Valentina Pivotti – University of Boston
Because of its temperature, pressure and precipitation seesaw in the world’s largest water basin, ENSO has been the central topic of a large body of literature. One particularly important question that drive current research is: can we predict ENSO states?
Knowing about an upcoming ENSO event could in fact inform weather forecasts in highly populated regions like India, China, South America and the East coast of Africa. Consequently, this would provide farmers, shepherds and fishermen with vital information for building resilience within their communities.
ENSO’s frequency is highly variable, and the key to make predictions is understanding its driving mechanisms. How to explain the initiation of ENSO is a matter of debate. This seminar will focus on one triggering mechanism: the Trade Wind Charging (TWC). The TWC consists of an extra-Equatorial wind-stress anomalous curl, which has been shown to have a strong 1-year lagged correlation with ENSO. Dynamically, the anomalous subtropical westerlies, together with the anomalous equatorial easterlies, induce integrated meridional mass transport into the Equator. This convergence of warm water masses results in subsurface heat changes, and a charged Equator is known to be an ENSO initiator.
Through statistical analysis, I will show how the relationship between ENSO and this triggering mechanism has changed throughout the XX century and how other drivers have also influenced the dynamic of ENSO.
Note: The seminar will be held at the CMCC premises in Bologna, Viale Berti Pichat 6/2 – Meeting Room (Second Floor).