Time profiles of CIR-associated suprathermal helium enhancement identified by STOF during the period from DOY 206 to DOY 211, 2003. Shown from top to bottom are the 5-min averaged solar wind proton speed, the thermal speed, and the proton density measured by PM and SWEPAM, the 4-min averaged interplanetary magnetic field strength measured by ACE/MAG, the 12-min averaged O⁷⁺/O⁶⁺ abundance ratio measured by ACE/SWICS, the 12-min mean charge state of iron measured by ACE/SWICS, the total pressure (), and three-hour-averaged helium fluxes and the corresponding background estimate from ~32 to 330 keV/nuc.