scholarly journals Accounting for the vertical distribution of emissions in atmospheric CO<sub>2</sub> simulations

2019 ◽  
Vol 19 (7) ◽  
pp. 4541-4559 ◽  
Author(s):  
Dominik Brunner ◽  
Gerrit Kuhlmann ◽  
Julia Marshall ◽  
Valentin Clément ◽  
Oliver Fuhrer ◽  
...  
Keyword(s):  
Power Plants ◽  
Atmospheric Transport ◽  
Traditional Approach ◽  
Vertical Mixing ◽  
Point Sources ◽  
Small Scale ◽  
Near Surface ◽  
Industrial Facilities ◽  
Scale Modeling ◽  
The Impact

Abstract. Inverse modeling of anthropogenic and biospheric CO2 fluxes from ground-based and satellite observations critically depends on the accuracy of atmospheric transport simulations. Previous studies emphasized the impact of errors in simulated winds and vertical mixing in the planetary boundary layer, whereas the potential importance of releasing emissions not only at the surface but distributing them in the vertical was largely neglected. Accounting for elevated emissions may be critical, since more than 50 % of CO2 in Europe is emitted by large point sources such as power plants and industrial facilities. In this study, we conduct high-resolution atmospheric simulations of CO2 with the mesoscale Consortium for Small-scale Modeling model extended with a module for the simulation of greenhouse gases (COSMO-GHG) over a domain covering the city of Berlin and several coal-fired power plants in eastern Germany, Poland and Czech Republic. By including separate tracers for anthropogenic CO2 emitted only at the surface or according to realistic, source-dependent profiles, we find that releasing CO2 only at the surface overestimates near-surface CO2 concentrations in the afternoon on average by 14 % in summer and 43 % in winter over the selected model domain. Differences in column-averaged dry air mole XCO2 fractions are smaller, between 5 % in winter and 8 % in summer, suggesting smaller yet non-negligible sensitivities for inversion modeling studies assimilating satellite rather than surface observations. The results suggest that the traditional approach of emitting CO2 only at the surface is problematic and that a proper allocation of emissions in the vertical deserves as much attention as an accurate simulation of atmospheric transport.

scholarly journals Accounting for the vertical distribution of emissions in atmospheric CO<sub>2</sub> simulations

2018 ◽  
Author(s):  
Dominik Brunner ◽  
Gerrit Kuhlmann ◽  
Julia Marshall ◽  
Valentin Clément ◽  
Oliver Fuhrer ◽  
...  
Keyword(s):  
Power Plants ◽  
Mesoscale Model ◽  
Atmospheric Transport ◽  
Traditional Approach ◽  
Vertical Mixing ◽  
Point Sources ◽  
Near Surface ◽  
Industrial Facilities ◽  
The Impact ◽  
The Vertical Distribution

Abstract. Inverse modeling of anthropogenic and biospheric CO2 fluxes from ground-based and satellite observations critically depends on the accuracy of atmospheric transport simulations. Previous studies emphasized the impact of errors in simulated winds and vertical mixing in the planetary boundary layer, whereas the potential importance of releasing emissions not only at the surface but distributing them in the vertical was largely neglected. Accounting for elevated emissions may be critical, since more than 50 % of CO2 in Europe is emitted by large point sources such as power plants and industrial facilities. In this study we conduct high-resolution atmospheric simulations of CO2 with the mesoscale model COSMO-GHG over a domain covering the city of Berlin and several coal-fired power plants in eastern Germany, Poland and the Czech Republic. By including separate tracers for anthropogenic CO2 emitted only at the surface or according to realistic, source-dependent profiles, we find that releasing CO2 only at the surface overestimates near-surface CO2 concentrations in the afternoon on average by 14 % in summer and 43 % in winter over the selected model domain. Differences in column mean dry air mole fractions XCO2 are smaller, between 5 % in winter and 8 % in summer, suggesting smaller yet non-negligible sensitivities for inversion modeling studies assimilating satellite rather than surface observations. The results suggests that the traditional approach of emitting CO2 only at the surface is problematic and that a proper allocation of emissions in the vertical deserves as much attention as an accurate simulation of atmospheric transport.

scholarly journals Regional pollution potentials of megacities and other major population centers

2007 ◽  
Vol 7 (14) ◽  
pp. 3969-3987 ◽  
Author(s):  
M. G. Lawrence ◽  
T. M. Butler ◽  
J. Steinkamp ◽  
B. R. Gurjar ◽  
J. Lelieveld
Keyword(s):  
Long Range ◽  
Atmospheric Chemistry ◽  
Atmospheric Transport ◽  
Deep Convection ◽  
Vertical Mixing ◽  
Geographical Location ◽  
Point Sources ◽  
High Latitudes ◽  
Near Surface ◽  
Regional Pollution

Abstract. Megacities and other major population centers represent large, concentrated sources of anthropogenic pollutants to the atmosphere, with consequences for both local air quality and for regional and global atmospheric chemistry. The tradeoffs between the regional buildup of pollutants near their sources versus long-range export depend on meteorological characteristics which vary as a function of geographical location and season. Both horizontal and vertical transport contribute to pollutant export, and the overall degree of export is strongly governed by the lifetimes of pollutants. We provide a first quantification of these tradeoffs and the main factors influencing them in terms of "regional pollution potentials", metrics based on simulations of representative tracers using the 3-D global model MATCH (Model of Atmospheric Transport and Chemistry). The tracers have three different lifetimes (1, 10, and 100 days) and are emitted from 36 continental large point sources. Several key features of the export characteristics emerge. For instance, long-range near-surface pollutant export is generally strongest in the middle and high latitudes, especially for source locations in Eurasia, for which 17–34% of a tracer with a 10-day lifetime is exported beyond 1000 km and still remains below 1 km altitude. On the other hand, pollutant export to the upper troposphere is greatest in the tropics, due to transport by deep convection, and for six source locations, more than 50% of the total mass of the 10-day lifetime tracer is found above 5 km altitude. Furthermore, not only are there order of magnitude interregional differences, such as between low and high latitudes, but also often substantial intraregional differences, which we discuss in light of the regional meteorological characteristics. We also contrast the roles of horizontal dilution and vertical mixing in reducing the pollution buildup in the regions including and surrounding the sources. For some regions such as Eurasia, dilution due to long-range horizontal transport governs the local and regional pollution buildup; however, on a global basis, differences in vertical mixing are dominant in determining the pollution buildup both around and further downwind of the source locations.

Impact of model resolution and transport uncertainties on the representation of CO2 emission plumes by global and regional atmospheric transport models

2020 ◽  
Author(s):  
Dominik Brunner ◽  
Jean-Matthieu Haussaire ◽  
Julia Marshall ◽  
Arjo Segers ◽  
Hugo Denier van der Gon ◽  
...  
Keyword(s):  
High Resolution ◽  
Power Plants ◽  
Atmospheric Transport ◽  
Vertical Mixing ◽  
Temporal Variations ◽  
Paris Agreement ◽  
Transport Models ◽  
Transport Modelling ◽  
Near Surface ◽  
Total Column

&lt;p&gt;Emissions of carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) will have to be drastically reduced in the coming decades to reach the goal of the Paris Agreement to limit the global temperature increase to no more than 2&amp;#176;C. To support this process, Europe is planning to establish a CO&lt;sub&gt;2&lt;/sub&gt; anthropogenic emission monitoring system, which will assist countries, cities and facility operators in monitoring their emissions and evaluating the progress towards their reduction targets. The system will combine measurements from ground-based networks with observations from a new constellation of CO&lt;sub&gt;2&lt;/sub&gt; satellites, which will provide high-resolution images of total column CO&lt;sub&gt;2&lt;/sub&gt; allowing tracking the plumes of large emission sources. A suite of atmospheric transport modelling systems will assimilate these observations and inversely estimate emissions from the continental to the country scale and down to the scale of individual cities and power plants.&lt;/p&gt;&lt;p&gt;In the European project &quot;CO&lt;sub&gt;2&lt;/sub&gt; Human Emissions&quot; (CHE), the components of such a modelling framework are explored, which includes the generation of a library of realistic atmospheric CO&lt;sub&gt;2&lt;/sub&gt; simulations. These &quot;nature runs&quot; are obtained by running global and regional atmospheric transport models at the highest possible resolution affordable today and using state-of-the-art inputs of anthropogenic emissions and natural CO&lt;sub&gt;2&lt;/sub&gt; fluxes. The library includes global simulations at 9 km x 9 km resolution with the CAMS-IFS model, European simulations at 5 km x 5 km resolution with WRF-GHG, COSMO-GHG and LOTOS-EUROS, and high-resolution simulations at 1 km x 1 km over the city of Berlin and several power plants with COSMO-GHG and LOTOS-EUROS.&lt;/p&gt;&lt;p&gt;Here we analyse and compare the model simulations to address the following questions: How realistically are atmospheric gradients in CO&lt;sub&gt;2&lt;/sub&gt; caused by spatial and temporal variations in biospheric and anthropogenic fluxes and by atmospheric dynamics represented at the different model resolutions? What resolution is required to resolve the plumes of individual cities and power plants? How large are the differences in near surface and total column CO&lt;sub&gt;2&lt;/sub&gt; due to uncertainties in atmospheric transport including uncertainties in vertical mixing? Information on transport uncertainties is derived from an ensemble of CAMS-IFS simulations and from the spread between the individual models.&lt;/p&gt;&lt;p&gt;Answering these questions is critical for the design of a future operational capacity to monitor anthropogenic CO&lt;sub&gt;2&lt;/sub&gt; emissions, which should optimally support decision makers at facility, city, and country scale as well as the global stocktake process of the Paris Agreement.&lt;/p&gt;

scholarly journals Detectability of CO<sub>2</sub> emission plumes of cities and power plants with the Copernicus Anthropogenic CO<sub>2</sub> Monitoring (CO2M) mission

2019 ◽  
Vol 12 (12) ◽  
pp. 6695-6719 ◽  
Author(s):  
Gerrit Kuhlmann ◽  
Grégoire Broquet ◽  
Julia Marshall ◽  
Valentin Clément ◽  
Armin Löscher ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Power Plants ◽  
Atmospheric Transport ◽  
Detection Algorithm ◽  
Daily Basis ◽  
Horizontal Resolution ◽  
Low Noise ◽  
Point Sources ◽  
Added Value ◽  
Small Scale

Abstract. High-resolution atmospheric transport simulations were used to investigate the potential for detecting carbon dioxide (CO2) plumes of the city of Berlin and neighboring power stations with the Copernicus Anthropogenic Carbon Dioxide Monitoring (CO2M) mission, which is a proposed constellation of CO2 satellites with imaging capabilities. The potential for detecting plumes was studied for satellite images of CO2 alone or in combination with images of nitrogen dioxide (NO2) and carbon monoxide (CO) to investigate the added value of measurements of other gases coemitted with CO2 that have better signal-to-noise ratios. The additional NO2 and CO images were either generated for instruments on the same CO2M satellites (2 km× 2 km resolution) or for the Sentinel-5 instrument (7.5 km× 7.5 km) assumed to fly 2 h earlier than CO2M. Realistic CO2, CO and NOX(=NO+NO2) fields were simulated at 1 km× 1 km horizontal resolution with the Consortium for Small-scale Modeling model extended with a module for the simulation of greenhouse gases (COSMO-GHG) for the year 2015, and they were used as input for an orbit simulator to generate synthetic observations of columns of CO2, CO and NO2 for constellations of up to six satellites. A simple plume detection algorithm was applied to detect coherent structures in the images of CO2, NO2 or CO against instrument noise and variability in background levels. Although six satellites with an assumed swath of 250 km were sufficient to overpass Berlin on a daily basis, only about 50 out of 365 plumes per year could be observed in conditions suitable for emission estimation due to frequent cloud cover. With the CO2 instrument only 6 and 16 of these 50 plumes could be detected assuming a high-noise (σVEG50=1.0 ppm) and low-noise (σVEG50=0.5 ppm) scenario, respectively, because the CO2 signals were often too weak. A CO instrument with specifications similar to the Sentinel-5 mission performed worse than the CO2 instrument, while the number of detectable plumes could be significantly increased to about 35 plumes with an NO2 instrument. CO2 and NO2 plumes were found to overlap to a large extent, although NOX had a limited lifetime (assumed to be 4 h) and although CO2 and NOX were emitted with different NOX:CO2 emission ratios by different source types with different temporal and vertical emission profiles. Using NO2 observations from the Sentinel-5 platform instead resulted in a significant spatial mismatch between NO2 and CO2 plumes due to the 2 h time difference between Sentinel-5 and CO2M. The plumes of the coal-fired power plant Jänschwalde were easier to detect with the CO2 instrument (about 40–45 plumes per year), but, again, an NO2 instrument could detect significantly more plumes (about 70). Auxiliary measurements of NO2 were thus found to greatly enhance the capability of detecting the location of CO2 plumes, which will be invaluable for the quantification of CO2 emissions from large point sources.

scholarly journals Joint inverse estimation of fossil fuel and biogenic CO2 fluxes in an urban environment: An observing system simulation experiment to assess the impact of multiple uncertainties

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Kai Wu ◽  
Thomas Lauvaux ◽  
Kenneth J. Davis ◽  
Aijun Deng ◽  
Israel Lopez Coto ◽  
...  
Keyword(s):  
High Resolution ◽  
Urban Environment ◽  
Co2 Emissions ◽  
Fossil Fuel ◽  
Atmospheric Transport ◽  
System Simulation ◽  
Co2 Flux ◽  
Point Sources ◽  
Co2 Fluxes ◽  
The Impact

The Indianapolis Flux Experiment aims to utilize a variety of atmospheric measurements and a high-resolution inversion system to estimate the temporal and spatial variation of anthropogenic greenhouse gas emissions from an urban environment. We present a Bayesian inversion system solving for fossil fuel and biogenic CO2 fluxes over the city of Indianapolis, IN. Both components were described at 1 km resolution to represent point sources and fine-scale structures such as highways in the a priori fluxes. With a series of Observing System Simulation Experiments, we evaluate the sensitivity of inverse flux estimates to various measurement deployment strategies and errors. We also test the impacts of flux error structures, biogenic CO2 fluxes and atmospheric transport errors on estimating fossil fuel CO2 emissions and their uncertainties. The results indicate that high-accuracy and high-precision measurements produce significant improvement in fossil fuel CO2 flux estimates. Systematic measurement errors of 1 ppm produce significantly biased inverse solutions, degrading the accuracy of retrieved emissions by about 1 µmol m–2 s–1 compared to the spatially averaged anthropogenic CO2 emissions of 5 µmol m–2 s–1. The presence of biogenic CO2 fluxes (similar magnitude to the anthropogenic fluxes) limits our ability to correct for random and systematic emission errors. However, assimilating continuous fossil fuel CO2 measurements with 1 ppm random error in addition to total CO2 measurements can partially compensate for the interference from biogenic CO2 fluxes. Moreover, systematic and random flux errors can be further reduced by reducing model-data mismatch errors caused by atmospheric transport uncertainty. Finally, the precision of the inverse flux estimate is highly sensitive to the correlation length scale in the prior emission errors. This work suggests that improved fossil fuel CO2 measurement technology, and better understanding of both prior flux and atmospheric transport errors are essential to improve the accuracy and precision of high-resolution urban CO2 flux estimates.

scholarly journals The Impact of Tides on the Bay of Biscay Dynamics

2020 ◽  
Vol 8 (8) ◽  
pp. 617
Author(s):  
John Karagiorgos ◽  
Vassilios Vervatis ◽  
Sarantis Sofianos
Keyword(s):  
Vertical Mixing ◽  
Ocean Model ◽  
Open Ocean ◽  
Small Scale ◽  
Bay Of Biscay ◽  
English Channel ◽  
Tidal Forcing ◽  
Freshwater Transport ◽  
One Year ◽  
The Impact

The impact of tides on the Bay of Biscay dynamics is investigated by means of an ocean model twin-experiment, consisted of two simulations with and without tidal forcing. The study is based on a high-resolution (1/36∘) regional configuration of NEMO (Nucleus for European Modelling of the Ocean) performing one-year simulations. The results highlight the imprint of tides on the thermohaline properties and circulation patterns in three distinct dynamical areas in the model domain: the abyssal plain, the Armorican shelf and the English Channel. When tides are activated, the bottom stress is increased in the shelf areas by about two orders of magnitude with respect to the open ocean, subsequently enhancing vertical mixing and weakening stratification in the bottom boundary layer. The most prominent feature reproduced only when tides are modelled, is the Ushant front near the entrance of the English Channel. Tides appear also to constrain the freshwater transport of rivers from the continental shelf to the open ocean. The spectral analysis revealed that the tidal forcing contributes to the SSH variance at high frequencies near the semidiurnal band and to the open ocean mesoscale and small-scale features in the presence of summer stratification pattern.

scholarly journals The constraint of CO<sub>2</sub> measurements made onboard passenger aircraft on surface-atmosphere fluxes: the impact of transport model errors in vertical mixing

2016 ◽  
Author(s):  
Shreeya Verma ◽  
Julia Marshall ◽  
Christoph Gerbig ◽  
Christian Roedenbeck ◽  
Kai Uwe Totsche
Keyword(s):  
Transport Model ◽  
Atmospheric Transport ◽  
Vertical Mixing ◽  
Synthetic Data ◽  
Vertical Profiles ◽  
Model Errors ◽  
Transport Models ◽  
Boundary Layer Height ◽  
Temporal Sampling ◽  
The Impact

Abstract. Inaccurate representation of atmospheric processes by transport models is a dominant source of uncertainty in inverse analyses and can lead to large discrepancies in the retrieved flux estimates. We investigate the impact of uncertainties in vertical transport as simulated by atmospheric transport models on fluxes retrieved using vertical profiles from aircraft as an observational constraint. Our numerical experiments are based on synthetic data with realistic spatial and temporal sampling of aircraft measurements. The impact of such uncertainties on the flux retrieved using the ground-based network with those retrieved using the aircraft profiles are compared. We find that the posterior flux retrieved using aircraft profiles is less susceptible to errors in boundary layer height as compared to the ground- based network. This highlights the benefit of utilizing atmospheric observations made onboard aircraft over surface measurements for flux estimation using inverse methods. We further use synthetic vertical profiles of CO2 in an inversion to estimate the potential of these measurements, which will be made available through the IAGOS (In-Service Aircraft for a Global Observing System) project in future, in constraining the regional carbon budget. Our results show that the regions tropical Africa and temperate Eurasia, that are under constrained by the existing surface based network, will benefit the most from these measurements, the reduction of posterior flux uncertainty being about 7 to 10 %.

scholarly journals Sensitivity of simulated CO<sub>2</sub> concentration to sub-annual variations in fossil fuel CO<sub>2</sub> emissions

2016 ◽  
Vol 16 (4) ◽  
pp. 1907-1918 ◽  
Author(s):  
Xia Zhang ◽  
Kevin R. Gurney ◽  
Peter Rayner ◽  
David Baker ◽  
Yu-ping Liu
Keyword(s):  
Fossil Fuel ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Vertical Mixing ◽  
Grid Cell ◽  
Co2 Concentration ◽  
Tracer Transport ◽  
Annual Variations ◽  
Atmospheric Co2 Concentrations ◽  
The Impact

Abstract. Recent advances in fossil fuel CO2 (FFCO2) emission inventories enable sensitivity tests of simulated atmospheric CO2 concentrations to sub-annual variations in FFCO2 emissions and what this implies for the interpretation of observed CO2. Six experiments are conducted to investigate the potential impact of three cycles of FFCO2 emission variability (diurnal, weekly and monthly) using a global tracer transport model. Results show an annual FFCO2 rectification varying from −1.35 to +0.13 ppm from the combination of all three cycles. This rectification is driven by a large negative diurnal FFCO2 rectification due to the covariation of diurnal FFCO2 emissions and diurnal vertical mixing, as well as a smaller positive seasonal FFCO2 rectification driven by the covariation of monthly FFCO2 emissions and monthly atmospheric transport. The diurnal FFCO2 emissions are responsible for a diurnal FFCO2 concentration amplitude of up to 9.12 ppm at the grid cell scale. Similarly, the monthly FFCO2 emissions are responsible for a simulated seasonal CO2 amplitude of up to 6.11 ppm at the grid cell scale. The impact of the diurnal FFCO2 emissions, when only sampled in the local afternoon, is also important, causing an increase of +1.13 ppmv at the grid cell scale. The simulated CO2 concentration impacts from the diurnally and seasonally varying FFCO2 emissions are centered over large source regions in the Northern Hemisphere, extending to downwind regions. This study demonstrates the influence of sub-annual variations in FFCO2 emissions on simulated CO2 concentration and suggests that inversion studies must take account of these variations in the affected regions.

scholarly journals Springtime nitrogen oxides and tropospheric ozone in Svalbard: results from the measurement station network

2021 ◽  
Author(s):  
Alena Dekhtyareva ◽  
Mark Hermanson ◽  
Anna Nikulina ◽  
Ove Hermansen ◽  
Tove Svendby ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Long Range ◽  
Wind Direction ◽  
Tropospheric Ozone ◽  
Power Plants ◽  
Large Scale ◽  
Atmospheric Transport ◽  
Atmospheric Stability ◽  
Highly Correlated ◽  
The Impact

Abstract. Svalbard is a remote and scarcely populated Arctic archipelago, and is considered to be mostly influenced by the long-range transported air pollution. However, there are also local emission sources such as coal and diesel power plants, snowmobiles and ships, but their influence on the background concentrations of trace gases have not been thoroughly assessed. This study is based on tropospheric ozone (O3) and nitrogen oxides (NOx) data collected in three main Svalbard settlements in spring 2017. In addition to these ground-based observations, radiosonde and O3 sondes soundings, ERA5 reanalysis and BrO satellite data have been applied in order to distinguish the impact of local and synoptic-scale conditions on the NOx and O3 chemistry. The measurement campaign was divided into several sub-periods based on the prevailing large-scale weather regimes.The local wind direction at the stations depended on the large-scale conditions, but was modified due to complex topography. The NOx concentration showed weak correlation for the different stations and depended strongly on the wind direction and atmospheric stability. On the contrary, the O3 concentration was highly correlated among the different measurement sites and was controlled by the long-range atmospheric transport to Svalbard. Lagrangian backward trajectories have been used to examine the origin and path of the air masses during the campaign.

scholarly journals Unmanned aerial vehicles reveal the impact of a total solar eclipse on the atmospheric surface layer

2019 ◽  
Vol 475 (2229) ◽  
pp. 20190212 ◽  
Author(s):  
Sean C. C. Bailey ◽  
Caleb A. Canter ◽  
Michael P. Sama ◽  
Adam L. Houston ◽  
Suzanne Weaver Smith
Keyword(s):  
Surface Layer ◽  
Unmanned Aerial Vehicles ◽  
Solar Eclipse ◽  
Atmospheric Surface Layer ◽  
Small Scale ◽  
Stable Layer ◽  
Holistic View ◽  
Near Surface ◽  
Aerial Vehicles ◽  
The Impact

We use unmanned aerial vehicles to interrogate the surface layer processes during a solar eclipse and gain a comprehensive look at the changes made to the atmospheric surface layer as a result of the rapid change of insolation. Measurements of the atmospheric surface layer structure made by the unmanned systems are connected to surface measurements to provide a holistic view of the impact of the eclipse on the near-surface behaviour, large-scale turbulent structures and small-scale turbulent dynamics. Different regimes of atmospheric surface layer behaviour were identified, with the most significant impact including the formation of a stable layer just after totality and evidence of Kelvin–Helmholtz waves appearing at the interface between this layer and the residual layer forming above it. The decrease in surface heating caused a commensurate decrease in buoyant turbulent production, which resulted in a rapid decay of the turbulence in the atmospheric surface layer both within the stable layer and in the mixed layer forming above it. Significant changes in the wind direction were imposed by the decrease in insolation, with evidence supporting the formation of a nocturnal jet, as well as backing of the wind vector within the stable layer.

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