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| Titel |
Fluxes of Nitrous Acid (HONO) above an Agricultural Field Side near Paris |
| VerfasserIn |
S. Laufs, M. Cazaunau, P. Stella, B. Loubet, R. Kurtenbach, P. Cellier, W. Mellouki, J. Kleffmann |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062697
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| Zusammenfassung |
| HONO is an important precursor of the OH radical, the detergent of the atmosphere. Field
measurements show high diurnal HONO mixing ratios that cannot be explained by
chemical models with known gas phase chemistry. Therefore, daytime sources
of HONO are still under discussion. During the last decade many experimental
investigation were performed to study heterogeneous production of HONO like
the photo enhanced reduction of NO2 on humic acids or photolysis of HNO3 on
surfaces. Recently, nitrite produced by bacteria, present in soil, was discussed as
a source of HONO as well. In addition gas phase sources like the photolysis of
nitrophenols, or the reaction of excited NO2 are discussed. Gradient measurements
show high mixing ratios of HONO even above the boundary layer. However, beside
intensive investigations on the sources of HONO, it is still an open question whether
heterogeneous or gas phase sources are more important in the atmosphere. Flux
measurements could represent a method to find the origin of missing sources of HONO.
Until now instruments are not sensitive and fast enough to do Eddy correlation
measurements for HONO. Alternatively, HONO fluxes are estimated by the Aerodynamic
Gradient (AGM), or Relaxed Eddy Accumulation (REA) methods. Here we present
HONO fluxes estimated by AGM and the LOPAP technique (Long Path Absorption
Photometer) above an agricultural field in Grignon, Paris (48°51’N, 1°58’E). Fluxes
during different seasons and different types of vegetations including bare soil will be
presented and compared with chemical corrected fluxes of NO, NO2 and O3, or other
parameters. |
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