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The poleward shift of storm tracks under global warming: A Lagrangian perspective
Author(s) -
Tamarin T.,
Kaspi Y.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl073633
Subject(s) - climatology , extratropical cyclone , middle latitudes , storm , advection , global warming , cyclone (programming language) , atmospheric sciences , environmental science , diabatic , storm track , latitude , potential vorticity , geology , climate change , meteorology , vorticity , vortex , geography , oceanography , physics , adiabatic process , geodesy , computer science , field programmable gate array , computer hardware , thermodynamics
Comprehensive models of climate change projections have shown that the latitudinal band of extratropical storms will likely shift poleward under global warming. Here we study this poleward shift from a Lagrangian storm perspective, through simulations with an idealized general circulation model. By employing a feature tracking technique to identify the storms, we demonstrate that the poleward motion of individual cyclones increases with increasing global mean temperature. A potential vorticity tendency analysis of the cyclone composites highlights two leading mechanisms responsible for enhanced poleward motion: nonlinear horizontal advection and diabatic heating associated with latent heat release. Our results imply that for a 4 K rise in the global mean surface temperature, the mean poleward displacement of cyclones increases by about 0.85° of latitude, and this occurs in addition to a poleward shift of about 0.6° in their mean genesis latitude. Changes in cyclone tracks may have a significant impact on midlatitude climate, especially in localized storm tracks such as the Atlantic and Pacific storm tracks, which may exhibit a more poleward deflected shape.