{"title":"Projected Changes of the Northern Annular Mode Linked to Seasonality of the ENSO Teleconnection","authors":"T. Kawamura, Y. Kosaka, S. Okajima, H. Nakamura","doi":"10.1029/2025GL118175","DOIUrl":null,"url":null,"abstract":"<p>The Northern Annular Mode (NAM) induces anomalous wintertime weather over the extratropical Northern Hemisphere as the leading mode of atmospheric circulation variability. Yet, modulations of its statistical properties in a changing climate need elucidating. This study investigates the seasonality of NAM variability and its modulations under global warming with a large-ensemble atmospheric simulation data set. We find that the Aleutian Low anomaly associated with the NAM strengthens in a warmer climate, which is linked to a seasonally earlier emergence of the Aleutian-Icelandic Low seesaw (AIS). The El Niño-Southern Oscillation (ENSO) teleconnection extends more eastward under global warming, which increases the ENSO-NAM correlation through the earlier AIS development. Our findings suggest increased predictability of the NAM under global warming, with uncertainties due to potential ENSO changes.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 18","pages":""},"PeriodicalIF":4.6000,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL118175","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geophysical Research Letters","FirstCategoryId":"89","ListUrlMain":"https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL118175","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The Northern Annular Mode (NAM) induces anomalous wintertime weather over the extratropical Northern Hemisphere as the leading mode of atmospheric circulation variability. Yet, modulations of its statistical properties in a changing climate need elucidating. This study investigates the seasonality of NAM variability and its modulations under global warming with a large-ensemble atmospheric simulation data set. We find that the Aleutian Low anomaly associated with the NAM strengthens in a warmer climate, which is linked to a seasonally earlier emergence of the Aleutian-Icelandic Low seesaw (AIS). The El Niño-Southern Oscillation (ENSO) teleconnection extends more eastward under global warming, which increases the ENSO-NAM correlation through the earlier AIS development. Our findings suggest increased predictability of the NAM under global warming, with uncertainties due to potential ENSO changes.
期刊介绍:
Geophysical Research Letters (GRL) publishes high-impact, innovative, and timely research on major scientific advances in all the major geoscience disciplines. Papers are communications-length articles and should have broad and immediate implications in their discipline or across the geosciences. GRLmaintains the fastest turn-around of all high-impact publications in the geosciences and works closely with authors to ensure broad visibility of top papers.