scholarly journals Inverse modeling of CH<sub>4</sub> emissions for 2010–2011 using different satellite retrieval products from GOSAT and SCIAMACHY

2014 ◽  
Vol 14 (8) ◽  
pp. 11493-11539 ◽  
Author(s):  
M. Alexe ◽  
P. Bergamaschi ◽  
A. Segers ◽  
R. Detmers ◽  
A. Butz ◽  
...  
Keyword(s):  
Inverse Modeling ◽  
Near Infrared ◽  
Total Carbon ◽  
Atmospheric Methane ◽  
Equatorial Africa ◽  
New Space ◽  
Institute Of Technology ◽  
Scanning Imaging ◽  
The University ◽  
Air Column

Abstract. Beginning in 2009 new space-borne observations of dry-air column-averaged mole fractions of atmospheric methane (XCH4) became available from the Thermal And Near infrared Sensor for carbon Observations–Fourier Transform Spectrometer (TANSO-FTS) instrument onboard the Greenhouse Gases Observing SATellite (GOSAT). Until April 2012 concurrent CH4 measurements were provided by the SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) instrument onboard ENVISAT. The GOSAT and SCIAMACHY XCH4 retrievals can be compared during their circa 32 month period of overlap. We estimate monthly average CH4 emissions between January 2010 and December 2011, using the TM5-4DVAR inverse modeling system. Additionally, high-accuracy measurements from the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA ESRL) global air sampling network are used, providing strong constraints of the remote surface atmosphere. We discuss five inversion scenarios that make use of different GOSAT and SCIAMACHY XCH4 retrieval products, including two sets of GOSAT proxy retrievals processed independently by the Netherlands Institute for Space Research (SRON)/Karlsruhe Institute of Technology (KIT), and the University of Leicester (UL), and the RemoTeC "Full-Physics" (FP) XCH4 retrievals available from SRON/KIT. 2 year average emission maps show a~good overall agreement among all GOSAT-based inversions, and compared to the SCIAMACHY-based inversion, with consistent flux adjustment patterns, particularly across Equatorial Africa and North America. The inversions are validated against independent shipboard and aircraft observations, and XCH4 measurements available from the Total Carbon Column Observing Network (TCCON). All GOSAT and SCIAMACHY inversions show very similar validation performance.

scholarly journals Assimilation of atmospheric methane products in the MACC-II system: from SCIAMACHY to TANSO and IASI

2014 ◽  
Vol 14 (2) ◽  
pp. 2553-2599
Author(s):  
S. Massart ◽  
A. Agusti-Panareda ◽  
I. Aben ◽  
A. Butz ◽  
F. Chevallier ◽  
...  
Keyword(s):  
Near Infrared ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
Winter Period ◽  
Tropical Region ◽  
Atmospheric Methane ◽  
Atmospheric Sounding ◽  
Scanning Imaging ◽  
Global Bias ◽  
The Impact

Abstract. The Monitoring Atmospheric Composition and Climate Interim Implementation (MACC-II) delayed-mode (DM) system has been producing an atmospheric methane (CH4) analysis 6 months behind real time since June 2009. This analysis used to rely on the assimilation of the CH4 product from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument on board Envisat. Recently the \\textit{Laboratoire de Météorologie Dynamique} (LMD) CH4 products from the Infrared Atmospheric Sounding Interferometer (IASI) and the SRON Netherlands Institute for Space Research CH4 products from the Thermal And Near-infrared Sensor for carbon Observation (TANSO) were added to the DM system. With the loss of Envisat in April 2012, the DM system has to now rely on the assimilation of methane data from TANSO and IASI. This paper documents the impact of this change in the observing system on the methane tropospheric analysis. It is based on four experiments: one free run and three analyses from respectively the assimilation of SCIAMACHY, TANSO and a combination of TANSO and IASI CH4 products in the MACC-II system. The period between December 2010 and April 2012 is studied. This corresponds to a period during which the performance of SCIAMACHY was deteriorating. The SCIAMACHY experiment globally underestimates the tropospheric methane by 35 part per billion (ppb) compared to the HIAPER Pole-to-Pole Observations (HIPPO) data and the methane column by 23 ppb compared the Total Carbon Column Observing Network (TCCON) data, when the global bias of the free run against the same HIPPO and TCCON data is respectively −5 ppb and 4 ppb. The assimilated TANSO product changed in October 2011 from version v.1 to version v.2.0. The analysis of version v.1 globally underestimates the tropospheric methane by 18 ppb compared to the HIPPO data and the column by 11 ppb compared to the TCCON data. In contrast, the analysis of version v.2.0 globally overestimates the column by 10 ppb. When the high density IASI data are added in the tropical region between 30° N and 30° S, the resulting analysis is slightly less biased in the troposphere than the TANSO analysis when compared to the HIPPO data. In the meantime, this IASI plus TANSO analysis presents the worst correlation with the HIPPO data. In terms of column, the addition of the IASI data to the version v.2.0 of the TANSO data has a significant impact, mainly over extratropical regions, reducing the global bias to 6 ppb. The analysis based on the assimilation of the combination of TANSO and IASI products as well as the SCIAMACHY analysis should nevertheless be used with caution when looking at the seasonal cycle or inter-hemispheric gradient because of the unavailability of the measurements over large regions during the local winter period.

scholarly journals Assimilation of atmospheric methane products into the MACC-II system: from SCIAMACHY to TANSO and IASI

2014 ◽  
Vol 14 (12) ◽  
pp. 6139-6158 ◽  
Author(s):  
S. Massart ◽  
A. Agusti-Panareda ◽  
I. Aben ◽  
A. Butz ◽  
F. Chevallier ◽  
...  
Keyword(s):  
Near Infrared ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
Tropical Region ◽  
Atmospheric Methane ◽  
Infrared Sensor ◽  
Atmospheric Sounding ◽  
Scanning Imaging ◽  
The Tropics ◽  
The Impact

Abstract. The Monitoring Atmospheric Composition and Climate Interim Implementation (MACC-II) delayed-mode (DM) system has been producing an atmospheric methane (CH4) analysis 6 months behind real time since June 2009. This analysis used to rely on the assimilation of the CH4 product from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument onboard Envisat. Recently the Laboratoire de Météorologie Dynamique (LMD) CH4 products from the Infrared Atmospheric Sounding Interferometer (IASI) and the SRON Netherlands Institute for Space Research CH4 products from the Thermal And Near-infrared Sensor for carbon Observation (TANSO) were added to the DM system. With the loss of Envisat in April 2012, the DM system now has to rely on the assimilation of methane data from TANSO and IASI. This paper documents the impact of this change in the observing system on the methane tropospheric analysis. It is based on four experiments: one free run and three analyses from respectively the assimilation of SCIAMACHY, TANSO and a combination of TANSO and IASI CH4 products in the MACC-II system. The period between December 2010 and April 2012 is studied. The SCIAMACHY experiment globally underestimates the tropospheric methane by 35 part per billion (ppb) compared to the HIAPER Pole-to-Pole Observations (HIPPO) data and by 28 ppb compared the Total Carbon Column Observing Network (TCCON) data, while the free run presents an underestimation of 5 ppb and 1 ppb against the same HIPPO and TCCON data, respectively. The assimilated TANSO product changed in October 2011 from version v.1 to version v.2.0. The analysis of version v.1 globally underestimates the tropospheric methane by 18 ppb compared to the HIPPO data and by 15 ppb compared to the TCCON data. In contrast, the analysis of version v.2.0 globally overestimates the column by 3 ppb. When the high density IASI data are added in the tropical region between 30° N and 30° S, their impact is mainly positive but more pronounced and effective when combined with version v.2.0 of the TANSO products. The resulting analysis globally underestimates the column-averaged dry-air mole fractions of methane (xCH4) just under 1 ppb on average compared to the TCCON data, whereas in the tropics it overestimates xCH4 by about 3 ppb. The random error is estimated to be less than 7 ppb when compared to TCCON data.

scholarly journals Large XCH<sub>4</sub> anomaly in summer 2013 over northeast Asia observed by GOSAT

2016 ◽  
Vol 16 (14) ◽  
pp. 9149-9161 ◽  
Author(s):  
Misa Ishizawa ◽  
Osamu Uchino ◽  
Isamu Morino ◽  
Makoto Inoue ◽  
Yukio Yoshida ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Northeast Asia ◽  
Total Carbon ◽  
East China ◽  
Limited Area ◽  
Atmospheric Methane ◽  
Flux Estimation

Abstract. Extremely high levels of column-averaged dry-air mole fractions of atmospheric methane (XCH4) were detected in August and September 2013 over northeast Asia (∼  20 ppb above the averaged summertime XCH4 over 2009–2012, after removing a long-term trend), as being retrieved from the Short-Wavelength InfraRed (SWIR) spectral data observed with the Thermal And Near-infrared Sensor for carbon Observation – Fourier Transform Spectrometer (TANSO-FTS) onboard Greenhouse Gases Observing Satellite (GOSAT). Similar enhancements of XCH4 were also observed by the ground-based measurements at two Total Carbon Column Observing Network (TCCON) sites in Japan. The analysis of surface CH4 concentrations observed at three monitoring sites around the Japan archipelago suggest that the extreme increase of XCH4 has occurred in a limited area. The model analysis was conducted to investigate this anomalously high XCH4 event, using an atmospheric transport model. The results indicate that the extreme increase of XCH4 is attributed to the anomalous atmospheric pressure pattern over East Asia during the summer of 2013, which effectively transported the CH4-rich air to Japan from the strong CH4 source areas in east China. The two Japanese TCCON sites, ∼  1000 km east–west apart each other, coincidentally located along the substantially CH4-rich air flow from east China. This analysis demonstrates the capability of GOSAT to monitor an XCH4 event on a synoptic scale. We anticipate that the synoptic information of XCH4 from GOSAT data contributes to improve our understanding of regional carbon cycle and the regional flux estimation.

scholarly journals Inverse modelling of CH<sub>4</sub> emissions for 2010–2011 using different satellite retrieval products from GOSAT and SCIAMACHY

2015 ◽  
Vol 15 (1) ◽  
pp. 113-133 ◽  
Author(s):  
M. Alexe ◽  
P. Bergamaschi ◽  
A. Segers ◽  
R. Detmers ◽  
A. Butz ◽  
...  
Keyword(s):  
North America ◽  
Near Infrared ◽  
Gas Production ◽  
Congo Basin ◽  
Total Carbon ◽  
Inverse Modelling ◽  
Atmospheric Methane ◽  
Ch4 Emissions ◽  
North East ◽  
South Central

Abstract. At the beginning of 2009 new space-borne observations of dry-air column-averaged mole fractions of atmospheric methane (XCH4) became available from the Thermal And Near infrared Sensor for carbon Observations–Fourier Transform Spectrometer (TANSO-FTS) instrument on board the Greenhouse Gases Observing SATellite (GOSAT). Until April 2012 concurrent {methane (CH4) retrievals} were provided by the SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) instrument on board the ENVironmental SATellite (ENVISAT). The GOSAT and SCIAMACHY XCH4 retrievals can be compared during the period of overlap. We estimate monthly average CH4 emissions between January 2010 and December 2011, using the TM5-4DVAR inverse modelling system. In addition to satellite data, high-accuracy measurements from the Cooperative Air Sampling Network of the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA ESRL) are used, providing strong constraints on the remote surface atmosphere. We discuss five inversion scenarios that make use of different GOSAT and SCIAMACHY XCH4 retrieval products, including two sets of GOSAT proxy retrievals processed independently by the Netherlands Institute for Space Research (SRON)/Karlsruhe Institute of Technology (KIT), and the University of Leicester (UL), and the RemoTeC "Full-Physics" (FP) XCH4 retrievals available from SRON/KIT. The GOSAT-based inversions show significant reductions in the root mean square (rms) difference between retrieved and modelled XCH4, and require much smaller bias corrections compared to the inversion using SCIAMACHY retrievals, reflecting the higher precision and relative accuracy of the GOSAT XCH4. Despite the large differences between the GOSAT and SCIAMACHY retrievals, 2-year average emission maps show overall good agreement among all satellite-based inversions, with consistent flux adjustment patterns, particularly across equatorial Africa and North America. Over North America, the satellite inversions result in a significant redistribution of CH4 emissions from North-East to South-Central United States. This result is consistent with recent independent studies suggesting a systematic underestimation of CH4 emissions from North American fossil fuel sources in bottom-up inventories, likely related to natural gas production facilities. Furthermore, all four satellite inversions yield lower CH4 fluxes across the Congo basin compared to the NOAA-only scenario, but higher emissions across tropical East Africa. The GOSAT and SCIAMACHY inversions show similar performance when validated against independent shipboard and aircraft observations, and XCH4 retrievals available from the Total Carbon Column Observing Network (TCCON).

Travels with an EM27, measurements of CO2 and CH4 below 45 degrees south.

2020 ◽  
Author(s):  
David F. Pollard ◽  
Dan Smale ◽  
Hue Tran ◽  
Jamie McGaw ◽  
Frank Hase ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Fourier Transform ◽  
New Zealand ◽  
Near Infrared ◽  
Austral Summer ◽  
Total Carbon ◽  
Fourier Transform Spectrometer ◽  
Solar Absorption ◽  
Institute Of Technology ◽  
Karlsruhe Institute

&lt;p&gt;During 2016 and again during 2019 through 2020 an EM27/SUN portable near infrared solar absorption Fourier Transform Spectrometer of the Karlsruhe Institute of Technology was transported first to Lauder, New Zealand (45.034S, 169.68E, alt. 370&amp;#160;m) and then to the Arrival Heights laboratory, Ross Island Antarctica (77.82S, 166.65E, 200&amp;#160;m). On the first occasion the EM27/SUN made the first ever near infrared solar absorption retrievals of carbon dioxide and methane in Antarctica over a period of two weeks. The second deployment had the aim of making retrievals in Antarctica throughout the 2019-2020 Austral summer.&lt;/p&gt;&lt;p&gt;We report on the comparison of retrievals of carbon dioxide and methane from the EM27 spectra with those made by the Total Carbon Column Observing Network (TCCON) stations at both Karlsruhe and Lauder and compare with similar comparisons made throughout the Collaborative Carbon Column Observing Network (COCCON), as well as the latitudinal extension of these measurements to Antarctica.&lt;/p&gt;&lt;p&gt;Further comparisons with observations from TROPOMI instrument on the Sentinel 5 precursor satellite will be discussed.&lt;/p&gt;

scholarly journals Large XCH<sub>4</sub> anomaly in summer 2013 over Northeast Asia observed by GOSAT

2015 ◽  
Vol 15 (17) ◽  
pp. 24995-25020 ◽  
Author(s):  
M. Ishizawa ◽  
O. Uchino ◽  
I. Morino ◽  
M. Inoue ◽  
Y. Yoshida ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Northeast Asia ◽  
Total Carbon ◽  
East China ◽  
Limited Area ◽  
Atmospheric Methane ◽  
Synoptic Scale ◽  
Comparable Accuracy

Abstract. Extremely high levels of column-averaged dry-air mole fractions of atmospheric methane (XCH4) were detected in August and September 2013 over Northeast Asia (~ 20 ppb above the averaged summertime XCH4 over 2009–2012, after removing a long-term trend), as being retrieved from the Short-Wavelength InfraRed (SWIR) spectral data observed with the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard Greenhouse Gases Observing Satellite (GOSAT). Similar enhancements of XCH4 were also observed by the ground-based measurements at two Total Carbon Column Observing Network (TCCON) sites in Japan. The analysis of surface CH4 concentrations observed at three monitoring sites around the Japan islands suggest that the extreme increase of XCH4 has occurred in a limited area. The model analysis was conducted to investigate this anomalously high XCH4 event, using an atmospheric transport model. The results indicate that the extreme increase of XCH4 is attributed to the anomalous atmospheric pressure pattern over East Asia during the summer of 2013, which effectively transported the CH4-rich air to Japan from the strong CH4 source areas in East China. The two Japanese TCCON sites, ~ 1000 km east-west apart each other, coincidentally located along the substantially CH4-rich air flow from East China. The GOSAT orbiting with three-day recurrence successfully observed the synoptic-scale XCH4 enhancement in the comparable accuracy to the TCCON data. This analysis demonstrates the capability of GOSAT to monitor an XCH4 event on a synoptic scale.

CARBON FOOTPRINT ASSESSMENT AT UNIVERSITI TEKNOLOGI MARA SERI ISKANDAR CAMPUS, MALAYSIA

2017 ◽  
Vol 2 (1) ◽  
pp. 59
Author(s):  
Nor Izana Mohd Shobri ◽  
Wan Noor Anira Hj Wan Ali ◽  
Norizan Mt Akhir ◽  
Siti Rasidah Md Sakip
Keyword(s):  
Total Energy ◽  
Carbon Footprint ◽  
Electrical Power ◽  
Total Carbon ◽  
Green House ◽  
Green House Gas ◽  
Carbon Footprint Assessment ◽  
The University ◽  
Electrical Consumption

The purpose of this study is to assess the carbon footprint emission at UiTM Perak, Seri Iskandar Campus. The assessment focuses on electrical power and transportation usage. Questionnaires were distributed to the staffs and students to survey their transportation usage in the year 2014 while for electrical consumption, the study used total energy consumed in the year 2014. Data was calculating with the formula by Green House Gas Protocol. Total carbon footprint produced by UiTM Perak, Seri Jskandar Campus in the year 2014 is 11842.09 MTC02' The result of the study is hoped to provide strategies for the university to reduce the carbon footprint emission.

INSULATION AGAINST ICE AT MEASURING WEIRS

1974 ◽  
Vol 5 (1) ◽  
pp. 32-49 ◽  
Author(s):  
JOHN TVEIT
Keyword(s):  
Hydraulic Engineering ◽  
Simple Method ◽  
Institute Of Technology ◽  
The University ◽  
Difficult Cases

This article deals with the problem of insulating measuring weirs to avoid ice disturbances. The development of a simple method for insulating a conventional V-weir is described. This method will serve its purpose in many cases. For more difficult cases a special type of a fully insulated weir is described. The experiments described were carried out by The Division of Hydraulic Engineering, The University of Trondheim, The Norwegian Institute of Technology, at the River and Harbour Laboratory of the University, and at the IHD representative basin Sagelva.

Near-Infrared Off-Axis Integrated Cavity Output Spectroscopic Gas Sensor for Real-Time, In Situ Atmospheric Methane Monitoring

2020 ◽  
pp. 1-1
Author(s):  
Kaiyuan Zheng ◽  
Chuantao Zheng ◽  
Haipeng Zhang ◽  
Junhao Li ◽  
Zidi Liu ◽  
...  
Keyword(s):  
Real Time ◽  
Gas Sensor ◽  
Near Infrared ◽  
Atmospheric Methane ◽  
Cavity Output
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