Storm track processes and the opposing influences of climate change


Extratropical cyclones are storm systems that are observed to travel preferentially within confined regions known as storm tracks. They contribute to precipitation, wind and temperature extremes in mid-latitudes. Cyclones tend to form where surface temperature gradients are large, and the jet stream influences their speed and direction of travel. Storm tracks shape the global climate through transport of energy and momentum. The intensity and location of storm tracks varies seasonally, and in response to other natural variations, such as changes in tropical sea surface temperature. A hierarchy of numerical models of the atmosphere–ocean system — from highly idealized to comprehensive — has been used to study and predict responses of storm tracks to anthropogenic climate change. The future position and intensity of storm tracks depend on processes that alter temperature gradients. However, different processes can have opposing influences on temperature gradients, which leads to a tug of war on storm track responses and makes future projections more difficult. For example, as climate warms, surface shortwave cloud radiative changes increase the Equator-to-pole temperature gradient, but at the same time, longwave cloud radiative changes reduce this gradient. Future progress depends on understanding and accurately quantifying the relative influence of such processes on the storm tracks.

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Figure 1: Wintertime (December–February, DJF, in the Northern Hemisphere and June–August, JJA, in the Southern Hemisphere) storm tracks.
Figure 2: Mid-latitude precipitation extremes associated with storm tracks.
Figure 3: Schematic of a storm track.
Figure 4: Coupling between tropical Pacific SST and the storm track.


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T.A.S. and A.V. are supported by the David and Lucile Packard Foundation. T.A.S is supported by the Alfred P. Sloan Foundation. We acknowledge support from the National Science Foundation (T.A.S., AGS-1538944; P.A.O., AGS-1148594; E.A.B., AGS-1419818). The National Center for Atmospheric Research is also supported by the National Science Foundation. Y.T.H. is supported by the Ministry of Science and Technology of Taiwan (104-2111-M-002-005). C.I.G. is supported by Israel Science Foundation (1558/14). C.L. is supported by Research Council of Norway project jetSTREAM (231716). We thank participants of the World Climate Research Program's Stratosphere–troposphere processes and their Role in Climate Workshop on the Storm Tracks. We thank S. Pfahl for Fig. 2 and the reviewers whose comments helped to significantly improve the submitted manuscript.

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Shaw, T., Baldwin, M., Barnes, E. et al. Storm track processes and the opposing influences of climate change. Nature Geosci 9, 656–664 (2016).

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