Solar QuasiBiennial Fluctuations Csilla Szasz and Johan Kero
Solar Quasi-Biennial Fluctuations Csilla Szasz and Johan Kero Heliophysical Observatory Debrecen
Swedish Institute of Space Physics
The Butterfly Diagram of the Present Debrecen Photoheliographic Data (DPD)
Umbra-Penumbra Area Ratio for Sunspots in the DPD
U/P Area Ratio for Sunspot Groups in the Debrecen Photoheliographic Results (DPR)
Mean U/P Area Ratio for Different Sizes of Spots in the DPD · U + P Area < 15 · 15 ≤ U + P Area < 50 · 50 ≤ U + P Area < 300
U/P Area Ratio as a Function of the Umbra Area · 1993 Max · 1995 Max · 1988 Min · 1994 Min
PSD Estimate for Monthly Mean U/P Area Ratio (with Subtracted DC-component) 1986 - 1989 1993 - 1996
Best Sinusoidal Fit - T ~ 24. 2 months
Best Polynomial Fit
Possible Physical Interpretations (still under investigation) • A fluctuation in the temperature and plasma pressure stratification of the photosphere • A quasi-biennial variation of sunspot magnetic configurations
Other Mid-Term Periodicities • • Solar Spectroscopic Temperature Measurements Solar Radius Measurements Sunspot and Sunspot Group Numbers Solar Neutrino Measurements Solar UV Measurements Solar Irradiance Measurements Shear Oscillation of the Solar Tachocline • Solar Wind Speed • aa-Index of Geomagnetic Activity • The Quasi-Biennial Oscillation in the Earth Tropical Stratosphere
QBO in the Tropical Stratosphere
Composite Irradiance Data
10 Months Moving Average of Irradiance Residuals
- Slides: 19