Esteban Abellán Seminar - Meridional movement of Pacific winds and their role in ENSO event onset and termination

Event type: 
Seminar
Date: 
23 August 2017
Time: 
2.00pm - 3.00pm
Location: 

Climate Change Research Centre seminar room, Level 4 Mathews Building, Kensington Campus, Sydney

Presenter: 
Esteban Abellán
UNSW Sydney, Climate Change Research Centre
Host: 
Climate Change Research Centre, UNSW, Australia

During the mature phase of El Niño-Southern Oscillation (ENSO) events, near the end of the calendar year, there is a southward shift of the zonal wind anomalies, which are centred around the equator prior to the event peak. I will talk about the role of this meridional wind movement in the termination of ENSO events by using simple and complex climate models. I will show that the addition of the southward wind shift in the simplified coupled model, based on a statistical atmospheric component, enhances the termination of El Niño events, making the events shorter. In part 2, I will talk about the representation of this meridional movement of the winds in CMIP5 models and how this feature is related to the seasonal synchronization of ENSO events. Finally, in part 3, I will present our main findings on the underlying processes leading up to the extreme 2015-16 El Niño and compare to the two previous record-breaking events in 1997-98 and 1982-83. The results suggest that the persistent location of the zonal wind stress anomalies north of the equator during the two years prior to the 2015-16 peak contrasts the more symmetric pattern and shorter duration observed during the other two events.

 

Brief Biography: Esteban Abellán is currently working on sea level changes with Dr. John Church as a Research Assistant in the Climate Change Research Centre at The University of New South Wales – Sydney. Esteban started his PhD in September 2013 and submitted his thesis in March 2017. His doctoral research focuses on the role of meridional movement of Pacific winds in El Niño-Southern Oscillation event onset and termination. He used simplified coupled models, reanalysis products and data from the state-of-the-art CMIP5 climate models.

Esteban has a Bachelor’s degree in Physics and a Master in Meteorology from University of Barcelona. Before his PhD, he was working at the Spanish Meteorological Agency on ensemble prediction systems applied to aeronautics. He has also operated the Barcelona radiosounding station for more than three years.