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 largeāensemble 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 AleutianāIcelandic Low seesaw (AIS). The El NiƱoāSouthern Oscillation (ENSO) teleconnection extends more eastward under global warming, which increases the ENSOāNAM correlation through the earlier AIS development. Our findings suggest increased predictability of the NAM under global warming, with uncertainties due to potential ENSO changes.
Observations from the Little Bunker
Last updated: October 16, 2025 02:57 AM
Atmospheric COā
424.4 ppm
+18.2
ppm/year
Atmospheric CHā
1933.54 ppb
+12.29
ppb/year
Global Temperature
+1.48 Ā°C
Peak: +1.73Ā°C
World Population
8.1 billion
+67
million/year