Based on the observation and reanalysis data through 1948―2004, the vertical shear of zonal wind, outgoing longwave radiation, and divergence fields in the lower and upper troposphere during summer are revealed to co...Based on the observation and reanalysis data through 1948―2004, the vertical shear of zonal wind, outgoing longwave radiation, and divergence fields in the lower and upper troposphere during summer are revealed to correlate significantly with the concurrent western North Pacific (WNP) typhoon fre-quency, and they therefore can be regarded as predictors for the WNP typhoon activity anomaly. After that, the 34-year (1970―2003) ensemble hindcast experiments are performed by the nine-level atmos-pheric general circulation model developed at the Institute of Atmospheric Physics Under the Chinese Academy of Sciences (IAP9L-AGCM), aiming to investigate the numerical predictability of the summer vertical shear of zonal wind and divergence field in the lower troposphere. It is found that the temporal correlation coefficients between the hindcast and observation are 0.70 and 0.62 for the vertical shear of zonal wind and divergence field, respectively. This suggests that the model possesses a large potential skill for predicting the large-scale climate background closely related to the WNP typhoon activity, and the model is therefore capable of performing the real-time numerical prediction of the WNP typhoon activity anomaly to some extent.展开更多
基金by the National Natural Science Foundation of China (Grant Nos. 40505017, 40631005 and 40620130113)the Innovation Project of the Institute of Atmospheric Physics, CAS (Grant No. IAP07205)
文摘Based on the observation and reanalysis data through 1948―2004, the vertical shear of zonal wind, outgoing longwave radiation, and divergence fields in the lower and upper troposphere during summer are revealed to correlate significantly with the concurrent western North Pacific (WNP) typhoon fre-quency, and they therefore can be regarded as predictors for the WNP typhoon activity anomaly. After that, the 34-year (1970―2003) ensemble hindcast experiments are performed by the nine-level atmos-pheric general circulation model developed at the Institute of Atmospheric Physics Under the Chinese Academy of Sciences (IAP9L-AGCM), aiming to investigate the numerical predictability of the summer vertical shear of zonal wind and divergence field in the lower troposphere. It is found that the temporal correlation coefficients between the hindcast and observation are 0.70 and 0.62 for the vertical shear of zonal wind and divergence field, respectively. This suggests that the model possesses a large potential skill for predicting the large-scale climate background closely related to the WNP typhoon activity, and the model is therefore capable of performing the real-time numerical prediction of the WNP typhoon activity anomaly to some extent.
