Regional climate model （RegCM3） was applied to explore the possible effects of land use changes （e.g., grassland degradation in this study） on local and regional climate over the Sanjiangyuan region in the Qinghai...Regional climate model （RegCM3） was applied to explore the possible effects of land use changes （e.g., grassland degradation in this study） on local and regional climate over the Sanjiangyuan region in the Qinghai-Tibet Plateau. Two multiyear （1991-1999） numerical simulation experiments were conducted： one was a control experiment with current land use and the other was a desertification experiment with potential grassland degradation. Preliminary analysis indicated that RegCM3 is appropriate for simulating land- climate interactions, as the patterns of the simulated surface air temperature, the summer precipitation, and the geopotential height fields are consistent with the observed values. The desertification over the Sanjiangyuan region will cause different climate effects in different regions depending on the surrounding environment and climate characteristics. The area with obvious change in surface air temperature inducing by grassland degradation over the Sanjiangyuan region is located in the Qinghai-Tibet Plateau. A winter surface air temperature drop and the other seasons＇ surface air temperature increase will be observed over the Qinghai-Tibet Plateau based on two numerical simulation experiments. Surface air temperature changes in spring are the largest （0.46℃）, and in winter are the smallest （smaller than 0.03℃）, indicating an increasing mean annual surface air temperature over the Qinghai-Tibet Plateau. Surface air temperature changes will be smaller and more complex over the surrounding region, with minor winter changes for the regions just outside the plateau and notable summer changes over the north of the Yangtze River. The reinforced summer heat source in the plateau will lead to an intensification of heat low, causing the West Pacific subtropical high to retreat eastward. This will be followed by a decrease of precipitation in summer. The plateau＇s climate tends to become warm and dry due to the grassland degradation over the Sanjiangyuan region.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
基金This research was supported by The Gansu province meteorological bureau and university cooperation project"Numerical Si mulation of the Influences of Tibetan Plateau Vegetation Variability on Regional Cli mate"The science andtechnology bureau of Sichuan province applicationtechnology research and development project"Study of Ecological SystemEvolutionin Sichuan andits Mechanism"(07JY029-036)The opening project of the Cheng-duinstitute of plateau meteorology China meteorological administration"Study of Influence of Tibetan Plateau Vegetation Variability on Regional Cli mate and its Mechanism"(LPM2006020).
基金Supported by the National Natural Science Foundation of China under Grant No.40671176the Science and Technology Commission of Shanghai Municipality under Grant Nos.08JC1408500 and 072512021
文摘Regional climate model （RegCM3） was applied to explore the possible effects of land use changes （e.g., grassland degradation in this study） on local and regional climate over the Sanjiangyuan region in the Qinghai-Tibet Plateau. Two multiyear （1991-1999） numerical simulation experiments were conducted： one was a control experiment with current land use and the other was a desertification experiment with potential grassland degradation. Preliminary analysis indicated that RegCM3 is appropriate for simulating land- climate interactions, as the patterns of the simulated surface air temperature, the summer precipitation, and the geopotential height fields are consistent with the observed values. The desertification over the Sanjiangyuan region will cause different climate effects in different regions depending on the surrounding environment and climate characteristics. The area with obvious change in surface air temperature inducing by grassland degradation over the Sanjiangyuan region is located in the Qinghai-Tibet Plateau. A winter surface air temperature drop and the other seasons＇ surface air temperature increase will be observed over the Qinghai-Tibet Plateau based on two numerical simulation experiments. Surface air temperature changes in spring are the largest （0.46℃）, and in winter are the smallest （smaller than 0.03℃）, indicating an increasing mean annual surface air temperature over the Qinghai-Tibet Plateau. Surface air temperature changes will be smaller and more complex over the surrounding region, with minor winter changes for the regions just outside the plateau and notable summer changes over the north of the Yangtze River. The reinforced summer heat source in the plateau will lead to an intensification of heat low, causing the West Pacific subtropical high to retreat eastward. This will be followed by a decrease of precipitation in summer. The plateau＇s climate tends to become warm and dry due to the grassland degradation over the Sanjiangyuan region.
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.
