Comparison of stochastic parameterizations in the framework of a coupled ocean–atmosphere model
<p>A new framework is proposed for the evaluation of stochastic subgrid-scale parameterizations in the context of the Modular Arbitrary-Order Ocean-Atmosphere Model (MAOOAM), a coupled ocean–atmosphere model of intermediate complexity. Two physically based parameterizations are investigate...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-08-01
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| Series: | Nonlinear Processes in Geophysics |
| Online Access: | https://www.nonlin-processes-geophys.net/25/605/2018/npg-25-605-2018.pdf |
| Summary: | <p>A new framework is proposed for the evaluation of stochastic
subgrid-scale parameterizations in the context of the Modular Arbitrary-Order
Ocean-Atmosphere Model (MAOOAM), a coupled ocean–atmosphere model of
intermediate complexity. Two physically based parameterizations are
investigated – the first one based on the singular perturbation of Markov
operators, also known as homogenization. The second one is a recently
proposed parameterization based on Ruelle's response theory. The two
parameterizations are implemented in a rigorous way, assuming however that
the unresolved-scale relevant statistics are Gaussian. They are extensively
tested for a low-order version known to exhibit low-frequency variability
(LFV), and some preliminary results are obtained for an intermediate-order
version. Several different configurations of the resolved–unresolved-scale
separations are then considered. Both parameterizations show remarkable
performances in correcting the impact of model errors, being even able to
change the modality of the probability distributions. Their respective
limitations are also discussed.</p> |
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| ISSN: | 1023-5809 1607-7946 |