The Abortion of the El Nino Event in 1993 and Its Comparison with the Typical El Nino Event

Over the equatorial centraleastern Pacific，there is an anomalous seawater warming event that is significantly different from the typical El Nino event. In 1993, for example, an anomalous warming event occurred in March with its peak in May, then it decayed rapidly. This warming event is referred to abortion of an El Nino event. By comparing the event in 1993 with the typical El Nino event, the authors explore the feature and the cause of the abortion of this event. It is found that the event in 1993 is a local airsea coupling phenomenon in the tropical centraleastern Pacific. Due to the relatively strong El Nino event during 1991-1992, the western Pacific warm pool was anomalously cold during 1992-1993, and the thermal condition was not suitable for the occurrence of an El Nino event in 1993. In this case, the eastward extension of the equatorial westerly anomaly in spring from the western Pacific to the central Pacific satisfied the dynamical condition for the occurrence of an El Nino event, but the basin scale Bjerknestype positive feedback failed to work due to the cold warm pool. As a result, the seawater warming in the equatorial centraleastern Pacific lasted for a short period, then it decayed rapidly, causing the abortion of an El Nino event.