This study finds that the meridional migration of tropical cyclogenesis (TCG) between June and November over the eastern North Pacific is mainly due to changes in the Hadley circulation and associated changes in the location of the intertropical convergence zone as modulated by ENSO and the interhemispheric temperature differential (ITD). These two factors are largely independent of each other and play significant and nearly equivalent roles in the meridional migration of TCG over the ENP from 1979 to 2018. Through the use of regression models, we find that the combination of these two factors has significant skill in capturing annual TCG meridional distribution over the ENP basin. June–October ENSO, as defined by Niño‐3.4, can be skillfully predicted with ∼1 season lead time, while ITD can be skillfully predicted ∼3 seasons in advance. This predictability allows for the potential for seasonal outlooks of TCG meridional movement over the ENP. The influence of ITD on TCG meridional migration over the ENP has repercussions on climate change timescales as well, due to the potential TCG meridional migration over the ENP in response to global warming. Under the Shared Socioeconomic Pathways 2–4.5 scenario, the ITD shows a robust increase among the 23 models of version 6 of the Coupled Model Intercomparison Project. However, the considerable uncertainty in the model response of ENSO to global warming reduces confidence in projections of TCG meridional migration over the ENP.

中文翻译：

---

北太平洋东部热带气旋发生的子午向迁移：半球温度差和ENSO的共同贡献

这项研究发现，北太平洋东部6月至11月间热带气旋作用（TCG）的子午向迁移主要是由于哈德利环流的变化以及受ENSO和半球温度调节的热带辐合带位置的相关变化。差分（ITD）。这两个因素在很大程度上彼此独立，并且在1979年至2018年期间TCG在ENP的子午向迁移中起着重要且几乎等效的作用。通过使用回归模型，我们发现这两个因素的组合在捕获ENP盆地上每年的TCG经线分布。根据Niño-3.4的定义，6月至10月的ENSO可以提前约1个季节的时间提前预测，而ITD可以提前约3个季节的时间准确预测。这种可预测性考虑到了ENP上TCG经线运动的季节性前景。由于对全球变暖的响应，ITD对ENP的TCG子午线迁移的影响也对气候变化的时间尺度产生了影响。在“共享的社会经济途径2-4.5”情景下，ITD显示了耦合模型比对项目的版本6的23种模型中的强劲增长。但是，ENSO对全球变暖的模型响应中存在很大的不确定性，这降低了对ENP上TCG子午线迁移预测的信心。由于全球变暖，潜在的TCG子午线在ENP上的经向迁移。在“共享的社会经济途径2-4.5”情景下，ITD显示了耦合模型比对项目的版本6的23种模型中的强劲增长。但是，ENSO对全球变暖的模型响应中存在很大的不确定性，这降低了对ENP上TCG子午线迁移预测的信心。由于全球变暖，潜在的TCG子午线在ENP上的经向迁移。在“共享的社会经济途径2-4.5”情景下，ITD显示了耦合模型比对项目的版本6的23种模型中的强劲增长。但是，ENSO对全球变暖的模型响应中存在很大的不确定性，这降低了对ENP上TCG子午线迁移预测的信心。