The document describes the PEcAn Project, which aims to provide accessible ecoinformatic tools for carbon-cycle model-data analysis and assimilation. It faces challenges from large and diverse data that requires fusing models and data. PEcAn creates a standardized database and modular tools in R to analyze data, assimilate it into models, and visualize outputs. It allows remote execution of models on databases and visualization. As a testbed, it aims to reconcile carbon information from multiple data streams in the Chequamegon-Ecosystem Atmosphere Study region.

1. The PEcAn Project:
Accessible ecoinformatic tools for
carbon-cycle model-data analysis and
assimilation

2. Friedlingstein et al 2006

3. Terrestrial
Biosphere
Models
● Biogeochemistry
● Ecophysiology
● Land Surface
● Vegetation
Community
Dietze and Latimer (2012) Forest Simulators. In Encyclopedia of Theoretical Ecology. University
of California Press.

5. 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

6. Accessibility

7. Ecosystem
Model
IN OUT
DATA
Standard
Model
Specific
Standard
Viz
Analysis
Analysis
Model
Parameters
DATABASE
PEcAn

8. 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

9. Global
Site level
Trait Meta-analysis
m
Yi
qi
so,i
ft
PRIOR PRIOR PRIOR
Prior
Parameter
Data
Obs. mean Obs. var
Site mean
Global mean Across-site var Within-site var
Hierarchical mean, common variance

10. Ensemble Estimate

11. Sensitivity Analysis
Prior
Posterior
NPP(Mg/ha)

12. Variance Decomposition
*can easily be
extended to driver and
IC uncertainties
*
Prior
Posterior

13. 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

14. State-Variable Data Assimilation
P∣y∝P y∣P
Updated State Data Model

16. Testbed: ChEAS
(Chequamegon-Ecosystem Atmosphere Study)
Goal: Reconcile carbon-cycle information from
multiple data streams

18. NSF ABI #1062547
http://pecanproject.org
https://github.com/PecanProject