The impact of upper tropospheric friction and Gill-type heating on the location and strength of the Tropical Easterly Jet: Idealized physics in a dry Atmospheric General Circulation Model

TL;DR

This study uses an idealized atmospheric model to investigate how upper tropospheric friction and Gill-type heating influence the location and strength of the Tropical Easterly Jet, revealing limitations of the Gill model for upper-level jet prediction.

Contribution

It demonstrates the importance of upper tropospheric friction in realistic TEJ simulation and highlights the inadequacy of the Gill model for upper-level jet dynamics.

Findings

Upper tropospheric friction is crucial for realistic TEJ patterns.

Gill heating alone cannot produce the TEJ at upper levels.

The Gill model is insufficient for explaining upper tropospheric jet features.

Abstract

An atmospheric general circulation model (AGCM) with idealized and complete physics has been used to evaluate the Tropical Easterly Jet (TEJ) jet. In idealized physics, the role of upper tropospheric friction has been found to be important in getting realistic upper tropospheric zonal wind patterns in response to heating. In idealized physics, the location and strength of the TEJ as a response to Gill heating has been studied. Though the Gill model is considered to be widely successful in capturing the lower tropospheric response, it is found to be inadequate in explaining the location and strength of the upper level TEJ. Heating from the Gill model and realistic upper tropospheric friction does not lead to the formation of a TEJ.