10/08/2023, 12:11 pm EDT

Why is Global Atmospheric Angular Momentum Negative Given El Nino Presence?

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.   
10/04/2023, 11:05 am EDT

Increased Solar Activity/Decrease in Sudden Stratospheric Warming Events

A mild El Nino winter is ahead for most of the northern hemisphere. Cold air bursts can still happen, although one way to trigger arctic outbreaks (sudden stratospheric warming) is less likely to occur due to the expectation of increased solar wind in the upper atmosphere as related to increased solar activity.
09/17/2023, 11:02 am EDT

Correlating Northeast Pacific SSTA and Europe Winter Temperature

When was the last cold winter season in Europe? Sprawling meteorological winter (DEC/JAN/FEB) cold was last observed during winter 2012-13. Since that time, 8 of 10 winter seasons have been warmer than normal across Europe. During the past 30 years, 7 widespread cold winter seasons have been observed clustering in the mid-to-late 1990’s and in the 2008-2013 period.
09/13/2023, 8:17 am EDT

Understanding The Difference Between Multivariate ENSO Index and Nino34 SSTA Index

The Multivariate ENSO Index (MEI.v2) and the Niño 3.4 Index value are two (of many) indices used to monitor the behavior and evolution of the El Niño Southern Oscillation (ENSO).  However, these two indices cannot be used as an apples-to-apples comparison. Both are distinctly different from each other in spatial resolution, temporal resolution and ocean-atmospheric variables considered in the computation of the indices.