Variability and changes in high impact hydrometeorological events

气候变化是一个不可避免的全球现象，将强烈影响加拿大。在加拿大的北极和亚北极地区，与海冰和积雪覆盖区域变化相关的反馈将放大预期的表面变暖，正如过去30年在加拿大北部和东北部观察到的那样。这些变化还将影响当地和南部偏远地区的高影响天气事件，因为这些天气事件依赖于这些区域反馈，这些反馈与通过气象系统向极地输送的热量强烈相互作用。然后，需要更好地预测区域尺度上不断变化的气象(基于天气事件的发生、持续时间和强度)，以及联合气候变量的相关变化，以增进我们对与大气环流驱动机制相互作用的地方或区域尺度影响之间的耦合的理解。事实上，与单变量模拟相关的许多关键过程已经被理解，但研究只是开始集中于开发联合或组合变量的预测，特别是当涉及到单变量的极值或变异性时。

Climate change is an unavoidable global phenomenon that will strongly affect Canada. Over Arctic and subarctic regions of Canada, feedbacks associated with regional changes in sea-ice and snow cover will amplify anticipated surface warming, as observed over the last three decades in northern and northeastern Canada. These changes will also affect high impact weather events, locally and over remote southern regions, as those depend on these regional feedbacks that strongly interact with poleward heat transports through meteorological systems. Then, better projections of the changing meteorology (based on occurrence, duration and intensity of weather events) at regional scales are needed, as well as pertinent changes in joint climatic variables to improve our understanding on the coupling between local or regional-scale influences that interact with atmospheric circulation driven mechanisms. In fact, many of the key processes relevant to the simulation of single variables are understood, but studies are only starting to focus on developing projections of joint or combined variables, especially when extremes or variability in the individual quantities are concerned.