The 11-year solar cycle in stratospheric ozone: Comparison between Umkehr and SBUVv8 and effects on surface erythemal irradiance
Tourpali, K., Zerefos, C.S., Balis, D.S., Bais, A.F.
[abstract] Ozone profiles derived from ground-based Umkehr measurements at five stations and from the merged data set of Solar Backscattered Ultra Violet (SBUVv8) satellite observations are used to estimate the seasonal influence of the 11-year solar signal in the vertical distribution of stratospheric ozone. Both data sets show a strong response (2-3% of the annual mean) in the upper stratosphere, a very small response in the middle tropical stratosphere and a secondary maximum (∼2%) in the tropical lower stratosphere, in accordance to earlier reports. Thus a sequence of high-low-high response is seen in the vertical pattern of the solar cycle effect on ozone in the tropics, with its position sensitive to season, as it appears to move across the equator in direction opposite to the location of the maximum solar insolation. Results from Umkehr and satellite observations are in good agreement at levels up to 35 km, while discrepancies (of up to 2%) found at higher levels (around 40 km) are largest in summer. Finally, the estimated erythemal irradiance response to the 11-year solar cycle, calculated for the observed ozone change during a solar cycle (minimum to maximum), showed an overall decrease in the irradiance at the surface which is maximum (-2% of annual mean) over the tropics.
Ελληνική έκδοση
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