scholarly journals Quantification of CH<sub>4</sub> emissions from waste disposal sites near the city of Madrid using ground- and space-based observations of COCCON, TROPOMI and IASI

2022 ◽  
Vol 22 (1) ◽  
pp. 295-317
Author(s):  
Qiansi Tu ◽  
Frank Hase ◽  
Matthias Schneider ◽  
Omaira García ◽  
Thomas Blumenstock ◽  
...  

Abstract. The objective of this study is to derive methane (CH4) emissions from three landfills, which are found to be the most significant CH4 sources in the metropolitan area of Madrid in Spain. We derive CH4 emissions from the CH4 enhancements observed by spaceborne and ground-based instruments. We apply satellite-based measurements from the TROPOspheric Monitoring Instrument (TROPOMI) and the Infrared Atmospheric Sounding Interferometer (IASI) together with measurements from the ground-based COllaborative Carbon Column Observing Network (COCCON) instruments. In 2018, a 2-week field campaign for measuring the atmospheric concentrations of greenhouse gases was performed in Madrid in the framework of Monitoring of the Greenhouse Gases Concentrations in Madrid (MEGEI-MAD) project. Five COCCON instruments were deployed at different locations around the Madrid city center, enabling the observation of total column-averaged CH4 mixing ratios (XCH4). Considering the prevalent wind regimes, we calculate the wind-assigned XCH4 anomalies for two opposite wind directions. Pronounced bipolar plumes are found when applying the method to NO2, which implies that our method of wind-assigned anomaly is suitable to estimate enhancements of trace gases at the urban level from satellite-based measurements. For quantifying the CH4 emissions, the wind-assigned plume method is applied to the TROPOMI XCH4 and to the lower tropospheric CH4 / dry-air column ratio (TXCH4) of the combined TROPOMI+IASI product. As CH4 emission strength we estimate 7.4 × 1025 ± 6.4 × 1024 molec. s−1 from the TROPOMI XCH4 data and 7.1 × 1025 ± 1.0 × 1025 molec. s−1 from the TROPOMI+IASI merged TXCH4 data. We use COCCON observations to estimate the local source strength as an independent method. COCCON observations indicate a weaker CH4 emission strength of 3.7 × 1025 molec. s−1 from a local source (the Valdemingómez waste plant) based on observations from a single day. This strength is lower than the one derived from the satellite observations, and it is a plausible result. This is because the analysis of the satellite data refers to a larger area, covering further emission sources in the study region, whereas the signal observed by COCCON is generated by a nearby local source. All emission rates estimated from the different observations are significantly larger than the emission rates provided via the official Spanish Register of Emissions and Pollutant Sources.

2021 ◽  
Author(s):  
Qiansi Tu ◽  
Frank Hase ◽  
Matthias Schneider ◽  
Omaira García ◽  
Thomas Blumenstock ◽  
...  

Abstract. The objective is to derive methane (CH4) emissions of the metropolitan city Madrid Spain from the CH4 enhancements seen by the space-borne and the ground-based instruments. This study applies satellite-based measurements from the TROPOspheric Monitoring Instrument (TROPOMI) and the Infrared Atmospheric Sounding Interferometer (IASI) together with measurements from the ground-based COllaborative Carbon Column Observing Network (COCCON) instruments. In 2018, a two-week field campaign for measuring the atmospheric concentrations of greenhouse gases was performed in Madrid in the framework of Monitoring greenhousE Gas EmIssions of Madrid city (MEGEI-MAD) project. Five COCCON instruments were deployed at different locations around the Madrid city center enabling the observation of total column averaged CH4 mixing ratios (XCH4). Using available wind data, the differences between CH4 columns observed at these locations allow to estimate the emissions emerging from the surrounded area. In addition, based on the dominating wind direction in the Madrid region, we calculate the difference of the satellite data maps for two opposite wind regimes (northeast – southwest, NE – SW). In the following, we refer to the resultant signal as the wind-assigned anomaly. We use TROPOMI tropospheric nitrogen dioxide (NO2) observations as a test to verify our method of wind-assigned anomaly and its implementation, taking advantage of the much better detectability of the plume due to the short lifetime and low background concentrations of NO2. Pronounced bipolar plumes are found along NE and SW wind direction, which implies that our method of wind-assigned anomaly is working as expected. The wind-assigned TROPOMI XCH4 anomaly shows much weaker symmetric plumes than NO2 due to the long lifetime of CH4 and in consequence a high accumulated background of CH4 in the atmosphere. The wind-assigned plume method is also applied to the tropospheric and upper tropospheric/stratospheric column averaged CH4 mixing ratio products (in the following referred to as TXCH4 and UTSXCH4) derived from a-posteriori merged Infrared Atmospheric Sounding Interferometer (IASI) profile and TROPOMI total column data. Based on the NE and SW wind fields, we developed a simple plume model locating the source at three waste disposal sites east of Madrid for CH4. As CH4 emission strength we estimate 7.4 × 1025 ± 6.4 × 1024 molec s−1 from the TROPOMI XCH4 data and 7.1 × 1025 ± 1.0 × 1025 molec s−1 from the TROPOMI&amp;IASI merged TXCH4 data. The COCCON observations indicate a weaker CH4 emission strength of around 3.7 × 1025 molec s−1 from local source (near to the Valdemingómez waste plant) in accordance with observations in a single day and. All emission rates estimated from the different observations are significantly larger than the emission rates provided via the official Spanish Register of Emissions and Pollutant Sources.


2006 ◽  
Vol 33 (7) ◽  
pp. 613 ◽  
Author(s):  
Francis M. Kelliher ◽  
Harry Clark ◽  
Zheng Li ◽  
Paul C. D. Newton ◽  
Anthony J. Parsons ◽  
...  

Keppler et al. (2006, Nature 439, 187–191) showed that plants produce methane (CH4) in aerobic environments, leading Lowe (2006, Nature 439, 148–149) to postulate that in countries such as New Zealand, where grazed pastures have replaced forests, the forests could have produced as much CH4 as the ruminants currently grazing these areas. Estimating CH4 emissions from up to 85 million ruminants in New Zealand is challenging and, for completeness, the capacity of forest and pastoral soils to oxidise CH4 should be included. On average, the CH4 emission rate of grazing ruminants is estimated to be 9.6 ± 2.6 g m–2 year–1 (±standard deviation), six times the corresponding estimate for an indigenous forest canopy (1.6 ± 1.1 g m–2 year–1). The forest’s soil is estimated to oxidise 0.9 ± 0.2 g m–2 year–1 more CH4 than representative soils beneath grazed pasture. Taking into account plant and animal sources and the soil’s oxidative capacity, the net CH4 emission rates of forest and grazed ecosystems are 0.6 ± 1.1 and 9.8 ± 2.6 g m–2 year–1, respectively.


2014 ◽  
Vol 54 (9) ◽  
pp. 1350 ◽  
Author(s):  
Arjan Jonker ◽  
German Molano ◽  
Christopher Antwi ◽  
Garry Waghorn

The objective of this study was to determine the circadian variation in methane (CH4) emissions from cattle fed lucerne silage at different feeding levels and feeding frequencies, to assist with interpretation of short ‘snapshot’ CH4 measurements used for predicting daily emissions. Eight Hereford × Friesian heifers (initially 20 months of age) were used in five consecutive periods (P1–5) of 14 days with CH4 emissions measured using respiration chambers for two consecutive days at the end of each period. Feed was restricted to intakes of ~6, 8, 8, 8 and 11 ± 1.3 (ad libitum) kg lucerne silage dry matter (DM), fed in 2, 2, 3, 4 or ad libitum (refilled twice daily) meals per day in P1–5, respectively. Daily CH4 production (g/day) was lower in P1 than in P2–4 (P < 0.05), which were lower than in P5 (P < 0.05), but CH4 yield (24.3 ± 1.23 g/kg DM) was unaffected by treatment. Among the five periods, CH4 emission rate (g/h) before feeding ranged from 1.8 to 6.5 g/h, time to peak CH4 production after start of feeding ranged from 19 to 40 min and peak CH4 production rate ranged from 11.1 to 17.5 g/h. The range in hourly CH4 emission rates during the day decreased with increasing feed intake level, but was unaffected by feeding frequency. In summary, the circadian pattern of CH4 emissions was affected by feed allowance and feeding frequency, and variation in CH4 emission rate was reduced with increasing intake, without affecting average daily yield (g CH4/kg DM intake).


2013 ◽  
Vol 10 (2) ◽  
pp. 753-788 ◽  
Author(s):  
J. R. Melton ◽  
R. Wania ◽  
E. L. Hodson ◽  
B. Poulter ◽  
B. Ringeval ◽  
...  

Abstract. Global wetlands are believed to be climate sensitive, and are the largest natural emitters of methane (CH4). Increased wetland CH4 emissions could act as a positive feedback to future warming. The Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP) investigated our present ability to simulate large-scale wetland characteristics and corresponding CH4 emissions. To ensure inter-comparability, we used a common experimental protocol driving all models with the same climate and carbon dioxide (CO2) forcing datasets. The WETCHIMP experiments were conducted for model equilibrium states as well as transient simulations covering the last century. Sensitivity experiments investigated model response to changes in selected forcing inputs (precipitation, temperature, and atmospheric CO2 concentration). Ten models participated, covering the spectrum from simple to relatively complex, including models tailored either for regional or global simulations. The models also varied in methods to calculate wetland size and location, with some models simulating wetland area prognostically, while other models relied on remotely sensed inundation datasets, or an approach intermediate between the two. Four major conclusions emerged from the project. First, the suite of models demonstrate extensive disagreement in their simulations of wetland areal extent and CH4 emissions, in both space and time. Simple metrics of wetland area, such as the latitudinal gradient, show large variability, principally between models that use inundation dataset information and those that independently determine wetland area. Agreement between the models improves for zonally summed CH4 emissions, but large variation between the models remains. For annual global CH4 emissions, the models vary by ±40% of the all-model mean (190 Tg CH4 yr−1). Second, all models show a strong positive response to increased atmospheric CO2 concentrations (857 ppm) in both CH4 emissions and wetland area. In response to increasing global temperatures (+3.4 °C globally spatially uniform), on average, the models decreased wetland area and CH4 fluxes, primarily in the tropics, but the magnitude and sign of the response varied greatly. Models were least sensitive to increased global precipitation (+3.9 % globally spatially uniform) with a consistent small positive response in CH4 fluxes and wetland area. Results from the 20th century transient simulation show that interactions between climate forcings could have strong non-linear effects. Third, we presently do not have sufficient wetland methane observation datasets adequate to evaluate model fluxes at a spatial scale comparable to model grid cells (commonly 0.5°). This limitation severely restricts our ability to model global wetland CH4 emissions with confidence. Our simulated wetland extents are also difficult to evaluate due to extensive disagreements between wetland mapping and remotely sensed inundation datasets. Fourth, the large range in predicted CH4 emission rates leads to the conclusion that there is both substantial parameter and structural uncertainty in large-scale CH4 emission models, even after uncertainties in wetland areas are accounted for.


2006 ◽  
Vol 33 (6) ◽  
pp. 521 ◽  
Author(s):  
Miko U. F. Kirschbaum ◽  
Dan Bruhn ◽  
David M. Etheridge ◽  
John R. Evans ◽  
Graham D. Farquhar ◽  
...  

A recent study by Keppler et al. (2006; Nature 439, 187–191) demonstrated CH4 emission from living and dead plant tissues under aerobic conditions. This work included some calculations to extrapolate the findings from the laboratory to the global scale and led various commentators to question the value of planting trees as a greenhouse mitigation option. The experimental work of Keppler et al. (2006) appears to be largely sound, although some concerns remain about the quantification of emission rates. However, whilst accepting their basic findings, we are critical of the method used for extrapolating results to a global scale. Using the same basic information, we present alternative calculations to estimate global aerobic plant CH4 emissions as 10–60 Mt CH4 year–1. This estimate is much smaller than the 62–236 Mt CH4 year–1 reported in the original study and can be more readily reconciled within the uncertainties in the established sources and sinks in the global CH4 budget. We also assessed their findings in terms of their possible relevance for planting trees as a greenhouse mitigation option. We conclude that consideration of aerobic CH4 emissions from plants would reduce the benefit of planting trees by between 0 and 4.4%. Hence, any offset from CH4 emission is small in comparison to the significant benefit from carbon sequestration. However, much critical information is still lacking about aerobic CH4 emission from plants. For example, we do not yet know the underlying mechanism for aerobic CH4 emission, how CH4 emissions change with light, temperature and the physiological state of leaves, whether emissions change over time under constant conditions, whether they are related to photosynthesis and how they relate to the chemical composition of biomass. Therefore, the present calculations must be seen as a preliminary attempt to assess the global significance from a basis of limited information and are likely to be revised as further information becomes available.


2015 ◽  
Vol 12 (4) ◽  
pp. 3469-3503 ◽  
Author(s):  
L. Olsson ◽  
S. Ye ◽  
X. Yu ◽  
M. Wei ◽  
K. W. Krauss ◽  
...  

Abstract. Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil temperature and vegetation on CH4 emissions and ecosystem respiration (Reco) from five coastal wetlands in the Liaohe Delta, northeast China: two Phragmites australis (common reed) wetlands, two Suaeda salsa (sea blite) marshes and a rice (Oryza sativa) paddy. Throughout the growing season, the Suaeda wetlands were net CH4 sinks whereas the Phragmites wetlands and the rice paddy were net CH4 sources emitting 1.2–6.1 g CH4 m−2 y−1. The Phragmites wetlands emitted the most CH4 per unit area and the most CH4 relative to CO2. The main controlling factors for the CH4 emissions were water table, temperature and salinity. The CH4 emission was accelerated at high and constant (or managed) water tables and decreased at water tables below the soil surface. High temperatures enhanced CH4 emissions, and emission rates were consistently low (< 1 mg CH4 m−2 h) at soil temperatures <18 °C. At salinity levels > 18 ppt, the CH4 emission rates were always low (< 1 mg CH4 m−2 h−1) probably because methanogens were outcompeted by sulphate reducing bacteria. Saline Phragmites wetlands can, however, emit significant amounts of CH4 as CH4 produced in deep soil layers are transported through the air-space tissue of the plants to the atmosphere. The CH4 emission from coastal wetlands can be reduced by creating fluctuating water tables, including water tables below the soil surface, as well as by occasional flooding by high-salinity water. The effects of water management schemes on the biological communities in the wetlands must, however, be carefully studied prior to the management in order to avoid undesirable effects on the wetland communities.


2011 ◽  
Vol 38 (2) ◽  
pp. 97 ◽  
Author(s):  
Mirwais M. Qaderi ◽  
David M. Reid

Recent studies using single environmental variables show that under aerobic conditions terrestrial plants can emit methane (CH4). However, the effects of multiple environmental factors – as components of global climate change – on aerobic CH4 emissions have been little studied. We examined the combined effects of temperature, carbon dioxide (CO2) and watering regime on CH4 emissions from six commonly cultivated crop species: faba bean, sunflower, pea, canola, barley and wheat. Plants were grown from seeds in controlled-environment growth chambers under two temperature regimes (24°C day/20°C night and 30°C day/26°C night), two CO2 concentrations (380 and 760 µmol mol–1) and two watering regimes (well watered and water stressed). Plants were grown first under 24/20°C for 1 week from sowing, and then placed under experimental conditions for a further week. After the specified time, plant growth, gas exchange and CH4 emission rates were determined. Our results revealed that higher temperature and water stress significantly enhance CH4 emissions from plants, whereas elevated CO2 had the opposite effect and partially reverses the promotive effects of these factors. We suggest that the despite the mitigating effects of rising atmospheric CO2, CH4 emission may be higher in the face of ongoing global climate change in warmer and drier environments.


2012 ◽  
Vol 9 (8) ◽  
pp. 11577-11654 ◽  
Author(s):  
J. R. Melton ◽  
R. Wania ◽  
E. L. Hodson ◽  
B. Poulter ◽  
B. Ringeval ◽  
...  

Abstract. Global wetlands are believed to be climate sensitive, and are the largest natural emitters of methane (CH4). Increased wetland CH4 emissions could act as a positive feedback to future warming. The Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP) investigated our present ability to simulate large scale wetland characteristics and corresponding CH4 emissions. To ensure inter-comparability, we used a common experimental protocol driving all models with the same climate and carbon dioxide (CO2) forcing datasets. The WETCHIMP experiments were conducted for model equilibrium states as well as transient simulations covering the last century. Sensitivity experiments investigated model response to changes in selected forcing inputs (precipitation, temperature, and atmospheric CO2 concentration). Ten models participated, covering the spectrum from simple to relatively complex, including models tailored either for regional or global simulations. The models also varied in methods to calculate wetland size and location with some models simulating wetland area prognostically, while other models relied on remotely-sensed inundation datasets, or an approach intermediate between the two. Four major conclusions emerged from the project. First, the suite of models demonstrate extensive disagreement in their simulations of wetland areal extent and CH4 emissions, in both space and time. Simple metrics of wetland area, such as the latitudinal gradient, show large variability, principally between models that use inundation dataset information and those that independently determine wetland area. Agreement between the models improves for zonally summed CH4 emissions, but large variation between the models remains. For annual global CH4 emissions, the models vary by ±40 % of the all model mean (190 Tg CH4 yr−1). Second, all models show a strong positive response to increased atmospheric CO2 concentrations (857 ppm) in both CH4 emissions and wetland area. In response to increasing global temperatures (+3.4 % globally spatially uniform), on average, the models decreased wetland area and CH4 fluxes, primarily in the tropics, but the magnitude and sign of the response varied greatly. Models were least sensitive to increased global precipitation (+3.9 % globally spatially uniform) with a consistent small positive response in CH4 fluxes and wetland area. Results from the 20th century transient simulation show that interactions between climate forcings could have strong non-linear effects. Third, we presently do not have sufficient wetland methane observation datasets adequate to evaluate model fluxes at a spatial scale comparable to model grid cells (commonly 0.5°). This limitation severely restricts our ability to model global wetland CH4 emissions with confidence. Our simulated wetland extents are also difficult to evaluate due to extensive disagreements between wetland mapping and remotely-sensed inundation datasets. And fourth, the large range in predicted CH4 emission rates leads to the conclusion that there is both substantial parameter and structural uncertainty in large-scale CH4 emission models, even after uncertainties in wetland areas are accounted for.


2015 ◽  
Vol 12 (16) ◽  
pp. 4965-4977 ◽  
Author(s):  
L. Olsson ◽  
S. Ye ◽  
X. Yu ◽  
M. Wei ◽  
K. W. Krauss ◽  
...  

Abstract. Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil temperature and vegetation on CH4 emissions and ecosystem respiration (Reco) from five coastal wetlands in the Liaohe Delta, Northeast China: two Phragmites australis (common reed) wetlands, two Suaeda salsa (sea blite) marshes and a rice (Oryza sativa) paddy. Throughout the growing season, the Suaeda wetlands were net CH4 sinks whereas the Phragmites wetlands and the rice paddy were net CH4 sources emitting 1.2–6.1 g CH4 m−2 yr−1. The Phragmites wetlands emitted the most CH4 per unit area and the most CH4 relative to CO2. The main controlling factors for the CH4 emissions were water table, temperature, soil organic carbon and salinity. The CH4 emission was accelerated at high and constant (or managed) water tables and decreased at water tables below the soil surface. High temperatures enhanced CH4 emissions, and emission rates were consistently low (< 1 mg CH4 m−2 h−1) at soil temperatures < 18 °C. At salinity levels > 18 ppt, the CH4 emission rates were always low (< 1 mg CH4 m−2 h−1) probably because methanogens were out-competed by sulphate-reducing bacteria. Saline Phragmites wetlands can, however, emit significant amounts of CH4 as CH4 produced in deep soil layers are transported through the air-space tissue of the plants to the atmosphere. The CH4 emission from coastal wetlands can be reduced by creating fluctuating water tables, including water tables below the soil surface, as well as by occasional flooding by high-salinity water. The effects of water management schemes on the biological communities in the wetlands must, however, be carefully studied prior to the management in order to avoid undesirable effects on the wetland communities.


2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Romdhane Ben Slama

The global warming which preoccupies humanity, is still considered to be linked to a single cause which is the emission of greenhouse gases, CO2 in particular. In this article, we try to show that, on the one hand, the greenhouse effect (the radiative imprisonment to use the scientific term) took place in conjunction with the infrared radiation emitted by the earth. The surplus of CO2 due to the combustion of fossil fuels, but also the surplus of infrared emissions from artificialized soils contribute together or each separately,  to the imbalance of the natural greenhouse effect and the trend of global warming. In addition, another actor acting directly and instantaneously on the warming of the ambient air is the heat released by fossil fuels estimated at 17415.1010 kWh / year inducing a rise in temperature of 0.122 ° C, or 12.2 ° C / century.


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