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| Titel |
Solar cycle and ENSO Variability of the Tropical Stratosphere: Comparisons and Implications |
| VerfasserIn |
L. Hood, B. Soukharev |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024267
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| Zusammenfassung |
| Multiple regression and correlative time series analyses of available long-term remote sensing
data sets are applied to estimate the solar cycle and ENSO components of interannual ozone,
temperature, and zonal wind variability in the tropical and subtropical stratosphere. For all
three quantities, the solar cycle response coefficients do not change appreciably when an
ENSO term is added to the regression model. This is because the ENSO signal in the data is
relatively weak due to the presence of other sources of interannual variability, especially an
irregular QBO. The ENSO ozone regression coefficient has significant negative values in the
tropical lower stratosphere (15 - 50 hPa) and significant positive values in the equatorial
middle stratosphere (5 - 10 hPa). In contrast, the solar ozone regression coefficient
has significant positive values in the tropical lower stratosphere and insignificant
values in the equatorial middle stratosphere. Similar vertical structures are found for
the respective temperature regression coefficients using the ERA-40 data set. The
ENSO regression coefficient in TOMS/SBUV total ozone data (representative of the
lower stratosphere) is statistically significant mainly over the tropical eastern Pacific
(90W - 180W) while the corresponding solar regression coefficient is significant at
all longitudes. As will be shown, these characteristics are consistent with those
expected for changes in the tropical upwelling rate (positive in the eastern Pacific
during El-Niño events and negative at all longitudes approaching solar maxima).
Implications for the origin of the solar cycle upwelling rate changes will be discussed. |
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