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Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Dec 18, 2015

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Page 1: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Slides for IPCC

Page 2: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Inverse Modeling of CO2

Air Parcel Air Parcel

Air Parcel

Sources Sinks

wind wind

SampleSample

Changes in CO2 in the air tell us about sources and sinks

Atmospheric budgets, or “inversions”

Page 3: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

3

Basic Atmospheric CO2

Inversion Components

GPP

ER

Lagrangian Particle Dispersion Model(LPDM) with Regional Atmospheric Modeling System (RAMS)

Calibrated CO2 concentrations Observations from Flux Towers

SiB3 model of biosphere fluxes

Fossil Fuel Emissions

Boundary Conditions

WLEF Tower (Park Falls WI, USA)

Page 4: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

4

“Observed” at 2PM on 7/7/2004: 368 ppm

“Calculated” for 2PM on 7/7/2004: 370 ppm - 3 ppm + 1 ppm - 2 ppm = 366 ppm

WLEF Tower

-2 ppm

1 ppm-3 ppm370 ppm

Transport Model: Conceptualizing

Carbon drawdown in upwind areas must be too strong since the observed CO2 at the tower is higher than what we predict

Final: 366 ppm

Page 5: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Black: air parcels in contact with surfaceRed: air parcels reach lateral boundaries

(20

days

of “

upst

ream

” tr

ansp

ort i

n 50

sec

onds

)

SiB-RAMS-LPDM

Back-Trajectories from WLEF Tower (400 m TV tower near Park Falls, WI)

Page 6: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Biome Mean Contributions (ppm) to Round Lake station CO2 , June-August 2007

GPP Respiration

Page 7: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Inversion Results for 2004: Weekly NEE corrections

A priori NEE calculated by Simple Biosphere Model (SiB3)

Difference from a priori NEE calculated by inversion model

Posterior NEE via the inversion (best optimized guess).

Page 8: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Regional Atmospheric CO2 Inversions

• Need good representation of transport

• Need good boundary conditions of CO2 from global inversion runs (e.g. CarbonTracker)

• Need reasonably accurate a prior guess of NEE patterns (e.g. crops)

• Can be difficult to partition out sink/source components in policy-relevant ways

• Need lots of concentration data• Computational demands

• Implicitly accounts for all surface sources and sinks of CO2

• Far more cost effective than inventory-based methods

• Great temporal resolution with in-situ instruments (hourly or less on measurements)

• Policy relevant inversion results (i.e. regional)

PROS CONS

Page 9: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

*Big Picture*

4 MgC

-4 MgC

1.5 MgC

2007 CarbonTracker Annual NEE Estimate 2007 SiB-CROP a priori NEE Estimate

Carbon Sink: 318 TgC NEE, MCI (2007) Carbon SINK: 81 TgC NEE, MCI (2007)

2007 Inventory Annual NEE Estimate

Carbon SINK: 130 TgC NEE, MCI (2007)

• Are the inventory data and the inversion data reconcilable?• Are the means relatively close?• Does the inventory mean sit within the confidence bounds of the inversion results?• What are the sensitivities of the inversion to difficult to quantify uncertainties, e.g. variations in transport and inversion setup.

2 MgC

-2 MgC

Page 10: Slides for IPCC. Inverse Modeling of CO 2 Air Parcel Sources Sinks wind Sample Changes in CO 2 in the air tell us about sources and sinks Atmospheric.

Mean daily NEE (weekly for summer months) for MCI region