<p>The Atlantic and Pacific storm tracks are regions of enhanced storm activity that shape the Northern Hemisphere climate. Basic theory predicts that stronger jet streams should accompany stronger storm activity. However, despite the Pacific jet being stronger in winter, Atlantic storms are more intense – a puzzling observation that has long challenged our understanding of midlatitude climate. Here, we address this paradox by examining how jet orientation affects interactions with midlatitude storms. Using 84 years of ERA5 data and winter storm tracks (validated with JRA-3Q), we show that the Pacific jet’s zonal structure causes storms to exit high-intensity jet regions rapidly. Conversely, the Atlantic jet’s tilted orientation aligns with storm trajectories, allowing storms to remain in high-intensity jet regions longer. Lagrangian energetic analyses reveal that while Pacific storms exhibit rapid initial growth, Atlantic storms remain longer in stronger baroclinic regions, enabling greater energy extraction, sustained growth, and higher peak intensities. These findings reconcile Northern Hemisphere winter storm activity with the energetic perspective on midlatitude climate and highlight the importance of representing individual storm dynamics for understanding present and future climates.</p>

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Stronger jet, weaker storms: a mechanistic perspective on the Atlantic-Pacific storm paradox

  • Or Hadas,
  • Yohai Kaspi

摘要

The Atlantic and Pacific storm tracks are regions of enhanced storm activity that shape the Northern Hemisphere climate. Basic theory predicts that stronger jet streams should accompany stronger storm activity. However, despite the Pacific jet being stronger in winter, Atlantic storms are more intense – a puzzling observation that has long challenged our understanding of midlatitude climate. Here, we address this paradox by examining how jet orientation affects interactions with midlatitude storms. Using 84 years of ERA5 data and winter storm tracks (validated with JRA-3Q), we show that the Pacific jet’s zonal structure causes storms to exit high-intensity jet regions rapidly. Conversely, the Atlantic jet’s tilted orientation aligns with storm trajectories, allowing storms to remain in high-intensity jet regions longer. Lagrangian energetic analyses reveal that while Pacific storms exhibit rapid initial growth, Atlantic storms remain longer in stronger baroclinic regions, enabling greater energy extraction, sustained growth, and higher peak intensities. These findings reconcile Northern Hemisphere winter storm activity with the energetic perspective on midlatitude climate and highlight the importance of representing individual storm dynamics for understanding present and future climates.