Development and Validation of an End-to-End Simulator and Gas Concentration Retrieval Processor Applied to the MERLIN Lidar Mission

International audienceIn the context of MERLIN (MEthane Remote LIdar missioN), a French-German spatial lidar mission dedicated to monitoring the atmospheric methane content, two software programs have been developed: LIDSIM (LIDar SIMulator) and PROLID (PROcessor LIDar). The objectives are to assess whether the instrument design meets the performance requirements and to study the sensitivity of this performance to geophysical parameters. LIDSIM is an end-to-end mission simulator and PROLID is a retrieval processor that provides mole fractions of methane in dry air, averaged over an atmospheric column. These two tools are described in this paper. Results of the validation tests and the first full orbit simulations are reported. Merlin target performance does not seem to be reachable but breakthrough performance is reached

An end-to-end simulator and gas concentration retrieval processor applied to the MERLIN lidar mission to check its performance and study its sensitivity to geophysical parameters

International audienc

An end-to-end simulator and gas concentration retrieval processor applied to the MERLIN lidar mission to check its performance and study its sensitivity to geophysical parameters

International audienc

Characterization of a novel strain from Aspergillus aculeatinus: from rhamnogalacturonan Itype pectin degradation to the application for juice clarification

International audienceIn fruit juice industry, the high concentration of pectins can leads to colloids formation, which caninduce filter clogging during the process (Cameron et al., 2017), with consequent effect on theyields of juice production. Four pectic domains can be described: Homogalacturonan (60%),Xylogalacturonan (XGA), Rhamnogalacturonan II (RGII) and Rhamnogalacturonan I (30%) (Mohnen,2008; Silva et al., 2016). Classical enzymatic cocktails used in industry are composed of pectinmethylesterase and polygalacturonase, both involved in HG degradation. These cocktails arelacking enzymatic activities that can effectively degrade RGI-type pectins (RGI-ases). The aim ofthis study was to assess the potential of one Aspergillus aculeatinus strain, O822, in secreting RGIdegradingenzyme and its application potential for fruit processing industry

Biocides désinfectants en agroalimentaire

National audienc

Humanisme et politique en France à la fin du Moyen Âge

Les quatorze communications réunies ici, auxquelles s’ajoutent les témoignages de ses collègues et amis du CNRS à Villejuif, rendent hommage à l’apport scientifique de Nicole Pons sur le sujet qui a été au centre de toute sa carrière : le premier humanisme français. Elles montrent comment son œuvre peut servir de modèle. La quête exigeante des manuscrits fait sortir de l’ombre des intellectuels liés par l’amitié et ouverts sur les auteurs italiens. Ces hommes, parfois illustres mais souvent anonymes, sont aussi des polémistes, qui ont mené de grands combats. Ils ne se sont pas contentés de vouloir résoudre le Grand Schisme ou de réformer le royaume en proie aux guerres civiles du temps de Charles VI. Ils se sont engagés de toute leur force contre les Anglais, pour rétablir l’Union avec les Grecs, pour asseoir le pouvoir légitime de Charles VII, qu’il s’agisse de sa filiation ou de ses droits… Par un jeu de miroir qui les renvoie aux auteurs antiques et surtout à Cicéron, ils croient à la vertu de leur plume pour dire le Vrai et pour changer le monde. C’est dire la belle continuité de leur mission que les terribles massacres de 1418 n’ont pas interrompue, et que ce colloque sait rendre en décrivant le foisonnement de leur pensée du début du XIVe à la fin du XVe siècle. Un style et une démarche qui n’étaient pas pour déplaire à Nicole Pons

Error Budget of the MEthane Remote LIdar missioN and Its Impact on the Uncertainties of the Global Methane Budget

International audienceMEthane Remote LIdar missioN (MERLIN) is a German‐French space mission, scheduled for launch in 2024 and built around an innovative light detecting and ranging instrument that will retrieve methane atmospheric weighted columns. MERLIN products will be assimilated into chemistry transport models to infer methane emissions and sinks. Here the expected performance of MERLIN to reduce uncertainties on methane emissions is estimated. A first complete error budget of the mission is proposed based on an analysis of the plausible causes of random and systematic errors. Systematic errors are spatially and temporally distributed on geophysical variables and then aggregated into an ensemble of 32 scenarios. Observing System Simulation Experiments are conducted, originally carrying both random and systematic errors. Although relatively small (±2.9 ppb), systematic errors are found to have a larger influence on MERLIN performances than random errors. The expected global mean uncertainty reduction on methane emissions compared to the prior knowledge is found to be 32%, limited by the impact of systematic errors. The uncertainty reduction over land reaches 60% when the largest desert regions are removed. At the latitudinal scale, the largest uncertainty reductions are achieved for temperate regions (84%) and then tropics (56%) and high latitudes (53%). Similar Observing System Simulation Experiments based on error scenarios for Greenhouse Gases Observing SATellite reveal that MERLIN should perform better than Greenhouse Gases Observing SATellite for most continental regions. The integration of error scenarios for MERLIN in another inversion system suggests similar results, albeit more optimistic in terms of uncertainty reduction