The isotope-equipped GCMs （general circulation models） are useful tools to investigate the isoscape in precipitation and water vapor, especially for the regions without enough in-situ observations. To study the spat...The isotope-equipped GCMs （general circulation models） are useful tools to investigate the isoscape in precipitation and water vapor, especially for the regions without enough in-situ observations. To study the spatial distribution and seasonal variation of precipitation isotopic composition in arid central Asia, several isotope-equipped GCMs are applied, and the long-term observations in two stations are used to verify the GCM-simulated results. Generally, seasonality of isotopic composition can be well simulated in each GCM, and the values of 6180 in precipitation are larger in summer months （from April to October） and lower in winter months （from November to March）. Higher latitude usually shows lower values of 6180 in precipitation, and lower latitude has higher values. The values of 5180 are relatively low in the eastern section, and higher in the western section. Among these simulations, ECHAM is good at describing the isotopic composition in the study region, which can be seen from the mean absolute error （MAE） and root-mean-square error （RMSE）. The ECHAM-derived values of 5180 in precipitation positively correlate with the observed series, and the correlation coefficient based on ECHAM is the largest among these GCMs.展开更多
Based on a 0.5°×0.5° daily gridded precipitation dataset and observations in mete- orological stations released by the National Meteorological Information Center, the interan- nual variation of areal pr...Based on a 0.5°×0.5° daily gridded precipitation dataset and observations in mete- orological stations released by the National Meteorological Information Center, the interan- nual variation of areal precipitation in the Qilian Mountains during 1961-2012 is investigated using principal component analysis （PCA） and regression analysis, and the relationship be- tween areal precipitation and drought accumulation intensity is also analyzed. The results indicate that the spatial distribution of precipitation in the Qilian Mountains can be well re- flected by the gridded dataset. The gridded data-based precipitation in mountainous region is generally larger than that in plain region, and the eastern section of the mountain range usu- ally has more precipitation than the western section. The annual mean areal precipitation in the Qilian Mountains is 724.9×108 m3, and the seasonal means in spring, summer, autumn and winter are 118.9×108 m3, 469.4×108 m3, 122.5×108 m3 and 14.1×108 m3, respectively. Summer is a season with the largest areal precipitation among the four seasons, and the proportion in summer is approximately 64.76%. The areal precipitation in summer, autumn and winter shows increasing trends, but a decreasing trend is seen in spring. Among the four seasons, summer have the largest trend magnitude of 1.7×108 m3-a-1. The correlation be- tween areal precipitation in the mountainous region and dry-wet conditions in the mountains and the surroundings can be well exhibited. There is a negative correlation between drought accumulation intensity and the larger areal precipitation is consistent with the weaker drought intensity for this region.展开更多
基金National Natural Science Foundation of China,No.41161012,No.41461003National Basic Research Program of China,No.2013CBA01801
文摘The isotope-equipped GCMs （general circulation models） are useful tools to investigate the isoscape in precipitation and water vapor, especially for the regions without enough in-situ observations. To study the spatial distribution and seasonal variation of precipitation isotopic composition in arid central Asia, several isotope-equipped GCMs are applied, and the long-term observations in two stations are used to verify the GCM-simulated results. Generally, seasonality of isotopic composition can be well simulated in each GCM, and the values of 6180 in precipitation are larger in summer months （from April to October） and lower in winter months （from November to March）. Higher latitude usually shows lower values of 6180 in precipitation, and lower latitude has higher values. The values of 5180 are relatively low in the eastern section, and higher in the western section. Among these simulations, ECHAM is good at describing the isotopic composition in the study region, which can be seen from the mean absolute error （MAE） and root-mean-square error （RMSE）. The ECHAM-derived values of 5180 in precipitation positively correlate with the observed series, and the correlation coefficient based on ECHAM is the largest among these GCMs.
基金National Natural Science Foundation of China,No.41461003National Basic Research Program of China(973Program),No.2013CBA01801
文摘Based on a 0.5°×0.5° daily gridded precipitation dataset and observations in mete- orological stations released by the National Meteorological Information Center, the interan- nual variation of areal precipitation in the Qilian Mountains during 1961-2012 is investigated using principal component analysis （PCA） and regression analysis, and the relationship be- tween areal precipitation and drought accumulation intensity is also analyzed. The results indicate that the spatial distribution of precipitation in the Qilian Mountains can be well re- flected by the gridded dataset. The gridded data-based precipitation in mountainous region is generally larger than that in plain region, and the eastern section of the mountain range usu- ally has more precipitation than the western section. The annual mean areal precipitation in the Qilian Mountains is 724.9×108 m3, and the seasonal means in spring, summer, autumn and winter are 118.9×108 m3, 469.4×108 m3, 122.5×108 m3 and 14.1×108 m3, respectively. Summer is a season with the largest areal precipitation among the four seasons, and the proportion in summer is approximately 64.76%. The areal precipitation in summer, autumn and winter shows increasing trends, but a decreasing trend is seen in spring. Among the four seasons, summer have the largest trend magnitude of 1.7×108 m3-a-1. The correlation be- tween areal precipitation in the mountainous region and dry-wet conditions in the mountains and the surroundings can be well exhibited. There is a negative correlation between drought accumulation intensity and the larger areal precipitation is consistent with the weaker drought intensity for this region.
