Ion Cyclotron Waves in the Inner Heliosphere L.K. Jian1, C.T. Russell1, J.G. Luhmann2, X. Blanco-Cano3

1IGPP & ESS, UCLA 2SSL, UCB 3IG, UNAM

SHINE session: New Questions about ENA, PUI, and ACR

0.3 AU Strong narrow-band ICWs are detected extensively and discretely in the solar wind at 0.3, 0.7, and 1 AU, far away from any shock or planetary influence. The waves are intrinsically left-hand polarized in the plasma frame, but appear both LH and RH polarized in the s/c frame, with highly variable frequency, suggesting they were probably generated by perpendicular pickup. The lower power and smaller occurrence rate of RH waves , and the decrease of wave power with heliocentric distance all support the closer-to-Sun generation and outward transport scenario. The waves are preferentially observed at small B-R angle, likely due to minimal damping associated with parallel-to-B propagation.