Projected changes of the Northern Annular Mode linked to seasonality of the ENSO teleconnection

\cite{Kawamura_2025} The Northern Annular Mode (NAM) is the dominant pattern of atmospheric circulation variability in the wintertime Northern Hemisphere extratropics. This study utilizes a large ensemble atmospheric simulation dataset to examine the seasonality of the NAM variability and its modulations under global warming. We show an enhancement of the Aleutian Low anomaly associated with the NAM in a warmer climate. This enhancement is related to the emergence of the Aleutian-Icelandic Low seesaw (AIS) from early winter, which is in contrast prominent only in late winter in the historical climate. The large ensemble reveals a significant increase in the fraction of the NAM variance explained by sea surface temperature and sea ice variability, suggesting a higher potential predictability. In particular, the eastward extension of the El Niño-Southern Oscillation (ENSO) teleconnection under global warming contributes to the AIS formation even in early winter and a higher NAM-ENSO correlation. Information & Authors Information Peer review timeline Published Geophysical Research Letters Version of Record19 Sep 2025Published Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 447views 314downloads Citations Download citation Takashi Kawamura, Yu Kosaka, Satoru Okajima, et al. Projected changes of the Northern Annular Mode linked to seasonality of the ENSO teleconnection. Authorea. 12 December 2025. DOI: https://doi.org/10.22541/au.172961979.91737935/v2 DOI: https://doi.org/10.22541/au.172961979.91737935/v2 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.