a complex origin, since several dynamical processes affect short time changes of the ozone level at a given location. Secondly, detrended fluctuation analysis is exploited to analyze two-point correlations of anomaly time series. Both models reproduce the characteristic geographic dependence of correlation strength over the overlapping area with empirical observations (latitude band between 60 degrees S and 60 degrees N). The values of precise correlation exponents are hard to obtain over regions where quasi-biennial oscillations or other strong nonstationarities (ozone hole) are present. In spite of all the numerical difficulties, significant long range correlations are detected for total ozone over all geographic locations.
    Full-text Article · Jun 2013 · Atmosphere
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    [Show abstract] [Hide abstract] ABSTRACT: We present the ambitions of the SWUSV (Space Weather and Ultraviolet Solar Variability) Microsatellite Mission that encompasses three major scientific objectives: (1) Space Weather including the prediction and detection of major eruptions and coronal mass ejections (Lyman-Alpha and Herzberg continuum imaging); (2) solar forcing on the climate through radiation and their interactions with the local stratosphere (UV spectral irradiance from 180 to 400 nm by bands of 20 nm, plus Lyman-Alpha and the CN bandhead); (3) simultaneous radiative budget of the Earth, UV to IR, with an accuracy better than 1% in differential. The paper briefly outlines the mission and describes the five proposed instruments of the model payload: SUAVE (Solar Ultraviolet Advanced Variability Experiment), an optimized telescope for FUV (Lyman-Alpha) and MUV (200–220 nm Herzberg continuum) imaging (sources of variability); UPR (Ultraviolet Passband Radiometers), with 64 UV filter radiometers; a vector magnetometer; thermal plasma measurements and Langmuir probes; and a total and spectral solar irradiance and Earth radiative budget ensemble (SERB, Solar irradiance & Earth Radiative Budget). SWUSV is proposed as a small mission to CNES and to ESA for a possible flight as early as 2017–2018.
    Full-text Article · May 2013 · Journal of Advanced Research
  • Dataset · May 2013
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    [Show abstract] [Hide abstract] ABSTRACT: We present the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5). This model includes an interactive carbon cycle, a representation of tropospheric and stratospheric chemistry, and a comprehensive representation of aerosols. As it represents the principal dynamical, physical, and bio-geochemical processes relevant to the climate system, it may be referred to as an Earth System Model. However, the IPSL-CM5 model may be used in a multitude of configurations associated with different boundary conditions and with a range of complexities in terms of processes and interactions. This paper presents an overview of the different model components and explains how they were coupled and used to simulate historical climate changes over the past 150 years and different scenarios of future climate change. A single version of the IPSL-CM5 model (IPSL-CM5A-LR) was used to provide climate projections associated with different socio-economic scenarios, including the different Representative Concentration Pathways considered by CMIP5 and several scenarios from the Special Report on Emission Scenarios considered by CMIP3. Results suggest that the magnitude of global warming projections primarily depends on the socio-economic scenario considered, that there is potential for an aggressive mitigation policy to limit global warming to about two degrees, and that the behavior of some components of the climate system such as the Arctic sea ice and the Atlantic Meridional Overturning Circulation may change drastically by the end of the twenty-first century in the case of a no climate policy scenario. Although the magnitude of regional temperature and precipitation changes depends fairly linearly on the magnitude of the projected global warming (and thus on the scenario considered), the geographical pattern of these changes is strikingly similar for the different scenarios. The representation of atmospheric physical processes in the model is shown to strongly influence the simulated climate variability and both the magnitude and pattern of the projected climate changes.
    Full-text Article · Feb 2013 · Climate Dynamics
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    Christine David · Alexander Haefele · Philippe Keckhut · [...] · M. Quatrevalet
    [Show abstract] [Hide abstract] ABSTRACT: We present an evaluation of observations from the Lidar Ozone and Aerosol for NDACC in Antarctica (LOANA) at the Dumont d’Urville station, Antarctica. This instrument is part of the Network for the Detection of Atmospheric Composition Change (NDACC), and ensures continuity with lidar measurements made since 1989 with the previous instrument at this site. This study is based on the dataset from 2008 to 2009, and comparisons are made with observations from balloon soundings, and from three satellite experiments: Aura/MLS, TIMED/SABER, and CALIOP/CALIPSO. The lidar ozone data are in very good agreement with the balloon sounding data (ECC sensor), revealing a bias of less than 3% between 17 and 34 km. For temperature, the lidar shows a low bias of −3 K at 20 km when compared with Aura/MLS. Between 30 and 50 km, the bias is less than 2 K. We also present our initial results showing diurnal variations in temperature. The amplitude of these diurnal cycles is on the order of 1 K and is unlikely to account for the temperature biases between LOANA and the reference instruments. Comparisons of total attenuated backscatter reveal good qualitative agreement between LOANA and CALIOP, with differences of less than 30% in the derived optical depth.
    Full-text Article · Aug 2012 · Polar Science
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    [Show abstract] [Hide abstract] ABSTRACT: Global aerosol and ozone distributions and their associated radiative forcings were simulated between 1850 and 2100 following a recent historical emission dataset and under the Representative Concentration Pathways (RCP) for the future. These simulations were used in an Earth System Model (ESM) to account for the changes in both radiatively and chemically active compounds, when simulating the climate evolution. The past negative stratospheric ozone trends results in a negative climate forcing culminating at 0.15 W.m-2 in the 90's. In the meantime, the tropospheric ozone burden increases generates a positive climate forcing peaking at 0.41 W.m-2. The future Powered by Editorial Manager® and Preprint Manager® from Aries Systems Corporation
    Full-text Article · May 2012 · Climate Dynamics
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    [Show abstract] [Hide abstract] ABSTRACT: The Global Atmosphere Watch of WMO includes several stations in Antarctica that keep a close eye on the ozone layer during the ozone hole season. Observations made during the ozone holes from 2003 to 2011 will be compared to each other and interpreted in light of the meteorological conditions. Satellite observations will be used to get a more general picture of the size and depth of the ozone hole and will also be used to calculate various metrics for ozone hole severity. In 2003, 2005 and 2006, the ozone hole was relatively large with more ozone loss than normal. This is in particular the case for 2006, which by most ozone hole metrics was the most severe ozone hole on record. On the other hand, the ozone holes of 2004, 2007 and 2010 were less severe than normal, and only the very special ozone hole of 2002 had less ozone depletion when one regards the ozone holes of the last decade. The ozone hole of 2011 suffered more ozone depletion than in 2010, but it was quite average in comparison to other years of the last decade. The interannual variability will be discussed with the help of meteorological data, such as temperature conditions, possibility for polar stratospheric clouds, vortex shape and vortex longevity. Observations will also be compared to 3-D chemical transport model calculations.
    Full-text Conference Paper · Apr 2012
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    [Show abstract] [Hide abstract] ABSTRACT: The Global Atmosphere Watch of WMO includes several stations in Antarctica that keep a close eye on the ozone layer during the ozone hole season. Observations made during the ozone holes from 2003 to 2010 will be compared to each other and interpreted in light of the meteorological conditions. Satellite observations will be used to get a more general picture of the size and depth of the ozone hole and will also be used to calculate various metrics for ozone hole severity. In 2003, 2005 and 2006, the ozone hole was relatively large with more ozone loss than normal. This is in particular the case for 2006, which by most ozone hole metrics was the most severe ozone holeon record. On the other hand, the ozone holes of 2004 ,2007 and 2010 were less severe than normal, and only the very special ozone hole of 2002 had less ozone depletion when one regards the ozone holes of the last decade. The interannual variability will be discussed with the help of meteorological data, such as temperature conditions, possibility for polar stratospheric clouds, vortex shape and vortex longevity. Observations will also be compared to 3-D chemical transport model calculations.
    Full-text Conference Paper · Apr 2011

Publication Stats

2k Citations

Institutions

  • 2010-2012
    • Polytech Paris-UPMC
      Lutetia Parisorum, Île-de-France, France
    • UPMC
      Pittsburgh, Pennsylvania, United States
  • 2009-2012
    • Université de Versailles Saint-Quentin
      Versailles, Île-de-France, France
  • 2002-2010
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France
  • 2002-2008
    • Pierre and Marie Curie University - Paris 6
      Lutetia Parisorum, Île-de-France, France
  • 2004
    • Institut Pierre Simon Laplace
      Lutetia Parisorum, Île-de-France, France