<p>Since 1980, tropical cyclones have migrated poleward, but it remains unclear whether this trend reflects long-term climate change or temporary climate variability. Here we investigate the drivers of this poleward migration using multiple observational datasets and global models that permit tropical cyclones. We show that a tripolar pattern of Pacific sea surface temperature variability strongly modulates the interannual variation of cyclone latitudes and largely drove the poleward migration over 1980–2024. The tripolar pattern influences tropical cyclones more effectively than either the El Niño/Southern Oscillation or the Hadley circulation. When its effects are removed, poleward migration is negligible. When it shows negative trends, the model simulates equatorward migration. As the pattern exhibits alternating multi-decadal trends but no long-term trend since 1970, its recent trend—and the associated poleward migration—is unlikely to persist. In ensemble projections under a warming scenario, tropical cyclone activity decreases overall, leading to fewer occurrences at high latitudes despite the poleward expansion of the Hadley cell. These results indicate that climate variability has played a dominant role in the observed poleward migration of tropical cyclones, and that future changes may differ markedly from the recent multi-decadal trends.</p>

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Poleward migration of tropical cyclones over 1980–2024 is dominated by Pacific variability

  • Wenyu Zhou,
  • L. Ruby Leung,
  • Chuan-Chieh Chang,
  • Ming Zhao,
  • Huang-Hsiung Hsu,
  • Hsin-Chien Liang,
  • Chia-Ying Tu,
  • Karthik Balaguru,
  • Jian Lu

摘要

Since 1980, tropical cyclones have migrated poleward, but it remains unclear whether this trend reflects long-term climate change or temporary climate variability. Here we investigate the drivers of this poleward migration using multiple observational datasets and global models that permit tropical cyclones. We show that a tripolar pattern of Pacific sea surface temperature variability strongly modulates the interannual variation of cyclone latitudes and largely drove the poleward migration over 1980–2024. The tripolar pattern influences tropical cyclones more effectively than either the El Niño/Southern Oscillation or the Hadley circulation. When its effects are removed, poleward migration is negligible. When it shows negative trends, the model simulates equatorward migration. As the pattern exhibits alternating multi-decadal trends but no long-term trend since 1970, its recent trend—and the associated poleward migration—is unlikely to persist. In ensemble projections under a warming scenario, tropical cyclone activity decreases overall, leading to fewer occurrences at high latitudes despite the poleward expansion of the Hadley cell. These results indicate that climate variability has played a dominant role in the observed poleward migration of tropical cyclones, and that future changes may differ markedly from the recent multi-decadal trends.