Until the 1980s, surprisingly few scientists were interested in the possible impact of the variability in solar activity on the Earth’s climate, until this gradually became a hotly disputed topic. For many years, there was a belief that everything boiled down to the total solar irradiance, i.e. the amount of radiated energy received on top of the atmosphere. This picture has been shattered by the discovery of many other different mechanisms that can operate on a wide range of spatial and temporal scales. More importantly, these mechanisms are coupled, requiring a comprehensive approach.
There is now strong scientific evidence for a climatic impact of solar variability that is measurable but tiny compared to the enormous impact of human activities. But the challenge of understanding the role of solar variability is far from over. One open question is what happened during the Maunder Minimum (1645-1715) when there were episodes of colder and wetter weather in some parts of the world. This puzzle can only be solved by bringing together multiple clues (so-called proxies of past solar activity) and physical models.
In this quick overview of the main mechanisms, the speaker will highlight some of the challenges posed by this fascinating interaction between our habitable planet and our nearest star.
Thierry Dudok de Wit is a professor in solar-terrestrial physics at the University of Orléans, France. He graduated and obtained his PhD at the Polytechnic Federal School in Lausanne. He has many interests as he held different positions and gradually migrated from the fields of fusion plasmas to fluid turbulence, followed by dynamical systems and now solar terrestrial-physics. The common thread is a strong interest in methodological approaches to characterise physical processes. Today he’s deeply involved in the Parker Solar Probe mission as instrument lead CoI.
Webinar was recorded on March 31, 2022