Surface and lightning sources of nitrogen oxides over the United States: Magnitudes, chemical evolution, and outflow
Why is this work in the frame?
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
No Canadian affiliation. An affiliation-only frame — the usual design — would never have seen this work. It is one of the works that make the case for inverting the frame.
Machine scores (provisional)
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
- Teacher spread
- 0.259 · how far apart the two teachers sit on this one work
- Validation status
score_only:v0-immature-baseline· verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it
Abstract
We use observations from two aircraft during the ICARTT campaign over the eastern United States and North Atlantic during summer 2004, interpreted with a global 3‐D model of tropospheric chemistry (GEOS‐Chem) to test current understanding of regional sources, chemical evolution, and export of NO x . The boundary layer NO x data provide top‐down verification of a 50% decrease in power plant and industry NO x emissions over the eastern United States between 1999 and 2004. Observed NO x concentrations at 8–12 km altitude were 0.55 ± 0.36 ppbv, much larger than in previous U.S. aircraft campaigns (ELCHEM, SUCCESS, SONEX) though consistent with data from the NOXAR program aboard commercial aircraft. We show that regional lightning is the dominant source of this upper tropospheric NO x and increases upper tropospheric ozone by 10 ppbv. Simulating ICARTT upper tropospheric NO x observations with GEOS‐Chem requires a factor of 4 increase in modeled NO x yield per flash (to 500 mol/flash). Observed OH concentrations were a factor of 2 lower than can be explained from current photochemical models, for reasons that are unclear. A NO y ‐CO correlation analysis of the fraction f of North American NO x emissions vented to the free troposphere as NO y (sum of NO x and its oxidation products) shows observed f = 16 ± 10% and modeled f = 14 ± 9%, consistent with previous studies. Export to the lower free troposphere is mostly HNO 3 but at higher altitudes is mostly PAN. The model successfully simulates NO y export efficiency and speciation, supporting previous model estimates of a large U.S. anthropogenic contribution to global tropospheric ozone through PAN export.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
The record
- Venue
- Journal of Geophysical Research Atmospheres
- Topic
- Atmospheric chemistry and aerosols
- Field
- Earth and Planetary Sciences
- Canadian institutions
- —
- Funders
- Langley Research CenterGoddard Space Flight CenterNational Oceanic and Atmospheric AdministrationDalhousie University
- Keywords
- TroposphereChemical transport modelLightning (connector)Atmospheric sciencesOutflowOzoneTropospheric ozoneEnvironmental scienceAltitude (triangle)ClimatologyMeteorologyAtmospheric chemistryGeologyPhysicsPower (physics)
- Has abstract in OpenAlex
- yes