Ozone production and transport over the Amazon Basin during the dry-to-wet and wet-to-dry transition seasons

Autor(es)

Bela, M. M. ^[1] ; Longo, K. M. ^[2] ; Freitas, S. R. ^[2] ; Moreira, D. S. ^[2] ; Beck, V. ^[3] ; Wofsy, S. C. ^[4] ; Gerbig, C. ^[3] ; Wiedemann, K. ^[4] ; Andreae, M. O. ^[5] ; Artaxo, P. ^[6]

Afiliação do(s) autor(es)

^[1] Natl Inst Space Res INPE, Ctr Earth Syst Sci CCST, Sao Jose Dos Campos - Brazil

^[2] Natl Inst Space Res INPE, Ctr Weather Forecast & Climate Studies, Cachoeira Paulista - Brazil

^[3] Max Planck Inst Biogeochem, D-07745 Jena - Germany

^[4] Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 - USA

^[5] Max Planck Inst Chem, Biogeochem Dept, D-55128 Mainz - Germany

^[6] Univ Sao Paulo, Inst Phys, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Atmospheric Chemistry and Physics; v. 15, n. 2, p. 757-782, 2015.
• Citações Web of Science: 12

Resumo

The Regional Carbon Balance in Amazonia (BARCA) campaign provided the first Amazon Basin-wide aircraft measurements of ozone (O-3) during both the dry-to-wet (November and December 2008) and wet-to-dry (May 2009) transition seasons. Extremely low background values (<20 ppb) were observed to the west and north of Manaus in both seasons and in all regions during the wet-to-dry transition. On the other hand, elevated O-3 levels (40-60 ppb) were seen during the dry-to-wet transition to the east and south of Manaus, where biomass burning emissions of O-3 precursors were present. Chemistry simulations with the CCATT-BRAMS and WRF-Chem models are within the error bars of the observed O-3 profiles in the boundary layer (0-3 km a.s.l.) in polluted conditions. However, the models overestimate O-3 in the boundary layer in clean conditions, despite lacking the predominant NO source from soil. In addition, O-3 simulated by the models was either within the error bars or lower than BARCA observations in mid-levels (3-5 km a.s.l.), and lower than total tropospheric O-3 retrieved from the OMI/MLS instruments, which is primarily comprised of middle troposphere O-3 and thus reflects long-range transport processes. Therefore, the models do a relatively poor job of representing the free troposphere-boundary layer gradient in O-3 compared with aircraft and satellite observations, which could be due to missing long-range and convective transport of O-3 at mid-levels. Additional simulations with WRF-Chem showed that the model O-3 production is very sensitive to both the O-3 deposition velocities and the NOx emissions, which were both about one-half of observed values. These results indicate the necessity of more realistic model representations of emissions, deposition, and convective processes for accurate monitoring and prediction of increases in O-3 production in the Amazon Basin as the regional population grows. (AU)

• Processo FAPESP: 08/58100-2 - Aeroclima: efeitos diretos e indiretos de aerossóis no clima da Amazônia e Pantanal
• Beneficiário: Paulo Eduardo Artaxo Netto
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático