1. Modelling protocols Marcel van Oijen (CEH-Edinburgh) With input from participants Garmisch Mar & May 2006, Protocol-GMP team, Protocol-UQ/UA team

2. The protocols of NEU Common Modelling Protocol Common Measurement Protocol UQ/UA protocol

3. NEU planned to produce 4 protocols: Month 7Measurement Month 9Modelling Month 10Uncertainty quantification & analysis in regional N r and GHG models Month 18Uncertainty quantification & analysis in plot scale models Discussion Garmisch (Mar & May 2006): The two uncertainty protocols will be combined. The protocols of NEU

4. Protocol-discussion: - Garmisch Mar 2006 - Garmisch May 2006 - Documents sent for discussion (minutes from meetings, protocol- outlines 4 Aug 2006) - Protocol-GMP team (Marcel van Oijen, Reiner Wassman, Pete Smith, GertJan Reinds, Peter Verweij) - Protocol-UQ/UA team (Marcel van Oijen, Gerard Heuvelink, Hans Kros, Kairsty Topp, Benoit Gabrielle, Mette L.) The 2 modelling protocols of NEU Conclusions: - Protocols should not be too prescriptive - Protocols should be short and refer to existing protocols - Protocols should make it easier for people to work to a high standard

5. Protocol-discussion: - Garmisch Mar 2006 - Garmisch May 2006 - Documents sent for discussion (minutes from meetings, protocol- outlines 4 Aug 2006) - Protocol-GMP team (Marcel van Oijen, Reiner Wassman, Pete Smith, GertJan Reinds, Peter Verweij) - Protocol-UQ/UA team (Marcel van Oijen, Gerard Heuvelink, Hans Kros, Kairsty Topp, Benoit Gabrielle, Mette L.) The 2 modelling protocols of NEU Conclusions: - Protocols should not be too prescriptive - Protocols should be short and refer to existing protocols - Protocols should make it easier for people to work to a high standard

6. Draft protocols for modelling 18 Sep 2006 Protocol-GMP (3 pp.) Protocol-UQ/UA (5 pp.)

7. Protocol-UQ/UA – page 1 1.1 Introduction 1.2 Web links to established protocols

8. Protocol-UQ/UA – page 2 2. Relevant NEU-documents 3. Glossary 4. Protocol summary 4.1 Commitments

9. Protocol-UQ/UA – page 2 4.1 Commitments In NEU, all modellers are committed to: Carry out UQ of their model and report: (1) The chosen UQ-method, (2) Output uncertainty. The UQ-method is chosen by the modeller but can be one of the recommended methods described in the following sections. UQ is carried out at least twice: near beginning (year 1 for plot-scale modellers, year 2 for regional scale modellers) and end of the NEU-project, but it is recommended to do this whenever significant new data have become available and whenever the model has changed.

10. Protocol-UQ/UA – page 3 4.2 Recommended work In NEU, all modellers are recommended to: -Carry out UA for their model and report: (1) The chosen UA-method, (2) The inputs that account for most of output uncertainty. It is recommended to carry out UA after each UQ and use the results for improvement of the modelling as well as to guide the collection of data. -Carry out a model comparison, possibly in collaboration with other groups, and report: (1) The method used for model comparison, (2) The relative probabilities of different models, model versions and/or model algorithms (i.e. submodels for specific processes or groups of processes) of being correct. Systematic comparison of completely different models is recommended for near the end of the project, systematic comparison of different model versions is recommended to be repeated throughout the period of model development in the first years of NEU.

11. Protocol-UQ/UA – page 3 5 UQ model inputs 5.1 Use of pdf’s 5.2 Expert judgment 5.3 From data to pdf 5.4 Bayesian approach 6 Uncertainty propagation 6.1 Monte Carlo (MC)

12. Protocol-UQ/UA – page 4 6.2 Latin Hypercube sampling 6.3 Screening 7 When new data come in 7.1 Repeat UQ 7.2 Bayesian Calibration (BC) and MCMC 7.3 BC: universal vs site-specific inputs 8 Uncertainty about model structure 8.1 Bayesian Model Comparison (BMC)

13. Protocol-UQ/UA – page 5 8.2 MODEVAL.XLS 10. References 9 Uncertainty Analysis (UA)

14. Garmisch, “Uncertainty workshop” May 2006 Model output uncertainty Data uncertainty Input uncertainty Structural uncertainty Measurement acc. & prec. Sampling / representation Parameters (initial constants, process coefficients) Environmental scenarios (weather, N-dep., CO2, land-use

15. 6.5 NEU C3: work on uncertainty

16. 6.6 NEU C6 work on uncertainty