Steve Humphries University of Essex Window on FACTS Project WOFTS

Discussion Topics n Personal perspective n Why modelling frequently fails to deliver n How to succeed! n Model of interactive O 3 /CO 2 effects WOFTS WINDOW ON FACTS

Personal Perspective n Frequent disappointment about reality of models. n Poor accountability of model predictions for ‘real World’ experiments. WOFTS WINDOW ON FACTS

Why Modelling Fails n Little interaction between modellers & experimenters. n Experimentalists are usually unable to access model directly. WOFTS WINDOW ON FACTS

Why Modelling Fails II n Models are complex with many equations, constants and parameters. ‘Black box’ nature of some models. n Rarely a framework for comparison of models. WOFTS WINDOW ON FACTS

How To Succeed n Work collaboratively with experimenters and other modelling efforts. n Experimentalists need easy and immediate access to models. WOFTS WINDOW ON FACTS

How To Succeed II n Use ‘state of the art’ programming tools to facilitate understanding. Enhance models with connectivity to data sources. n Use mechanistic/process based models with a high degree of parameter accountability. WOFTS WINDOW ON FACTS

O 3 /CO 2 Model Global warming increases isoprene emission rates Isoprene Methane positive feedback In the presence of OH and NOx Ozone (O 3 ) CO 2 Sequestering of CO 2 in biomass, a negative feedback dependent on the interactive effects of concurrent increasing temperatures Phytotoxic ozone reduces sequestering of CO 2 a positive feedback Interactive feedback effects of CO 2, O 3 and isoprene atmospheric chemistry on climate and vegetation (adapted from Martin, 1997) WOFTS WINDOW ON FACTS

O 3 /CO 2 Results n Linear relationship between effective ozone dose (efd) above a threshold and measured percent reduction in V cmax. (wheat: Triticum aestivum L. Avalon) n Stomatal conductance is an important factor in determining efd with feedback from V cmax effects. WOFTS WINDOW ON FACTS

WOFTS WINDOW ON FACTS 0 nmol mol -1 Peak 200 nmol mol -1 O 3 /CO 2 Model 350 µ mol mol µ mol mol -1 4hr Exposure

Mechanism of O 3 Model O3O3 Stomatal conductance Rubisco WOFTS WINDOW ON FACTS

O 3 /CO 2 Model n Model allows testing of interactive O 3 /g s /V cmax hypothesis not possible experimentally. n Allows scaling from leaf level results to canopy and beyond. WOFTS WINDOW ON FACTS

WOFTS n Builds on 6 years experience with interactive Windows TM software WIMOVAC n Parameterised successfully for a range of plant types. WOFTS WINDOW ON FACTS

WOFTS FACTS Database WOFTS Compiler WOFTS Sub-models User options/inputs Data Viewer User options GIS database MapsGraphics/ Animations Spreadsheets/ Tables Model set-up Measurements, predictions, and inter-comparisons WOFTS User interface Parameter database Data HELP utility WINDOW ON FACTS

WOFTS WINDOW ON FACTS

What happens next n Further collaboration with FACTS teams to develop an interactive O 3 /CO 2 model unifying experimental results at all sites. n Model should be easy to use, Windows TM based, and shared with investigators at an early stage. (A personal vision) WOFTS WINDOW ON FACTS

What happens next II n Documentation for the model should be prepared and distributed to investigators on an open WWW internet site. (Current site: n Serving as an advertisement for the projects involved and a shared data/technical resource. (A personal vision) WOFTS WINDOW ON FACTS