Nonlinear Development of ULF waves in the Upstream of Earth’s Bow Shock
Tuesday, 2 September 2014
Regency Ballroom (Hyatt Regency)
Ensang Lee1, George K Parks2, Naiguo Lin3, Jinhy Hong1,4, Khan-Hyuk Kim5, Dong-Hun Lee6, Jongho Seon1 and Ho Jin1, (1)Kyung Hee University, School of Space Research, Yongin, South Korea, (2)Univ California, Berkeley, CA, United States, (3)Univ California Berkeley, Berkeley, CA, United States, (4)KAIST, Daejeon, South Korea, (5)Kyung Hee University, Yongin, South Korea, (6)Kyung Hee Univ, Gyeonggi, South Korea
Abstract:
In the upstream region of Earth's bow shock ULF waves are frequently observed. These waves are usually observed in association with backstreaming ions from the bow shock. In this study we report observations of nonlinear development of the ULF waves using the multi-point measurements from the Cluster spacecraft when the spacecraft were separated as large as ~1.5 RE. The small amplitude waves observed by the spacecraft (C3) at farther upstream rapidly grew and became nonlinear as they were observed by the spacecraft (C1) downstream from C3. Intense ion beams backstreaming from the bow shock were observed with the small amplitude waves at C3, but the beams were dissipated into diffuse distributions at C1, where the waves became nonlinear. We will discuss detailed characteristics of the wave-particle interactions resulting in the nonlinear development of the waves.
