Deliverable No. 1.1 Model Assessment Plan

Having a thorough model assessment capacity is critical for the APPLICATE project in order to establish the ability of existing models in simulating Arctic weather and climate along with Arctic-midlatitude interactions, provide guidance for APPLICATE model development activities, and to measure the impact and hence success of the APPLICATE project.

This Model Assessment Plan outlines the project’s model assessment strategy, making extensive use of the concept of metrics and diagnostics, and utilizing comprehensive sets of observational data. In this context the Plan focuses on evaluating the model’s ability to represent

• critical Arctic processes,

• linkages between the Arctic and mid-latitude weather and climate, and

• user-relevant parameters.

The plan also outlines how the metrics and diagnostics will feed into the Earth System Model Evaluation Tool (ESMValTool), a tool used by the international research community for evaluating climate models.

Importantly, the Plan also considers the evaluation of numerical weather prediction (NWP) models and seasonal forecasting systems. This assessment will not only provide the basis for enhancing prediction capacity; it will also lead to insight into the origin of model error and contributes to providing guidance for the design of the observing system.

Regional Arctic heat budget analyses will be used to assess the ability of models to reproduce key processes in the Arctic and to identify important feedbacks and processes affecting Arctic climate variability and sea ice change.

Towards the end of the project, the potential will be explored for the heat budget and process-based metrics developed within APPLICATE to provide observation-based constraints on the climate models to reduce uncertainty in future projections.

To facilitate effective management of WP1 timelines are given for the different and critical relationships to other WPs are outlined.

The APPLICATE Model Assessment Plan is a “living document” that will be updated regularly (approximately every 6 months).