Dynamics of water in the climate of Earth’s atmosphere
- Date: Monday 1 March 2021, 15:00 – 16:00
- Location: Online event
- Type: Seminars, Applied Mathematics
- Cost: Free
Douglas Parker. University of Leeds. Applied Mathematics seminar.
Water is the most significant greenhouse gas, it is responsible for many of the most high-impact weather and climate patterns, and its abundance is vital for life on earth. However, the representation of cloud fields in climate models, whether simple or complex, remains unsatisfactory. Water exists in the atmosphere in all 3 phases (vapour, liquid, solid), often co-existing within the same air parcels. Changes in phase cause latent heating terms, and represent non-differentiable functions. Such systems typically cannot be linearised, and may not be receptive to traditional approaches of analysis. Examples of how latent heating modifies some classical fluid dynamical systems will be shown (“Rainy-Benard” and semigeostrophic systems if time allows).
An important consequence of latent heating is conditional convective instability, which leads to cumulonimbus storms (such as thunderstorms). Convective available potential energy can be held in a system without being released until a dynamical or thermodynamic trigger occurs. Conditional instability leads to stochastic behaviour and makes weather and climate prediction very challenging, especially for the tropics. We are realising that new statistical and machine-learning forecasting solutions are needed (to complement traditional numerical weather predictions solving the Navier-Stokes equations).
Water is a vital part of the human environment over land. Land-atmosphere feedbacks can influence the distributions of rainfall over the tropical continents, and are important to land-use planning. Ongoing work is testing dynamical models of these processes with a view to understanding climate change impacts.
The aims of the talk will be to introduce myself and my research interests to colleagues in the School of Mathematics; to share some results and ideas around water and climate; and to pose some open questions where I think that deeper mathematical analysis could be fruitful.
Meeting ID: 814 7949 4529