Decadal trends in global CO emissions as seen by MOPITT

Abstract. Negative trends of carbon monoxide (CO) concentrations are observed in the recent decade by both surface measurements and satellite retrievals over many regions of the globe, but they are not well explained by current emission inventories. Here, we analyse the observed CO concentration decline with an atmospheric inversion that simultaneously optimizes the two main CO sources (surface emissions and atmospheric hydrocarbon oxidations) and the main CO sink (atmospheric hydroxyl radical OH oxidation). Satellite CO column retrievals from Measurements of Pollution in the Troposphere (MOPITT), version 6, and surface observations of methane and methyl chloroform mole fractions are assimilated jointly for the period covering 2002–2011. Compared to the model simulation prescribed with prior emission inventories, trends in the optimized CO concentrations show better agreement with that of independent surface in situ measurements. At the global scale, the atmospheric inversion primarily interprets the CO concentration decline as a decrease in the CO emissions (−2.3 % yr−1), more than twice the negative trend estimated by the prior emission inventories (−1.0 % yr−1). The spatial distribution of the inferred decrease in CO emissions indicates contributions from western Europe (−4.0 % yr−1), the United States (−4.6 % yr−1) and East Asia (−1.2 % yr−1), where anthropogenic fuel combustion generally dominates the overall CO emissions, and also from Australia (−5.3 % yr−1), the Indo-China Peninsula (−5.6 % yr−1), Indonesia (−6.7 % y−1), and South America (−3 % yr−1), where CO emissions are mostly due to biomass burning. In contradiction with the bottom-up inventories that report an increase of 2 % yr−1 over China during the study period, a significant emission decrease of 1.1 % yr−1 is inferred by the inversion. A large decrease in CO emission factors due to technology improvements would outweigh the increase in carbon fuel combustions and may explain this decrease. Independent satellite formaldehyde (CH2O) column retrievals confirm the absence of large-scale trends in the atmospheric source of CO. However, it should be noted that the CH2O retrievals are not assimilated and OH concentrations are optimized at a very large scale in this study.

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Decadal trends in global CO emissions as seen by MOPITT

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-14505-2015 ◽

2015 ◽

Vol 15 (10) ◽

pp. 14505-14547 ◽

Cited By ~ 4

Author(s):

Y. Yin ◽

F. Chevallier ◽

P. Ciais ◽

G. Broquet ◽

A. Fortems-Cheiney ◽

...

Keyword(s):

Biomass Burning ◽

Chemical Oxidation ◽

In Situ Measurements ◽

Negative Trend ◽

Emission Inventories ◽

Co Concentration ◽

Co Emission ◽

Co Concentrations ◽

Atmospheric Inversion

Abstract. Negative trends of carbon monoxide (CO) concentrations are observed in the recent decade by both surface measurements and satellite retrievals over many regions, but they are not well explained by current emission inventories. Here, we attribute the observed CO concentration decline with an atmospheric inversion that simultaneously optimizes the two main CO sources (surface emissions and atmospheric hydrocarbon oxidations) and the main CO sink (atmospheric hydroxyl radical OH oxidation) by assimilating observations of CO and other chemically related tracers. Satellite CO column retrievals from Measurements of Pollution in the Troposphere (MOPITT), version 6, and surface in-situ measurements of methane and methyl-chloroform mole fractions are assimilated jointly for the period of 2002–2011. Compared to the prior simulation, the optimized CO concentrations show better agreement with independent surface in-situ measurements in terms of both distributions and trends. At the global scale, the atmospheric inversion primarily interprets the CO concentration decline as a decrease in the CO emissions, and finds noticeable trends neither in the chemical oxidation sources of CO, nor in the OH concentrations that regulate CO sinks. The latitudinal comparison of the model state with independent formaldehyde (CH2O) columns retrieved from the Ozone Measurement Instrument (OMI) confirms the absence of large-scale trends in the atmospheric source of CO. The global CO emission decreased by 17% during the decade, more than twice the negative trend estimated by emission inventories. The spatial distribution of the inferred decrease of CO emissions indicates contributions from both a decrease in fossil- and bio-fuel emissions over Europe, the USA and Asia, and from a decrease in biomass burning emissions in South America, Indonesia, Australia and Boreal regions. An emission decrease of 2% yr−1 is inferred in China, one of the main emitting regions, in contradiction with the bottom-up inventories that report an increase of 2% yr−1 during the study period. A large decrease in CO emission factors due to technology improvements would outweigh the increase of carbon fuel combustions and may explain the observed decrease. In Africa, instead of the negative trend (1% yr−1) reported by CO emission inventories mainly contributed by biomass burning, a positive trend (1.5% yr−1) is found by the atmospheric inversion, suggesting different trends between satellite-detected burned areas and CO emissions.

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Explaining the Unexpected: Political Science and the Surprises of 1989 and 2011

Perspectives on Politics ◽

10.1017/s1537592714000899 ◽

2014 ◽

Vol 12 (2) ◽

pp. 394-408 ◽

Cited By ~ 14

Author(s):

Marc Morjé Howard ◽

Meir R. Walters

Keyword(s):

Large Scale ◽

Western Europe ◽

Arab World ◽

The United States ◽

Regime Type ◽

Mass Mobilization ◽

Protest Movements ◽

Democratic Reform ◽

The Past ◽

Political Transformations

Political scientists have been caught by surprise by some of the world’s most dramatic political transformations. To assess how the discipline fared in explaining two of the most large-scale and unexpected developments of the past decades, we compare scholarship around the time of popular mobilization in Eastern Europe in 1989 and the Arab world in 2011. We argue that while scholars cannot be expected topredictutterly extraordinary events such as revolutions and mass mobilization, in these two cases disciplinary trends left scholars ill-prepared toexplainthem. Political scientists used similar paradigms to study both regions, emphasizing their failure to develop politically and economically along the lines of Western Europe and the United States. Sovietologists tended to study the communist bloc as either anomalously totalitarian or modernizing towards “convergence” with the West. Likewise, political scientists studying the Arab world focused disproportionately on the prospects for democratization or the barriers to it, and they now risk treating the 2011 protest movements essentially as non-events if they are not clearly tied to institutional democratic reform. By broadening their research agendas beyond a focus on regime type, political scientists will be better prepared to understand future changes in the Middle East and elsewhere.

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Modelling the main ionospheric trough using the Electron Density Assimilative Model (EDAM) with assimilated GPS TEC

Annales Geophysicae ◽

10.5194/angeo-36-125-2018 ◽

2018 ◽

Vol 36 (1) ◽

pp. 125-138 ◽

Cited By ~ 2

Author(s):

James A. D. Parker ◽

S. Eleri Pryse ◽

Natasha Jackson-Booth ◽

Rachel A. Buckland

Keyword(s):

Electron Density ◽

Large Scale ◽

Western Europe ◽

Global Scale ◽

Electron Content ◽

Total Electron ◽

Radio Science ◽

Ionospheric Physics ◽

Main Ionospheric Trough ◽

Plasma Distribution

Abstract. The main ionospheric trough is a large-scale spatial depletion in the electron density distribution at the interface between the high- and mid-latitude ionosphere. In western Europe it appears in early evening, progresses equatorward during the night, and retreats rapidly poleward at dawn. It exhibits substantial day-to-day variability and under conditions of increased geomagnetic activity it moves progressively to lower latitudes. Steep gradients on the trough-walls on either side of the trough minimum, and their variability, can cause problems for radio applications. Numerous studies have sought to characterize and quantify the trough behaviour. The Electron Density Assimilative Model (EDAM) models the ionosphere on a global scale. It assimilates observations into a background ionosphere, the International Reference Ionosphere 2007 (IRI2007), to provide a full 3-D representation of the ionospheric plasma distribution at specified times and days. This current investigation studied the capability of EDAM to model the ionosphere in the region of the main trough. Total electron content (TEC) measurements from 46 GPS stations in western Europe from September to December 2002 were assimilated into EDAM to provide a model of the ionosphere in the trough region. Vertical electron content profiles through the model revealed the trough and the detail of its structure. Statistical results are presented of the latitude of the trough minimum, TEC at the minimum and of other defined parameters that characterize the trough structure. The results are compared with previous observations made with the Navy Ionospheric Monitoring System (NIMS), and reveal the potential of EDAM to model the large-scale structure of the ionosphere. Keywords. Ionosphere (midlatitude ionosphere; modelling and forecasting) – radio science (ionospheric physics)

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Integrating Agricultural Practices into the TRIPLEX-GHG Model v2.0 for Simulating Global Cropland Nitrous Oxide Emissions: Model Development and Evaluation

10.5194/gmd-2021-23 ◽

2021 ◽

Author(s):

Hanxiong Song ◽

Changhui Peng ◽

Kerou Zhang ◽

Qiuan Zhu

Keyword(s):

Nitrous Oxide ◽

Large Scale ◽

Consumption Rate ◽

Model Simulation ◽

Model Development ◽

Agricultural Practices ◽

Global Scale ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Highly Correlated

Abstract. Nitrous oxide (N2O) emissions from croplands are one of the most important greenhouse gas sources, and it is difficult to simulate on a large scale. In order to simulate N2O emissions from global croplands, a new version of the process-based TRIPLEX-GHG model was developed by coupling the major agricultural activities. The coefficient of the NO3− consumption rate for denitrification (COEdNO3) was found to be the most sensitive parameter based on sensitivity analysis, and it was calibrated using field data from 39 observation sites across major croplands globally. The model performed well when simulating the magnitude of the daily N2O emissions and was able to capture the temporal patterns of the N2O emissions. The COEdNO3 ranged from 0.01 to 0.05, and the continental mean of the parameter was used for the model validation. The validation results indicate that the means of the measured daily N2O fluxes during the experiment periods are highly correlated with the modeled results (R2 = 0.87). Consequently, our model simulation results demonstrate that the new version of the TRIPLEX-GHG model can reliably simulate N2O emissions from various croplands at the global scale.

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Using a new divergence method to quantify methane emissions with TROPOMI on Sentinel-5p

10.5194/egusphere-egu21-12565 ◽

2021 ◽

Author(s):

Mengyao Liu ◽

Ronald Van der A ◽

Michiel Van Weele ◽

Henk Eskes ◽

Xiao Lu ◽

...

Keyword(s):

Large Scale ◽

A Priori ◽

The United States ◽

Global Scale ◽

Methane Emissions ◽

Atmospheric Methane ◽

Permian Basin ◽

Wind Speeds ◽

Gas Fields ◽

Oil Gas

The high-resolution Tropospheric Monitoring Instrument (TROPOMI) satellite observations of atmospheric methane offer a powerful tool to identify emission hot spots and quantify regional emissions. The divergence of horizontal fluxes of NO2 has already been proven to be an efficient way to resolve and quantify high sources on a global scale. Since the lifetime of CH4 is in the order of 10 years, the sinks can be ignored at the synoptic time scale which makes the divergence method even more applicable to CH4 than to short-lived NO2.&#160; Because plumes of newly emitted CH4 disperse within the Planetary Boundary Layer (PBL), we first convert the satellite observed total column average (XCH4) to a regional enhancement of methane in the PBL (&#8710;XCH4_PBL) by using the CAMS global methane background reanalysis fields above the PBL. These model fields represent the transport- and chemically-modulated large-scale distribution of methane. Secondly, the divergence of &#8710;XCH4_PBL is derived by the use of the wind speeds halfway within the PBL. Based on the divergence, methane emissions are estimated on a 0.25&#176;&#215; 0.25&#176; grid. We tested our new method for Texas in the United States and quantified methane emissions from the well-known oil-gas fields in the Permian Basin, as well as from &#8211; less well quantitatively established &#8211; oil-gas fields located in southern coastal areas.&#160; Compared to traditional inverse methods, our method is not restricted by an a priori emission inventory and so far unidentified local sources (i.e. emissions from livestock in feed yards) may be found. Due to its computational efficiency, the method might be applied in the near future globally on the current spatial resolution.

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Progress and Prospects of Some Key Technologies for Space Nuclear Reactor

10.1115/icone28-63357 ◽

2021 ◽

Author(s):

Nailiang Zhuang ◽

Chenhao Yang ◽

Yiqi Zhao ◽

Yongnian Song ◽

Xiaobin Tang

Keyword(s):

Soviet Union ◽

Large Scale ◽

Nuclear Reactor ◽

Historical Review ◽

Recent Decade ◽

The United States ◽

Space Missions ◽

The European Union ◽

Space Applications ◽

Key Technologies

Abstract With the increasing demands of versatile and long-lasting requirements of deep space missions, space nuclear reactor (SNR) power system is becoming the most potential energy source compared to conventional solar-battery and chemical energy in the future large-scale and long-life space missions. Since the very first successful launch of SNR system (SNAP-10A) in 1965, the United States, the Soviet Union / Russia, the European Union, Japan, Brazil and China have proposed various technical routes and schemes for SNR technologies over the past few decades. This paper presents a historical review of several key technologies (i.e., space nuclear reactor system and thermoelectric conversion system), especially focus on technical progress for recent decade and discusses on-going development activities. The paper also presents a forecast of potential future space applications of these key technologies.

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Guestworkers: Lessons from Western Europe

ILR Review ◽

10.1177/001979398003300303 ◽

1980 ◽

Vol 33 (3) ◽

pp. 315-330 ◽

Cited By ~ 22

Author(s):

Philip L. Martin ◽

Mark J. Miller

Keyword(s):

Migrant Workers ◽

Large Scale ◽

Western Europe ◽

Illegal Immigration ◽

The United States ◽

Economic Benefits ◽

Federal Republic Of Germany ◽

Short Term ◽

Similar Program ◽

Source Countries

This article appraises the postwar guestworker programs in France, Switzerland, and the Federal Republic of Germany in light of the proposal that a similar program be adopted in the United States. The authors agree that these programs provided significant short-term economic benefits in meeting the labor shortages experienced in Western Europe until recently. These programs also created several serious problems, however, leading the authors to conclude that a large-scale American temporary worker program (1) may reduce but not end illegal immigration; (2) will evolve into a resident, not short-term, worker program; (3) is likely to produce discrimination against migrant workers; (4) will not improve U.S. relations with labor-source countries; and (5) will exacerbate the employment problems of American minorities.

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COUNTERING TERRORISM IN EUROPE AND THE USA: PROBLEMS AND SOLUTIONS

Urgent Problems of Europe ◽

10.31249/ape/2021.04.01 ◽

2021 ◽

Author(s):

Olga Novikova ◽

Keyword(s):

United States ◽

Social Media ◽

Large Scale ◽

Western Europe ◽

The United States ◽

Law Enforcement Agencies ◽

Predisposing Factor ◽

Sociological Factors ◽

Problems And Solutions ◽

The Usa

Beginning with an overview of the threats of terrorism in Europe and the USA, the author offers a survey of factors that have been identified as influencing the practices of counterterrorism or law enforcement agencies. Massive counterterrorism operations in Syria and Iraq as well as effectiveness of the counterterrorism authorities curbed large-scale attacks of jihadists in both Western Europe and the United States. But with one of the Islamic State’s key goals being the formation of a new society, rather than simply military victories, the dissemination of its brand and ideology via mainstream social media becomes critical to achieving ISIS’ strategic goals. A surge in the Muslim population with subsequent high Muslim unemployment has been shown to be a predisposing factor for radicalization of the part of Muslim diasporas and its recruitment into the global jihad. The EU-members and the United States need to work more closely on disrupting jihadists’ social media, travel, recruitment and logistics, countering terrorist finance, protecting potential targets. The importance of sharing information is specifically underlined. But the polarisation of society, discrimination and other psychological and sociological factors can reinforce people’s vulnerability to radical discourse. Thus, counter-terrorism should not be purely repressive: integration and iclusion would contribute to prevention efforts, assuming that a more cohesive and inclusive society can help prevent the spread of extremist ideologies leading to terrorism.

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Technological Trends and Significance of the Essential Ocean Variables by the Indian Moored Observatories: Relevance to UN Decade of Ocean Sciences

Marine Technology Society Journal ◽

10.4031/mtsj.55.3.8 ◽

2021 ◽

Vol 55 (3) ◽

pp. 34-49

Author(s):

Ramasamy Venkatesan ◽

Manickavasagam Arul Muthiah ◽

Narayanaswamy Vedachalam ◽

Gopal Vengatesan ◽

Krishnamoorthy Ramesh ◽

...

Keyword(s):

Sustainable Development ◽

Large Scale ◽

The United States ◽

Global Scale ◽

Global Ocean ◽

Comprehensive Overview ◽

Essential Information ◽

Ocean Science ◽

Observation Network ◽

Ocean Observing

Abstract The ocean plays a key role in regulating the climate as well as supporting diverse ecosystems. Technology is the key for the sustained and precise in-situ spatio-temporal measurements of the physical, biological, biogeochemical, and near-atmospheric meteorological parameters essential for carrying out effective assessments of the status, variability, and change in the ocean ecosystems and for creating policies at the right time. The United Nations Decade of Ocean Science for Sustainable Development 2021‐2030 provides a timeframe to build a comprehensive, sustainable, and data-based informed decision-making global ocean observing system. This demands global-scale investigations, trans-disciplinary science, and mechanisms to integrate and distribute data that otherwise would appear to be disparate. The essential ocean variables (EOVs) conceptualized by the Global Ocean Observing System (GOOS) of UNESCO's Intergovernmental Oceanographic Commission guide observation of the ocean. In order to achieve the goal of UN Decade envisaged and to have an Earth System approach under the World Meteorological Organization reforms, it is imperative to address globally and nationally relevant indicators and assessments, which require increased sharing of data and analytical methods, sustained long-term and large-scale observations, and resources dedicated to these tasks. Technology for observing the ocean is important, which is not addressed in detail in the recent past. In this paper we provide a comprehensive overview of Sensor versus Essential Ocean Variable from our experience in sustained 25 years of moored ocean observation network and collaborating with institutions and experts in the United States and GOOS. An attempt has been made to furnish an overview for any group or nation to start or sustain an observation network using EOVs with guiding principles of Findable, Accessible, Interoperable, Reusable data that is targeted to deliver essential information needed for sustainable development and protecting ocean health.

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Sources of uncertainties in modelling black carbon at the global scale

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-2595-2010 ◽

2010 ◽

Vol 10 (6) ◽

pp. 2595-2611 ◽

Cited By ~ 138

Author(s):

E. Vignati ◽

M. Karl ◽

M. Krol ◽

J. Wilson ◽

P. Stier ◽

...

Keyword(s):

Black Carbon ◽

Large Scale ◽

Elemental Carbon ◽

Removal Rate ◽

Global Scale ◽

Polar Regions ◽

Emission Inventories ◽

Simplified Approach ◽

Microphysical Properties ◽

Carbon Concentrations

Abstract. Our understanding of the global black carbon (BC) cycle is essentially qualitative due to uncertainties in our knowledge of its properties. This work investigates two source of uncertainties in modelling black carbon: those due to the use of different schemes for BC ageing and its removal rate in the global Transport-Chemistry model TM5 and those due to the uncertainties in the definition and quantification of the observations, which propagate through to both the emission inventories, and the measurements used for the model evaluation. The schemes for the atmospheric processing of black carbon that have been tested with the model are (i) a simple approach considering BC as bulk aerosol and a simple treatment of the removal with fixed 70% of in-cloud black carbon concentrations scavenged by clouds and removed when rain is present and (ii) a more complete description of microphysical ageing within an aerosol dynamics model, where removal is coupled to the microphysical properties of the aerosol, which results in a global average of 40% in-cloud black carbon that is scavenged in clouds and subsequently removed by rain, thus resulting in a longer atmospheric lifetime. This difference is reflected in comparisons between both sets of modelled results and the measurements. Close to the sources, both anthropogenic and vegetation fire source regions, the model results do not differ significantly, indicating that the emissions are the prevailing mechanism determining the concentrations and the choice of the aerosol scheme does not influence the levels. In more remote areas such as oceanic and polar regions the differences can be orders of magnitude, due to the differences between the two schemes. The more complete description reproduces the seasonal trend of the black carbon observations in those areas, although not always the magnitude of the signal, while the more simplified approach underestimates black carbon concentrations by orders of magnitude. The sensitivity to wet scavenging has been tested by varying in-cloud and below-cloud removal. BC lifetime increases by 10% when large scale and convective scale precipitation removal efficiency are reduced by 30%, while the variation is very small when below-cloud scavenging is zero. Since the emission inventories are representative of elemental carbon-like substance, the model output should be compared to elemental carbon measurements and if known, the ratio of black carbon to elemental carbon mass should be taken into account when the model is compared with black carbon observations.

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