Ice Cores, Climate and Sea Ice

Physics Colloquium 14th November 2014 delivered by Prof Eric Wolff The polar ice sheets hold one of Earth’s great sedimentary records. By drilling ice cores from Greenland and Antarctica, we can obtain ice that fell as snow, extending back so far 800,000 years in Antarctica and over 125,000 years in Greenland. Ice cores contain information about climate and numerous other environmental parameters; crucially the air bubbles trapped in the ice give access to the past composition of the atmosphere, including the greenhouse gas concentrations. In this talk I will first discuss the strengths and weaknesses of ice cores, and then demonstrate how ice cores are collected. I will then present a few examples of the knowledge we have gained from ice cores – about greenhouse gases, about glacial/interglacial cycles, and about rapid climate changes most likely induced by changes in ocean heat transport. I will present an example of how we are trying to use ice cores to reconstruct the past extent of sea ice, a critical component of climate feedbacks. Finally I will discuss prospects for obtaining even older ice in the future. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/

Om Podcasten

The Department of Physics public lecture series. An exciting series of lectures about the research at Oxford Physics take place throughout the academic year. Looking at topics diverse as the creation of the universe to the science of climate change. Features episodes previously published as: (1) 'Oxford Physics Alumni': "Informal interviews with physics alumni at events, lectures and other alumni related activities." (2) 'Physics and Philosophy: Arguments, Experiments and a Few Things in Between': "A series which explores some of the links between physics and philosophy, two of the most fundamental ways with which we try to answer our questions about the world around us. A number of the most pertinent topics which bridge the disciplines are discussed - the nature of space and time, the unpredictable results of quantum mechanics and their surprising consequences and perhaps most fundamentally, the nature of the mind and how far science can go towards explaining and understanding it. Featuring interviews with Dr. Christopher Palmer, Prof. Frank Arntzenius, Prof. Vlatko Vedral, Dr. David Wallace and Prof. Roger Penrose."