Alex, Indrani, Marissa and co-authors publish paper on the relationship between low clouds, the equatorial cold tongue, and the ITCZ

On February 16, Alex, Indrani, Marissa and co-authors (Gregory Cesana and Charlotte DeMott) published a paper entitled, “Dynamical Importance of the Trade Wind Inversion in Suppressing the Southeast Pacific ITCZ” in the Journal of Geophysical Research: Atmospheres (https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JD039571). Congrats to everyone involved!

The three key points of the paper are:

• East Pacific ITCZ surface wind convergence is strongly controlled by SST and boundary layer (BL) horizontal temperature gradients
• SST gradients overemphasize the equatorial cold tongue leading to excessive equatorial divergence and latitudinally confined double ITCZs
• BL temperature gradients show a shallow cold tongue and deep cold air below the trade wind inversion are key to maintaining a northern ITCZ

Conceptual figure of the importance of cooling at the top of low clouds and near the equatorial cold tongue on wind convergence in the Inter-Tropical Convergence Zone (ITCZ) over the east Pacific Ocean. Illustration by Caitlin Guttu and Natalie Renier, WHOI.