Forced by the realistic SST, an atmospheric general circulation model (AGCM) with 9 sigma levels in vertical and rhomboidal truncation at wave number 15 in the horizontal is run for 16 years with and without the Tibet...Forced by the realistic SST, an atmospheric general circulation model (AGCM) with 9 sigma levels in vertical and rhomboidal truncation at wave number 15 in the horizontal is run for 16 years with and without the Tibetan Plateau respectively(called TP and NTP experiment). The result simulated is used to investigate the influence of the Tibetan Plateau on the interannual variability of Asian monsoon. It is found that the interannual variability of Asian monsoon associated with El Nino/La Nina in NTP experiment is quite different from that in TP experiment. With the Tibetan Plateau included, the results are consistent with the observation very well. To a great extent, the anomalous variation of Asian monsoon during El Nino/La Nina period in observation is due to the existence of the Tibetan Plateau. Therefore, the topography of the Tibetan Plateau is an important factor to the interannual variability of Asian monsoon.展开更多
An atmospheric general circulation model (AGCM) with 9 sigma levels in the vertical and rhomboidal trunction at wave number 15 in the horizontal is run for 10 years with and without the Tibetan Plateau respectively (c...An atmospheric general circulation model (AGCM) with 9 sigma levels in the vertical and rhomboidal trunction at wave number 15 in the horizontal is run for 10 years with and without the Tibetan Plateau respectively (called TP and NTP experiment). The result simulated is used to investigate the influence of the Tibetan Plateau on the interannual variability of atmospheric circulation over tropical Pacific. It is found that the spatial and temporal distributions of the interannual variability of the wind field over tropical Pacific in TP experiment and those in NTP experiment agree with each other except for the intensity, and both of them are consistent with observations well. Further analysis shows that in El Nino period the Tibetan Plateau strengthens the intensity of El Nino event, while in La Nina period it weakens the intensity of La Nina.展开更多
The interdecadal circumglobal teleconnection （ID-CGT） pattern is the dominant circulation mode over the NH during boreal summer on the interdecadal time scale. Its temporal evolution is synchronous with that of the ...The interdecadal circumglobal teleconnection （ID-CGT） pattern is the dominant circulation mode over the NH during boreal summer on the interdecadal time scale. Its temporal evolution is synchronous with that of the Atlantic Multidecadal Oscillation （AMO）. In this study, through analyzing the results of sensitivity experiments using five AGCMs driven by specified AMO-related SST anomalies （SSTAs） in the North Atlantic, the authors investigate whether the ID-CGT is excited by the AMO. Two out of the five models simulate the barotropic stationary wave pattern located along the westerly jet, suggesting that the ID-CGT pattern should be excited, at least partially, by the AMO- related SSTAs. Model results suggest that the ID-CGT pattern plays a role in linking the AMO and NH summer land SAT perturbations on the interdecadal time scale.展开更多
Recent studies have demonstrated a persistent decreasing trend in the spring sensible heat(SH) source over the Tibetan Plateau(TP) during the past three decades. By comparing simulations from nine state-of-the-art atm...Recent studies have demonstrated a persistent decreasing trend in the spring sensible heat(SH) source over the Tibetan Plateau(TP) during the past three decades. By comparing simulations from nine state-of-the-art atmospheric general circulation models(AGCMs) driven by historical forcing fields with both observational data and five reanalysis datasets, the authors found that the AGCMs are unable to reproduce the change in the SH flux over the TP. This deficiency arises because the observed decreasing trend in SH flux depends primarily on the change in surface wind speed according to the bulk formula, whereas in the models it is also influenced largely by changes in the land-air temperature difference related to the systematic cold bias. In addition, an obvious discrepancy exists in other aspects of the diabatic heating simulated by the models, suggesting that a significant improvement is required in the physical schemes associated with land surface processes and diabatic heating over the complicated topography.展开更多
文摘Forced by the realistic SST, an atmospheric general circulation model (AGCM) with 9 sigma levels in vertical and rhomboidal truncation at wave number 15 in the horizontal is run for 16 years with and without the Tibetan Plateau respectively(called TP and NTP experiment). The result simulated is used to investigate the influence of the Tibetan Plateau on the interannual variability of Asian monsoon. It is found that the interannual variability of Asian monsoon associated with El Nino/La Nina in NTP experiment is quite different from that in TP experiment. With the Tibetan Plateau included, the results are consistent with the observation very well. To a great extent, the anomalous variation of Asian monsoon during El Nino/La Nina period in observation is due to the existence of the Tibetan Plateau. Therefore, the topography of the Tibetan Plateau is an important factor to the interannual variability of Asian monsoon.
文摘An atmospheric general circulation model (AGCM) with 9 sigma levels in the vertical and rhomboidal trunction at wave number 15 in the horizontal is run for 10 years with and without the Tibetan Plateau respectively (called TP and NTP experiment). The result simulated is used to investigate the influence of the Tibetan Plateau on the interannual variability of atmospheric circulation over tropical Pacific. It is found that the spatial and temporal distributions of the interannual variability of the wind field over tropical Pacific in TP experiment and those in NTP experiment agree with each other except for the intensity, and both of them are consistent with observations well. Further analysis shows that in El Nino period the Tibetan Plateau strengthens the intensity of El Nino event, while in La Nina period it weakens the intensity of La Nina.
基金supported by the National Basic Research Program of China[grant number 2012CB955202]the National Natural Science Foundation of China[grant numbers 41005040 and 41023002]the R&D Special Fund for Public Welfare Industry(Meteorology)[grant number GYHY201506012]
文摘The interdecadal circumglobal teleconnection （ID-CGT） pattern is the dominant circulation mode over the NH during boreal summer on the interdecadal time scale. Its temporal evolution is synchronous with that of the Atlantic Multidecadal Oscillation （AMO）. In this study, through analyzing the results of sensitivity experiments using five AGCMs driven by specified AMO-related SST anomalies （SSTAs） in the North Atlantic, the authors investigate whether the ID-CGT is excited by the AMO. Two out of the five models simulate the barotropic stationary wave pattern located along the westerly jet, suggesting that the ID-CGT pattern should be excited, at least partially, by the AMO- related SSTAs. Model results suggest that the ID-CGT pattern plays a role in linking the AMO and NH summer land SAT perturbations on the interdecadal time scale.
基金supported jointly by the Strategic Priority Research Program-Climate Change: Carbon Budget and Related Issues of the Chinese Academy of Sciences (Grant No. XDA-05110303)the Chinese Ministry of Science and Technology (Grant No. 2010CB951703)+2 种基金the National Natural Science Foundation of China (Grant No. 41175070)Special Fund for Public Welfare Industry (meteorology) administered by the Chinese Ministry of Finance and Ministry of Science and Technology (Grant No. GYHY201406001)Key Laboratory of Meteorological Disaster, Nanjing University of Information Science and Technology, Ministry of Education (Grand No. KLME1309)
文摘Recent studies have demonstrated a persistent decreasing trend in the spring sensible heat(SH) source over the Tibetan Plateau(TP) during the past three decades. By comparing simulations from nine state-of-the-art atmospheric general circulation models(AGCMs) driven by historical forcing fields with both observational data and five reanalysis datasets, the authors found that the AGCMs are unable to reproduce the change in the SH flux over the TP. This deficiency arises because the observed decreasing trend in SH flux depends primarily on the change in surface wind speed according to the bulk formula, whereas in the models it is also influenced largely by changes in the land-air temperature difference related to the systematic cold bias. In addition, an obvious discrepancy exists in other aspects of the diabatic heating simulated by the models, suggesting that a significant improvement is required in the physical schemes associated with land surface processes and diabatic heating over the complicated topography.
