Role of chemical production and depositional losses on formaldehyde in the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM)

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(22), P. 12903 - 12924

Published: Nov. 21, 2024

Abstract. Formaldehyde (HCHO) is an important air pollutant with direct cancer risk and ozone-forming potential. HCHO sources are complex because both directly emitted produced from oxidation of most gas-phase reactive organic carbon. We update the secondary production in Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) Multiscale Air Quality (CMAQ) model. Production isoprene monoterpenes increased, correcting underestimate current version. Simulated June–August surface during peak photochemical (11:00–15:00 LT, local time) increased by 0.6 ppb (32 %) over southeastern USA 0.2 (13 contiguous USA. The compares more favorably satellite-based observations TROPOspheric Monitoring Instrument (TROPOMI) aircraft-based observations. Evaluation against hourly indicates a missing nighttime sink that can be improved deposition, which reduces nocturnal (20:00–04:00 LT) 1.1 (36 0.5 (29 ability CRACMM to capture levels at midday improved, particularly sites northeastern USA, while although still lower than observed. Using established assessment methods, lifetime exposure population (∼ 320 million) ambient predicted here may result 6200 cases, 40 % controllable anthropogenic emissions nitrogen oxides compounds. updates will available version 2 (CRACMM2) CMAQv5.5.

Language: Английский

Evolution of three pairs of PAH with different molecular weights and aging products OPAH: Insights from OPAH/PAH high-time resolution hazes

Atmospheric Environment, Journal Year: 2025, Volume and Issue: 356, P. 121294 - 121294

Published: May 16, 2025

Language: Английский