Changes in the characteristics of austral winter (June–July–August) synoptic activity in three domains (Africa, Australia and South America) of the extratropical Southern Hemisphere projected with the Regional Climate Model version 4 (RegCM4) are presented. The model is nested in three global climate models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5) under the Representative Concentration Pathway 8.5. The model grid spacing is 25 km and the simulations cover the period 1970–2100. Synoptic activity is analyzed using both Eulerian and Lagrangian approaches. The Eulerian analysis shows an increase of the synoptic activity south of 40° S in the RegCM4 and GCMs ensembles for the future (2080–2099) compared to the present (1995–2014), but this signal does not necessarily indicate an increase in the cyclone frequency since it includes cyclonic and anticyclonic features. The Lagrangian analysis, however, indicates a decrease in the frequency of cyclones, with a positive tendency towards stronger systems, although the latter is not statistically significant at 95% confidence level. Lifetime, traveled distance and mean speed of the cyclones do not present statistically significant changes in the future climate. On the other hand, a significant increase in both intensity and extension of areas affected by precipitation associated with cyclones is found. As a consequence, there is a statistically significant trend of individual cyclones to produce more rainfall in the future.

提出了区域气候模式第4版（RegCM4）预测的温带南半球三个区域（非洲，澳大利亚和南美）的南方冬季（6月至7月至8月）天气活动特征的变化。该模型嵌套在“代表浓度路径8.5”下的耦合模型比较项目第5阶段（CMIP5）的三个全球气候模型（GCM）中。模型的网格间距为25 km，模拟范围为1970–2100年。使用欧拉和拉格朗日方法分析天气活动。欧拉分析表明，与现在（1995-2014）相比，RegCM4和GCM集合在未来（2080-2099）的天气活动增加了，但是此信号不一定表示气旋频率增加，因为它具有气旋和反气旋特征。然而，拉格朗日分析表明，旋风的频率降低，有朝更强系统发展的积极趋势，尽管后者在95％的置信度水平上没有统计学意义。气旋的寿命，行进距离和平均速度在未来的气候中没有统计学上的显着变化。另一方面，发现受旋风影响的降水影响区域的强度和延伸都显着增加。结果，从统计学上讲，各个旋风分离器将来会产生更多的降雨。表示气旋频率降低，有朝更强系统发展的积极趋势，尽管后者在95％的置信度水平上没有统计学意义。气旋的寿命，行进距离和平均速度在未来的气候中没有统计学上的显着变化。另一方面，发现受旋风影响的降水影响区域的强度和延伸都显着增加。结果，从统计学上讲，各个旋风分离器将来会产生更多的降雨。表示气旋频率降低，有朝更强系统发展的积极趋势，尽管后者在95％的置信度水平上没有统计学意义。气旋的寿命，行进距离和平均速度在未来的气候中没有统计学上的显着变化。另一方面，发现受旋风影响的降水影响区域的强度和延伸都显着增加。结果，从统计学上讲，各个旋风分离器将来会产生更多的降雨。另一方面，发现受旋风影响的降水影响区域的强度和延伸都显着增加。结果，从统计学上讲，各个旋风分离器将来会产生更多的降雨。另一方面，发现受旋风影响的降水影响区域的强度和延伸都显着增加。结果，从统计学上讲，各个旋风分离器将来会产生更多的降雨。