AbstractThe way in which equatorial sea surface temperature (s.s.t.) anomalies may interact with the atmosphere is discussed. A simple model is developed to simulate this air‐sea interaction in the Australian region. It is shown that the model can correctly simulate many interesting aspects of the observed statistical behaviour of the ocean‐atmosphere system, including the seasonal variation in persistence of pressure anomalies, the seasonal variation in pressurev. s.s.t correlation, a biennial oscillation in the atmosphere and ocean, and certain lag correlations between pressure, temperature and rainfall. It is concluded that the air‐sea interaction simulated by the model is an important control on the behaviour of the atmosphere and