A Strengthened Teleconnection of the Quasi‐Biennial Oscillation and Tropical Easterly Jet in the Past Decades in E3SMv1

Abstract

Abstract The Energy Exascale Earth System Model version 1 (E3SMv1) is a new global model that can generate a weakened tropical easterly jet (TEJ) during the easterly quasi‐biennial oscillation (EQBO) and a strengthened TEJ during the westerly QBO (WQBO), which is referred to as the QBO‐TEJ teleconnection. Although the longitudinal structure of the QBO‐TEJ teleconnection is different between reanalysis and simulations, we hypothesize that simulations can still provide insights into the observed long‐term changes in the QBO‐TEJ teleconnection. The Atmospheric Model Intercomparison Project historical simulations (AMIP‐historical) generate a strengthened trend in the correlation between the QBO and TEJ indices in the period of 1950–2014 as in reanalysis. The comparison of the AMIP‐historical and the Coupled Model Intercomparison Project coupled historical simulations (coupled‐historical) shows that the warming of the Indian Ocean has played a vital role in the strengthened QBO‐TEJ teleconnection over the past six decades.

Keywords

• QBO
• tropical easterly jet
• stratosphere‐troposphere interaction