Chemistry–climate interactions of aerosol nitrate from lightning

Tost, H.

doi:10.5194/acp-17-1125-2017

Cited by 26 publications

(18 citation statements)

References 69 publications

(58 reference statements)

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“…Using the GEOS-Chem model, Barret et al (2016) previously showed that Asian lightning NO x emissions make a major contribution to the photochemical ozone production within the ASM anticyclone. On the other hand, the direct impact of lightning NO x emissions on chemical and microphysical properties of global UT aerosols has recently received attention (Tost, 2017). Tost showed a major contribution from lightning NO x emissions to the UT nitrate aerosol burden in a global chemistry-climate model.…”

Section: Contribution Of Lightning No X To Nitrate In the Atalmentioning

confidence: 99%

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

et al. 2020

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The Asian Tropopause Aerosol Layer (ATAL) represents an accumulation of aerosol in the upper troposphere and lower stratosphere associated with the Asian Summer Monsoon. Here we simulate the ATAL for summer 2013 with the GEOS‐Chem chemical transport model and explore the likely composition of ATAL aerosols and the relative contributions of regional anthropogenic sources versus those from farther afield. The model indicates significant contributions from organic aerosol, nitrate, sulfate, and ammonium aerosol, with regional anthropogenic precursor sources dominant. The model underestimates aerosol backscatter in the ATAL during summer 2013, compared with Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite instrument. Tests of a more physically based treatment of wet scavenging of SO2 in convective updrafts raise sulfate, eliminating the low bias with respect to CALIPSO backscatter in the ATAL, but lead to an unacceptable high bias of sulfate compared with in situ observations from aircraft over the United States. Source apportionment of the model results indicate the dominance of regional anthropogenic emissions from China and the Indian subcontinent to aerosol concentrations in the ATAL; ~60% of sulfate in the ATAL region in August 2013 is attributable to anthropogenic sources of SO2 from China (~30%) and from the Indian subcontinent (~30%), twice as much as in previously published estimates. Nitrate aerosol is found to be a dominant component of aerosol composition on the southern flank of the Asian Summer Monsoon anticyclone. Lightning sources of NOx are found to make a significant (10–15%) contribution to nitrate in the ATAL for the case studied.

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Section: Contribution Of Lightning No X To Nitrate In the Atalmentioning

confidence: 99%

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

et al. 2020

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“…The uptake of SO 2 , HNO 3 , and NH 3 and the aqueousphase oxidation of SO 2 by H 2 O 2 and O 3 in clouds are calculated by the SCAV submodel (Tost et al, 2006a(Tost et al, , 2007a. The scavenging of gases and aerosols by wet deposition is calculated by the SCAV submodel (Tost et al, 2006a), and their removal through dry deposition is calculated by the DRY-DEP submodel . The SEDI submodel with a first-order trapezoid scheme is used to calculate the sedimentation of aerosols .…”

Section: Model Description and Setupmentioning

confidence: 99%

Modeling the aerosol chemical composition of the tropopause over the Tibetan Plateau during the Asian summer monsoon

Brühl

et al. 2019

Atmos. Chem. Phys.

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Enhanced aerosol abundance in the upper troposphere and lower stratosphere (UTLS) associated with the Asian summer monsoon (ASM) is referred to as the Asian Tropopause Aerosol Layer (ATAL). The chemical composition, microphysical properties, and climate effects of aerosols in the ATAL have been the subject of discussion over the past decade. In this work, we use the ECHAM/MESSy Atmospheric Chemistry (EMAC) general circulation model at a relatively fine grid resolution (about 1.1 × 1.1 • ) to numerically simulate the emissions, chemistry, and transport of aerosols and their precursors in the UTLS within the ASM anticyclone during the years 2010-2012. We find a pronounced maximum of aerosol extinction in the UTLS over the Tibetan Plateau, which to a large extent is caused by mineral dust emitted from the northern Tibetan Plateau and slope areas, lofted to an altitude of at least 10 km, and accumulating within the anticyclonic circulation. We also find that the emissions and convection of ammonia in the central main body of the Tibetan Plateau make a great contribution to the enhancement of gas-phase NH 3 in the UTLS over the Tibetan Plateau and ASM anticyclone region. Our simulations show that mineral dust, water-soluble compounds, such as nitrate and sulfate, and associated liquid water dominate aerosol extinction in the UTLS within the ASM anticyclone. Due to shielding of high background sulfate concentrations outside the anticyclone from volcanoes, a relative minimum of aerosol extinction within the anticyclone in the lower stratosphere is simulated, being most pronounced in 2011, when the Nabro eruption occurred. In contrast to mineral dust and nitrate concentrations, sulfate increases with increasing altitude due to the larger volcano effects in the lower stratosphere compared to the upper troposphere. Our study indicates that the UTLS over the Tibetan Plateau can act as a well-defined conduit for natural and anthropogenic gases and aerosols into the stratosphere.

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“…4 we will extend the comparison with various observations. Finally, physical loss processes, like dry deposition, wet deposition, and sedimentation of aerosol, are explicitly considered by the submodels DRYDEP, SEDI, and SCAV (Kerkweg et al, 2006;Tost et al, 2006a).…”

Section: Emac Modelmentioning

confidence: 99%

Implementation of a comprehensive ice crystal formation parameterization for cirrus and mixed-phase clouds in the EMAC model (based on MESSy 2.53)

et al. 2018

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A comprehensive ice nucleation parameterization has been implemented in the global chemistry-climate model EMAC to improve the representation of ice crystal number concentrations (ICNCs). The parameterization of Barahona and Nenes (2009, hereafter BN09) allows for the treatment of ice nucleation taking into account the competition for water vapour between homogeneous and heterogeneous nucleation in cirrus clouds. Furthermore, the influence of chemically heterogeneous, polydisperse aerosols is considered by applying one of the multiple ice nucleating particle parameterizations which are included in BN09 to compute the heterogeneously formed ice crystals. BN09 has been modified in order to consider the pre-existing ice crystal effect and implemented to operate both in the cirrus and in the mixedphase regimes. Compared to the standard EMAC parameterizations, BN09 produces fewer ice crystals in the upper troposphere but higher ICNCs in the middle troposphere, especially in the Northern Hemisphere where ice nucleating mineral dust particles are relatively abundant. Overall, IC-NCs agree well with the observations, especially in cold cirrus clouds (at temperatures below 205 K), although they are underestimated between 200 and 220 K. As BN09 takes into account processes which were previously neglected by the standard version of the model, it is recommended for future EMAC simulations.

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Chemistry–climate interactions of aerosol nitrate from lightning

Cited by 26 publications

References 69 publications

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

Estimates of Regional Source Contributions to the Asian Tropopause Aerosol Layer Using a Chemical Transport Model

Modeling the aerosol chemical composition of the tropopause over the Tibetan Plateau during the Asian summer monsoon

Implementation of a comprehensive ice crystal formation parameterization for cirrus and mixed-phase clouds in the EMAC model (based on MESSy 2.53)

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