大气科学
大氣科學
대기과학
Chinese Journal of Atmospheric Sciences
2015年
6期
1123-1135
,共13页
阈值%极端气候%预估
閾值%極耑氣候%預估
역치%겁단기후%예고
Threshold%Climate extremes%Projection
本文基于耦合模式比较计划第五阶段(CMIP5)的18个全球气候模式的模拟结果,预估了全球平均气温在不同典型浓度路径(RCPs)下达到2°C、3°C和4°C阈值时,中国地区气温和降水的变化,并采用了具有稳定统计意义的27个极端气候指标定量评估了全球平均气温达到不同阈值时,中国地区极端气候事件的可能变化。结果表明,未来我国平均气温增幅将高于全球平均增暖,极端暖事件(如暖夜、暖昼、热带夜)明显增多,达到4°C阈值时,暖夜指数相比参考时段增加约49.9%。极端冷事件(如冷夜、冷昼、霜冻)减少。随全球气温升高,中国北方平均降水增多。在不同升温阈值下,中国地区降水的极端性都体现出增强的趋势,强降水事件发生频率(如中雨日数、大雨日数)和强度(如五日最大降水量、极端强降水量)都明显增加。随升温阈值的升高,这些变化幅度更大,在RCP8.5情景下全球升温3°C和4°C时,中国平均五日最大降水分别增加12.5 mm和17.0 mm。我国西南地区极端降水强度的增幅高于其他地区。
本文基于耦閤模式比較計劃第五階段(CMIP5)的18箇全毬氣候模式的模擬結果,預估瞭全毬平均氣溫在不同典型濃度路徑(RCPs)下達到2°C、3°C和4°C閾值時,中國地區氣溫和降水的變化,併採用瞭具有穩定統計意義的27箇極耑氣候指標定量評估瞭全毬平均氣溫達到不同閾值時,中國地區極耑氣候事件的可能變化。結果錶明,未來我國平均氣溫增幅將高于全毬平均增暖,極耑暖事件(如暖夜、暖晝、熱帶夜)明顯增多,達到4°C閾值時,暖夜指數相比參攷時段增加約49.9%。極耑冷事件(如冷夜、冷晝、霜凍)減少。隨全毬氣溫升高,中國北方平均降水增多。在不同升溫閾值下,中國地區降水的極耑性都體現齣增彊的趨勢,彊降水事件髮生頻率(如中雨日數、大雨日數)和彊度(如五日最大降水量、極耑彊降水量)都明顯增加。隨升溫閾值的升高,這些變化幅度更大,在RCP8.5情景下全毬升溫3°C和4°C時,中國平均五日最大降水分彆增加12.5 mm和17.0 mm。我國西南地區極耑降水彊度的增幅高于其他地區。
본문기우우합모식비교계화제오계단(CMIP5)적18개전구기후모식적모의결과,예고료전구평균기온재불동전형농도로경(RCPs)하체도2°C、3°C화4°C역치시,중국지구기온화강수적변화,병채용료구유은정통계의의적27개겁단기후지표정량평고료전구평균기온체도불동역치시,중국지구겁단기후사건적가능변화。결과표명,미래아국평균기온증폭장고우전구평균증난,겁단난사건(여난야、난주、열대야)명현증다,체도4°C역치시,난야지수상비삼고시단증가약49.9%。겁단랭사건(여랭야、랭주、상동)감소。수전구기온승고,중국북방평균강수증다。재불동승온역치하,중국지구강수적겁단성도체현출증강적추세,강강수사건발생빈솔(여중우일수、대우일수)화강도(여오일최대강수량、겁단강강수량)도명현증가。수승온역치적승고,저사변화폭도경대,재RCP8.5정경하전구승온3°C화4°C시,중국평균오일최대강수분별증가12.5 mm화17.0 mm。아국서남지구겁단강수강도적증폭고우기타지구。
Due to human-induced global warming, global Average Surface Air Temperature (ASAT) will reach certain thresholds with reference to the pre-industrial period. Quantitative assessments of climate extremes across China when reaching these thresholds are important indicators in disaster risk management and policymaking. In this study, based on outputs of 18 General Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5), 27 climate-extreme indices computed with a consistent methodology are used to quantify the changes in the mean and extreme climate across China when the 2°C, 3°C, and 4°C thresholds under different Representative Concentration Pathways (RCP) scenarios are exceeded. In general, the ASAT warms faster over China than the global mean in the 21st century. Extreme warm events (e.g., warm nights, warm days, and tropical nights) increase greatly, while extreme cold events (e.g., cold nights, cold days, and frost days) decrease. When the 4°C threshold is exceeded, warm nights index (spatially averaged over China) are projected to show an increase of about 49.9% relative to the reference period. Accompanied by the increase in global mean temperature, the northern part of China will see more precipitation when the 2°C threshold is exceeded. Extreme precipitation shows obvious intensification in both frequency and magnitude when different temperature thresholds are exceeded. China is dominated by lengthening heavy and very heavy precipitation days and increasing maximum consecutive 5-day precipitation and extremely wet days. Under the RCP8.5 scenario, the maximum consecutive 5-day precipitation amount increases by 12.5 mm and 17.0 mm when the global ASAT becomes 3°C and 4°C warmer, respectively. The changes are found to be more pronounced under higher temperature thresholds. Southwest China, however, exhibits larger changes in the magnitude of extreme precipitation than other regions.