Emissions of primary aerosol and precursor gases in the year 2000 and 1750 prescribed data-sets for AeroCom.

Inventories for global aerosol and aerosol precursor emissions have been collected (based on published inventories and published simulations), assessed and prepared for the year 2000 (present-day conditions) and for the year 1750 (pre-industrial conditions). These global datasets establish a comprehensive source for emission input to global modeling, when simulating the aerosol impact on climate with state-of-the-art aerosol component modules. As these modules stratify aerosol into dust, sea-salt, sulfate, organic matter and soot, for all these aerosol types global fields on emission strength and recommendations for injection altitude and particulate size are provided. Temporal resolution varies between daily (dust and sea-salt), monthly (wild-land fires) and annual (all other emissions). These datasets benchmark aerosol emissions according to the knowledge in the year 2004. They are intended to serve as systematic constraints in sensitivity studies of the AeroCom initiative, which seeks to quantify (actual) uncertainties in aerosol global modeling

Intercomparison of air quality models in a megacity: Towards an operational ensemble forecasting system for São Paulo

An intercomparison of four air quality models is performed in the tropical megacity of Sao Paulo with the perspective of developing an air quality forecasting system based on a regional model ensemble. During three contrasting periods marked by different types of pollution events, we analyze the concentrations of the main regulated pollutants (Ozone, CO, SO2, NOx, PM2.5 and PM10) compared to observations of a dense air quality monitoring network. The modeled concentrations of CO, PM and NOx are in good agreement with the observations for the temporal variability and the range of variation. However, the transport of pollutants due to biomass burning pollution events can strongly affect the air quality in the metropolitan area of Sao Paulo with increases of CO, PM2.5 and PM10, and is associated with an important inter-model variability. Our results show that each model has periods and pollutants for which it has the best agreement. The observed day-to-day variability of ozone concentration is well reproduced by the models, as well as the average diurnal cycle in terms of timing. Overall the performance for ozone of the median of the regional model ensemble is the best in terms of time and magnitude because it takes advantage of the capabilities of each model. Therefore, an ensemble prediction of regional models is promising for an operational air quality forecasting system for the megacity of Sao Paulo.This article is a direct contribution to the research themes of the Klimapolis Lab-836 oratory (klimapolis.net), which is funded by the German Federal Ministry of Education837 and Research (BMBF)

Contribution à l'étude de la commande prédictive sous contraintes par approche géométrique

Cette thèse traite de la commande prédictive sous contraintes par une approche géométrique. On s'intéresse à la géométrie des domaines faisables décrits par des ensembles de contraintes linéaires conduisant à des ensembles polyédraux. La dynamique du système à commander intervenant dans la structure des contraintes fait que les domaines faisables sont dépendants vis-à-vis des paramètres du contexte. Cette dépendance se traduit finalement dans la paramétrisation des problèmes d'optimisation qui doivent être résolus à chaque pas d'échantillonnage. La structure des domaines faisables pour la séquence optimale de commande est étudiée par l'intermédiaire du concept de polyèdre paramétré. Le mémoire propose les formulations explicites pour des optimisations quadratiques/linéaires multiparamétriques correspondant aux lois prédictives dans le cas nominal et robuste.L'originalité de l'approche, qui réside dans cette vision géométrique, permet des contributions dans l'analyse des phénomènes de redondance de l'ensemble de contraintes et ensuite dans le partitionnement de l'espace des paramètres en régions correspondant à des sous-ensembles non redondantss localement pouvant être ainsi utilisés lors de l'implémentation en ligne. Ceci peut être vu comme une liaison entre les méthodes exclusivement basées sur des optimisations en ligne et celles basées sur des formulations explicites.En ayant comme base le domaine faisable, des conditions nécessaires et suffisantes de faisabilité de la loi prédictive sont établies et leurs relations avec la stabilité du système bouclée est soulignée par l'intermédiaire de la théorie des ensembles invariants.This thesis is a contribution to the study of the predictive control under constraints essentially using a geometrical approach. The feasible domain resulting from a set of linear constraints is represented by a polyhedron. But, since the dynamics of the system to be controlled intervenes in the structure of the constraints, it results a parameterization of the optimization problem to be solved on line. The structure of the feasible region can then be analyzed through the concept of parameterized polyhedron.This characterization of the feasible domain initially enables to establish necessary and sufficient feasibility conditions for the predictive law, the relationships with the stability of the closed loop system being highlighted using the invariant set theory. Analysing the position of the unconstrained optimum with respect to the polyhedral feasible domain can lead to a partitioning of the parameters space, allowing the construction of an explicit formulation of the predictive law as well in the nominal case as for multiparametric optimizations constructed with robustness improvement purposes. The originality of the approach, related to this geometrical point of view, allows, beside the construction of explicit laws, the analysis of the redundancy phenomenon. It proposes a partition of the parameters space in regions corresponding to subsets of constraints locally nonredundant. All these results lead to off-line design procedures for the predictive laws such that their effective implementation may use techniques spread from on-line optimization to fully explicit piecewise laws evaluated by look-up table positioning mechanisms.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Analysis of Atmospheric Aerosol Optical Properties in the Northeast Brazilian Atmosphere with Remote Sensing Data from MODIS and CALIOP/CALIPSO Satellites, AERONET Photometers and a Ground-Based Lidar

A 12-year analysis, from 2005 to 2016, of atmospheric aerosol optical properties focusing for the first time on Northeast Brazil (NEB) was performed based on four different remote sensing datasets: the Moderate Resolution Imaging Spectroradiometer (MODIS), the Aerosol Robotic Network (AERONET), the Cloud-Aerosol LIDAR with Orthogonal Polarization (CALIOP) and a ground-based Lidar from Natal. We evaluated and identified distinct aerosol types, considering Aerosol Optical Depth (AOD) and Angstrom Exponent (AE). All analyses show that over the NEB, a low aerosol scenario prevails, while there are two distinct seasons of more elevated AOD that occur every year, from August to October and January to March. According to MODIS, AOD values ranges from 0.04 to 0.52 over the region with a mean of 0.20 and occasionally isolated outliers of up to 1.21. Aerosol types were identified as sea spray, biomass burning, and dust aerosols mostly transported from tropical Africa. Three case studies on days with elevated AOD were performed. All cases identified the same aerosol types and modeled HYSPLIT backward trajectories confirmed their source-dependent origins. This analysis is motivated by the implementation of an atmospheric chemistry model with an advanced data assimilation system that will use the observational database over NEB with the model to overcome high uncertainties in the model results induced by still unvalidated emission inventories

Global wildland fire emissions from 1960 to 2000

In many regions of the world, fires are an important and highly variable source of air pollutant emissions, and they thus constitute a significant if not dominant factor controlling the interannual variability of the atmospheric composition. This paper describes the 41-year inventory of vegetation fire emissions constructed for the Reanalysis of the Tropospheric chemical composition over the past 40 years project (RETRO), a global modeling study to investigate the trends and variability of tropospheric ozone and other air pollutants over the past decades. It is the first attempt to construct a global emissions data set with monthly time resolution over such a long period. The inventory is based on a literature review, on estimates from different satellite products, and on a numerical model with a semiphysical approach to simulate fire occurrence and fire spread. Burned areas, carbon consumption, and total carbon release are estimated for 13 continental-scale regions, including explicit treatment of some major burning events such as Indonesia in 1997 and 1998. Global carbon emissions from this inventory range from 1410 to 3140 Tg C/a with the minimum and maximum occurring in 1974 and 1992, respectively (mean of 2078 Tg C/a). Emissions of other species are also reported (mean CO of 330 Tg/a, NOx of 4.6 Tg N/a, CH2O of 3.9 Tg/a, CH4 of 15.4 Tg/a, BC of 2.2 Tg/a, OC of 17.6 Tg/a, SO2 of 2.2 Tg/a). The uncertainties of these estimates remain high even for later years where satellite data products are available. Future versions of this inventory may benefit from ongoing analysis of burned areas from satellite data going back to 1982