Grand Challenges in Ocean and Climate Modelling - STFC's ...

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Challenge 3: Climate Uncertainty AMOC simulated with GENIE-1 (Marsh et al., 2007) How the climate will change in the future is far from certain. For a particular model, different outcomes will be obtained for different parameter settings in the model (“parameter uncertainty”). The figure shows how the Atlantic Meridional Overturning Circulation (AMOC) might change in the future (for a given warming scenario) in the GENIE model, depending on how various parameters in the model are chosen. To properly assess the model’s response, about 10,000 – 100,000 runs would be needed to span the parameter space using naïve Monte Carlo methods.
Challenge 3: Climate Uncertainty Future AMOC simulated with GENIE-1 (Challenor et al., 2008) If we build an “emulator” (a statistical approximation to the full climate model) we can reduce this number of runs to 0(100 - 1000) we can now apply statistical techniques, so that the probability of the collapse of the AMOC (for instance) can be derived. (Such methods are being developed in the “Managing Uncertainty in Complex Models” project, to minimise the number of runs we do). For GENIE, the probability of AMOC collapse (with drastic implications for cooling of European climate in the future) was estimated at about 30% (Challenor et al., 2006). However, GENIE has simplified physics (e.g. planetary geostrophic ocean) and a coarse resolution (3-10°, 8 ocean depth levels). The exercise should now be repeated for higher resolution full-physics GCMs which include more of the relevant processes. Such models have order 100 uncertain parameters so our training ensemble will need to be bigger.
Page 1 and 2: Grand Challenges in Ocean and Clima
Page 3 and 4: Internal Wave Processes Internal wa
Page 5 and 6: Mixing near the Shelf Break (Bay of
Page 7 and 8: Example from the Indian Ocean: Masc
Page 9 and 10: Inferred Vertical Diffusivities (Mi
Page 11 and 12: Internal Waves at Station 17 (Troug
Page 13: Challenge 2: Global Carbon Cycle Me
Page 17 and 18: Practical Issues: 1: Storage a) Per
Page 19 and 20: Practical Issues: 3: People a) Staf

Grand Challenges in Ocean and Climate Modelling - STFC's ...

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