TIDE-FORMING FORCES AND THE ANOMALY OF THE ATMOSPHERIC CIRCULATION

We have found that tide-forming forces have an important triggering effect on the abnormal changes in the atmospheric mction.They are different from classical tide-forming forces.The atmospheric tides in the troposphere dcpend primarily upon the tide-forming forces at the time of astronomical singularities.There are three resonance areas,i.c.,the areas close to 54.7°and 90°from the sublunar point at the time of astronomical singularities,and the ≤2°area of the sublunar point.The superposition of the resonance arcas of sevcral astronomical singularities may excite anomalies of the atmospheric circulation,including the adjustment and continual anomalies of the extraong waves,the subtropical high and the blocking situation.It is hoped that our research can make contributions to thc improvement of medium-range,monthly and seasonai numerical predictions.