A semi-operational real time short-term climate prediction system has been developed in the Center of Climate and Environment Prediction Research (CCEPRE), Institute of Atmospheric Physics/Chinese Academy of Sciences....A semi-operational real time short-term climate prediction system has been developed in the Center of Climate and Environment Prediction Research (CCEPRE), Institute of Atmospheric Physics/Chinese Academy of Sciences. The system consists of the following components: the AGCM and OGCM and their coupling, initial conditions and initialization, practical schemes of anomaly prediction, ensemble prediction and its standard deviation, correction of GCM output, and verification of prediction. The experiences of semi-operational real-time prediction by using this system for six years (1989-1994) and of hindcasting for 1980-1989 are reported. It is shown that in most cases large positive and negative anomalies of summer precipitation resulting in disastrous climate events such as severe flood or drought over East Asia can be well predicted for two seasons in advance, although the quantitatively statistical skill scores are only satisfactory due to the difficulty in correctly predicting the signs of small anomalies. Some methods for removing the systematic errors and introducing corrections to the GCM output are suggested. The sensitivity of prediction to the initial conditions and the problem of ensemble prediction are also discussed in the paper.展开更多
The regional climate model RegCM3 has been one-way nested into IAP9L-AGCM, the nine-level atmospheric general circulation model of the Institute of Atmospheric Physics, Chinese Academy of Sciences, to perform a 20-yr ...The regional climate model RegCM3 has been one-way nested into IAP9L-AGCM, the nine-level atmospheric general circulation model of the Institute of Atmospheric Physics, Chinese Academy of Sciences, to perform a 20-yr （1982-2001） hindcast experiment on extraseaonal short-term prediction of China summer climate. The nested prediction system is referred to as RegCM3_IAP9L-AGCM in this paper. The results show that hindeasted climate fields such as 500-hPa geopotential height, 200- and 850-hPa zonal winds from RegCM3_IAP9L-AGCM have positive anomaly correlation coefficients （ACCs） with the observations, and are better than those from the stand-alone IAP9L-AGCM. Except for the 850-hPa wind field, the positive ACCs of the other two fields with observations both pass the 90% confidence level and display a zonal distribution. The results indicate that the positive correlation of summer precipitation anomaly percentage between the nested prediction system and observations covers most parts of China except for downstream of the Yangtze River and north of Northeast and Northwest China. The nested prediction system and the IAP9L-AGCM exhibit different hindcast skills over different regions of China, and the former demonstrates a higher skill over South China than the latter in predicting the summer precipitation.展开更多
Using the nine-level Atmospheric General Circulation Model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, 30-year extraseasonal short-term ensemble hincast of win...Using the nine-level Atmospheric General Circulation Model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, 30-year extraseasonal short-term ensemble hincast of winter climate is performed, with integrations starting from annual autumn during 1969—1998. Winter climate predictability over China is then evaluated for the first time. It follows that the predictability is higher in tropics than in extratropics. Also, it is higher over ocean compared with land, especially for surface air temperature. With height increasing in troposphere, the predictability of geopotential height slightly changes zonally, but for weakening of band-ship distribution and dropping near the date line. Of all analyzed variables, the prediction skill of air temperature and geopotential height (precipitation) is the highest (smallest). In addition, the predictability of winter climate over China and even East Asia enhances obviously during ENSO cycle, especially during La Nia phase. Simulation comparison against verifying analysis for surface temperature anomaly exhibits the model抯 skill in predicting surface temperature抯 interannual variation trend in winter.展开更多
文摘A semi-operational real time short-term climate prediction system has been developed in the Center of Climate and Environment Prediction Research (CCEPRE), Institute of Atmospheric Physics/Chinese Academy of Sciences. The system consists of the following components: the AGCM and OGCM and their coupling, initial conditions and initialization, practical schemes of anomaly prediction, ensemble prediction and its standard deviation, correction of GCM output, and verification of prediction. The experiences of semi-operational real-time prediction by using this system for six years (1989-1994) and of hindcasting for 1980-1989 are reported. It is shown that in most cases large positive and negative anomalies of summer precipitation resulting in disastrous climate events such as severe flood or drought over East Asia can be well predicted for two seasons in advance, although the quantitatively statistical skill scores are only satisfactory due to the difficulty in correctly predicting the signs of small anomalies. Some methods for removing the systematic errors and introducing corrections to the GCM output are suggested. The sensitivity of prediction to the initial conditions and the problem of ensemble prediction are also discussed in the paper.
基金Supported by the National Basic Research Program of China(2009CB421407)Special Public Welfare Research Fund for Meteorological Profession of China Meteorological Administration(GYHY201006022)+2 种基金Knowledge Innovation Project of the Chinese Academy of Sciences(KZCX2-YW-Q11-03)National Natural Science Foundation of China(40805030)K.C.Wang Education Foundation of Hong Kong
文摘The regional climate model RegCM3 has been one-way nested into IAP9L-AGCM, the nine-level atmospheric general circulation model of the Institute of Atmospheric Physics, Chinese Academy of Sciences, to perform a 20-yr （1982-2001） hindcast experiment on extraseaonal short-term prediction of China summer climate. The nested prediction system is referred to as RegCM3_IAP9L-AGCM in this paper. The results show that hindeasted climate fields such as 500-hPa geopotential height, 200- and 850-hPa zonal winds from RegCM3_IAP9L-AGCM have positive anomaly correlation coefficients （ACCs） with the observations, and are better than those from the stand-alone IAP9L-AGCM. Except for the 850-hPa wind field, the positive ACCs of the other two fields with observations both pass the 90% confidence level and display a zonal distribution. The results indicate that the positive correlation of summer precipitation anomaly percentage between the nested prediction system and observations covers most parts of China except for downstream of the Yangtze River and north of Northeast and Northwest China. The nested prediction system and the IAP9L-AGCM exhibit different hindcast skills over different regions of China, and the former demonstrates a higher skill over South China than the latter in predicting the summer precipitation.
基金This work was jointly supported by the National Natural Science Foundation of China(Grant No.40125014)the Chinese Academy of Sciences(Grant No.KZCX2-203).
文摘Using the nine-level Atmospheric General Circulation Model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, 30-year extraseasonal short-term ensemble hincast of winter climate is performed, with integrations starting from annual autumn during 1969—1998. Winter climate predictability over China is then evaluated for the first time. It follows that the predictability is higher in tropics than in extratropics. Also, it is higher over ocean compared with land, especially for surface air temperature. With height increasing in troposphere, the predictability of geopotential height slightly changes zonally, but for weakening of band-ship distribution and dropping near the date line. Of all analyzed variables, the prediction skill of air temperature and geopotential height (precipitation) is the highest (smallest). In addition, the predictability of winter climate over China and even East Asia enhances obviously during ENSO cycle, especially during La Nia phase. Simulation comparison against verifying analysis for surface temperature anomaly exhibits the model抯 skill in predicting surface temperature抯 interannual variation trend in winter.
