Nov 13, 2017

Enhanced poleward propagation of storms under climate change

by
Talia Tamarin-Brodsky, Yohai Kaspi
,
Nature Geoscience
  • 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