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Carbon dioxide (CO2) and methane (CH4) are the two main greenhouse gases (GHG)emitted by human activities. To better understand their concentration and vertical distributionin several key regions and to prepare future space missions dedicated to GHG, the MAGICinitiative has been put in place. MAGIC stands for: Monitoring of Atmospheric compositionand Greenhouse gases through multi-Instruments Campaigns. Gathering about 40 scientistsall together, the campaigns have two main goals: (i) to better understand the vertical exchangeof GHG along the atmospheric column, in connection with atmospheric transport, sourcesand sinks of the gases at the surface and in the atmosphere; (ii) to contribute to thepreparation and validation of space missions dedicated to the monitoring of greenhousegases. To address these objectives, various instruments are deployed on various platforms:aircraft, balloons, ground. They perform simultaneous observations of GHG concentration:direct in-situ observations at the surface or along the vertical, total and partial weightedcolumns. The MAGIC campaigns rely on SAFIRE Falcon20 measurements of gasconcentrations, temperature/humidity/wind/particles and GHG (CO2/CH4/CO/H2O)between 0 and 11 km altitude. The Falcon20 allows flying under any satellite tracksand making 0-11 km profiles at specific locations, such as ICOS/TCCON sites.They are complemented by balloon-borne instruments making 0-30 km profileswith AirCore atmospheric samplers and Amulse light laser-diode spectrometerslaunched at Aire-sur-l’Adour and Trainou, as well as by measurements of total columnswith portable Fourier Transform Spectrometers from the ground (EM27sun andCHRIS). The 2 first MAGIC campaigns have been organized in January and May 2018, the latter inthe framework of the CoMet (Carbon dioxide and Methane) campaign lead by DLR. Inparticular, on May 24th, a coordinated flight between SAFIRE/Falcon20 and DLR/HALO hasbeen performed to compare the column of CH4 measured by the lidar CHARM-F on boardHALO to the column computed from simultaneous Falcon20 and AirCore profiles.Altogether, 2 research aircrafts, 23 launches of meteorological balloons, four ICOSinstrumented sites and a dozen instruments for measuring the concentration of gases havebeen deployed for the 2018 campaign. This talk will present the results obtained during the MAGIC2018 campaign and highlightthe strong benefit of having simultaneous measurements by aircraft, balloons andground-based FTS to validate space missions. Plans for next MAGIC campaigns that will beorganized in July 2019 in France and in summer 2020 tentatively in Sweden will begiven. [ABSTRACT FROM AUTHOR]

A better understanding of greenhouse gas surface sources and sinks is required in order to adress the global challenge of climate change. Spaceborne remote estimations of their atmospheric concentration can offer the global coverage that is necessary to improve the constraints on those fluxes, thus enabling a better monitoring of anthropogenic emissions. Consequently, striving for this goal, several satellite missions have been designed during the past decade, and the TCCON ground-based network provides an essential validation resource for their estimations. Most of these results are obtained thanks to Bayesian optimal estimation, an inverse method that is well-know for its sensitivity to the a priori choice. This work proposes to quantify the influence of a priori CO2 concentration profile covariance choice in term of total column retrieval bias. Several a priori covariance matrices will be compared and used in a Bayesian optimal estimation inversion scheme based on 4A/OP radiative transfer model and GEISA spectroscopic database, evaluated thanks to calc-obs spectral residuals computed for hundreds of observations for which atmospheric situations are known. The matrices will be taken from regular TCCON a priori profile databases, CAMS analyses or derived from a profile climatology of profiles measured by balloon-borne AirCores. The performance of the retrieval procedure will then be assessed against atmospheric profiles of CO2 acquired at several stations as well as during the 2018 Monitoring of Atmospheric composition and Greenhouse gases through multi-Instruments Campaign (MAGIC). [ABSTRACT FROM AUTHOR]

In the context of rising concerns about climate changes, the monitoring of essential climate variables from space is of great interest. One of the fundamental drivers of our climate system is the balance between the net incoming solar radiation and the outgoing radiation from the Earth and its atmosphere. For the past decades, several spaceborne missions aimed at measuring the outgoing radiation of the Earth system. Since the years 2000s, hyperspectral sounders allowed the retrieval of vertically resolved atmospheric parameters. The objective of the poster is to present the first results of the exploitation of a hyperspectral sounder to retrieve the outgoing longwave radiation and the vertical longwave cooling rate. The hyperspectral sounder IASI, first launched on the platform MetOp-A in October 2006, then on MetOp-B in September 2012 and recently on MetOp-C in Novembers 2018 offers 20 years of measurement of the Earth's outgoing longwave radiation, its spectral range covers a large portion of the longwave spectrum. IASI provides essential data to retrieve the vertical atmospheric parameters such as temperature profiles or concentration of main constituents and to study their variability on climatic timescales. Using the radiative transfer code 4A and the spectroscopic database GEISA, the OLR and the vertical sources and sinks of radiative energy can be retrieved from IASI data. In the context of the Radiative Forcing Model Intercomparison Project, the first OLR and vertical longwave cooling retrieval are presented in comparison with other datasets. [ABSTRACT FROM AUTHOR]