Event

Forcing the Circumglobal Teleconnection pattern

Wednesday, November 13, 2019 14:30to15:30

Burnside Hall Room 934, 805 rue Sherbrooke Ouest, Montreal, QC, H3A 0B9, CA

Student Seminar Series

Department of Atmospheric & Oceanic Sciences

presents

a talk by

Nicholas Soulard
PhD student

Forcing the Circumglobal Teleconnection pattern

When the South Asian jet is in a particular phase, there exists a circumglobal teleconnection pattern (CGT) whereby circulation disturbances originating near the jet entrance, or within the jet, remain trapped and can propagate around the globe. Recent studies have shown that this CGT pattern is associated with convection in the vicinity of India; however the cause-effect relationship remains unclear. This study aims to elucidate whether the CGT can be forced to occur given a convective anomaly near this location, or if this convective activity is simply the result of the CGT. We use both reanalysis data, and linear model results to determine whether this, or any other tropical convective forcing can induce this circumglobal pattern. By running the model multiple times with a forcing induced at a different location each time, we can construct a map of locations likely to force the CGT. We can then support these results using lagged composites from reanalysis data. Our results show that not only does a forcing in the Indian Ocean induce this pattern, but convective anomalies elsewhere in the Tropics result in circulation anomalies that also resemble the CGT.