| Autor: |
Hennigan, C. J., Sullivan, A. P., Fountoukis, C. I., Nenes, A., Hecobian, A., Vargas, O., Case Hanks, A. T., Huey, L. G., Lefer, B. L., Russell, A. G., Weber, R. J. |
| Přispěvatelé: |
EGU, Publication |
| Rok vydání: |
2008 |
| Předmět: |
|
| DOI: |
10.5194/acpd-8-4811-2008 |
| Popis: |
Measurements of atmospheric gases and fine particle chemistry were made in the Mexico City Metropolitan Area (MCMA) at a site ~30 km down wind of the city center. Ammonium nitrate (NH4NO3) dominated the inorganic aerosol fraction and showed a distinct diurnal signature characterized by rapid morning production and a rapid mid-day concentration decrease. The concentration increase was due to both secondary formation and entrainment from the free troposphere. A majority (approximately two-thirds) of the midday concentration decrease was caused by dilution from boundary layer expansion, however a significant fraction (approximately one-third) of the nitrate loss was due to particle evaporation. The water-soluble organic carbon fraction of fine particles (WSOC) and nitrate were highly correlated (R2=0.80) for the entire three-day analysis period, however the WSOC-nitrate correlation was highest (R2=0.88) between the hours of 08:00?12:45, indicating similar sources and processing during this period. The results show that WSOC also experienced evaporation losses and that a significant fraction of the MCMA secondary organic aerosol (SOA) measured at the surface was semi-volatile. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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