Post on 05-Jul-2015
The PEcAn Project:Accessible ecoinformatic tools for
carbon-cycle model-data analysis and assimilation
Friedlingstein et al 2006
Terrestrial Biosphere
Models
● Biogeochemistry
● Ecophysiology
● Land Surface
● Vegetation Community
Dietze and Latimer (2012) Forest Simulators. In Encyclopedia of Theoretical Ecology. University of California Press.
Challenges
● Explosion in data volume and diversity● No one data source provides a complete picture
of the terrestrial biosphere● Limited by ability to use data
– Informatics
– Model-Data Fusion
– Uncertainty
– Accessibility
Accessibility
EcosystemModel
IN OUT
DATA
Standard
ModelSpecific
Standard
Viz
AnalysisAnalysis
ModelParameters
DATABASE
PEcAn
Backend
● PostGRE SQL Database– Data, Inputs, Runs, Provenance
● Modules (mostly R)– Model analysis, Data analysis, Data Assimilation,
conversions / informatics, model interfaces, visualization
● Accessibility– Released as VM
– Web: Database, Model execution / history, Vis, RStudio Server
– Remote / HPC execution
Global
Site level
Trait Meta-analysis
m
Yi
qi
so,i
ft
PRIOR PRIOR PRIOR
Prior
Parameter
DataObs. mean Obs. var
Site mean
Global mean Across-site var Within-site var
Hierarchical mean, common variance
Ensemble Estimate
Sensitivity Analysis
PriorPosteriorN
PP
(M
g/h
a)
Variance Decomposition
*can easily be extended to driver and IC uncertainties
*
PriorPosterior
Parameter Data Assimilation
Generalized Priors (weak)
Prior
Meta-analysis Posterior
Posterior
Traits
Eddy
Flux
Prior Posterior
Forest
Inventory
Prior Posterior
Prior Posterior
Prior Posterior
Hydrology
Experiments
Remote
Sensing
State-Variable Data Assimilation
P ∣y ∝P y∣P Updated State Data Model
Testbed: ChEAS(Chequamegon-Ecosystem Atmosphere Study)
Goal: Reconcile carbon-cycle information from multiple data streams