Initial results from the Diurnal land/atmosphere coupling experiment (DICE)

Results from the GLACE experiment highlighted the areas of the globe that were “hotspots” for land/atmosphere coupling, with stronger coupling strength between soil moisture and precipitation. However, the results from this experiment also showed that there was wide variation in the strength of coupling at the hotspot regions between the participating models. Further analysis following the protocol of the GLACE experiment suggested that interactions between the atmospheric parametrisations were responsible the land/atmosphere coupling strength in some models, but our understanding of these interactions within models is limited.

DICE is an international experiment designed to identify and understand the interactions and feedbacks between the land and atmospheric boundary layer. The GABLS2 (CASES99) experiment has been re-visited, but with the land surface community included within the analysis. This has allowed a multi-stage project whereby the sensitivity characteristics of each component (land and atmosphere) can be assessed and compared with the characteristics of the coupled simulations.

In this presentation we will give details of the experimental protocol, including the justification for each of the stages. Initial results from the experiment will be presented along with conclusions about characteristics of the integrated system responsible for the coupling strength in the models.