scholarly journals Assessment of Urban CO2 Measurement and Source Attribution in Munich Based on TDLAS-WMS and Trajectory Analysis

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 58 ◽  
Author(s):  
Lijuan Lan ◽  
Homa Ghasemifard ◽  
Ye Yuan ◽  
Stephan Hachinger ◽  
Xinxu Zhao ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
Urban Areas ◽  
Anthropogenic Activities ◽  
Co2 Concentration ◽  
Tunable Diode Laser ◽  
Cavity Surface ◽  
Emission Sources ◽  
Source Attribution ◽  
The North ◽  
Co2 Concentrations

Anthropogenic carbon dioxide (CO2) emissions mainly come from cities and their surrounding areas. Thus, continuous measuring of CO2 in urban areas is of great significance to studying human CO2 emissions. We developed a compact, precise, and self-calibrated in-situ CO2/H2O sensor based on TDLAS (tunable diode laser absorption spectroscopy), WMS (wavelength modulation spectroscopy), and VCSEL (vertical-cavity surface-emitting laser). Multi-harmonic detection is utilized to improve the precision of both measurements to 0.02 ppm for CO2 and 1.0 ppm for H2O. Using the developed sensor, we measured CO2 concentrations continuously in the city center of Munich, Germany, from February 2018 to January 2019. Urban CO2 concentrations are strongly affected by several factors, including vegetation photosynthesis and respiration (VPR), planetary boundary layer (PBL) height, and anthropogenic activities. In order to further understand the anthropogenic contribution in terms of CO2 sources, the HySPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model was applied to calculate six-hour backward trajectories. We analyzed the winter CO2 with the trajectory clustering, PSCF (potential source contribution function), and CWT (concentration weighted trajectory) methods, and found that local emissions have a great impact on urban CO2 concentration, with main emission sources in the north and southeast directions of the measurement site. In situations with an uneven trajectory distribution, PSCF proves somewhat superior in predicting the potential emission sources compared to CWT.

scholarly journals Detecting the Responses of CO2 Column Abundances to Anthropogenic Emissions from Satellite Observations of GOSAT and OCO-2

2021 ◽  
Vol 13 (17) ◽  
pp. 3524
Author(s):  
Mengya Sheng ◽  
Liping Lei ◽  
Zhao-Cheng Zeng ◽  
Weiqiang Rao ◽  
Shaoqing Zhang
Keyword(s):  
Co2 Emissions ◽  
Urban Areas ◽  
Atmospheric Transport ◽  
Southern Oscillation ◽  
Regional Scale ◽  
Co2 Concentration ◽  
Anthropogenic Emissions ◽  
Urban Agglomerations ◽  
Anthropogenic Co2

The continuing increase in atmospheric CO2 concentration caused by anthropogenic CO2 emissions significantly contributes to climate change driven by global warming. Satellite measurements of long-term CO2 data with global coverage improve our understanding of global carbon cycles. However, the sensitivity of the space-borne measurements to anthropogenic emissions on a regional scale is less explored because of data sparsity in space and time caused by impacts from geophysical factors such as aerosols and clouds. Here, we used global land mapping column averaged dry-air mole fractions of CO2 (XCO2) data (Mapping-XCO2), generated from a spatio-temporal geostatistical method using GOSAT and OCO-2 observations from April 2009 to December 2020, to investigate the responses of XCO2 to anthropogenic emissions at both global and regional scales. Our results show that the long-term trend of global XCO2 growth rate from Mapping-XCO2, which is consistent with that from ground observations, shows interannual variations caused by the El Niño Southern Oscillation (ENSO). The spatial distributions of XCO2 anomalies, derived from removing background from the Mapping-XCO2 data, reveal XCO2 enhancements of about 1.5–3.5 ppm due to anthropogenic emissions and seasonal biomass burning in the wintertime. Furthermore, a clustering analysis applied to seasonal XCO2 clearly reveals the spatial patterns of atmospheric transport and terrestrial biosphere CO2 fluxes, which help better understand and analyze regional XCO2 changes that are associated with atmospheric transport. To quantify regional anomalies of CO2 emissions, we selected three representative urban agglomerations as our study areas, including the Beijing-Tian-Hebei region (BTH), the Yangtze River Delta urban agglomerations (YRD), and the high-density urban areas in the eastern USA (EUSA). The results show that the XCO2 anomalies in winter well capture the several-ppm enhancement due to anthropogenic CO2 emissions. For BTH, YRD, and EUSA, regional positive anomalies of 2.47 ± 0.37 ppm, 2.20 ± 0.36 ppm, and 1.38 ± 0.33 ppm, respectively, can be detected during winter months from 2009 to 2020. These anomalies are slightly higher than model simulations from CarbonTracker-CO2. In addition, we compared the variations in regional XCO2 anomalies and NO2 columns during the lockdown of the COVID-19 pandemic from January to March 2020. Interestingly, the results demonstrate that the variations of XCO2 anomalies have a positive correlation with the decline of NO2 columns during this period. These correlations, moreover, are associated with the features of emitting sources. These results suggest that we can use simultaneously observed NO2, because of its high detectivity and co-emission with CO2, to assist the analysis and verification of CO2 emissions in future studies.

scholarly journals Surface water pollution risk assessment of wadis, Mekerra and Saïda, in the North-Western of Algeria

2021 ◽  
Vol 15 (1) ◽  
pp. 109-123
Author(s):  
Ahmed Guenfoud ◽  
Mohamed Benyahia ◽  
Abdelkader Bouderbala
Keyword(s):  
Urban Areas ◽  
Anthropogenic Activities ◽  
Microbiological Quality ◽  
Pollution Index ◽  
High Water ◽  
Organic Pollution ◽  
Real Problem ◽  
Main Stream ◽  
The West ◽  
The North

Considered as the main stream of hydrographic network of Mactaa’s basin, in the west highlands of Algeria, both wadis, Mekerra and Saïda, are affected by pollution which is generated by anthropogenic activities. Makara and Saïda wadis cross the urban areas of Sidi-Bel-Abbes and Saïda respectively, in the west of Algeria, which constitute a real problem of human safety. In order to identify the pollution state on these wadis, samples have been collected during three periods of time (June 2011, July 2012 and April 2013) in the goal to characterize the physico-chemical and bacteriological quality of surface water.Results obtained describe clearly the existence of chemical and organic pollution in both wadis at high levels of calcium, magnesium, chlorides, nitrates, nitrites, phosphate, DBO5 and dissolved oxygen. The evaluation of organic pollution index (OPI) confirmed that there is a high organic pollution, upstream, which increases with high water passage towards urban areas of both cities (OPI).The bacteriological analysis results obtained show presence of high contents of faecal bacteria contamination (total coliforms (TC), faecal coliforms (TC) and faecal streptococci(FS))principally in wadi Saïda. The relationship between FC/FS justifies the predominance of human origin than of animal as source of contamination. While, the determination of microbiological quality index (MQI), for each wadi, confirms degradation of microbiological quality by the faecal pollution, mainly in Saïda urban area.

scholarly journals COVID-19 lockdown induced changes in NO<sub>2</sub> levels across India observed by multi-satellite and surface observations

2020 ◽  
Author(s):  
Akash Biswal ◽  
Vikas Singh ◽  
Shweta Singh ◽  
Amit P. Kesarkar ◽  
Khaiwal Ravindra ◽  
...  
Keyword(s):  
Urban Areas ◽  
Substantial Reduction ◽  
Monitoring Network ◽  
Emission Sources ◽  
Ozone Monitoring Instrument ◽  
Fire Emissions ◽  
Monitoring Instrument ◽  
North East ◽  
The North ◽  
Surface Observations

Abstract. We have estimated the spatial changes in NO2 levels over different regions of India during the COVID-19 lockdown (25th March–3rd May 2020) using the satellite-based tropospheric column NO2 observed by the Ozone Monitoring Instrument (OMI) and the Tropospheric Monitoring Instrument (TROPOMI), as well as surface NO2 concentrations obtained from the Central Pollution Control Board (CPCB) monitoring network. A substantial reduction in NO2 levels was observed across India during the lockdown compared to the same period during previous business-as-usual years, except for some regions that were influenced by anomalous fires in 2020. The reduction (negative change) over the urban agglomerations was substantial (∼ 20–40 %) and directly proportional to the urban size and population density. Rural regions across India also experienced lower NO2 values by ∼ 15–25 %. Localised enhancement of NO2 associated with isolated emission increase scattered across India, were also detected. Observed percentage changes in satellite and surface observations were consistent across most regions and cities, but the surface observations were subject to larger variability depending on their proximity to the local emission sources. Observations also indicate NO2 enhancements of up to ∼ 25 % during the lockdown associated with fire emissions over the north-east, and some parts of central regions. In addition, the cities located near the large fire emission sources show much smaller NO2 reduction than other urban areas as the decrease at the surface was masked by enhancement in NO2 due to the transport of the fire emissions.

scholarly journals COVID-19 lockdown-induced changes in NO<sub>2</sub> levels across India observed by multi-satellite and surface observations

2021 ◽  
Vol 21 (6) ◽  
pp. 5235-5251
Author(s):  
Akash Biswal ◽  
Vikas Singh ◽  
Shweta Singh ◽  
Amit P. Kesarkar ◽  
Khaiwal Ravindra ◽  
...  
Keyword(s):  
Urban Areas ◽  
Substantial Reduction ◽  
Monitoring Network ◽  
Emission Sources ◽  
Ozone Monitoring Instrument ◽  
Fire Emissions ◽  
Monitoring Instrument ◽  
North East ◽  
The North ◽  
Surface Observations

Abstract. We have estimated the spatial changes in NO2 levels over different regions of India during the COVID-19 lockdown (25 March–3 May 2020) using the satellite-based tropospheric column NO2 observed by the Ozone Monitoring Instrument (OMI) and the Tropospheric Monitoring Instrument (TROPOMI), as well as surface NO2 concentrations obtained from the Central Pollution Control Board (CPCB) monitoring network. A substantial reduction in NO2 levels was observed across India during the lockdown compared to the same period during previous business-as-usual years, except for some regions that were influenced by anomalous fires in 2020. The reduction (negative change) over the urban agglomerations was substantial (∼ 20 %–40 %) and directly proportional to the urban size and population density. Rural regions across India also experienced lower NO2 values by ∼ 15 %–25 %. Localised enhancements in NO2 associated with isolated emission increase scattered across India were also detected. Observed percentage changes in satellite and surface observations were consistent across most regions and cities, but the surface observations were subject to larger variability depending on their proximity to the local emission sources. Observations also indicate NO2 enhancements of up to ∼ 25 % during the lockdown associated with fire emissions over the north-east of India and some parts of the central regions. In addition, the cities located near the large fire emission sources show much smaller NO2 reduction than other urban areas as the decrease at the surface was masked by enhancement in NO2 due to the transport of the fire emissions.

scholarly journals Dynamics of global atmospheric CO<sub>2</sub> concentration from 1850 to 2010: a linear approximation

2014 ◽  
Vol 11 (9) ◽  
pp. 13957-13983 ◽  
Author(s):  
W. Wang ◽  
R. Nemani
Keyword(s):  
Co2 Emissions ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Box Model ◽  
Modeling Framework ◽  
Elevated Atmospheric Co2 ◽  
Atmospheric Co2 Concentration ◽  
Co2 Concentrations ◽  
Anthropogenic Co2 ◽  
Atmospheric Co2 Concentrations

Abstract. The increase in anthropogenic CO2 emissions largely followed an exponential path between 1850 and 2010, and the corresponding increases in atmospheric CO2 concentration were almost constantly proportional to the emissions by the so-called "airborne fraction". These observations suggest that the dynamics of atmospheric CO2 concentration through this time period may be properly approximated as a linear system. We demonstrate this hypothesis by deriving a linear box-model to describe carbon exchanges between the atmosphere and the surface reservoirs under the influence of disturbances such as anthropogenic CO2 emissions and global temperature changes. We show that the box model accurately simulates the observed atmospheric CO2 concentrations and growth rates across interannual to multi-decadal time scales. The model also allows us to analytically examine the dynamics of such changes/variations, linking its characteristic disturbance-response functions to bio-geophysically meaningful parameters. In particular, our results suggest that the elevated atmospheric CO2 concentrations have significantly promoted the gross carbon uptake by the terrestrial biosphere. However, such "fertilization" effects are partially offset by enhanced carbon release from surface reservoirs promoted by warmer temperatures. The result of these interactions appears to be a decline in net efficiency in sequestering atmospheric CO2 by ∼30% since 1960s. We believe that the linear modeling framework outlined in this paper provides a convenient tool to diagnose the observed atmospheric CO2 dynamics and monitor their future changes.

scholarly journals Effects of CO<sub>2</sub>, continental distribution, topography and vegetation changes on the climate at the Middle Miocene: a model study

2010 ◽  
Vol 6 (2) ◽  
pp. 489-535 ◽  
Author(s):  
A.-J. Henrot ◽  
L. François ◽  
E. Favre ◽  
M. Butzin ◽  
M. Ouberdous ◽  
...  
Keyword(s):  
Atmospheric Carbon Dioxide ◽  
Middle Miocene ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
The Tibetan Plateau ◽  
Humid Climate ◽  
The North ◽  
Co2 Concentrations ◽  
Reduced Height ◽  
Atmospheric Co2 Concentrations

Abstract. The Middle Miocene was one of the last warm periods of the Neogene, culminating with the Middle Miocene Climatic Optimum (MMCO, approximatively 17–15 Ma). Several proxy-based reconstructions support warmer and more humid climate during the MMCO. The mechanisms responsible for the warming at MMCO and particulary the role of the atmospheric carbon dioxide CO2 are still highly debated. Here we carried out a series of sensitivity experiments with the model of intermediate complexity Planet Simulator, investigating the contributions of the absence of ice on the continents, the opening of the Central American and Eastern Tethys Seaways, the lowering of the topography on land, the effect of various atmospheric CO2 concentrations and the vegetation retroaction. Our results show that a higher than present-day CO2 concentration is necessary to generate a warmer climate at all latitudes at the Middle Miocene, in agreement with the terrestrial proxy reconstructions which suggest high atmospheric CO2 concentrations at MMCO. Nevertheless, the changes in sea-surface conditions and the lowering of the topography on land also produce significant local warming that may, locally, even be stronger than the CO2 induced temperature increases. The lowering of the topography leads to a more zonal atmospheric circulation and allows the westerly flow to continue over the lowered Plateaus at mid-latitudes. The reduced height of the Tibetan Plateau notably prevents the development of a monsoon-like circulation, whereas the reduction of elevations of the North American and European reliefs strongly increases precipitation from northwestern to eastern Europe. The changes in vegetation cover contributes to maintain and even to intensify the the warm and humid conditions produced by the other factors, suggesting that the vegetation-climate interactions could help to improve the model-data comparison.

scholarly journals Modeling of Atmospheric Carbon Dioxide (CO2) Concentrations as a Function of Fossil-Fuel and Land-Use Change CO2 Emissions Coupled with Oceanic and Terrestrial Sequestration

Climate ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 61
Author(s):  
John P. O’Connor
Keyword(s):  
Carbon Dioxide ◽  
Land Use ◽  
Land Use Change ◽  
Co2 Emissions ◽  
Fossil Fuel ◽  
Co2 Concentration ◽  
Fuel Combustion ◽  
Full Time ◽  
Fossil Fuel Combustion ◽  
Co2 Concentrations

In this work, a semi-empirical relationship of carbon dioxide emissions with atmospheric CO2 concentrations has been developed that is capable of closely replicating observations from 1751 to 2018. The analysis was completed using data from fossil-fuel-based and land-use change based CO2 emissions, both singly and together. Evaluation of emissions data from 1750 to 1890 yields a linear CO2 concentration component that may be attributed to the net flux from land-use changes combined with a rapidly varying component of the terrestrial sink. This linear component is then coupled across the full-time period with a CO2 concentration calculation using fossil-fuel combustion/cement production emissions with a single, fixed fossil-fuel combustion airborne fraction [AFFF] value that is determined by the ocean sink coupled with the remaining slowly varying component of the land sink. The analysis of the data shows that AFFF has remained constant at 51.3% over the past 268 years. However, considering the broad range of variables including emission and sink processes influencing the climate, it may not be expected that a single value for AFFF would accurately reproduce the measured changes in CO2 concentrations during the industrial era.

scholarly journals Relation between CO2 emissions and crude oil combustion in Iraq

2021 ◽  
Vol 30 (3) ◽  
pp. 379-387
Author(s):  
Ahmed Hassan ◽  
Hasan Azeez
Keyword(s):  
Carbon Dioxide ◽  
Crude Oil ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Co2 Concentration ◽  
Annual Data ◽  
Co2 Concentrations ◽  
Starting Point ◽  
The World ◽  
Analysis Center

Fossil fuel is the main source for CO2 emissions that causes global warming. This fact is the starting point for this paper, that consider on three different sources of data: crude oil used to calculate CO2 emissions for Iraq for the period from 1980 to 2018; annual data of total CO2 emissions available from the Carbon Dioxide Information Analysis Center (CDIAC) for Iraq and the world for the period from 1980 to 2014; and CO2 concentrations for Iraq for the period from 2002 to 2006 and for the world for the period from 1980 to 2018. The result is a multifaceted according to the dataset sources. Carbon dioxide emissions calculated from Iraqi crude oil was increased from 1.29 Mt in 2012 to 1.97 Mt in 2018. The world and Iraq CO2 emissions with different slop of average line that was 0.5 for world, 0.003 for Iraq, while increased exponential function from 2008 to 2014 to reach 36 and 0.17 Mt, respectively. The highest value of Iraqi CO2 concentration was 403 ppm in 2016, while the global CO2 concentrations slowly increased with slop line equal to 1.75 ppm per year, from minimum value of 338.6 ppm was in 1980, while maximum value of 407.05 ppm was in 2018, that’s mean no decreased in CO2 concentration unless emissions addressed.

scholarly journals Sensitivity to the sources of uncertainties in the modeling of atmospheric CO<sub>2</sub> concentration within and in the vicinity of Paris

2021 ◽  
Vol 21 (13) ◽  
pp. 10707-10726
Author(s):  
Jinghui Lian ◽  
François-Marie Bréon ◽  
Grégoire Broquet ◽  
Thomas Lauvaux ◽  
Bo Zheng ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Co2 Emissions ◽  
Vertical Mixing ◽  
Co2 Concentration ◽  
Atmospheric Modeling ◽  
Inversion Method ◽  
Model Data ◽  
Co2 Concentrations ◽  
Paris Area ◽  
The City

Abstract. The top-down atmospheric inversion method that couples atmospheric CO2 observations with an atmospheric transport model has been used extensively to quantify CO2 emissions from cities. However, the potential of the method is limited by several sources of misfits between the measured and modeled CO2 that are of different origins than the targeted CO2 emissions. This study investigates the critical sources of errors that can compromise the estimates of the city-scale emissions and identifies the signal of emissions that has to be filtered when doing inversions. A set of 1-year forward simulations is carried out using the WRF-Chem model at a horizontal resolution of 1 km focusing on the Paris area with different anthropogenic emission inventories, physical parameterizations, and CO2 boundary conditions. The simulated CO2 concentrations are compared with in situ observations from six continuous monitoring stations located within Paris and its vicinity. Results highlight large nighttime model–data misfits, especially in winter within the city, which are attributed to large uncertainties in the diurnal profile of anthropogenic emissions as well as to errors in the vertical mixing near the surface in the WRF-Chem model. The nighttime biogenic respiration to the CO2 concentration is a significant source of modeling errors during the growing season outside the city. When winds are from continental Europe and the CO2 concentration of incoming air masses is influenced by remote emissions and large-scale biogenic fluxes, differences in the simulated CO2 induced by the two different boundary conditions (CAMS and CarbonTracker) can be of up to 5 ppm. Nevertheless, our results demonstrate the potential of our optimal CO2 atmospheric modeling system to be utilized in atmospheric inversions of CO2 emissions over the Paris metropolitan area. We evaluated the model performances in terms of wind, vertical mixing, and CO2 model–data mismatches, and we developed a filtering algorithm for outliers due to local contamination and unfavorable meteorological conditions. Analysis of model–data misfit indicates that future inversions at the mesoscale should only use afternoon urban CO2 measurements in winter and suburban measurements in summer. Finally, we determined that errors related to CO2 boundary conditions can be overcome by including distant background observations to constrain the boundary inflow or by assimilating CO2 gradients of upwind–downwind stations rather than by assimilating absolute CO2 concentrations.

Measuring of particulate matter levels in the greater area of Athens at two different monitoring sites

2014 ◽  
Vol 16 (5) ◽  
pp. 883-892 ◽  
Keyword(s):  
Atmospheric Transport ◽  
Anthropogenic Activities ◽  
Heavy Traffic ◽  
Field Measurements ◽  
Sampling Period ◽  
Emission Sources ◽  
Direct Reading ◽  
Commercial Activities ◽  
The North ◽  
Different Characteristics

<p>Simultaneous PM<sub>10 </sub>and PM<sub>2<em>.</em>5 </sub>sampling was conducted for a six months period, at two sites of different characteristics. The first site was located in an urban background location in the North-Eastern part of GAA, affected by primary emission sources and particle transport from other parts of the GAA basin. The second site was located in central Athens, at a busy roadway, affected by heavy traffic-related and commercial activities. Additionally, continuous field measurements of PM fractions were also performed using direct-reading monitor in parallel with gravimetric samplers. The mean PM<sub>10</sub> and PM<sub>2.5 </sub>concentrations for the sampling period were 26.2 and 13.7μg m<sup>-3</sup> and 40.1 and 22.8 μg m<sup>-3</sup> for ZOG and ARI, respectively. The PM<sub>2.5</sub>/PM<sub>10</sub> ratio found 0.52 and 0.57 for ZOG and ARI, respectively. The coefficient of variation calculated equal to 0.40 for both fractions. Additionally, the weekday/weekend discernment of the particulate concentration levels for each site display different characteristics of the emission sources and composition, while the diurnal distribution of particulate levels demonstrated the dependence of the PM levels on anthropogenic activities and habits.</p> <p>Both the local meteorological conditions and the air mass history indicating long-range atmospheric transport of particles are significant parameters that influence the levels of PM.</p>

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