A special lecture by Dr Jan Zika from the University of Southampton, National Oceanography Centre, UK
Abstract
What physical mechanisms set the deep ocean circulation? How will it respond if the atmosphere becomes warmer and windier? How does water constrain the response of the climate to warming and how can we use the ocean to detect this response?
In any thermodynamic problem the mere choice of coordinate system can be potent and far-reaching. In 1824 Carnot wanted to understand how exchanges of heat and entropy affected a steam engine. So, he distilled the problem into a diagram with temperature as one axis and entropy as the other. This simple step led to what is now known as the Carnot Cycle and from it the general understanding of the bounds on the efficiency of all heat engines. When approaching the problem of the ocean’s thermohaline circulation (thermo meaning heat and haline meaning salt) we did so with a simple quantitative diagram with heat as one axis and salt as the other. This simple change of perspective has led to dramatic insights into the way the ocean works and how we measure it.
In this talk I will introduce the novel framework developed during and beyond my PhD and will show how this approach is helping us to disentangle some of the key questions outlined above.
Biography
In 2005 Jan completed a combined Mathematics/Physics degree at the University of Tasmania with 1st class Honours in Astrophysics. From 2006 till 2009 Jan undertook a PhD through the University of New South Wales, and CSIRO Marine and Atmospheric Laboratories in Hobart, Tasmania. As his Thesis, Jan developed a new inverse technique for estimating rates of vertical and lateral diffusion in the global ocean.
From 2009-2011 Jan undertook a Postdoctoral Research Fellowship in Grenoble, France and in 2011-2012 Jan was a Research Fellow at the Climate Change Research Centre at the University of New South Wales in Sydney Australia. His emphasis there moved towards new and innovative methods for understanding the global climate system and change.
From 2012 Jan has been a NERC Research Fellow at the University of Southampton, National Oceanography Centre. There he works with a range of students, post-doctoral fellows and other collaborators on climate related problems with a focus on the ocean’s water masses, their origins and fate.