Characteristics of middle- to low-latitude Pi2 excited by bursty bulk flows - Cao, J; Duan, J; Du, A; Ma, Y; Liu, Z; Zhou, GC; Yang, D; Zhang, T; Li, X; Vellante, M; Reme, H; Dandouras, I; et al. (JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2008)