Variability in Extratropical Storm Tracks Under Climate Change: A Study

Strategic Insights -

Scientists have made a significant breakthrough in understanding the impact of climate change on extratropical storm tracks, a crucial component of the climate system. A recent study published in the Proceedings of the National Academy of Sciences of the United States of America found that the southern storm track intensifies in simulations of 21st century climate change, and the seasonal cycle of storm-track intensity increases in amplitude in both hemispheres.

Key Takeaways:

  • The study revealed that the southern storm track intensifies in the multimodel mean of simulations of 21st century climate change.
  • The seasonal cycle of storm-track intensity increases in amplitude in both hemispheres, with a stronger southern storm track in response to present-day global warming.
  • The researchers used observations of the present-day seasonal cycle to confirm the relationship between storm-track intensity and the mean available potential energy of the atmosphere.
  • The study found that storm-track intensity is not related in a simple way to global-mean surface temperature, and that a stronger southern storm track in response to present-day global warming does not imply it was also stronger in hothouse climates of the past.
  • P.A. O'Gorman and colleagues from the Massachusetts Institute of Technology conducted this research.
  • The study's findings suggest that storm-track intensity can be affected by various climate change factors, including changes in atmospheric energy and ocean circulation.

Statistics:

  • 21st century climate change: simulations showed a significant increase in the southern storm track intensity.
  • Amplitude of storm-track intensity: increased in both hemispheres, particularly in the southern hemisphere.
  • Global-mean surface temperature: not directly correlated with storm-track intensity, according to the study's findings.
  • Present-day global warming: led to a stronger southern storm track in simulations.
  • Hothouse climates of the past: did not show a significant correlation with storm-track intensity or global-mean surface temperature.

Sources:

  • Proceedings of the National Academy of Sciences of the United States of America (Understanding the varied response of the extratropical storm tracks to climate change. Proceedings of the National Academy of Sciences of the United States of America, 2010;107(45):19176-80)
  • Massachusetts Institute of Technology, Cambridge, MA 02139, United States, contact: P.A. O'Gorman