Suivi atmosphérique des émissions de CO2 de la région parisienne

2021 ◽  
pp. 030
Author(s):  
Philippe Ciais ◽  
Michel Ramonet ◽  
Thomas Lauvaux ◽  
François-Marie Bréon ◽  
Jinghui Lian ◽  
...  

Les avancées scientifiques permettent un suivi des émissions des villes à partir de mesures des concentrations atmosphériques de CO2 sur un réseau de stations et de méthodes d'inversion fondées sur des modèles de météorologie et de transport atmosphérique à méso-échelle. Nous prenons pour exemple l'agglomération de Paris. Les mesures atmosphériques collectées par un réseau de stations urbaines et périurbaines sont présentées, ainsi que les résultats d'une inversion des émissions et les directions de recherche pour affiner ces estimations. Enfin, la signature du premier confinement lié à la Covid-19 pendant le printemps 2020 sur les mesures atmosphériques de CO2 est présentée et suggère une forte réduction des émissions. Scientific advances enable the monitoring of urban CO2 emissions from in situ measurements of atmospheric CO2 concentrations and atmospheric inversion methods based on mesoscale meteorological models. We use the Paris urban area as an example. Atmospheric measurements collected at a network of urban and suburban stations are presented, as well as the results of an atmospheric inversion of the city emissions, and research directions to refine these estimates. The signature of the Covid-19 lockdown measures in the spring 2020 on the urban atmospheric CO2 signals is presented, indicative of a strong reduction of emissions.

2019 ◽  
Vol 19 (22) ◽  
pp. 13809-13825 ◽  
Author(s):  
Jinghui Lian ◽  
François-Marie Bréon ◽  
Grégoire Broquet ◽  
T. Scott Zaccheo ◽  
Jeremy Dobler ◽  
...  

Abstract. In 2015, the Greenhouse gas Laser Imaging Tomography Experiment (GreenLITE™) measurement system was deployed for a long-duration experiment in the center of Paris, France. The system measures near-surface atmospheric CO2 concentrations integrated along 30 horizontal chords ranging in length from 2.3 to 5.2 km and covering an area of 25 km2 over the complex urban environment. In this study, we use this observing system together with six conventional in situ point measurements and the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and two urban canopy schemes (Urban Canopy Model – UCM; Building Effect Parameterization – BEP) at a horizontal resolution of 1 km to analyze the temporal and spatial variations in CO2 concentrations within the city of Paris and its vicinity for the 1-year period spanning December 2015 to November 2016. Such an analysis aims at supporting the development of CO2 atmospheric inversion systems at the city scale. Results show that both urban canopy schemes in the WRF-Chem model are capable of reproducing the seasonal cycle and most of the synoptic variations in the atmospheric CO2 point measurements over the suburban areas as well as the general corresponding spatial differences in CO2 concentration that span the urban area. However, within the city, there are larger discrepancies between the observations and the model results with very distinct features during winter and summer. During winter, the GreenLITE™ measurements clearly demonstrate that one urban canopy scheme (BEP) provides a much better description of temporal variations and horizontal differences in CO2 concentrations than the other (UCM) does. During summer, much larger CO2 horizontal differences are indicated by the GreenLITE™ system than both the in situ measurements and the model results, with systematic east–west variations.


2019 ◽  
Author(s):  
Jinghui Lian ◽  
François-Marie Bréon ◽  
Grégoire Broquet ◽  
T. Scott Zaccheo ◽  
Jeremy Dobler ◽  
...  

Abstract. In 2015, the Greenhouse gas Laser Imaging Tomography Experiment (GreenLITETM) measurement system was deployed for a long-duration experiment in the center of Paris, France. The system measures near-surface atmospheric CO2 concentrations integrated along 30 horizontal chords ranging in length from 2.3 km to 5.2 km and covering an area of 25 km2 over the complex urban environment. In this study, we use this observing system together with six conventional in-situ point measurements and the WRF-Chem model coupled with two urban canopy schemes (UCM, BEP) at a horizontal resolution of 1 km to analyze the temporal and spatial variations of CO2 concentrations within the Paris city and its vicinity for the 1-year period spanning December 2015 to November 2016. Such an analysis aims at supporting the development of CO2 atmospheric inversion systems at the city scale. Results show that both urban canopy schemes in the WRF-Chem model are capable of reproducing the seasonal cycle and most of the synoptic variations in the atmospheric CO2 point measurements over the suburban areas, as well as the general corresponding spatial differences in CO2 concentration that span the urban area. However, within the city, there are larger discrepancies between the observations and the model results with very distinct features during winter and summer. During winter, the GreenLITETM measurements clearly demonstrate that one urban canopy scheme (BEP) provides a much better description of temporal variations and horizontal differences in CO2 concentrations than the other (UCM) does. During summer, much larger CO2 horizontal differences are indicated by the GreenLITETM system than both the in-situ measurements and the model results, with systematic east-west variations.


Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 86
Author(s):  
Paola Mazzoglio ◽  
Andrea Parodi ◽  
Antonio Parodi

In this work, we describe the integration of Weather and Research Forecasting (WRF) forecasts produced by CIMA Research Foundation within ITHACA Extreme Rainfall Detection System (ERDS) to increase the forecasting skills of the overall early warning system. The entire workflow is applied to the heavy rainfall event that affected the city of Palermo on 15 July 2020, causing urban flooding due to an exceptional rainfall amount of more than 130 mm recorded in about 2.5 h. This rainfall event was not properly forecasted by meteorological models operational at the time of the event, thus not allowing to issue an adequate alert over that area. The results highlight that the improvement in the quantitative precipitation scenario forecast skills, supported by the adoption of the H2020 LEXIS computing facilities and by the assimilation of in situ observations, allowed the ERDS system to improve the prediction of the peak rainfall depths, thus paving the way to the potential issuing of an alert over the Palermo area.


2011 ◽  
Vol 8 (5) ◽  
pp. 9235-9281 ◽  
Author(s):  
K. M. Hart ◽  
B. W. Moran ◽  
C. C. R. Allen ◽  
V. Kouloumbos ◽  
S. F. Oppenheimer ◽  
...  

Abstract. Sequestration of CO2 via biological sinks is a matter of great scientific importance due to their potential to lower atmospheric CO2 levels. In this study a custom built incubation chamber was used to cultivate a soil microbial community, under ideal conditions, to investigate soil chemoautotrophy. The internal atmospheric CO2 concentrations were monitored and used to estimate the mass of CO2 uptake. It was found after careful background corrections that 256.4 μg CO2 kg−1 dry soil was removed from the chamber atmosphere over 16 h. Comparisons were made to photosynthetic controls (i.e. grass and soil algae) whereupon it was observed that the chemoautotrophic fraction sequestered 2.6 and 5.4 % of that taken up by grass and soil algae respectively. Using isotopically labelled 13CO2 and GCMS-IRMS it was also possible to extract and identify labelled fatty acids after a short incubation time, hence confirming the CO2 uptake potential of the soil slurry. Provided with favourable conditions, chemoautotrophic soil bacteria have the potential to make a significant impact on inorganic carbon sequestration within the environment. The results of this in vivo study have provided ground work for future studies intending to mimic the in situ environment by providing a reliable method for investigating CO2 uptake by soil microorganisms.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 384
Author(s):  
Yaroslav Bezyk ◽  
Izabela Sówka ◽  
Maciej Górka ◽  
Jan Blachowski

Understanding the magnitude and distribution of the mixes of the near-ground carbon dioxide (CO2) components spatially (related to the surface characteristics) and temporally (over seasonal timescales) is critical to evaluating present and future climate impacts. Thus, the application of in situ measurement approaches, combined with the spatial interpolation methods, will help to explore variations in source contribution to the total CO2 mixing ratios in the urban atmosphere. This study presents the spatial characteristic and temporal trend of atmospheric CO2 levels observed within the city of Wroclaw, Poland for the July 2017–August 2018 period. The seasonal variability of atmospheric CO2 around the city was directly measured at the selected sites using flask sampling with a Picarro G2201-I Cavity Ring-Down Spectroscopy (CRDS) technique. The current work aimed at determining the accuracy of the interpolation techniques and adjusting the interpolation parameters for estimating the magnitude of CO2 time series/seasonal variability in terms of limited observations during the vegetation and non-vegetation periods. The objective was to evaluate how different interpolation methods will affect the assessment of air pollutant levels in the urban environment and identify the optimal sampling strategy. The study discusses the schemes for optimization of the interpolation results that may be adopted in areas where no observations are available, which is based on the kriging error predictions for an appropriate spatial density of measurement locations. Finally, the interpolation results were extended regarding the average prediction bias by exploring additional experimental configurations and introducing the limitation of the future sampling strategy on the seasonal representation of the CO2 levels in the urban area.


2014 ◽  
Vol 70 (11) ◽  
pp. 1825-1837 ◽  
Author(s):  
K. De Vleeschauwer ◽  
J. Weustenraad ◽  
C. Nolf ◽  
V. Wolfs ◽  
B. De Meulder ◽  
...  

Urbanization and climate change trends put strong pressures on urban water systems. Temporal variations in rainfall, runoff and water availability increase, and need to be compensated for by innovative adaptation strategies. One of these is stormwater retention and infiltration in open and/or green spaces in the city (blue–green water integration). This study evaluated the efficiency of three adaptation strategies for the city of Turnhout in Belgium, namely source control as a result of blue–green water integration, retention basins located downstream of the stormwater sewers, and end-of-pipe solutions based on river flood control reservoirs. The efficiency of these options is quantified by the reduction in sewer and river flood frequencies and volumes, and sewer overflow volumes. This is done by means of long-term simulations (100-year rainfall simulations) using an integrated conceptual sewer–river model calibrated to full hydrodynamic sewer and river models. Results show that combining open, green zones in the city with stormwater retention and infiltration for only 1% of the total city runoff area would lead to a 30 to 50% reduction in sewer flood volumes for return periods in the range 10–100 years. This is due to the additional surface storage and infiltration and consequent reduction in urban runoff. However, the impact of this source control option on downstream river floods is limited. Stormwater retention downstream of the sewer system gives a strong reduction in peak discharges to the receiving river. However due to the difference in response time between the sewer and river systems, this does not lead to a strong reduction in river flood frequency. The paper shows the importance of improving the interface between urban design and water management, and between sewer and river flood management.


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