Science Source

Enhanced poleward propagation of storms under climate change

States that models suggest that storm tracks — regions of large atmospheric weather variability that influence the distribution of temperature, precipitation and wind in the extratropics — shift poleward under global warming
States that while the poleward shift is a robust response across most models, there is currently no consensus on the underlying dynamical mechanism
Presents a new perspective on the poleward shift, which is based on a Lagrangian view of the storm tracks
Applies a storm-tracking algorithm to an ensemble of CMIP5 models
Shows that in addition to a poleward shift in the genesis latitude of the storms, associated with the shift in baroclinicity, the latitudinal displacement of cyclonic storms increases under global warming
Shows that the increased latitudinal propagation in a warmer climate is a result of stronger upper-level winds and increased atmospheric water vapour