Data · dataset · 2026
Black carbon over Mexico: The effect of atmospheric transport on mixing state, mass absorption cross-section, and BC/CO ratios
Listed in National Center for Atmospheric Research
A single particle soot photometer (SP2) was operated on the NCAR C-130 during the MIRAGE campaign (part of MILAGRO), sampling black carbon (BC) over Mexico.
Description
The highest BC concentrations were measured over Mexico City (sometimes as much as 2 μg/m3) and over hill-fires to the south of the city. The age of plumes outside of Mexico City was determined using a combination of HYSPLIT trajectories, WRF-FLEXPART modeling and CMET balloon tracks.
As expected, older, diluted air masses had lower BC concentrations. A comparison of carbon monoxide (CO) and BC suggests a CO background of around 65 ppbv, and a background-corrected BC/COnet ratio of 2.89±0.89 (ng/m3-STP)/ppbv (average ± standard deviation). This ratio is similar for fresh emissions over Mexico City, as well as for aged airmasses.
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Comparison of light absorption measured with a particle soot absorption photometer (PSAP) and the SP2 BC suggests a BC mass-normalized absorption cross-section (MAC) of 10.9±2.1 m2/g at 660 nm (or 13.1 m2/g @ 550 nm, assuming MAC is inversely dependent on wavelength). This appears independent of aging and similar to the expected absorption cross-section for aged BC, but values, particularly in fresh emissions, could be biased high due to instrument artifacts.
SP2-derived BC coating indicators show a prominent thinly-coated BC mode over the Mexico City Metropolitan Area (MCMA), while older air masses show both thinly-coated and thickly-coated BC. Some 2-day-old plumes do not show a prominent thickly-coated BC mode, possibly due to preferential wet scavenging of the likely-hydrophilic thickly-coated BC.
Links
Get the data
- Publisher page n2t.org/ark:/85065/d77w6d66 ↗
documentation · download · from data ucar edu
Where it is published
- data.ucar.edu /dataset/black-carbon-over-mexico-the-effect-of-atmospheric-tra… ↗
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=4d87a6c1-1e0d-4565-b2d2-0eb5df32e… ↗
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 | 4d87a6c1-1e0d-4565-b2d2-0eb5df32e0dd | 11 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 |