 |
| Titel |
The annual cycle of hydrogen peroxide: an indicator of chemical instability? |
| VerfasserIn |
R. W. Stewart |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 4, no. 4 ; Nr. 4, no. 4 (2004-06-25), S.933-946 |
| Datensatznummer |
250001830
|
| Publikation (Nr.) |
 copernicus.org/acp-4-933-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| A box model has been used to study the annual cycle in
hydrogen peroxide concentrations with the objective of determining whether
the observed difference in summer and winter values reflects instability in
the underlying photochemistry. The model is run in both steady-state and
time-dependent modes. The steady-state calculations show that, for some
range of NOx background levels, two stable solutions to the continuity
equations exist for a period of days in spring and fall. The corresponding
time-dependent model indicates that, for sufficiently high background
NOx concentrations, the spring and fall changes in H2O2
concentration may be interpreted as a forced transition between the two
underlying stable regimes. The spring transition is more rapid than that in
fall, an asymmetry that becomes more marked as background NOx
increases. This asymmetry is related to the different time scales involved
in chemical production and loss of H2O2. Observations of the
spring increase in H2O2 concentration may therefore provide a
better measure of the change in the underlying chemical regime than does the
fall decrease. The model results developed in this paper will be compared
with two sets of observations that cover annual variations of peroxide
concentrations under different background pollution conditions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|