The time variability of the Rome neutron monitor data (SVIRCO Observatory: INAF/IFSI-Roma and UNIRomaTre collaboration; rigidity threshold about 6.3 GV) from 1964 to 2004 was analyzed by using the Empirical Mode Decomposition (EMD) technique. Two prominent scales of variability have been identified: the ∼ 11-yr (Schwabe) cycle and the quasi biennial oscillations (QBOs). It is shown that the superposition of the two waves reproduces fairly well the long-term trend of the SVIRCO data. Moreover, the QBO role in producing the Gnevyshev Gap is discussed. A significant correlation has also been found between QBOs of the heliomagnetic field and cosmic ray intensity only during even solar activity cycles, with possible implications for cosmic ray modulation.
Time variability of the Rome cosmic ray intensity
CARBONE, Vincenzo
2011-01-01
Abstract
The time variability of the Rome neutron monitor data (SVIRCO Observatory: INAF/IFSI-Roma and UNIRomaTre collaboration; rigidity threshold about 6.3 GV) from 1964 to 2004 was analyzed by using the Empirical Mode Decomposition (EMD) technique. Two prominent scales of variability have been identified: the ∼ 11-yr (Schwabe) cycle and the quasi biennial oscillations (QBOs). It is shown that the superposition of the two waves reproduces fairly well the long-term trend of the SVIRCO data. Moreover, the QBO role in producing the Gnevyshev Gap is discussed. A significant correlation has also been found between QBOs of the heliomagnetic field and cosmic ray intensity only during even solar activity cycles, with possible implications for cosmic ray modulation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.