Modélisation inverse des émissions du monoxyde de carbone

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Biogenic VOC emissions from forested Amazonian landscapes

A tethered balloon-sampling platform was used to study biogenic volatile organic compounds (BVOCs) in the atmospheric boundary layer in three distinct moist tropical forest ecoregions, as well as an extensive pasture area, in Amazonia. Approximately 24-40 soundings, including as many as four VOC samples collected simultaneously at various altitudes, were made at each site. Concentrations in the mixed layer increased during morning hours and were relatively constant midday through afternoon. Since most important meteorological and chemical parameters were very similar among the sites during the measurement periods, a BVOC canopy emission model was used with a model of the chemistry of the boundary layer to reproduce the atmospheric concentrations observed. The simulations indicated significantly different midday landscape isoprene and a-pinene emission rates for the three forest ecoregions (2200, 5300, 9800 ìgm-2 h-1 isoprene and 90, 120, and 180 ìgm-2 h-1 a-pinene for the three moist forest ecoregions studied, respectively). The differences in emissions among the ecoregions may be attributed to the species composition, which were markedly different and in which the percentage of isoprene and terpene emitting species also differed significantly.Pages: 651-66

Dataset associated with "Temporal variability largely explains difference in top-down and bottom-up estimates of methane emissions from a natural gas production region"

This dataset includes input and output data used in the bottom-up model described in the associated manuscript and accompanying Supplemental Information Appendix. Additionally, the input dataset includes a ReadMe.txt describing it, and each of the output datasets includes a ReadMe.txt and a FileListing.txt describing their contents.This study is the first to spatially and temporally align top-down and bottom-up methane emission estimates for a natural gas production basin, using multi-scale emission measurements and detailed activity data reporting. We show that episodic venting from manual liquid unloadings, which occur at a small fraction of natural gas well pads, drives a factor-of-two temporal variation in the basin-scale emission rate of a US dry shale gas play. The mid-afternoon peak emission rate aligns with the sampling time of all regional aircraft emission studies, which target well-mixed boundary layer conditions present in the afternoon. A mechanistic understanding of emission estimates derived from various methods is critical for unbiased emission verification and effective GHG emission mitigation. Our results demonstrate that direct comparison of emission estimates from methods covering widely different time scales can be misleading

Observations of carbon monoxide and aerosols from the terra satellite: northern hemisphere variability

Measurements from the Terra satellite launched in December of 1999 provide a global record of the recent interannual variability of tropospheric air quality: carbon monoxide (CO) from the Measurement of Pollution in the Troposphere (MOPITT) instrument and aerosol optical depth (AOD) from the Moderate-Resolution Imaging Spectroradiometer (MODIS). This paper compares and contrasts these data sets with a view to understanding the general features of the overall pollutant loading of the Northern Hemisphere (NH). We present a detailed examination of the seasonal and recent interannual variability of the fine mode AOD and CO column, first considering the variation of the global zonal average for both quantities, and then concentrating on several geographical regions with the aim of isolating different emissions. In a zonal sense, the principal NH sources are related to anthropogenic urban and industrial activity. We show that both the CO and the AOD zonal seasonal variations reflect the atmospheric oxidant concentration, which determines the primary sink of CO and the production of sulfate aerosol. As a consequence, the seasonal cycles are several months out of phase, with perturbations resulting from sporadic wildfire or biomass-burning emissions. In these cases, carbonaceous particles dominate the AOD, and this results in the best correlation with the CO column. Of the 4 years of data available from the Terra satellite, the winter and spring of 2002-2003 showed anomalously high NH pollution compared to the previous years. This was a result of fires in western Russia in the late summer and fall of 2002 and intense fires in the southeast of Russia in the spring and summer of 2003. We examine these events using fire counts from MODIS to indicate the burning regions and investigate how the timing of the fires in relation to atmospheric oxidant concentrations affects the resultant seasonal pollutant loadings. Finally, we trace the emissions from these fires to indicate how intense local pollution sources can impact continental-and global-scale air quality

Multi-laboratory compilation of atmospheric carbon monoxide data for the period 1989-2020; obspack_co_1_GLOBALVIEWplus_v2.0_2021-12-08

A full list of all creators for this product can be found at www.esrl.noaa.gov/gmd/ccgg/obspack/providerlist/obspack_co_1_GLOBALVIEWplus_v2.0_2021-12-08.html. This product is constructed using the Observation Package (ObsPack) framework [Masarie et al., 2014; www.earth-syst-sci-data.net/6/375/2014/]. The framework is designed to bring together atmospheric greenhouse gas (GHG) observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. ObsPack products are intended to support GHG budget studies and represent a new generation of cooperative value-added GHG data products. This product includes 249 atmospheric carbon dioxide datasets derived from observations made by 25 laboratories from 10 countries. Data for the period 1989-2020 (where available) are included