scholarly journals The MOPITT Version 6 product: algorithm enhancements and validation

2014 ◽  
Vol 7 (6) ◽  
pp. 6113-6139 ◽  
Author(s):  
M. N. Deeter ◽  
S. Martínez-Alonso ◽  
D. P. Edwards ◽  
L. K. Emmons ◽  
J. C. Gille ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Retrospective Analysis ◽  
Transport Model ◽  
A Priori ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
Upper Troposphere ◽  
Modern Era ◽  
Retrieval Bias ◽  
Co Concentrations

Abstract. The MOPITT Version 6 (V6) product for carbon monoxide (CO) incorporates several enhancements which will benefit many users of MOPITT data. V6 algorithm improvements are described in detail, and V6 validation results are presented. First, a geolocation bias related to the orientation of the MOPITT instrument relative to the TERRA platform was characterized and eliminated. Second, the variable a priori for CO concentrations for V6 is based on simulations performed with the CAM-Chem chemical transport model for the years 2000–2009 instead of the model-derived climatology for 1997–2004 used for V5. Third, meteorological fields required for V6 retrieval processing are extracted from the MERRA ("Modern-Era Retrospective Analysis For Research And Applications") reanalysis. Finally, a significant latitude-dependent retrieval bias in the upper troposphere in Version 5 products has been substantially reduced.

scholarly journals The MOPITT Version 6 product: algorithm enhancements and validation

2014 ◽  
Vol 7 (11) ◽  
pp. 3623-3632 ◽  
Author(s):  
M. N. Deeter ◽  
S. Martínez-Alonso ◽  
D. P. Edwards ◽  
L. K. Emmons ◽  
J. C. Gille ◽  
...  
Keyword(s):  
Transport Model ◽  
A Priori ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
Upper Troposphere ◽  
Community Atmosphere Model ◽  
Model Community ◽  
Modern Era ◽  
Retrieval Bias ◽  
Co Concentrations

Abstract. The Measurements of Pollution in the Troposphere (MOPITT) Version 6 (V6) product for carbon monoxide (CO) incorporates several enhancements which will benefit many users of MOPITT data. V6 algorithm improvements are described in detail, and V6 validation results are presented. First, a geolocation bias related to the orientation of the MOPITT instrument relative to the TERRA platform was characterized and eliminated. Second, the variable a priori for CO concentrations for V6 is based on simulations performed with the chemical transport model Community Atmosphere Model with Chemistry (CAM-chem) for the years 2000–2009 instead of the model-derived climatology for 1997–2004 used for V5. Third, meteorological fields required for V6 retrieval processing are extracted from the MERRA (Modern-Era Retrospective Analysis For Research And Applications) reanalysis. Finally, a significant latitude-dependent retrieval bias in the upper troposphere in Version 5 products has been substantially reduced.

scholarly journals Estimated total emissions of trace gases from the Canberra wildfires of 2003: a new method using satellite measurements of aerosol optical depth and the MOZART chemical transport model

2010 ◽  
Vol 10 (1) ◽  
pp. 977-1004
Author(s):  
C. Paton-Walsh ◽  
L. K. Emmons ◽  
S. R. Wilson
Keyword(s):  
Carbon Monoxide ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Transport Model ◽  
Trace Gases ◽  
Chemical Transport ◽  
New Method ◽  
Chemical Transport Model ◽  
Additional Tool ◽  
Vegetation Fires

Abstract. In this paper we describe a new method for estimating trace gas emissions from large vegetation fires using measurements of aerosol optical depth from the MODIS instruments onboard NASA's Terra and Aqua satellites, combined with the atmospheric chemical transport model MOZART. The model allows for an estimate of double counting of enhanced levels of aerosol optical depth in consecutive satellite overpasses. Using this method we infer an estimated total emission of 10±3 Tg of carbon monoxide from the Canberra fires of 2003. Emissions estimates for several other trace gases are also given. An assessment of the uncertainties in the new method is made and we show that our estimate agrees (within expected uncertainties) with estimates made using current conventional methods of multiplying together factors for the area burned, fuel load, the combustion efficiency and the emission factor for carbon monoxide. The new method for estimating emissions from large vegetation fires described in this paper has some significant uncertainties, but these are mainly quantifiable and largely independent of the uncertainties inherent in conventional techniques. Thus we conclude that the new method is a useful additional tool for characterising emissions from vegetation fires.

scholarly journals New constraints on biogenic emissions using satellite-based estimates of carbon monoxide fluxes

2019 ◽  
Vol 19 (21) ◽  
pp. 13569-13579 ◽  
Author(s):  
Helen M. Worden ◽  
A. Anthony Bloom ◽  
John R. Worden ◽  
Zhe Jiang ◽  
Eloise A. Marais ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Transport Model ◽  
A Priori ◽  
Primary Source ◽  
Biogenic Emissions ◽  
Chemical Production ◽  
Chemical Transport Model ◽  
Ozone Monitoring Instrument ◽  
Top Down ◽  
Decadal Scale

Abstract. Biogenic non-methane volatile organic compounds (NMVOCs) emitted from vegetation are a primary source for the chemical production of carbon monoxide (CO) in the atmosphere, and these biogenic emissions account for about 18 % of the global CO burden. Partitioning CO fluxes to different source types in top-down inversion methods is challenging; typically a simple scaling of the posterior flux to prior flux values for fossil fuel, biogenic and biomass burning sources is used. Here we show top-down estimates of biogenic CO fluxes using a Bayesian inference approach, which explicitly accounts for both posterior and a priori CO flux uncertainties. This approach re-partitions CO fluxes following inversion of Measurements Of Pollution In The Troposphere (MOPITT) CO observations with the GEOS-Chem model, a global chemical transport model driven by assimilated meteorology from the NASA Goddard Earth Observing System (GEOS). We compare these results to the prior information for CO used to represent biogenic NMVOCs from GEOS-Chem, which uses the Model of Emissions of Gases and Aerosols from Nature (MEGAN) for biogenic emissions. We evaluate the a posteriori biogenic CO fluxes against top-down estimates of isoprene fluxes using Ozone Monitoring Instrument (OMI) formaldehyde observations. We find similar seasonality and spatial consistency in the posterior CO and top-down isoprene estimates globally. For the African savanna region, both top-down CO and isoprene seasonality vary significantly from the MEGAN a priori inventory. This method for estimating biogenic sources of CO will provide an independent constraint on modeled biogenic emissions and has the potential for diagnosing decadal-scale changes in emissions due to land-use change and climate variability.

scholarly journals Estimated total emissions of trace gases from the Canberra Wildfires of 2003: a new method using satellite measurements of aerosol optical depth & the MOZART chemical transport model

2010 ◽  
Vol 10 (12) ◽  
pp. 5739-5748 ◽  
Author(s):  
C. Paton-Walsh ◽  
L. K. Emmons ◽  
S. R. Wilson
Keyword(s):  
Carbon Monoxide ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Transport Model ◽  
Chemical Transport ◽  
New Method ◽  
Chemical Transport Model ◽  
Satellite Measurements ◽  
Additional Tool ◽  
Vegetation Fires

Abstract. In this paper we describe a new method for estimating trace gas emissions from large vegetation fires using satellite measurements of aerosol optical depth (AOD) at 550 nm, combined with an atmospheric chemical transport model. The method uses a threshold value to screen out normal levels of AOD that may be caused by raised dust, sea salt aerosols or diffuse smoke transported from distant fires. Using this method we infer an estimated total emission of 15±5 Tg of carbon monoxide, 0.05±0.02 Tg of hydrogen cyanide, 0.11±0.03 Tg of ammonia, 0.25±0.07 Tg of formaldehyde, 0.03±0.01 of acetylene, 0.10±0.03 Tg of ethylene, 0.03±0.01 Tg of ethane, 0.21±0.06 Tg of formic acid and 0.28±0.09 Tg of methanol released to the atmosphere from the Canberra fires of 2003. An assessment of the uncertainties in the new method is made and we show that our estimate agrees (within expected uncertainties) with estimates made using current conventional methods of multiplying together factors for the area burned, fuel load, the combustion efficiency and the emission factor for carbon monoxide. A simpler estimate derived directly from the satellite AOD measurements is also shown to be in agreement with conventional estimates, suggesting that the method may, under certain meteorological conditions, be applied without the complication of using a chemical transport model. The new method is suitable for estimating emissions from distinct large fire episodes and although it has some significant uncertainties, these are largely independent of the uncertainties inherent in conventional techniques. Thus we conclude that the new method is a useful additional tool for characterising emissions from vegetation fires.

scholarly journals Characteristics of intercontinental transport of tropospheric ozone from Africa to Asia

2017 ◽  
Author(s):  
Han Han ◽  
Jane Liu ◽  
Huiling Yuan ◽  
Ye Zhu ◽  
Yue Wu ◽  
...  
Keyword(s):  
Tropospheric Ozone ◽  
Transport Model ◽  
Chemical Transport ◽  
Early Spring ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Chemical Transport Model ◽  
Upper Troposphere ◽  
Intercontinental Transport ◽  
Global Chemical Transport Model

Abstract. Based on 20-year simulations using a global chemical transport model, GEOS-Chem, and a trajectory model, HYSPLIT, the transport of ozone produced in the African troposphere to Asia is investigated. The study shows that the influence of African ozone on Asia varies largely in time and space. In the middle and upper troposphere, the inflow of African ozone to Asia peaks around 25° N, being the largest in boreal winter and early spring (> 10 ppbv) and the lowest in boreal summer (

scholarly journals Global and regional effects of the photochemistry of CH<sub>3</sub>O<sub>2</sub>NO<sub>2</sub>: evidence from ARCTAS

2011 ◽  
Vol 11 (1) ◽  
pp. 2233-2262
Author(s):  
E. C. Browne ◽  
A. E. Perring ◽  
P. J. Wooldridge ◽  
E. Apel ◽  
S. R. Hall ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Biomass Burning ◽  
Low Temperatures ◽  
Transport Model ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
Upper Troposphere ◽  
Regional Effects ◽  
Global Chemical Transport Model ◽  
Lightning Nox

Abstract. Using measurements from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) experiment, we show that methyl peroxy nitrate (CH3O2NO2) is present in concentrations of ~5–15 pptv in the springtime arctic upper troposphere. We investigate the regional and global effects of CH3O2NO2 by including its chemistry in the GEOS-CHEM 3-D global chemical transport model. We find that at temperatures below 240 K inclusion of CH3O2NO2 chemistry results in decreases of up to ~20% in NOx, ~20% in N2O5, ~5% in HNO3, ~2% in ozone, and increases in methyl hydrogen peroxide of up to ~14%. Larger changes are observed in biomass burning plumes lofted to high altitude. Additionally, by sequestering NOx at low temperatures, CH3O2NO2 decreases the cycling of HO2 to OH, resulting in a larger upper tropospheric HO2 to OH ratio. These results may impact some estimates of lightning NOx sources as well as help explain differences between models and measurements of upper tropospheric composition.

scholarly journals Global and regional effects of the photochemistry of CH<sub>3</sub>O<sub>2</sub>NO<sub>2</sub>: evidence from ARCTAS

2011 ◽  
Vol 11 (9) ◽  
pp. 4209-4219 ◽  
Author(s):  
E. C. Browne ◽  
A. E. Perring ◽  
P. J. Wooldridge ◽  
E. Apel ◽  
S. R. Hall ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Biomass Burning ◽  
Low Temperatures ◽  
Transport Model ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
Upper Troposphere ◽  
Regional Effects ◽  
Global Chemical Transport Model ◽  
Lightning Nox

Abstract. Using measurements from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) experiment, we show that methyl peroxy nitrate (CH3O2NO2) is present in concentrations of ~5–15 pptv in the springtime arctic upper troposphere. We investigate the regional and global effects of CH3O2NO2 by including its chemistry in the GEOS-Chem 3-D global chemical transport model. We find that at temperatures below 240 K inclusion of CH3O2NO2 chemistry results in decreases of up to ~20 % in NOx, ~20 % in N2O5, ~5 % in HNO3, ~2 % in ozone, and increases in methyl hydrogen peroxide of up to ~14 %. Larger changes are observed in biomass burning plumes lofted to high altitude. Additionally, by sequestering NOx at low temperatures, CH3O2NO2 decreases the cycling of HO2 to OH, resulting in a larger upper tropospheric HO2 to OH ratio. These results may impact some estimates of lightning NOx sources as well as help explain differences between models and measurements of upper tropospheric composition.

scholarly journals New Constraints on Biogenic Emissions using Satellite-Based Estimates of Carbon Monoxide Fluxes

2019 ◽  
Author(s):  
Helen M. Worden ◽  
A. Anthony Bloom ◽  
John R. Worden ◽  
Zhe Jiang ◽  
Eloise Marais ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Transport Model ◽  
A Priori ◽  
Primary Source ◽  
Biogenic Emissions ◽  
Chemical Production ◽  
Chemical Transport Model ◽  
Ozone Monitoring Instrument ◽  
Top Down ◽  
Decadal Scale

Abstract. Biogenic non-methane volatile organic compounds (NMVOCs) emitted from vegetation are a primary source for the chemical production of carbon monoxide (CO) in the atmosphere and these biogenic emissions account for about 18 % of the global CO burden. Partitioning CO fluxes to different source types in top-down inversion methods is challenging and typically a simple scaling of the posterior flux to prior flux values for fossil fuel, biogenic and biomass burning sources is used. Here we show top-down estimates of biogenic CO fluxes using a Bayesian inference approach, which explicitly accounts for both posterior and a priori CO flux uncertainties. This approach re-partitions CO fluxes following inversion of Measurements Of Pollution In The Troposphere (MOPITT) CO observations with the GEOS-Chem model, a global chemical transport model driven by assimilated meteorology from the NASA Goddard Earth Observing System (GEOS). We compare these results to the prior information for CO used to represent biogenic NMVOCs from GEOS-Chem, which uses the Model of Emissions of Gases and Aerosols from Nature (MEGAN) for biogenic emissions. We evaluate the a posteriori biogenic CO fluxes against top-down estimates of isoprene fluxes using Ozone Monitoring Instrument (OMI) formaldehyde observations. We find similar seasonality and spatial consistency in the posterior CO and top-down isoprene estimates globally. For the African savanna region, both top-down CO and isoprene seasonality vary significantly from the MEGAN apriori inventory. This method for estimating biogenic sources of CO will provide an independent constraint on modelled biogenic emissions and has the potential for diagnosing decadal-scale changes in emissions due to land-use change and climate variability.

First estimate of NO2 in the upper troposphere from TROPOMI

2020 ◽  
Author(s):  
Eloise Marais ◽  
Joanna Joiner ◽  
Sungyeon Choi
Keyword(s):  
Transport Model ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
Ozone Monitoring Instrument ◽  
Commercial Aircraft ◽  
Upper Troposphere ◽  
Aircraft Observations ◽  
Research Aircraft ◽  
Ozone Monitoring ◽  
Sky Conditions

&lt;p&gt;Nitrogen oxides (NO&lt;sub&gt; x&lt;/sub&gt; = NO + NO&lt;sub&gt;2&lt;/sub&gt;) in the upper troposphere (~10-12 km) are effective at producing ozone in the upper troposphere where ozone is a potent greenhouse gas. Observations of NO&lt;sub&gt;x&lt;/sub&gt; in the upper troposphere are limited in time to a few intensive research aircraft campaigns and in space to commercial aircraft campaigns. There are satellite-derived observations of NO&lt;sub&gt;2&lt;/sub&gt; in the upper troposphere from the Ozone Monitoring Instrument (OMI), but these are at very coarse resolutions (seasonal, &gt; 2,000 km). The high-resolution Sentinel-5P/TROPOMI instrument offers higher spatial resolution and better cloud-resolving capability than OMI. Here we use synthetic columns of NO&lt;sub&gt;2&lt;/sub&gt; from the GEOS-Chem chemical transport model to assess feasibility of deriving NO&lt;sub&gt;2&lt;/sub&gt; in the upper troposphere using partial columns of NO&lt;sub&gt;2&lt;/sub&gt; above cloudy scenes (the so-called cloud-slicing technique). The model is also used to quantify errors induced by uncertainties in cloud-top height and to determine whether NO&lt;sub&gt;2&lt;/sub&gt; over cloudy scenes is representative of all-sky conditions (the &quot;truth&quot;). We find that the cloud-slicing approach is spatially consistent (R =0.5) with the &quot;truth&quot;, but with a small (10 pptv) bias in background NO&lt;sub&gt;2&lt;/sub&gt;. Cloud-slicing is then applied to TROPOMI total columns of NO&lt;sub&gt;2&lt;/sub&gt; to derive near-global observations of NO&lt;sub&gt;2&lt;/sub&gt; in the upper troposphere and assessed against the existing OMI products and aircraft observations from NASA DC8 aircraft campaigns.&lt;/p&gt;

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