Data · dataset · 2026
Summertime influence of Asian pollution in the free troposphere over North America
Listed in National Center for Atmospheric Research
We analyze aircraft observations obtained during INTEX-A (1 July to 14 August 2004) to examine the summertime influence of Asian pollution in the free troposphere over North America.
Description
By applying correlation analysis and principal component analysis (PCA) to the observations between 6 and 12 km, we find dominant influences from recent convection and lightning (13% of observations), Asia (7%), the lower stratosphere (7%), and boreal forest fires (2%), with the remaining 71% assigned to background.
Asian air masses are marked by high levels of CO, O₃, HCN, PAN, C₂H₂, C₆H₆, methanol, and SO₄ 2- . The partitioning of NO y species in the Asian plumes is dominated by PAN (â¼600 pptv), with varying NO x /HNO₃ ratios in individual plumes, consistent with individual transit times of 3â9 days. Export of Asian pollution occurred in warm conveyor belts of midlatitude cyclones, deep convection, and in typhoons.
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Compared to Asian outflow measurements during spring, INTEX-A observations display lower levels of anthropogenic pollutants (CO, C₃H₈, C₂H6, C₆H₆) due to shorter summer lifetimes; higher levels of biogenic tracers (methanol and acetone) because of a more active biosphere; and higher levels of PAN, NO x , HNO₃, and O₃ reflecting active photochemistry, possibly enhanced by efficient NO y export and lightning. The high ÎO₃/ÎCO ratio (0.76 mol/mol) in Asian plumes during INTEX-A is due to strong photochemical production and, in some cases, mixing with stratospheric air along isentropic surfaces.
The GEOS-Chem global model captures the timing and location of the Asian plumes. However, it significantly underestimates the magnitude of observed enhancements in CO, O₃, PAN and NO x .
Links
Get the data
- Publisher page n2t.org/ark:/85065/d77m086h ↗
documentation · download · from data ucar edu
Where it is published
- data.ucar.edu /dataset/summertime-influence-of-asian-pollution-in-the-free-tr… ↗
National Center for Atmospheric Research dataset page
landing page · from data ucar edu
Catalogue records · 1
- CKAN API data.ucar.edu/api/3/action/package_show?id=3815360b-97a5-4e80-8ca8-eda5cd7c0… ↗
metadata API · from data ucar edu
Topics
- From keywords
- Earth & Environmental Science · Ocean & Atmospheric Science
Provenance · 1 source records, 7 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| National Center for Atmospheric Research | 3815360b-97a5-4e80-8ca8-eda5cd7c09dc | 12 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| concepts[field].local:field:earth-environmental | mapping · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| concepts[field].local:field:ocean-atmospheric | mapping · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| created_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| description | source · data ucar edu | connector:data_ucar_edu@1.0.0 | /notes |
| publication_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| title | source · data ucar edu | connector:data_ucar_edu@1.0.0 | /title |
| updated_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 |