Global temperature update

Antarctic sea ice shape develops a global temperature control especially during winter

Currently, SSTs reached a new maximum while global temperatures are below recent years max levels.

The main reason seems to be a cold wave over Antarctica. The circulation around the south pole is characterized by large straight planetary waves of the jet.

At the same time Antarctic sea ice has a round shape with its extent near historical mean values.

It seems that Antarctic sea ice acts like a shield protecting Antarctica from perturbations originating from the tropics.

Here an article I made on Antarctic sea ice shape: https://www.linkedin.com/pulse/antarctic-sea-ice-decline-shape-matters-jan-umsonst-dzsge/

In general jet stream theory a jet with smaller North/south temperature gradients in a sector can be more easily being disturbed animated to develop large scale waves, which does not seem to be the case currently.


This is noteworthy as El Nino forcing currently affects the Southern Hemisphere circulation as upper air is directed to the south but not being able to disturb the planetary waves just feeding into it.

The coming weeks with an intensifying El Nino impact on global circulation it will be interesting if Southern Hemisphere will be disturbed in such a way that warm and moist air masses are advected in one sector over the sea ice reducing it and thereby paving the way to a SH circulation developing a wavier pattern with large wave allowing the intrusion of warm and moist air over Antarctica which would then raise global surface air temperatures as these heatwaves can become extensive during recent winter with temperature values some 30-40°C above normal in local hot spots...