Data Assimilation in the NCEO(National Centre for Earth Observation)

Peter Jan van LeeuwenData-Assimilation Research Centre DARC

University of Reading

NCEO Structure

EO for climate diagnosisand prediction

(Integrating Theme)

Global carbon cycle

Atmosphericcomposition

Dynamic Earth and geo-hazards

Cryosphere andpolar oceans

Data assimilation and treatment of uncertainty(Cross Cutting Theme)

Training

Capability and knowledge exchange

Wider NERC supported EO programme

Hazardous weather and

water resources

EO informatics(Underpinning Theme)

What is data assimilation?

Solution is pdf!

NO INVERSION !!!

Bayes theorem:

High-resolution weather predictionMet Office system

/ 1.5km

(c) MeteoFrance

The Carbon Cycle Data Assimilation System

Assimilation of FAPAR and atm. CO2 flask data to optimise parameter values (and uncertainties) of a

process-based terrestrial ecosystem model (BETHY). (Scholze et al., Bristol)

Posterior uncertainties on parameters

Relative Error Reduction1–opt/prior

Net C fluxes and their uncertainties

Long term mean fluxes to atmosphere (gC/m2/year) and uncertainties

Forests and climate change

Science 320, 1444 (2008); Gordon B. Bonan, et al. Forests and Climate Change

INTRO » CONTEXT » DATA ASSIMILATION » SCALING ISSUES » SOLUTION

Scales of Flux Observations

Global

1000x1000 km

100x100 km

10x10 km

1x1 km

100x100 m

10x10 m

1x1 m

≤10x10 cm

≤Second

Minute

Hour

Day

Month

Year

≥Decade

Photo Christian Morel /www.ourpolarheritiage.comPhoto Christian Morel /www.ourpolarheritiage.com

CO2

CH4

N2O

SF6

COH2

222Rn

Rank histogram truth vs. particles1000 dimensional system