He investigates global climate change

He investigates global climate change

Anastasios Tsonis is an atmospheric scientist and distinguished professor at the University of Wisconsin–Milwaukee. His research focuses on the study of climate dynamics and global change.

He was born in Elefsis, Greece, in May 13, 1953 where he grew up with his brother, Panagiotis. He studied physics and mathematics at the Aristotelian University in Thessaloniki, where he received his BS in 1976. He traveled to Montreal, Canada, where he studied atmospheric sciences, receiving his Ph.D in 1982 from McGill University.



For the next three years he was a post-doctoral fellow at the Atmospheric Environmental Service, Cloud Physics Division, at Downsview, Ontario. In 1985, he joined the Department of Geosciences at the University of Wisconsin -Milwaukee (UWM) as an Assistant Professor and then as a Distinguished Professor in the Department of Mathematical Sciences, plus the leader in the Atmospheric Sciences program.

His work has focused on the study of Atmospheric Sciences, specifically in the areas of climate dynamics and global change. He was one of the first scientists to promote the application of Chaos theory and nonlinear data analysis in Atmospheric Sciences. Along with Jim Elsner, in a series of papers in the late 1980s they popularized and introduced this theory to meteorologists.



Their research has led to the Tsonis criterion, a method bearing their names, and two statistical tests bearing their names. The Tsonis Criterion refers to the necessary number of points required in attractor reconstructions. In the mathematical field of dynamical systems, an attractor is a set of numerical values toward which a system tends to evolve, for a wide variety of starting conditions of the system. System values that get close enough to the attractor values remain close even if slightly disturbed.



The Tsonis-Elsner method is a method used to distinguish low-dimensional chaos from random fractal processes, and the Elsner-Tsonis test is a statistical test designed to assess the significance of climate oscillations.


Lorenz Curve


In 2004 he was the first to apply the concepts of “small-world” networks to atmospheric sciences. His research in this area has led to the discovery of a new dynamical mechanism for major climate shifts, which explains all major global temperature shifts in the 20th and 21st century. He has also done significant research in the area of global change, and have published a theory about the relationship of global temperature and the frequency of El Niño.



His interdisciplinary efforts and collaborations in nonlinear methods have resulted in over 15 papers in the subjects of Biology, Economics, Linguistics, and Psychology. With his brother Panagiotis, have published several important papers on the mathematical properties of DNA sequences, and have developed a hypothesis regarding the mathematical framework for memories and dreams. This hypothesis has recently been verified experimentally.



Anastasios Tsonis is a member of the Global Warming Policy Foundation. He has held associate editor positions for Nonlinear Processes in Geophysics and Journal of Hydrology. He has been an invited speaker at over 30 meetings, and have authored eight scientific books.