Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires
<p><span id="page6272"/>Tropospheric nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub>)</span> measured from satellites has been widely used to track anthropogenic NO<span class="inline-formula"><sub><i>x...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-06-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/6271/2023/acp-23-6271-2023.pdf |
| _version_ | 1797809208165400576 |
|---|---|
| author | R. Dang D. J. Jacob V. Shah V. Shah V. Shah S. D. Eastham S. D. Eastham T. M. Fritz L. J. Mickley T. Liu Y. Wang Y. Wang J. Wang J. Wang |
| author_facet | R. Dang D. J. Jacob V. Shah V. Shah V. Shah S. D. Eastham S. D. Eastham T. M. Fritz L. J. Mickley T. Liu Y. Wang Y. Wang J. Wang J. Wang |
| author_sort | R. Dang |
| collection | DOAJ |
| description | <p><span id="page6272"/>Tropospheric nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub>)</span> measured from
satellites has been widely used to track anthropogenic NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions,
but its retrieval and interpretation can be complicated by the free tropospheric NO<span class="inline-formula"><sub>2</sub></span> background to which satellite measurements are
particularly sensitive. Tropospheric NO<span class="inline-formula"><sub>2</sub></span> vertical column densities
(VCDs) from the spaceborne Ozone Monitoring Instrument (OMI) averaged over the contiguous US
(CONUS) show no trend after 2009, despite sustained decreases in
anthropogenic NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions, implying an important and rising
contribution from the free tropospheric background. Here, we use the
GEOS-Chem chemical transport model applied to the simulation of OMI NO<span class="inline-formula"><sub>2</sub></span>
to better understand the sources and trends of background NO<span class="inline-formula"><sub>2</sub></span> over
CONUS. The previous model underestimate of the background is largely corrected
by the consideration of aerosol nitrate photolysis, which increases the
model NO<span class="inline-formula"><sub>2</sub></span> VCDs by 13 % on an annual basis (25 % in spring) and
also increases the air mass factor (AMF) to convert the tropospheric slant
column densities (SCDs) inferred from the OMI spectra into VCDs by 7 % on
an annual basis (11 % in spring). The increase in the AMF decreases the
retrieved NO<span class="inline-formula"><sub>2</sub></span> VCDs in the satellite observations, contributing to the
improved agreement with the model. Accounting for the 2009–2017 increase in
aircraft NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions drives only a 1.4 % mean increase in NO<span class="inline-formula"><sub>2</sub></span>
VCDs over CONUS and a 2 % increase in the AMF, but the combination of
decreasing surface NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions and increasing aircraft emissions is
expected to drive a 14 % increase in the AMF over the next decade that
will be necessary to account for in the interpretation of satellite NO<span class="inline-formula"><sub>2</sub></span>
trends. Fire smoke identification with the National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System (HMS)
indicates that wildfires contribute 1 %–8 % of OMI NO<span class="inline-formula"><sub>2</sub></span> VCDs over the
western US in June–September and that this contribution has been increasing
since 2009, contributing to the flattening of OMI NO<span class="inline-formula"><sub>2</sub></span> trends. Future
analyses of NO<span class="inline-formula"><sub>2</sub></span> trends from satellite data to infer trends in surface
NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions must critically consider the effects of a rising free tropospheric background due to increasing emissions from aircraft, fires,
and possibly lightning.</p> |
| first_indexed | 2024-03-13T06:49:05Z |
| format | Article |
| id | doaj.art-0784c2fa9c1942c4a59ae39168a2be61 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-03-13T06:49:05Z |
| publishDate | 2023-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-0784c2fa9c1942c4a59ae39168a2be612023-06-07T18:43:28ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242023-06-01236271628410.5194/acp-23-6271-2023Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open firesR. Dang0D. J. Jacob1V. Shah2V. Shah3V. Shah4S. D. Eastham5S. D. Eastham6T. M. Fritz7L. J. Mickley8T. Liu9Y. Wang10Y. Wang11J. Wang12J. Wang13John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USAJohn A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USAJohn A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USAnow at: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USAnow at: Science Systems and Applications, Inc., Lanham, MD 20706, USADepartment of Aeronautics and Astronautics, Laboratory for Aviation and the Environment, Massachusetts Institute of Technology, Cambridge, MA 02139, USAJoint Program on the Science and Policy of Global Change, Massachusetts Institute of Technology, Cambridge, MA 02139, USADepartment of Aeronautics and Astronautics, Laboratory for Aviation and the Environment, Massachusetts Institute of Technology, Cambridge, MA 02139, USAJohn A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USADepartment of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USACenter for Global and Regional Environmental Research, Iowa Technology Institute, The University of Iowa, Iowa City, IA 52242, USADepartment of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USACenter for Global and Regional Environmental Research, Iowa Technology Institute, The University of Iowa, Iowa City, IA 52242, USADepartment of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USA<p><span id="page6272"/>Tropospheric nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub>)</span> measured from satellites has been widely used to track anthropogenic NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions, but its retrieval and interpretation can be complicated by the free tropospheric NO<span class="inline-formula"><sub>2</sub></span> background to which satellite measurements are particularly sensitive. Tropospheric NO<span class="inline-formula"><sub>2</sub></span> vertical column densities (VCDs) from the spaceborne Ozone Monitoring Instrument (OMI) averaged over the contiguous US (CONUS) show no trend after 2009, despite sustained decreases in anthropogenic NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions, implying an important and rising contribution from the free tropospheric background. Here, we use the GEOS-Chem chemical transport model applied to the simulation of OMI NO<span class="inline-formula"><sub>2</sub></span> to better understand the sources and trends of background NO<span class="inline-formula"><sub>2</sub></span> over CONUS. The previous model underestimate of the background is largely corrected by the consideration of aerosol nitrate photolysis, which increases the model NO<span class="inline-formula"><sub>2</sub></span> VCDs by 13 % on an annual basis (25 % in spring) and also increases the air mass factor (AMF) to convert the tropospheric slant column densities (SCDs) inferred from the OMI spectra into VCDs by 7 % on an annual basis (11 % in spring). The increase in the AMF decreases the retrieved NO<span class="inline-formula"><sub>2</sub></span> VCDs in the satellite observations, contributing to the improved agreement with the model. Accounting for the 2009–2017 increase in aircraft NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions drives only a 1.4 % mean increase in NO<span class="inline-formula"><sub>2</sub></span> VCDs over CONUS and a 2 % increase in the AMF, but the combination of decreasing surface NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions and increasing aircraft emissions is expected to drive a 14 % increase in the AMF over the next decade that will be necessary to account for in the interpretation of satellite NO<span class="inline-formula"><sub>2</sub></span> trends. Fire smoke identification with the National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System (HMS) indicates that wildfires contribute 1 %–8 % of OMI NO<span class="inline-formula"><sub>2</sub></span> VCDs over the western US in June–September and that this contribution has been increasing since 2009, contributing to the flattening of OMI NO<span class="inline-formula"><sub>2</sub></span> trends. Future analyses of NO<span class="inline-formula"><sub>2</sub></span> trends from satellite data to infer trends in surface NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions must critically consider the effects of a rising free tropospheric background due to increasing emissions from aircraft, fires, and possibly lightning.</p>https://acp.copernicus.org/articles/23/6271/2023/acp-23-6271-2023.pdf |
| spellingShingle | R. Dang D. J. Jacob V. Shah V. Shah V. Shah S. D. Eastham S. D. Eastham T. M. Fritz L. J. Mickley T. Liu Y. Wang Y. Wang J. Wang J. Wang Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires Atmospheric Chemistry and Physics |
| title | Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires |
| title_full | Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires |
| title_fullStr | Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires |
| title_full_unstemmed | Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires |
| title_short | Background nitrogen dioxide (NO<sub>2</sub>) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open fires |
| title_sort | background nitrogen dioxide no sub 2 sub over the united states and its implications for satellite observations and trends effects of nitrate photolysis aircraft and open fires |
| url | https://acp.copernicus.org/articles/23/6271/2023/acp-23-6271-2023.pdf |
| work_keys_str_mv | AT rdang backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT djjacob backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT vshah backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT vshah backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT vshah backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT sdeastham backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT sdeastham backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT tmfritz backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT ljmickley backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT tliu backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT ywang backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT ywang backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT jwang backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires AT jwang backgroundnitrogendioxidenosub2subovertheunitedstatesanditsimplicationsforsatelliteobservationsandtrendseffectsofnitratephotolysisaircraftandopenfires |