Environmental Science and Engineering Seminar

Previous studies have suggested that Arctic Amplification (accelerated warming of the Arctic compared to the rest of the globe) has and will continue to influence the midlatitude jet-stream. Here, observed and model-based trends in North Atlantic jet-stream activity are presented in the context of Arctic amplification. Present-day trends are shown to be less certain than suggested by previous studies, with no evidence of deviations in blocking frequency or jet variability over the past 30 years from what might be expected from natural variability. 

Climate model projections of the 21st Century (CMIP5 multi-model ensemble) also provide insight into the relative importance of future Arctic warming on the potential fate of North Atlantic jet variability. It is demonstrated that while all models exhibit amplified Arctic warming over the coming century, significant model spread is found in the response of the North Atlantic jet-stream. Arctic warming is further explored in the context of explaining this spread in the model responses.