Projected Changes in Climate Extremes Using CMIP6 Simulations Over SREX Regions
Projected Changes in Climate Extremes Using CMIP6 Simulations Over SREX Regions
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DOI：
10.1007/s41748-021-00250-5
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发表时间：
2021-08-23
影响因子：
7.2
通讯作者：
Nadeem, Imran
中科院分区：
文献类型：
--
作者：
Almazroui, Mansour;Saeed, Fahad;Nadeem, Imran
本文介绍了极端温度和降水事件的预测变化，使用耦合模式相互比较项目第6阶段（CMIP 6）的数据，本世纪中叶（2036-2065）和本世纪末（2070-2099）的参考期（1985-2014）。研究了4种社会经济情景下的年最高气温（TXx）、极端热浪日数（HWFI）、年最大连续5天降水量（RX 5d）和连续干旱日数（CDD）4个指标（SSP 1 -2.6; SSP 2 -4.5; SSP 3 -7.0; SSP 5 -8.5）及其26份关于管理极端事件和灾害风险以推进气候变化适应（SREX）地区的特别报告。预测显示，陆地上极端高温和降水的强度和频率将增加。最热日的强度（由TXx测量）预计在热带以外地区比在热带地区增加更多，而极热日的频率（由HWFI测量）预计在热带地区增加更多。干旱频率（根据CDD测量）预计将在巴西、地中海、南非和澳大利亚增加更多。与此同时，亚洲季风区（即，南亚、东亚和东南亚）在世纪晚些时候更容易发生极端山洪事件，如较高的RX 5天指数预测所示。预测的极端变化揭示了每个SREX区域内的大空间变异性。所研究的极端事件的空间变异性随着温室气体浓度的增加而增加，并且在21世纪末更高。在低排放情景SSP 1 -2.6下，极端情况及其空间变异模式的预测变化最小。我们的研究结果表明，温室气体浓度的增加导致极端及其强度的大幅增加。因此，限制二氧化碳排放量可以大大限制与21世纪极端事件增加相关的风险。
This paper presents projected changes in extreme temperature and precipitation events by using Coupled Model Intercomparison Project phase 6 (CMIP6) data for mid-century (2036-2065) and end-century (2070-2099) periods with respect to the reference period (1985-2014). Four indices namely, Annual maximum of maximum temperature (TXx), Extreme heat wave days frequency (HWFI), Annual maximum consecutive 5-day precipitation (RX5day), and Consecutive Dry Days (CDD) were investigated under four socioeconomic scenarios (SSP1-2.6; SSP2-4.5; SSP3-7.0; SSP5-8.5) over the entire globe and its 26 Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) regions. The projections show an increase in intensity and frequency of hot temperature and precipitation extremes over land. The intensity of the hottest days (as measured by TXx) is projected to increase more in extratropical regions than in the tropics, while the frequency of extremely hot days (as measured by HWFI) is projected to increase more in the tropics. Drought frequency (as measured by CDD) is projected to increase more over Brazil, the Mediterranean, South Africa, and Australia. Meanwhile, the Asian monsoon regions (i.e., South Asia, East Asia, and Southeast Asia) become more prone to extreme flash flooding events later in the twenty-first century as shown by the higher RX5day index projections. The projected changes in extremes reveal large spatial variability within each SREX region. The spatial variability of the studied extreme events increases with increasing greenhouse gas concentration (GHG) and is higher at the end of the twenty-first century. The projected change in the extremes and the pattern of their spatial variability is minimum under the low-emission scenario SSP1-2.6. Our results indicate that an increased concentration of GHG leads to substantial increases in the extremes and their intensities. Hence, limiting CO2 emissions could substantially limit the risks associated with increases in extreme events in the twenty-first century.