Seasonal variability of NO_x emissions over east China constrained by satellite observations: Implications for combustion and microbial sources

Abstract

[1] Observations of tropospheric column densities of NO 2 obtained from the Global Ozone Monitoring Experiment (GOME) for a 3-year period (1997, 1998, and 2000) are used to derive average seasonal variations in surface emissions of NO x from east China (100-123°E, 20-42°N). The retrieval allows for zonal variations in the contribution of the stratosphere to the NO 2 column and removes a bias of ±10% on the seasonality of retrieved columns introduced by cloud screening. The top-down inventory is constructed using an inversion approach with a global 3-D chemical transport model (GEOS-Chem) and combined subsequently with the a priori inventory to develop an a posteriori inventory. The contribution of background NO 2 arising from nonsurface sources (lightning) and long-range transport of emissions originating outside of east China is accounted for in the inversion. The a posteriori estimate of overall emissions for east China, 4.66 Tg N/yr (±30% uncertainty), is 33% higher than the a priori value and is shown to improve agreement with surface measurements of nitrate wet deposition and concentrations of NO y observed in China. On the basis of multiple constraints on the spatial and seasonal variations of combustion and microbial processes, the a posteriori inventory is partitioned among emissions from biomass burning, fuel combustion, and microbial activity (or soil emissions). Emission of NO x from biomass burning in east China is estimated as 0.08 TgN/yr ± 50% in the a posteriori inventory, increased by about a factor of 2 from the a priori estimate. The resulting a posteriori inventory for fuel combustion (3.72 TgN/yr ± 32%) is about 15% higher than the a priori and exhibits a distinct maximum in winter, in contrast to the weak seasonality indicated in the a priori inventory. The a posteriori value for the microbial source of NO x (0.85 TgN/yr ± 40%) is about a factor of 3 higher than the a priori value, amounting to 23% of combustion sources for east China and significantly higher than a priori value of 7%. The microbial source is unimportant in winter. It peaks in summer, accounting for as much as 43% of the combustion source for that season, and is significant also in spring and fall. This seasonality is attributed to the timing of fertilizer application and to the influence of seasonally variable environmental factors including temperature and precipitation.

Ground‐level nitrogen dioxide concentrations inferred from the satellite‐borne Ozone Monitoring Instrument

“…[13] Several previous studies have used GEOS-Chem to interpret in situ measurements of reactive nitrogen Wang et al, 2004;Hudman et al, 2004Hudman et al, , 2007Martin et al, 2006] as well as observations of tropospheric NO 2 columns from satellite instruments [Martin et al, 2003a[Martin et al, , 2004bJaeglé et al, 2005;Guerova et al, 2006;Sauvage et al, 2007;Wang et al, 2007bWang et al, , 2007aBoersma et al, 2008aBoersma et al, , 2008bBucsela et al, 2008]. GEOS-Chem simulations generally agree to within 30% of measured NO x , HNO 3 , and PAN over eastern North America Hudman et al, 2007;Singh et al, 2007] [15] Figure 1 shows seasonal mean tropospheric NO 2 columns from OMI and GEOS-Chem.…”

Steps towards a mechanistic model of global soil nitric oxide emissions: implementation and space based-constraints

“…The largest emissions are predicted over Northern Hemisphere agricultural regions (India, northeastern China, and the central United States) and over northern equatorial Africa. Disagreement exists between this estimate and top-down estimates, which indicate that YL95 underestimates emissions by factors of 2-3 in several regions including the United States, Mexico, eastern China, and northern equatorial African grasslands (Jaeglé et al, 2005;Wang et al, 2007;Boersma et al, 2008). Globally, space-based observations of NO 2 columns from the Global Ozone Monitoring Experiment (GOME, 40 × 320 km 2 nadir footprint, with global coverage ∼ weekly) were used to derive an a posteriori yearly global S NO x source of 8.9 Tg N yr −1 , 68 % greater than YL95 S NO x estimates (Jaeglé et al, 2005).…”

“…Regional comparisons with surface and satellite observations, however, suggest the standard YL95 scheme results in emissions that are a factor of 2-4 too low (e.g., Jaeglé et al, 2005;Wang et al, 2007;Boersma et al, 2008;Zhao and Wang, 2009;Steinkamp and Lawrence, 2011;Lin, 2012). In principle, it is possible to create a set of regionally corrected parameters, as Bertram et al (2005) Potter et al (1996) 9.7 Ecosystem production and soil C-N biosphere model.…”

Global Potential for Wind-Generated Electricity

“…GEOS data (including GEOS-5 and previous versions) have been used extensively in a variety of atmospheric chemistry investigations and have proved valuable not only in the interpretation of a wide range of atmospheric chemical measurements (6)(7)(8) but also in use of these measurements in an inverse mode to obtain improved estimates for emissions of important atmospheric species (9-11). The GEOS-5 simulation is employed here in a detailed study of the potential for globally distributed wind-generated electricity in 2006.…”