A Framework for Understanding How Dynamics Shape Temperature Distributions

Understanding what physically sets the shape of temperature distributions will enable more robust predictions of local temperature with global warming. We derive the relationship between the temperature distribution shape and the advection of temperature conditionally averaged at each temperature percentile. This enables quantification of the shift of each percentile that is due to changes in the mean temperature, in horizontal temperature advection, and other processes (e.g., radiation and convection). We use this relationship to examine global model simulations in an idealized aquaplanet model with increasing carbon dioxide. Changes in the distribution with doubling and quadrupling of carbon dioxide are significant, and they are caused by different processes. We find that midlatitude temperature distributions can be explained mostly by the horizontal advection, except in the upper and lower 10% of the distribution.