Numerical study for potential predictability of short— term anomalous climate change caused by El nino

Abstract

In this paper, the two-layer IAP model with sea surface temperature anomalies in the equatorial central-eastern Pacific is used to investigate potential predictability of global short—term anomalous climate change caused by El Nino via the “switching” experiments. The experimental results show that short—term anomalous climate change in the tropics is mainly caused by instantaneous response of tropical atmosphere to SSTA in the tropics. The effective period of this kind of anomalous climate is shorter and about monthly scale. In the high latitudes, the anomalous climate is mainly caused by the lag response of atmosphere to SSTA in the tropics. The strongest influence appears in the month after a half year when the SSTA in the tropics disappears. Therefore, potential predictability of short-term anomalous climate change may be reached to one year; anomalous climate change in the middle-latitudes is not only. affected by instantaneous response to SSTA in the tropics, but also by lag response to that. Therefore, short-term climate change prediction with monthly time scale can be not only done by using SSTA in the tropics, but also prediction of short- term climate after a half year can be done and its effective predictable period may be reached to one year.