We request an allocation to support two research projects with the UK Met Office weather and climate model, the Unified Model.
The goal of our first project, funded by NASA, is to use chamber experiments from the CLOUD laboratory at CERN together with NASA aircraft observations to improve representations of aerosol formation and growth in climate models. We will incorporate parameterizations of particle formation and growth rates from the CERN CLOUD chamber into the Unified Model, which will be used to run both regional and global simulations over Korea, Colorado and Houston. The ultimate aim is to improve global climate simulations of the aerosol indirect effect, leading to better constraints on aerosol radiative forcing and predicted global temperature rises.
The goal of our second project, also funded via a subcontract from Oak Ridge National Laboratory, is to improve our ability to represent aerosol-cloud interactions in weather and climate models by studying aerosol effects on visibility and fog. Visibility is of obvious interest to aviation safety, the military, and other users of transportation, but it is also a diagnostic for aerosol-cloud interactions, and field measurements and simulations focused on fog also may shed light on aerosol-cloud interaction effects relevant to the global climate. Aerosols are well known to profoundly affect visibility in fog but detailed studies of their microphysical interactions are relatively sparse. We aim to improve the ability of weather forecast models to predict fog thickness and duration in polluted areas by more fully accounting for aerosol-fog interactions.