Valentina Collavini

My current PhD topic: How does land shape the Walker circulation?

The presence of the Pacific Walker circulation is generally attributed to the zonal sea surface temperature (SST) gradient in the equatorial Pacific Ocean. While easterly winds transport warm surface waters westward, the upwelling of cold deep waters to the east sustains the Eastern Pacific cold tongue. This drives a closed overturning atmospheric circulation characterized by ascending motion over the Maritime Continent and descending motion over the Eastern Pacific.

This East-West SST gradient is then appointed as the main reason for the existence of the Walker circulation. However, I challenge this canonical view by suggesting that the presence of land to the east of this overturning circulation plays a fundamental role in setting the Walker circulation in the first place.

I am running aquaplanet simulations in ICON XPP to understand which are the properties of an idealized land patch that most importantly affect the Walker circulation.