Janni Yuval

Human-induced weakening of the Northern Hemisphere tropical circulation - Nature Analysis of sea-level pressure measurements shows that, in agreement with the latest suite of climate models, the Hadley circulation has considerably weakened in the Northern Hemisphere over recent de...

@rahmstorf.bsky.social - at the time of our previous paper that showed that the Hadley cell has weakened in recent decades (www.nature.com/articles/s41...) you asked me what implication does it have for precipitation. This is what we found.

6/ Our work offers a more refined prediction for subtropical precipitation changes by better constraining Hadley Cell weakening.

5) We show that the constraint work where the Hadley cell is more active - over Asia, Africa, & the Pacific.

4/ How we applied it: 1. We linked observable sea-level pressure changes to Hadley Cell strength. 2. Then, we related this constrained Hadley Cell weakening to projected increases in subtropical precipitation using the moisture budget.

3/ We used an 'emergent constraint' approach. This means we find relationships in climate models between an observable current climate feature (predictor) and a future climate projection (predictand). This helps refine future projections.

2/ Why is this important? Predicting future precipitation changes is tough, largely due to uncertainties in how atmospheric circulation will evolve. The Hadley Cell is a key player in tropical circulation, influencing rainfall patterns.

This is my first post in bsky!
1/ New Nature Climate Change paper - main results: 1. The Northern Hadley circulation weakening will likely be larger than predicted. 2. This leads to a greater increase in subtropical precipitation.
#ClimateScience
Paper link: www.nature.com/articles/s41...