Satellite mapping of rain‐induced nitric oxide emissions from soils

Abstract

[1] We use space-based observations of NO 2 columns from the Global Ozone Monitoring Experiment (GOME) to map the spatial and seasonal variations of NO x emissions over Africa during 2000. The GOME observations show not only enhanced tropospheric NO 2 columns from biomass burning during the dry season but also comparable enhancements from soil emissions during the rainy season over the Sahel. These soil emissions occur in strong pulses lasting 1-3 weeks following the onset of rain, and affect 3 million km 2 of semiarid sub-Saharan savanna. Surface observations of NO 2 from the International Global Atmospheric Chemistry (IGAC)/Deposition of Biochemically Important Trace Species (DEBITS)/Africa (IDAF) network over West Africa provide further evidence for a strong role for microbial soil sources. By combining inverse modeling of GOME NO 2 columns with space-based observations of fires, we estimate that soils contribute 3.3 ± 1.8 TgN/year, similar to the biomass burning source (3.8 ± 2.1 TgN/year), and thus account for 40% of surface NO x emissions over Africa. Extrapolating to all the tropics, we estimate a 7.3 TgN/year biogenic soil source, which is a factor of 2 larger compared to model-based inventories but agrees with observationbased inventories. These large soil NO x emissions are likely to significantly contribute to the ozone enhancement originating from tropical Africa.

Application of thermal-dissociation laser induced fluorescence (TD-LIF) to measurement of HNO<sub>3</sub>, Σalkyl nitrates, Σperoxy nitrates, and NO<sub>2</sub> fluxes using eddy covariance

“…are significant contributors to N dry deposition, and recent research indicates that surface interactions affect atmospheric concentrations and partitioning of these species. For example, extreme changes in the atmospheric reactive nitrogen budget following biomass burning or rain events have been observed (Bertram et al, 2005;Jaegle et al, 2004;Zhang et al, 2002). Few studies have investigated the magnitude and mechanisms of ecosystemscale exchange of NO 2 , peroxy nitrates, alkyl nitrates or Published by Copernicus GmbH on behalf of the European Geosciences Union.…”

Intercomparison of SCIAMACHY and OMI tropospheric NO2 columns: Observing the diurnal evolution of chemistry and emissions from space

“…Data sets of tropospheric NO 2 columns retrieved from the Global Ozone Monitoring Experiment (GOME), the Scanning Imaging Absorption Chartography (SCIAMACHY) and the Ozone Monitoring Experiment (OMI) now span more than 10 years (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) and have been used for trend studies van der A et al, 2006a]. GOME and SCIAMACHY tropospheric NO 2 data has been used to estimate surface emissions of NO x [Martin et al, 2003;Jaeglé et al, 2004Jaeglé et al, , 2005Müller and Stavrakou, 2005;Bertram et al, 2005;Toenges-Schüller et al, 2006;Konovalov et al, 2006;Martin et al, 2006;Kim et al, 2006] and lightning NO x production [Boersma et al, 2005;Beirle et al, 2006;Martin et al, 2007].…”

Evaluation of GOME satellite measurements of tropospheric NO2 and HCHO using regional data from aircraft campaigns in the southeastern United States

“…GOME observations are being applied to a wide range of issues including continental outflow [Spichtinger et al, 2001;Richter and Burrows, 2002;Stohl et al, 2003;Wenig et al, 2003], constraints on emission inventories of NO x [Leue et al, 2001;Martin et al, 2003b;Beirle et al, 2003;Jaeglé et al, 2004] and VOCs [Abbot et al, 2003;Palmer et al, 2003], and to distinguish between NO xsensitive and NO x -saturated regimes of ozone production . However, evaluations of GOME with in situ observations have been limited by sparse spatial sampling in the lower mixed layer [Heland et al, 2002;Ladstätter-Weißenmayer et al, 2003].…”