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
及图 Observed features great amount of convective cloud in the western pacific 1992010100 授课教师：张洋7
授课教师：张洋 7 Observed features great amount of convective cloud in the western pacific
Observed features Walker Circulation viewed as an air-sea coupled,self- maintained system Convective Loop Equator Thermocline 120°E 80'W Adapted from NOAA 授课教师：张洋8
授课教师：张洋 8 Observed features Walker Circulation viewed as an air-sea coupled, selfmaintained system Adapted from NOAA
ENSO and Walker Circulation EI Nino is defined by prolonged differences in tropical Pacific Ocean SST when compared with the average value.The accepted definition is a warming or cooling of at least 0.5 C averaged over the east-central tropical Pacific Ocean. Typically,this anomaly happens at irregular intervals of 2-7 years and lasts nine months to two years. The Southern Oscillation is the atmospheric component of EI Nino.This component is an oscillation in surface air pressure between the tropical eastern and the western Pacific Ocean waters.The strength of the Southern Oscillation is measured by the Southern Oscillation Index(SOl).The SOl is computed from fluctuations in the surface air pressure difference between Tahiti and Darwin,Australia. 授课教师：张洋 9
授课教师：张洋 9 ENSO and Walker Circulation n El Niño is defined by prolonged differences in tropical Pacific Ocean SST when compared with the average value. The accepted definition is a warming or cooling of at least 0.5 °C averaged over the east-central tropical Pacific Ocean. Typically, this anomaly happens at irregular intervals of 2–7 years and lasts nine months to two years. n The Southern Oscillation is the atmospheric component of El Niño. This component is an oscillation in surface air pressure between the tropical eastern and the western Pacific Ocean waters. The strength of the Southern Oscillation is measured by the Southern Oscillation Index (SOI). The SOI is computed from fluctuations in the surface air pressure difference between Tahiti and Darwin, Australia