BEXCO - Room F(201/202/203/204)
[SH153] CIR associated cosmic ray intensity variation measured with the PAMELA experiment.
- Riccardo MUNINI
- Riccardo MUNINI (INFN Trieste, Italy)
- Alessandro BRUNO (University of Bari, Italy)
- Eric CHRISTIAN (Heliophysics Science Division, NASA/GSFC, USA)
- Georgia DE NOLFO (NASA/GSFC, USA)
- Matteo MARTUCCI (Department of Physics, University of Rome "Tor Vergata", Italy)
- Matteo MERGE (Department of Physics, University of Rome "Tor Vergata", Italy)
- James RYAN (Space Science Center, University of New Hampshire, USA)
- Steven STOCHAJ (Electrical and Computer Engineering, New Mexico State University, USA)
- Valeria DI FELICE (INFN Roma-2 , Agenzia Spaziale Italiana (ASI) Science Data Center, Italy)
- Ulisse BRAVAR (Space Science Center, University of New Hampshire, USA)
- Mirko BOEZIO (INFN Trieste, Italy)
New results on the short-time variation of the cosmic radiation measured by the PAMELA in a wide rigidity range (0.5-10 GV) between late December 2006 and March 2007 with the PAMELA experiment are presented. A clear 13.5 days cyclical variation is observed in the proton intensity during this period as well as shorter time scale variations. The amplitude of these variations is between 5% and 15%. This phenomena has been interpreted in association to the presence of prominent structures of compressed plasma in the solar wind named corotating interaction regions (CIRs). CIR are formed at the leading edges of corotating high-speed solar wind streams originating in coronal holes as they interact with the preceding slow solar wind. This features are particularly prominent during period of solar minimum cycle as in 2006. Time evolution of the solar wind parameter has been studied in order to correlate CIRs with short time proton variation observed in the PAMELA data.