Biogenic nitrogen oxide emissions from soils – impact on NOx and ozone over West Africa during AMMA (African Monsoon Multidisciplinary Experiment): modelling study
Open Access
- 6 May 2008
- journal article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 8 (9), 2351-2363
- https://doi.org/10.5194/acp-8-2351-2008
Abstract
Nitrogen oxide biogenic emissions from soils are driven by soil and environmental parameters. The relationship between these parameters and NO fluxes is highly non linear. A new algorithm, based on a neural network calculation, is used to reproduce the NO biogenic emissions linked to precipitations in the Sahel on the 6 August 2006 during the AMMA campaign. This algorithm has been coupled in the surface scheme of a coupled chemistry dynamics model (MesoNH Chemistry) to estimate the impact of the NO emissions on NOx and O3 formation in the lower troposphere for this particular episode. Four different simulations on the same domain and at the same period are compared: one with anthropogenic emissions only, one with soil NO emissions from a static inventory, at low time and space resolution, one with NO emissions from neural network, and one with NO from neural network plus lightning NOx. The influence of NOx from lightning is limited to the upper troposphere. The NO emission from soils calculated with neural network responds to changes in soil moisture giving enhanced emissions over the wetted soil, as observed by aircraft measurements after the passing of a convective system. The subsequent enhancement of NOx and ozone is limited to the lowest layers of the atmosphere in modelling, whereas measurements show higher concentrations above 1000 m. The neural network algorithm, applied in the Sahel region for one particular day of the wet season, allows an immediate response of fluxes to environmental parameters, unlike static emission inventories. Stewart et al (2008) is a companion paper to this one which looks at NOx and ozone concentrations in the boundary layer as measured on a research aircraft, examines how they vary with respect to the soil moisture, as indicated by surface temperature anomalies, and deduces NOx fluxes. In this current paper the model-derived results are compared to the observations and calculated fluxes presented by Stewart et al (2008).Keywords
This publication has 51 references indexed in Scilit:
- Diurnal cycle of dust and cirrus over West Africa as seen from Meteosat Second Generation satellite and a regional forecast modelGeophysical Research Letters, 2007
- Statistical modeling of global soil NOx emissionsGlobal Biogeochemical Cycles, 2005
- Temporal variations of fluxes of NO, NO2, N2O, CO2, and CH4 in a tropical rain forest ecosystemGlobal Biogeochemical Cycles, 2004
- Impact of Asian emissions on observations at Trinidad Head, California, during ITCT 2K2Journal of Geophysical Research: Solid Earth, 2004
- Description of the Mesoscale Nonhydrostatic Chemistry model and application to a transboundary pollution episode between northern France and southern EnglandJournal of Geophysical Research: Solid Earth, 2003
- Global soil‐biogenic NOx emissions and the role of canopy processesJournal of Geophysical Research: Solid Earth, 2002
- Regional inventory of nitric oxide and nitrous oxide emissions for forest soils of southeast Germany using the biogeochemical model PnET‐N‐DNDCJournal of Geophysical Research: Atmospheres, 2001
- Observed distributions of nitrogen oxides in the remote free troposphere from the Nasa Global Tropospheric Experiment ProgramsReviews of Geophysics, 2000
- Process modeling of controls on nitrogen trace gas emissions from soils worldwideJournal of Geophysical Research: Atmospheres, 1996
- A global model of natural volatile organic compound emissionsJournal of Geophysical Research: Solid Earth, 1995