Investigation of the Structure and Predictability of the First Mode of Stratospheric Variability Based on the INM RAS Climate Model

V. V. Vorobyeva and E. M. Volodin

The first empirical orthogonal function (EOF) of intraannual evolution of temperature averaged along the circle of latitude in the 0–60-km layer is calculated using the data of the 500-year preindustrial experiment with the climate model of the Institute of Numerical Mathematics of Russian Academy of Sciences (INM RAS). It is shown that the first EOF represents temperature anomalies which propagate downward from the upper stratosphere during December–April. Such anomalies are preceded by the anomaly of the meridional heat flux in the polar upper stratosphere in December. Using the ensemble of numerical experiments with the climate model, it was demonstrated that it is possible to predict the projection of temperature anomaly corresponding to the first EOF in December–April, to the first mode according to initial data for December 1.