The extreme temperature has more outstanding impact on ecology and water resources in arid regions than the average temperature.Using the downscaled daily temperature data from 21 Coupled Model Inter-comparison Projec...The extreme temperature has more outstanding impact on ecology and water resources in arid regions than the average temperature.Using the downscaled daily temperature data from 21 Coupled Model Inter-comparison Project(CMIP)models of NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)and the observation data,this paper analyzed the changes in temporal and spatiotemporal variation of temperature extremes,i.e.,the maximum temperature(Tmax)and minimum temperature(Tmin),in the Kaidu-Kongqi River basin in Northwest China over the period 2020–2050 based on the evaluation of preferred Multi-Model Ensemble(MME).Results showed that the Partial Least Square ensemble mean participated by Preferred Models(PM-PLS)was better representing the temporal change and spatial distribution of temperature extremes during 1961–2005 and was chosen to project the future change.In 2020–2050,the increasing rate of Tmax(Tmin)under RCP(Representative Concentration Pathway)8.5 will be 2.0(1.6)times that under RCP4.5,and that of Tmin will be larger than that of Tmax under each corresponding RCP.Tmin will keep contributing more to global warming than Tmax.The spatial distribution characteristics of Tmax and Tmin under the two RCPs will overall the same;but compared to the baseline period(1986–2005),the increments of Tmax and Tmin in plain area will be larger than those in mountainous area.With the emission concentration increased,however,the response of Tmax in mountainous area will be more sensitive than that in plain area,and that of Tmin will be equivalently sensitive in mountainous area and plain area.The impacts induced by Tmin will be universal and farreaching.Results of spatiotemporal variation of temperature extremes indicate that large increases in the magnitude of warming in the basin may occur in the future.The projections can provide the scientific basis for water and land plan management and disaster prevention and mitigation in the inland river basin.展开更多
西北干旱区水资源问题突出,全球变暖将进一步加剧其水资源短缺,研究未来气候变化对流域水资源合理分配和使用具有重要意义。本文利用CRU(Climate Research Unit)数据和DCHP(Downscaled CMIP3 and CMIP5 Climate and Hydrology Projectio...西北干旱区水资源问题突出,全球变暖将进一步加剧其水资源短缺,研究未来气候变化对流域水资源合理分配和使用具有重要意义。本文利用CRU(Climate Research Unit)数据和DCHP(Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections)提供的32个经BCSD降尺度的CMIP5(全球耦合模式比较计划第五阶段)模式气温数据,采用线性倾向估计、滑动平均、M-K(Mann-Kendall)检验及滑动T(MMT)等检验法,以西北干旱区典型流域开都-孔雀河流域为例,通过对1950—2005年的年平均气温、年平均最高气温与年平均最低气温3个指标的变化趋势及突变年份进行检测,评估各模式及模式集合平均对气温变化的模拟能力。研究结果表明:①12个模式能够准确模拟出1950—2005年流域内各气温指标的显著增加趋势,8个模式能够模拟出部分气温指标的增温趋势,但均低估了增温速率,集合平均也存在同样问题;②除FIO-ESM与MPI-ESM-MR能够准确模拟出气温突变时间外,绝大多数模式不能够准确模拟出。基于优选模式的集合平均PM-PLS和PM-EE对突变的模拟能力总体上优于单个模式,其中PM-PLS模拟能力更优;③对PM-PLS模式集合平均进一步评价,发现其能较好地再现流域气温线性趋势的时空变化总体特征,但仍存在增温速率低估的问题。采用气候模式进行未来气候预估仍需加强模式优选及多模式集合平均方法的深入研究。展开更多
基金supported by the National Natural Science Foundation of China(41561023)China Scholarship Council(201808655036)。
文摘The extreme temperature has more outstanding impact on ecology and water resources in arid regions than the average temperature.Using the downscaled daily temperature data from 21 Coupled Model Inter-comparison Project(CMIP)models of NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)and the observation data,this paper analyzed the changes in temporal and spatiotemporal variation of temperature extremes,i.e.,the maximum temperature(Tmax)and minimum temperature(Tmin),in the Kaidu-Kongqi River basin in Northwest China over the period 2020–2050 based on the evaluation of preferred Multi-Model Ensemble(MME).Results showed that the Partial Least Square ensemble mean participated by Preferred Models(PM-PLS)was better representing the temporal change and spatial distribution of temperature extremes during 1961–2005 and was chosen to project the future change.In 2020–2050,the increasing rate of Tmax(Tmin)under RCP(Representative Concentration Pathway)8.5 will be 2.0(1.6)times that under RCP4.5,and that of Tmin will be larger than that of Tmax under each corresponding RCP.Tmin will keep contributing more to global warming than Tmax.The spatial distribution characteristics of Tmax and Tmin under the two RCPs will overall the same;but compared to the baseline period(1986–2005),the increments of Tmax and Tmin in plain area will be larger than those in mountainous area.With the emission concentration increased,however,the response of Tmax in mountainous area will be more sensitive than that in plain area,and that of Tmin will be equivalently sensitive in mountainous area and plain area.The impacts induced by Tmin will be universal and farreaching.Results of spatiotemporal variation of temperature extremes indicate that large increases in the magnitude of warming in the basin may occur in the future.The projections can provide the scientific basis for water and land plan management and disaster prevention and mitigation in the inland river basin.
文摘西北干旱区水资源问题突出,全球变暖将进一步加剧其水资源短缺,研究未来气候变化对流域水资源合理分配和使用具有重要意义。本文利用CRU(Climate Research Unit)数据和DCHP(Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections)提供的32个经BCSD降尺度的CMIP5(全球耦合模式比较计划第五阶段)模式气温数据,采用线性倾向估计、滑动平均、M-K(Mann-Kendall)检验及滑动T(MMT)等检验法,以西北干旱区典型流域开都-孔雀河流域为例,通过对1950—2005年的年平均气温、年平均最高气温与年平均最低气温3个指标的变化趋势及突变年份进行检测,评估各模式及模式集合平均对气温变化的模拟能力。研究结果表明:①12个模式能够准确模拟出1950—2005年流域内各气温指标的显著增加趋势,8个模式能够模拟出部分气温指标的增温趋势,但均低估了增温速率,集合平均也存在同样问题;②除FIO-ESM与MPI-ESM-MR能够准确模拟出气温突变时间外,绝大多数模式不能够准确模拟出。基于优选模式的集合平均PM-PLS和PM-EE对突变的模拟能力总体上优于单个模式,其中PM-PLS模拟能力更优;③对PM-PLS模式集合平均进一步评价,发现其能较好地再现流域气温线性趋势的时空变化总体特征,但仍存在增温速率低估的问题。采用气候模式进行未来气候预估仍需加强模式优选及多模式集合平均方法的深入研究。
