Changes of temperature and precipitation extremes in a typical arid and semiarid zone: Observations and multi‐model ensemble projections
Changes of temperature and precipitation extremes in a typical arid and semiarid zone: Observations and multi‐model ensemble projections
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DOI：
10.1002/joc.6510
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发表时间：
2020-02
期刊：
影响因子：
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通讯作者：
Cuiping Zhao;Jiaguo Gong;Hao Wang;Su-hong Wei;Qianggong Song;Yuyan Zhou
中科院分区：
文献类型：
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作者：
Cuiping Zhao;Jiaguo Gong;Hao Wang;Su-hong Wei;Qianggong Song;Yuyan Zhou
研究了典型干旱半干旱区(甘肃省中国)气温和降水极值的时空变化，包括最新观测(1960年-2016年)和美国国家航空航天局地球交换全球每日缩小尺度预测(NEX-GDDP)数据集，该数据集基于Mann-Kendall检验、线性回归、5年平滑平均和贝叶斯模型平均(BMA)方法对未来(2017年-2099年)气候预测进行了统计缩小尺度耦合模式间比较计划(CMIP5)。结果表明：(A)1960-2016年间，除日较差(DTR)略有下降外，其他温度极端指数均呈显著变化趋势。年区域夜间温度上升速度快于白天温度。在季节序列中，凉夜(Tn10p)和凉日(TX10p)显著减少，暖夜(Tn90p)和暖日(TX90p)在所有季节都显著增加。(2)除最大1d降水量(RX1DAY)和简单日强度指数(SDII)空间格局一致性较弱外，其他极端降水指数均呈下降趋势。从空间特征看，西部地区总降水量呈增加趋势，东部地区呈显著减少趋势。在季节序列中，冬季RX1DAY和最大5日降水量(RX5DAY)显著高于春、夏、秋。(C)在21世纪，可以观察到温暖指数的正趋势(即夏季、热带白天、温暖的夜晚和温暖的白天)和寒冷指数的负趋势(即霜冻的白天、冰天、凉爽的夜晚和寒冷的白天)。连续干旱日数(CDD)略有减少，强降水日数(R10)、极湿日数(R99p)、RX5DAY和SDII明显增加，表明2017-2099年将出现更多极端降水。研究成果对完善区域水资源与生态环境管理战略，特别是干旱半干旱地区的水资源与生态环境管理具有实际意义。
The spatiotemporal changes of temperature and precipitation extremes in a typical arid and semiarid zone (Gansu Province, China) were investigated, including the latest observations (1960–2016) and the National Aeronautics and Space Administration Earth Exchange Global Daily Downscaled Projections (NEX‐GDDP) dataset that provides statistically downscaled Coupled Model Inter‐comparison Project Phase 5 (CMIP5) future climate projections (2017–2099) based on the Mann–Kendall test, linear regression, 5‐year smoothed average and Bayesian model average (BMA) methods. The results show the following: (a) Apart from a slight decrease of diurnal temperature range (DTR), other temperature extreme indices presented significant trends over 1960–2016. Annual regional nighttime temperature increased at a faster rate than daytime temperature. In the seasonal series, cool nights (TN10p) and cool days (TX10p) showed significant decreases and warm nights (TN90p) and warm days (TX90p) significantly increased in all seasons. (b) Precipitation extreme indices showed decreasing trends, except for the max 1‐day precipitation (RX1DAY) and simple daily intensity index (SDII) with a weaker coherence of spatial patterns. From the perspective of spatial characteristics, the western area had an increasing trend of total precipitation while the east had a significant decreasing trend. In the seasonal series, a significant increase of RX1DAY and the max 5‐day precipitation (RX5DAY) was found in winter, as compared with spring, summer and autumn. (c) Positive trends in warm indices (i.e., summer days, tropical days, warm nights and warm days) and negative trends in cold indices (i.e., frost days, ice days, cool nights and cool days) can be observed in the 21st century. A slightly decreasing consecutive dry days (CDD), together with obviously increasing heavy precipitation days (R10), extremely wet days (R99p), RX5DAY and SDII, suggests more extreme precipitation for 2017–2099. The results are of practical use in improving regional strategies for water resources and eco‐environment management, especially for arid and semiarid regions.