If you thought climate models would perform badly with convective parameterisations turned off, then think again.

Convective parameterizations are widely believed to be essential for realistic simulations of the atmosphere, but are crude in today’s weather and climate models.

CLEX researchers, report on what happens when a number of these models are run with these schemes simply turned off.

Many people expect that models will perform very badly without these schemes, but we find that the model climatologies over most regions are actually similar and errors only slightly worse.

However, extreme precipitation is strongly overestimated with the schemes turned off, and rain on land is too weak.

We conclude that model biases in time-averaged climate are not as sensitive to how convection is treated in the model as widely believed, and that to fix them probably requires improving other things in the atmosphere model. Only extreme precipitation remained sensitive to convective schemes.

  • Paper: Maher, P., Vallis, G. K., Sherwood, S. C., Webb, M. J., & Sansom, P. G. (2018). The impact of parameterized convection on climatological precipitation in atmospheric global climate models. Geophysical Research Letters, 45, 3728–3736. https://doi.org/10.1002/2017GL076826