Temporal-Spatial Distributions of Predictability Limit of Short-Term Climate
短期气候可预报期限的时空分布

Based on the nonlinear error growth dynamics introduced by the authors recently,the temporal-spatial distributions of predictability limit of monthly and seasonal mean geopotential height and temperature fields are investigated.The results are summarized as follows:(i) For the 500-hPa height field,the predictability limit of monthly and seasonal means shows obvious differences between the tropics and middle-high latitudes.The predictability limit of monthly and seasonal means is largest in the tropics,and decreases quickly from the tropics to middle-high latitudes of southern and northern hemispheres.In the tropics,the predictability limit of monthly means is beyond 6 months with the maximum value exceeding 9 months,and the predictability limit of seasonal means is beyond 8 months with the maximum value exceeding 11 months.However,in mid-high latitudes,the predictability limit of monthly means is only 2-3 months,and the predictability limit of seasonal means is only 4-5 months.(ii) The spatial distributions of predictability limit of monthly and seasonal means vary obviously with season.In winter,the predictability limit of monthly and seasonal means is large in the other regions besides the tropics,including the North Pacific,the North Atlantic,and Antarctic,where the predictability limit is much higher than that in summer.In summer,the predictability limit of monthly and seasonal means decreases in the most regions except North Africa and West Asia.(iii) Temporal-spatial distributions of predictability limit of monthly and seasonal mean 500-hPa temperature fields are similar to those of 500-hPa geopotential height field.In the most tropical regions,however,the predictability limit of 500-hPa geopotential height field is higher than that of 500-hPa temperature field,thus the former is more applicable as the long-term predictand than the latter.