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Titel |
Tropospheric ozone variability in the tropics from ENSO to MJO and shorter timescales |
VerfasserIn |
J. R. Ziemke, A. R. Douglass, L. D. Oman, S. E. Strahan, B. N. Duncan |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 14 ; Nr. 15, no. 14 (2015-07-22), S.8037-8049 |
Datensatznummer |
250119916
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Publikation (Nr.) |
copernicus.org/acp-15-8037-2015.pdf |
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Zusammenfassung |
Aura OMI and MLS measurements are combined to produce daily maps of
tropospheric ozone beginning October 2004. We show that El Niño-Southern
Oscillation (ENSO) related inter-annual change in tropospheric ozone in the
tropics is small in relation to combined intra-seasonal/Madden–Julian
Oscillation (MJO) and shorter timescale variability by a factor of ~ 3–10
(largest in the Atlantic). Outgoing longwave radiation (OLR), taken as a
proxy for convection, suggests that convection is a dominant driver of
large-scale variability of tropospheric ozone in the Pacific from
inter-annual (e.g., ENSO) to weekly periods. We compare tropospheric ozone
and OLR satellite observations with two simulations: (1) the Goddard Earth
Observing System (GEOS) chemistry-climate model (CCM) that uses observed sea
surface temperatures and is otherwise free-running, and (2) the NASA Global
Modeling Initiative (GMI) chemical transport model (CTM) that is driven by
Modern Era Retrospective-Analysis for Research and Applications (MERRA)
analyses. It is shown that the CTM-simulated ozone accurately matches
measurements for timescales from ENSO to intra-seasonal/MJO and even
1–2-week periods. The CCM simulation reproduces ENSO variability but not
shorter timescales. These analyses suggest that a model used to delineate
temporal and/or spatial properties of tropospheric ozone and convection in the
tropics must reproduce both ENSO and non-ENSO variability. |
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