Steve Humphries University of Essex Window on FACTS Project WOFTS

Steve HumphriesSteve HumphriesUniversity of EssexUniversity of Essex

WWindow indow oon n FACTSFACTS Project Project

WOFTSWOFTS

Discussion TopicsDiscussion Topics Personal perspectivePersonal perspective

Why modelling frequently fails to Why modelling frequently fails to deliverdeliver

How to succeed!How to succeed!

Model of interactive OModel of interactive O33/CO/CO22 effects effects

WOFTS WINDOW ON FACTS

Personal Personal PerspectivePerspective

Frequent disappointment about Frequent disappointment about reality of models.reality of models.

Poor accountability of model predictions Poor accountability of model predictions for ‘real World’ experiments.for ‘real World’ experiments.


Why Modelling FailsWhy Modelling Fails

Little interaction between modellers & Little interaction between modellers & experimenters.experimenters.

Experimentalists are usually unable to Experimentalists are usually unable to access model directly.access model directly.


Why Modelling Fails Why Modelling Fails IIII

Models are complex with many Models are complex with many equations, constants and parameters. equations, constants and parameters. ‘Black box’ nature of some models.‘Black box’ nature of some models.

Rarely a framework for comparison of Rarely a framework for comparison of models.models.


How To SucceedHow To Succeed

Work collaboratively with Work collaboratively with experimenters and other modelling experimenters and other modelling efforts.efforts.

Experimentalists need easy and Experimentalists need easy and immediate access to models.immediate access to models.


How To Succeed IIHow To Succeed II

Use ‘state of the art’ programming tools Use ‘state of the art’ programming tools to facilitate understanding. Enhance to facilitate understanding. Enhance models with connectivity to data sources.models with connectivity to data sources.

Use mechanistic/process based models Use mechanistic/process based models with a high degree of parameter with a high degree of parameter accountability.accountability.


OO33/CO/CO22 Model Model

Global warmingincreases isoprene emission rates

Isoprene Methanepositive feedback

In the presence of OH and NOx

Ozone (O3)

CO2

Sequestering of CO2 in biomass,a negative feedback dependent on the interactive effects of concurrent increasing temperatures

Phytotoxic ozone reduces sequestering of CO2 a positive feedback

Interactive feedback effects of COInteractive feedback effects of CO22, O, O33 and isoprene atmospheric chemistry on climate and and isoprene atmospheric chemistry on climate and

vegetation (adapted from Martin, 1997)vegetation (adapted from Martin, 1997)


OO33/CO/CO22 Results Results Linear relationship between effective Linear relationship between effective

ozone dose (ozone dose (efdefd) above a threshold ) above a threshold and measured percent reduction in and measured percent reduction in VVcmaxcmax. . (wheat: (wheat: Triticum aestivum Triticum aestivum L. Avalon)L. Avalon)

Stomatal conductance is an Stomatal conductance is an important factor in determining important factor in determining efd efd with feedback from Vwith feedback from Vcmaxcmax effects. effects.



Time (hrs)

0 6 12 18 24

Ass

imila

tion

rate

(µm

ol m

-2gr

ound

s-1

)0

10

20

30

40

50

0 nmol mol-1

Peak 200 nmol mol-1

OO33/CO/CO22 Model Model

Ozone concentration (nmol mol-1)

0 100 200 300 400

Vcm

ax (

%)

0

20

40

60

80

100

350 µmol mol-1

650 µmol mol-1

4hr Exposure

Mechanism of OMechanism of O33 ModelModel

O3

Stomatal

conductance

C a lc u la te W , W , Wc j p

C a lc u la te A g ro ss

C a lc u la te g s

R e d u c e g b y f ra c tio nin d ica ted b y w a te r

s t re s s m o d u le

s

N ew e s tim a te C iN e w C =

o ld C ?i

iO

ldes

timat

eof

Cis

notw

ithi

nto

lera

nce

limit

sof

new

estim

ate

iF in is h ite r a t io n

N o

Y E S

Rubisco

t

OseffO dtFgOF0 )0(333 )](['


OO33/CO/CO22 Model Model Model allows testing of interactive Model allows testing of interactive

OO33/g/gss/V/Vcmaxcmax hypothesis not possible hypothesis not possible experimentally.experimentally.

Allows scaling from leaf level Allows scaling from leaf level results to canopy and beyond.results to canopy and beyond.


WOFTS WOFTS

Builds on 6 years experience with Builds on 6 years experience with interactive Windowsinteractive WindowsTMTM software software WIMOVAC WIMOVAC

Parameterised successfully for a Parameterised successfully for a range of plant types.range of plant types.


WOFTS

FACTS

Database

WOFTS

Compiler

WOFTS

Sub-models

User options/inputs

Data

ViewerUser options

GIS

database

Maps Graphics/

Animations

Spreadsheets/

Tables

Model set-up

Measurements, predictions, and inter-comparisons

WOFTS

User interface

Parameter

databaseData

HELP

utility

WINDOW ON FACTS


What happens next What happens next

Further collaboration with FACTS Further collaboration with FACTS teams to develop an interactive teams to develop an interactive OO33/CO/CO22 model unifying model unifying experimental results at all sites.experimental results at all sites.

Model should be easy to use, Model should be easy to use, WindowsWindowsTMTM based, and shared with based, and shared with investigators at an early stage.investigators at an early stage.

(A personal vision)


What happens What happens next II next II

Documentation for the model should be Documentation for the model should be prepared and distributed to prepared and distributed to investigators on an open WWW internet investigators on an open WWW internet site. site. (Current site: (Current site: http://www.essex.ac.uk/biology/wimovac/homepage.htm)http://www.essex.ac.uk/biology/wimovac/homepage.htm)

Serving as an advertisement for the Serving as an advertisement for the projects involved and a shared projects involved and a shared data/technical resource. data/technical resource.

(A personal vision)


Documents

Steve Humphries University of Essex Window on FACTS Project WOFTS