Climate model development is currently undergoing profound expansion with the application of cutting-edge technologies such as machine learning, the development of process resolving models on ever finer scales and the improved representation of climate variability and trends. However, deficiencies in model simulations remain and work to address these continues as we strive to understand our rapidly changing climate. Observations are a vital for improving models: guiding development foci and for evaluation of model performance. At the same time the observational ecosystem is constantly changing not least due to shifting funding priorities for both space and earth-based observation networks. Nevertheless, recent years have seen increased engagement between observation providers and the modelling community and, importantly, the start of significant improvements in communicating observation quality and uncertainty. The interface between observations and models is complex and identifying the correct observational dataset for a specific application is not always straightforward, particularly for satellite-derived CDRs, where retrieval assumption and algorithm choices can generate uncertainties comparable to the model differences. Developments in this space recognise that better communication between observational and modelling communities is required and a number of initiatives provide platforms which allow access to datasets in standardised formats or peer reviewed and traceable methods to produce model validation diagnostics.

The WCRP core project CLIVAR and the WCRP ESMO working group WGORC are jointly organising this session with the aim to build stronger links between observational and modelling communities and explore recent advances in the use of observations for evaluating climate models.

We invite submissions on innovative approaches comparing models and observations including, but not limited to, the detailed consideration of uncertainties, use of ensembles and the use of novel observational datasets. We also welcome studies which use observations to assess processes across the coupled climate system and presentations showcasing recent developments in tools and platforms and data driven methods for model/observation comparisons.