On the multi-decadal variability of the tropical stratosphere
Dr. Fernando Iglesias-Suarez
Research Associate
Institute of Atmospheric Physics
German Aerospace Center
Wednesday, October 20th at 14:00-15:00 UTC
All attendees must register through the following link: https://univ-lille-fr.zoom.us/webinar/register/WN_YLiStgAqS5awrXINxMTsGw
Abstract
Natural variability is an important component of the climate system which can mask anthropogenically-induced changes. Observational estimates and modeling evidence suggest an acceleration of the stratospheric Brewer-Dobson circulation (BDC) over the recent past, driven by climate change and stratospheric ozone depletion. Yet, low-frequency natural variability can compromise the detection of such forced changes. Here, we explore the naturally varying strength of the BDC and how this has consequences for the composition of the stratosphere. We show, using observations and model simulations, that multi-decadal natural variability in the Pacific Ocean -namely the Interdecadal Pacific Oscillation, IPO- is linked to the BDC. This troposphere-stratosphere interaction helps us disentangle structural changes in the BDC associated with human interferences. Furthermore, naturally occurring slow changes in transport can help us understand recent low levels of ozone in the middle tropical stratosphere, which is in apparent disagreement with the expected ozone recovery. These findings have implications for both reconciling theory and observed changes in the circulation and composition of the tropical stratosphere.
Dr. Fernando Iglesias-Suarez is a climate scientist with a strong interest in developing and applying machine learning techniques (ML) to advance climate models and analysis, understanding links and interactions with other parts of the Earth system to address the scientific challenges of global change.
By training, he is an Environmental scientist and worked for few years as a consultant. He obtained MSc in Climate Change at the University of East Anglia (UEA) “Investigating geoengineering solutions to meet the 2ºC target.” His PhD focused on stratospheric ozone and climate interactions.
After graduation, he continued to explore the role of natural halogens in tropospheric ozone in a changing climate at the Spanish National Research Council (CSIC).
Finally, he joined the Earth System Model Evaluation and Analysis Department at the German Aerospace Center (DLR). Within the “Understanding and Modelling the Earth System with Machine Learning (USMILE)” project, he focused on developing new methods and approaches via ML means to eliminate long-standing systematic errors in climate models and to provide more robust climate projections.