Replicating the Hadley Cell edge and subtropical jet latitude disconnect in idealized atmospheric models

Recent work has shown that variability of the subtropical jet’s (STJ) latitude, phiSTJ is not coupled to that of the Hadley Cell (HC) edge, phiHC, but the reason for this disconnect has not been examined in detail. Here, we use meteorological reanalysis, comprehensive climate models, and an idealized atmospheric model to examine the cause of the distinct behavior of the STJ and HC. We find that a decoupling of phiHC and phiSTJ can occur in a dry general circulation model, indicating that large-scale dynamical processes are sufficient to reproduce the metrics’ relationship without explicit variability in the zonal structure, convective processes, or sea surface temperature variability. With that said, a phiHC and phiSTJ disconnect is dependent on the model simulating an accurate climatological basic state.

Weather and Climate Dynamics