May 24, 2018

Atmospheric blocking as a traffic jam in the jet stream

by
Noboru Nakamura, Clare S. Y. Huang
,
Science
  • States that atmospheric blocking due to anomalous, persistent meandering of the jet stream often causes weather extremes in the midlatitudes
  • States that despite its ubiquity, the onset mechanism of blocking is not well understood
  • Demonstrates with meteorological data that there exists a close analogy between blocking and traffic congestion on a highway, and that they can be described by a common mathematical theory
  • The theory predicts that the jet stream has a capacity for the flux of wave activity (a measure of meandering), just as the highway has traffic capacity, and when it is exceeded, blocking manifests as congestion
  • Stationary waves modulate the jet stream’s capacity for transient waves and localize block formation
  • Climate change likely affects blocking frequency by modifying the jet stream’s proximity to capacity