摘要
内循环降水率是本地蒸发产生的降水与总降水量的比值,可以表征陆气相互作用的强度。本研究使用准等熵拉格朗日后向轨迹追踪模型(Quasi-isentropic backward trajectory,QIBT),基于全球陆面数据同化产品(Global Land Data Assimilation Systems,GLDAS)的降水和蒸发数据,以及ERA-Interim再分析资料(ERAI),选取降水量与气候平均态相当的2001年,研究了青藏高原内循环降水率。其次,使用2001年ERAI降水和蒸发数据替换GLDAS数据,分析地表数据不确定性对内循环降水率的影响,最后,选取30年降水和蒸发量的极端情况,探讨了极端干湿年对内循环降水率的影响。结果表明,青藏高原内循环降水率东南部小于西北部,年平均内循环降水率为0.42。极端干年大于2001年,极端湿年小于2001年。使用再分析资料的降水和蒸发数据后,内循环降水率减小为0.28,与再分析资料对青藏高原降水量的高估有关。
Precipitation recycling ratio is the local evaporation that contributes to the local precipitation.It is an indication of land-atmosphere interaction over the Qinghai-Tibetan Plateau(QTP).This study was based on the Global Land Data Assimilation Systems(GLDAS) and the ERA-Interim(ERAI) data by using the Quasi-isentropic backward trajectory(QIBT) model.The study used the precipitation and evaporation from the GLDAS and other variables from the ERAI data to run the QIBT model.The precipitation recycling ratio was analyzed in2001,a climatological averaged precipitation year.To evaluate the influence of the precipitation and evaporation to the results of precipitation recycling ratio,two tests were applied.One is to replace the precipitation and evaporation from the GLDAS with that from the ERAI.After the precipitation and evaporation in the GLDAS were replaced with that in the ERAI,the influence of the replacement was evaluated.Another is to replace the precipitation and evaporation in 2001 with that in extreme wet and dry years during 1982-2011(30 years).The variations of precipitation recycling ratio in extreme wet and dry year were also evaluated.The results are as follows:Precipitation recycling ratio in the northwest is stronger than that in the southeast over the QTP.The average precipitation recycling ratio is 0.42 over the QTP with the precipitation and evaporation from the GLDAS.Precipitation recycling ratio in some regions in the northern part of the QTP is larger than 0.50.Precipitation recycling ratio is 0.28 when the precipitation and evaporation in the GLDAS were replaced with the precipitation and evaporation in the ERAI. Precipitation recycling ratio is 0.31 for extreme dry year and 0.25 for extreme wet year.Precipitation recycling ratio is stronger in the extreme dry year than in the extreme wet year.The influence of replacement from GLDAS to ERAI is larger than that of replacement from normal year to extreme years.The higher precipitation in the ERAI than the GLDAS is the reason for the lower preci
作者
续昱
高艳红
XU Yu;GAO Yanhong(Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;University of Chinese Academy of Sciences,Beijing 100049,China;Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan University,Shanghai 200438,China)
出处
《高原气象》
CSCD
北大核心
2020年第3期499-510,共12页
Plateau Meteorology
基金
中国科学院战略性先导科技专项(XDA2006010202)
第二次青藏高原科考项目(2019QZKK010314)
国家自然科学基金项目(91537211,91537105)。
