10/08/2023, 12:11 pm EDT
Historically, global atmospheric angular momentum (GLAAM) has tendency to increase during El Nino due to increased vertical wind shear and upper-level wind increase in the subtropics of both hemispheres. The increased wind in the global subtropics increases GLAAM. However, despite El Nino presence in late 2023, GLAAM has shifted negative. Proposed is the unusual negative shift in GLAAM is due to the warming of the mid-latitude oceans of the past decade or so lowering or eliminating south-to-north subtropical oceanic thermal gradient, vertical wind shear, and wind aloft.