Continuous Structural Parameterization: A method for representing
different model parameterizations within one structure demonstrated for
atmospheric convection
Abstract
Continuous Structural Parameterization (CSP) is a method for
approximating different numerical model parameterizations of the same
process as functions of the same gridscale variables. This allows
systematic comparison of parameterizations with each other and
observations or resolved simulations of the same process. Using the
example of two convection schemes running in the Met Office Unified
Model (UM), we show that a CSP is able to capture concisely the broad
behavior of the two schemes, and differences between the
parameterizations and resolved convection simulated by a high resolution
simulation. When the original convection schemes are replaced with their
CSP emulators within the UM, basic features of the original model
climate and some features of climate change are reproduced,
demonstrating that CSP can capture much of the important behavior of the
schemes. Our results open the possibility that future work will estimate
uncertainty in model projections of climate change from estimates of
uncertainty in simulation of the relevant physical processes.