The Cold Pool Model Intercomparison Project (CP-MIP)

Atmospheric cold pools form when cool downdrafts from cumulus clouds spread out laterally at the surface. The cool surface air suppresses convection and erases clouds around the downdraft. Over the oceans, the resulting cloud-free areas are often larger than 100 km, and turbulence and clouds recover only after many hours. The properties, mechanisms, lifecycle, and radiative effect of cold pools are currently not well understood. This is in part because the key processes of cold pools proceed on scales below the resolution of large scale models, and in part because of model biases in cold pool simulations by high resolution models.

The Cold Pool Model Intercomparison Project (CP-MIP) seeks to investigate and improve the fidelity of model representation of convective cold pools. The goals of CP-MIP are the identification, characterization, and quantification of model biases through comparison with observed cold pool statistics, the convergence of models towards a robust basis for the study of cold pools, and the improved representation of cold pools in high resolution and large scale simulations.

We introduce CP-MIP, describe the approaches and objectives, and set out the elements of CP-MIP. The first stage of CP-MIP focuses on shallow convective cold pools over the tropical oceans, which are primarily associated with trade cumulus clouds. Observations from the EUREC4A and ATOMIC field campaigns, and modeling efforts from the CP-MIP partner projects contribute to CP-MIP. We present an analysis of first results.