SC Seminar Hannah Christensen

Machine Learning for Stochastic Parametrisation

When
10 Jun 2021 from 4 p.m. to 10 Jun 2021 5 p.m. CEST (GMT+0200)
Where
online
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https://cwi-nl.zoom.us/j/86156254037?pwd=QnpVTlZqdnpnaDdvNm83TlM3MTFZUT09

Meeting ID: 861 5625 4037
Passcode: 364032

Hannah Christensen (Oxford): Machine Learning for Stochastic Parametrisation

Atmospheric models used for weather and climate prediction are traditionally formulated in a deterministic manner. In other words, given a particular state of the resolved scale variables, the most likely forcing from the sub-grid scale motion is estimated and used to predict the evolution of the large-scale flow. However, the lack of scale-separation in the atmosphere means that this approach is a large source of error in forecasts. Over the last decade an alternative paradigm has developed: the use of stochastic techniques to characterise uncertainty in small-scale processes. These techniques are now widely used across weather, seasonal forecasting, and climate timescales.

While there has been significant progress in emulating parametrisation schemes using machine learning, the focus has been entirely on deterministic parametrisations. In this presentation I will discuss data driven approaches for stochastic parametrisation. I will describe experiments which develop a stochastic parametrisation using the generative adversarial network (GAN) machine learning framework for a simple atmospheric model. I will conclude by discussing the potential for this approach in complex weather and climate prediction models.