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| Titel |
Climate effects of aerosol nitrate from lightning |
| VerfasserIn |
Holger Tost, Dong Yeong Chang, Kirsty Pringle |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250094360
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| Publikation (Nr.) |
 EGU/EGU2014-9764.pdf |
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| Zusammenfassung |
| The atmospheric aerosol, especially secondary semi-volatile aerosol species, are still a major
uncertainty in the assessment of aerosol - climate interactions.
In this study, we try to reduce some of the uncertainty by systematically analysing the effects
of aerosol nitrate originating from lightning NOx production under present day and
preindustrial conditions. As the formation of aerosol nitrate, mostly in the form of NH4NO3,
is more efficient at colder temperatures such as in the middle and upper troposphere and
lightning represents an upper tropospheric source after chemical conversion of the
NOx to HNO3, the vertical distribution of aerosol nitrate can have a substantially
different impact on the climate system compared to surface emitted hydrophilic aerosol
compounds.
To analyse theses effects, we will present decadal global model simulation results,
investigating whether the nitrate from lightning in addition to the cooling by additional
scattering (direct effect) causes positive or negative indirect aerosol effects.
A potential cooling could result from the increase in CCN activity for low clouds, but as the
nitrate will also substantially affect the upper troposphere it also plays a role in the IN activity
of aerosol particles. Due to coating effects the IN number could be potentially decreased,
reducing short wave cloud effects of high clouds. |
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