Observed features RH Combined uchi and w (5N-5S) DEC 1999-FEB 2000 Mean 100 200 80 00 6 40 400 85时 500 600 I1s 70 Abrupt variation 000 00E 120E 140E 160E 160 160M 140W 120W 19W 80W Adapted from Emanuel,2005 授课教师：张洋 6授课教师：张洋 6 Observed features Abrupt variation Adapted from Emanuel, 2005