CO 2 Source / Sink Inversion History, Computational Requirements

Transcription

1 CO 2 Source / Sink Inverion itory, Computational Requirement Anna M. Michalak Department of Civil & Environmental Engineering Department of Atmopheric, Oceanic & Space Science Univerity of Michigan

2 Invere Modeling

3 Forward v. Invere Modeling Forward modeling Invere modeling

4 CO 2 Fluxe Preent Knowledge 5.5 ± 0.3 Peta (10 15 ) gram of carbon/year 3.3 ± 0.2 To Atmophere 1.6 ± 0.8 Atmopheric Carbon Foil Fuel Land Ue Change Ocean Uptake Unidentified Sink Atmopheric Storage To Land/Ocean 2.0 ± 0.6 = uman Input Uptake 1.8 ± 1.5 Source: Diane Wickland (NASA)

5 Global Ditribution of Atmopheric Carbon Dioxide Atmopheric growth rate ~ 3 ± 0.1 Gt C/year Source: NOAA-CMDL

6 Where i the Miing Sink (c. 1995)? Require uptake O 2 /N 2, invere modeling ugget terretrial Source: Kevin Gurney, CSU Northern hemiphere

7 Carbon and Climate Future? Given nearly identical human emiion, model project dramatically different future. Carbon A.M. Michalak cycle feedback are among the larget ource of uncertainty for future climate.

8 Spatio-temporal variability of CO 2 Simulated 2-hourly column CO 2 Source: A.M. Michalak Olen & Randeron (amichala@umich.edu) (2004)

9 Source of Atmopheric CO 2 Information North American Carbon Program

10 Regional Flux Etimation Example meaurement ite: WLEF tall tower (447m) in Wiconin CO 2 flux meaurement at: 30, 122 and 396 m CO 2 mixing ratio meaurement at: 11, 30, 76, 122, 244 and 396 m Photo credit: B. Stephen, UND Citation crew, COBRA

11 Local Flux Etimation Example Meaurement Site UMBS Flux emipherical image from the top of the 46 meter UMBS~Flux meteorological tower Intrumentation above the UMBS canopy i ued to etimate canopy-level carbon uptake The UMBS meteorological tower i 46 m tall with ga ampling port at 8 different height Source: Peter Curti, Ohio State U.

12 What What Surface Surface Fluxe Fluxe to Atmopheric to Sample Sample See? See? 24 June 2000: Particle Trajectorie Latitude Longitude eight Above Ground Level (km) Longitude -24 hour -48 hour -72 hour -96 hour -120 hour Source: Arlyn Andrew, NOAA-CMDL

13 The hitory of atmopheric invere modeling Oberved CO 2 growth rate / latitudinal gradient * Very large region inverion Large region inverion Bayeian large region inverion Bayeian grid cale inverion Geotatitical method Aimilation of data from multiple ource

14 Linear Tranport m m i i i m m i i i i y y y y = = K K , 2,2 1,1 " # % & " # % & = " # % & m m n n n m m n y y y M K M O M M K K M 2 1,,2,1 2, 2,2 2,1 1, 1,2 1,1 2 1 data tranport fluxe Ue tranport model to generate Oberve y at n time / location Invert to find Were the problem imple: y 1 =

15 Need for Additional Information Current network of atmopheric ampling ite require additional information to contrain fluxe: Problem i ill-conditioned Problem i under-determined (at leat in ome area) There are variou ource of error: Meaurement error Tranport model error Aggregation error One olution i to aimilate additional information through a Bayeian approach

16 Bayeian Inference Applied to Invere Modeling for Trace Ga Surface Flux Etimation Poterior probability of urface flux ditribution Likelihood of fluxe given atmopheric ditribution Prior information about fluxe y : available obervation (n1) : urface flux ditribution (m1) p(y) probability of meaurement

17 Bayeian Formalim Ue data, y, prior flux etimate, p, and model (with Green function matrix ) to etimate fluxe, Etimate obtained by minimizing: Solution i Etimate, have covariance Reidual:

18 Large Region Inverion TranCom 3 Site & Bai Region TranCom, Gurney et al 2003

19 Tranport Gridcale Inverion Rödenbeck et al. 2003

20 Determinitic v. Stochatic Component of Flux Etimate Remember: X Contant Component X Variable Component Q T " (flux bet etimate) January 2000

21 Uncertainty on Bet Etimate (Variable Trend) Jan 1999 Land Jan 1999 Ocean

22 Auxiliary Data Slide provided by Sharon Gourdji and Kim Mueller

23 Takahahi pco 2 databae Source: Colm Sweeney, NOAA-CMDL 1,183,000 meaurement ( )