the inverse regional ocean modeling system:

59
The Inverse Regional Ocean Modeling System: Development and Application to Data Assimilation of Coastal Mesoscale Eddies. Di Lorenzo, E., Moore, A., H. Arango, B. Chua, B. D. Cornuelle , A. J. Miller and Bennett A.

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The Inverse Regional Ocean Modeling System: Development and Application to Data Assimilation of Coastal Mesoscale Eddies. Di Lorenzo, E., Moore, A., H. Arango, B. Chua, B. D. Cornuelle , A. J. Miller and Bennett A. Goals. A brief overview of the Inverse Regional Ocean Modeling System - PowerPoint PPT Presentation

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Page 1: The Inverse Regional Ocean Modeling System:

The Inverse Regional Ocean Modeling System:

Development and Application to Data Assimilation of Coastal Mesoscale Eddies.

Di Lorenzo, E., Moore, A., H. Arango, B. Chua, B. D. Cornuelle , A. J. Miller and Bennett A.

Page 2: The Inverse Regional Ocean Modeling System:

• A brief overview of the Inverse Regional Ocean Modeling System

• How do we assimilate data using the ROMS set of models

• Examples, (a) zonal baroclinic jet and (b) mesoscale eddies in the Southern California Current

Goals

Page 3: The Inverse Regional Ocean Modeling System:

Inverse Regional Ocean Modeling System (IROMS)

Chua and Bennett (2001)

Inverse Ocean Modeling System (IOMs)

Moore et al. (2003)

NL-ROMS, TL-ROMS, REP-ROMS, AD-ROMS

To implement a representer-based generalized inverse method to solve weak constraint data assimilation into a non-linear model

a 4D-variational data assimilation system for high-resolution basin-wide and coastal oceanic flows

Page 4: The Inverse Regional Ocean Modeling System:

N ttt

¶= +

¶+eu F

u( ) ( ) ( )

( ) (( ) ( ) )B BN t tt

¶= + - ++

¶uuA F eu

uB

B

N¶º

¶u

Au

def:NL-ROMS:

REP-ROMS:

also referred to as Picard Iterations

( )( ) ( )n

B BnN t

= + - +¶

A uuu Fu

n ®u u

Approximation of NONLINEAR DYNAMICS

do =1n ® ¥

enddo

1B

n-ºu u

(STEP 1)

Page 5: The Inverse Regional Ocean Modeling System:

( ) (( ) ( ) )B BN t tt

¶= + - ++

¶uuA F eu

uREP-ROMS: BB

B

N¶º

= -

u

Au

s u u

def:

Representer Tangent Linear Model

Page 6: The Inverse Regional Ocean Modeling System:

( )tt

¶=

¶+

sAs e

T

λ

TL-ROMS:

AD-ROMS:

( ) (( ) ( ) )B BN t tt

¶= + - ++

¶uuA F eu

uREP-ROMS: BB

B

N¶º

= -

u

Au

s u u

def:

Representer Tangent Linear Model

Perturbation Tangent Linear Model

Adjoint Model

Page 7: The Inverse Regional Ocean Modeling System:

( )tt

¶=

¶+

sAs e

T

λ

TL-ROMS:

AD-ROMS:

( ) (( ) ( ) )B BN t tt

¶= + - ++

¶uuA F eu

uREP-ROMS:

Page 8: The Inverse Regional Ocean Modeling System:

( )tt

¶= +

¶s

As e

T

λ

TL-ROMS:

AD-ROMS:

( ) (( ) ( ) )B BN t tt

¶= + - + +

¶uuA F eu

uREP-ROMS:

Small Errors 1) model missing

dynamics

2) boundary conditions errors

3) Initial conditions errors

(STEP 2)

Page 9: The Inverse Regional Ocean Modeling System:

( )tt

¶= +

¶s

As eTL-ROMS:

AD-ROMS:

REP-ROMS:

T

λ

( )( ) ( ) ( )B BN t tt

¶= + - + +

¶u

u A u u F e

Page 10: The Inverse Regional Ocean Modeling System:

( )tt

¶= +

¶s

As eTL-ROMS:

AD-ROMS:

REP-ROMS:

T

λ

( )( ) ( ) ( )B BN t tt

¶= + - + +

¶u

u A u u F e

Integral Solutions

( ) ( , ) ( ) ( (', ) ') '0

0 0

Nt

Nt

NN t tt t t ttt d= +ò R es R s …..

Page 11: The Inverse Regional Ocean Modeling System:

( )tt

¶= +

¶s

As eTL-ROMS:

AD-ROMS:

REP-ROMS:

T

λ

( )( ) ( ) ( )B BN t tt

¶= + - + +

¶u

u A u u F e

Tangent Linear Propagator

Integral Solutions

( ) ( ) (( , ')( ' ') , )0

0 0

Nt

NN Nt

t t dtt t tt t= +òR R es s …..

Page 12: The Inverse Regional Ocean Modeling System:

( )tt

¶= +

¶s

As eTL-ROMS:

AD-ROMS:

REP-ROMS:

T

λ

( )( ) ( ) ( )B BN t tt

¶= + - + +

¶u

u A u u F e

( ) ( ) (( , ')( ' ') , )0

0 0

Nt

NN Nt

t t dtt t tt t= +òR R es s

Tangent Linear Propagator

Integral Solutions

Page 13: The Inverse Regional Ocean Modeling System:

TL-ROMS:

AD-ROMS:

REP-ROMS:

T

λ

( )( ) ( ) ( )B BN t tt

¶= + - + +

¶u

u A u u F e

( ) ( ) (( , ')( ' ') , )0

0 0

Nt

NN Nt

t t dtt t tt t= +òR R es s

Integral Solutions

( ) ( )( , ) ( ', () ) '0

0 00

NT TN

t

Nt

t t tt t t t dt= +òR R fλ λ

( )tt

¶= +

¶s

As e

Adjoint Propagator

Page 14: The Inverse Regional Ocean Modeling System:

TL-ROMS:

AD-ROMS:

REP-ROMS:

( ) ( ) (( , ')( ' ') , )0

0 0

Nt

NN Nt

t t dtt t tt t= +òR R es s

Integral Solutions

( ) ( )( , ) ( ', () ) '0

0 00

NT TN

t

Nt

t t tt t t t dt= +òR R fλ λ

[ ]( , ) ( ', )( ) ( ( ')) ( ) ( ') '0

00

N

N N

t

N Bt

t t N t dtt t t t t= + + +òR eu u FR u

Adjoint Propagator

Tangent Linear Propagator

Page 15: The Inverse Regional Ocean Modeling System:

TL-ROMS:

( ) ( , ) ( ) ( ', ) ( ') '0

0 0

Nt

N N Nt

t t t t t t t dt= +òs R s R e

How is the tangent linear model useful for assimilation?

Page 16: The Inverse Regional Ocean Modeling System:

TL-ROMS:

( , ) ( ) ( ', ) '( () ')0

0 0

Nt

N NNt

t t t t t t dtt = +òR s R es

ASSIMILATION (1) Problem Statement

®d1) Set of observations

2) Model trajectory

3) Find that minimizes

( )t®u

Sampling functional

ˆ ( )tu ˆ ( )( ') '0

T

ttt dt® - ò ud H

Page 17: The Inverse Regional Ocean Modeling System:

TL-ROMS:

( , ) ( ) ( ', ) '( () ')0

0 0

Nt

N NNt

t t t t t t dtt = +òR s R es

(ˆ ( )) ()tt t= +u u sBest Model Estimate

Initial Guess Corrections

ASSIMILATION (1) Problem Statement

®d1) Set of observations

2) Model trajectory

3) Find that minimizes

( )t®u

Sampling functional

ˆ ( )tu ˆ ( )( ') '0

T

ttt dt® - ò ud H

Page 18: The Inverse Regional Ocean Modeling System:

TL-ROMS:

ˆ®d1) Initial model-data misfit

2) Model Tangent Linear trajectory

3) Find that minimizes

( )t® s

( , ) ( ) ( ', ) '( () ')0

0 0

Nt

N NNt

t t t t t t dtt = +òR s R es

( )ts (ˆ ( )) '' '0

T

ttt dt® - ò H sd

ASSIMILATION (2) Modeling the Corrections

(ˆ ( )) ()tt t= +u u sBest Model Estimate

Initial Guess Corrections

Page 19: The Inverse Regional Ocean Modeling System:

TL-ROMS:

( , ) ( ) ( ') )'( ( , ) '0

0 0

Nt

N NNt

t tt dtt ttt= +ò R es R s

ASSIMILATION (2) Modeling the Corrections

(( )() )0 000 t ttt = - =e es

( )t® s

( )ts (ˆ ( )) '' '0

T

ttt dt® - ò H sd

ˆ®d1) Initial model-data misfit

2) Model Tangent Linear trajectory

3) Find that minimizes

Page 20: The Inverse Regional Ocean Modeling System:

TL-ROMS:

ASSIMILATION (2) Modeling the Corrections

( )0te

( )te

Corrections to initial conditions

Corrections to model dynamics and boundary conditions

( , ) ( ) ( ') )'( ( , ) '0

0 0

Nt

N NNt

t tt dtt ttt= +ò R es R s

( )t® s

( )ts (ˆ ( )) '' '0

T

ttt dt® - ò H sd

ˆ®d

(( )() )0 000 t ttt = - =e es

1) Initial model-data misfit

2) Model Tangent Linear trajectory

3) Find that minimizes

Page 21: The Inverse Regional Ocean Modeling System:

ˆ®d1) Initial model-data misfit

2) Corrections to Model State

3) Find that minimizes

( )t®e'

ˆ ( ') ( ' ', ( '' ' ' ')')0 0

T t

t ttt t t dt dt® - ò òd H R e

ASSIMILATION (2) Modeling the Corrections

( )0te

( )te

Corrections to initial conditions

Corrections to model dynamics and boundary conditions

( )te

Page 22: The Inverse Regional Ocean Modeling System:

ˆ®d1) Initial model-data misfit

2) Correction to Model Initial Guess

3) Find that minimizes

( )0t®e

ˆ ( ' () , ') ')(0

0 0

T

tt t t t dt® - ò H R ed

ASSIMILATION (2) Modeling the Corrections

( )0te

( )te

Corrections to initial conditions

Corrections to model dynamics and boundary conditions

( )0te

Assume we seek to correct only the initial conditions

STRONG CONSTRAINT

Page 23: The Inverse Regional Ocean Modeling System:

ASSIMILATION (2) Modeling the Corrections

ASSIMILATION (3) Cost Function

ˆ®d1) Initial model-data misfit

2) Correction to Model Initial Guess

3) Find that minimizes

( )0t®e

ˆ ( ' () , ') ')(0

0 0

T

tt t t t dt® - ò H R ed( )0te

ˆ ˆ[ ] ( ') ( , ') ' ( ') ( , ') '0 0

0 0 00 01

TT T

t tJ t t t dt t t t dt-é ù é ù

= - -ê ú ê úê ú ê úë û ë ûò òe e eH R RCd d Hε

10 0T -+ Pe e

Page 24: The Inverse Regional Ocean Modeling System:

ASSIMILATION (2) Modeling the Corrections

ASSIMILATION (3) Cost Function

ˆ®d1) Initial model-data misfit

2) Correction to Model Initial Guess

3) Find that minimizes

( )0t®e

ˆ ( ' () , ') ')(0

0 0

T

tt t t t dt® - ò H R ed( )0te

2) corrections should not exceed our assumptions about the errors in model initial condition.

1) corrections should reduce misfit within observational error

ˆ ˆ[ ] ( ') ( , ') ' ( ') ( , ') '0 0

0 0 00 01

TT T

t tJ t t t dt t t t dt-é ù é ù

= - -ê ú ê úê ú ê úë û ë ûò òe e eH R RCd d Hε

10 0T -+ Pe e

Page 25: The Inverse Regional Ocean Modeling System:

ASSIMILATION (3) Cost Function

ˆ ˆ[ ] ( ') ( , ') ' ( ') ( , ') '0 0

0 0 00 01

TT T

t tJ t t t dt t t t dt-é ù é ù

= - -ê ú ê úê ú ê úë û ë ûò òe e eH R RCd d Hε

10 0T -+ Pe e

Page 26: The Inverse Regional Ocean Modeling System:

ASSIMILATION (3) Cost Function

( ') ( , ') ' ( ') ( , 'ˆ[ ] 'ˆ )0 0

0 0 001

0

T T

t t

T

t t t dt t t t dtJ -é ù é ù= - -ê ú ê ú

ê ú ê úë û ë ûò òe e eH R RCd Hdε

10 0T -+ Pe e

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:

G is a mapping matrix of dimensions

observations X model space

Page 27: The Inverse Regional Ocean Modeling System:

ASSIMILATION (3) Cost Function

ˆ ˆ[ ] ( ') ( , ') ' ( ') ( , ') '0 0

10 0 0 0 0

TT T

t tJ t t t dt t t t dt-é ù é ù

= - -ê ú ê úê ú ê úë û ë ûò òe d H R e C d H R eε

10 0T -+e P e

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:

G is a mapping matrix of dimensions

observations X model space

ˆ ˆ[ ] 1 10 0 0 0 0

TTJ - -é ù é ù= - - +ê ú ê úë û ë ûd dC Pe eG eGe eε

Page 28: The Inverse Regional Ocean Modeling System:

ASSIMILATION (3) Cost Function

ˆ ˆ[ ] ( ') ( , ') ' ( ') ( , ') '0 0

10 0 0 0 0

TT T

t tJ t t t dt t t t dt-é ù é ù

= - -ê ú ê úê ú ê úë û ë ûò òe d H R e C d H R eε

10 0T -+e P e

ˆ ˆ[ ] 1 10 0 0 0 0

TTJ - -é ù é ù= - - +ê ú ê úë û ë ûd dC Pe eG eGe eε

( ) ˆ

ˆ

1 10

1 0T T - - -+ - =G G G CeP dC

H14444444244444443

Minimize J

Page 29: The Inverse Regional Ocean Modeling System:

( ) ˆ

ˆ

1 10

1 0T T - - -+ - =G G G CeP dC

H14444444244444443

4DVAR inversion

Hessian Matrix

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:

Page 30: The Inverse Regional Ocean Modeling System:

( ) ˆ

ˆ

1 10

1 0T T - - -+ - =G G G CeP dC

H14444444244444443

( )( ) ˆ

ˆ0

1

n

T T

-+ =dGP CG eGP

P β14444442444444314444244443

4DVAR inversion

IOM representer-based inversion

Hessian Matrix

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:

Page 31: The Inverse Regional Ocean Modeling System:

( ) ˆ

ˆ

1 10

1 0T T - - -+ - =G G G CeP dC

H14444444244444443

( )( ) ˆ

ˆ0

1

n

T T

-+ =dGP CG eGP

P β14444442444444314444244443

4DVAR inversion

IOM representer-based inversion

Hessian Matrix

Stabilized Representer Matrix

Representer Coefficients

µ TºR GPG

Representer Matrix

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:

Page 32: The Inverse Regional Ocean Modeling System:

Representer Matrix

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:What is the physical meaning ofthe Representer Matrix?

( )( ) ˆ

ˆ

1

0

n

T T

-+ =C PG e dGPG

P β14444442444444314444244443

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

µ TºR GPG

Page 33: The Inverse Regional Ocean Modeling System:

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

µ TºR GPG

Representer Matrix

µ ( ') ( , ') ' ( ', ) ( ') '0 0

0 0

T TT T

t tt t t dt t t t dtº ò òP R HR H R

Representer Matrix

( )( ) ˆ

ˆ

1

0

n

T T

-+ =C PG e dGPG

P β14444442444444314444244443

TL-ROMS AD-ROMS

µR

Page 34: The Inverse Regional Ocean Modeling System:

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

µ ( ') ( , ') ' ( ', ) ( ') '0 0

0 0

T TT T

t tt t t dt t t t dtº ò òP R HR H R

Representer Matrix

( )( ) ˆ

ˆ

1

0

n

T T

-+ =C PG e dGPG

P β14444442444444314444244443

Assume a special assimilation case:

( ) ( ) t t T= -

=

I

P

H

I

Observations = Full model state at time T

Diagonal Covariance with unit variance

µR

Page 35: The Inverse Regional Ocean Modeling System:

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

µ ( ' ) ( , ') ' ( ', ) ( ' ) '0 0

0 0

T TT

t tt T t t dt t t t T dt º - -ò òI IRR RI

Representer Matrix

( )( ) ˆ

ˆ

1

0

n

T T

-+ =C PG e dGPG

P β14444442444444314444244443

Assume a special assimilation case:

Observations = Full model state at time T

Diagonal Covariance with unit variance

µR

( ) ( ) t t T= -

=

I

P

H

I

Page 36: The Inverse Regional Ocean Modeling System:

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

Representer Matrix

( )( ) ˆ

ˆ

1

0

n

T T

-+ =C PG e dGPG

P β14444442444444314444244443

µR

µ ( , ) ( , )0 0Tt T T tº R RR

Page 37: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR

)( () T TT ssAssume you want to compute the model spatial covariance at time T

Page 38: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR

)( () T TT ssAssume you want to compute the model spatial covariance at time T

(( , )( ) )0 0T T tt T=R sλ

STEP 1) AD-ROMS

Page 39: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR

)( () T TT ssAssume you want to compute the model spatial covariance at time T

( , ) (( ) )0 0T T tt T=R sλ

STEP 1) AD-ROMS

( )

(( , ) () , ( ))0 0

0

T

t

Tt T T tT = sRs Rλ

144444424444443

STEP 2) run TL-ROMS forced with ( )0tλ

Page 40: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR

)( () T TT ssAssume you want to compute the model spatial covariance at time T

( )

(( , ) () , ( ))0 0

0

T

t

Tt T T tT = sRs Rλ

144444424444443

STEP 2) run TL-ROMS forced with ( )0tλ

STEP 3) multiply by and take expected value

( , ) ( , )) ( ) ( )) (( 0 0T TTT Tt tT T T T=

I

s sR R ss1444442444443

( )T Ts

(( , )( ) )0 0T T tt T=R sλ

STEP 1) AD-ROMS

Page 41: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR

)( () T TT ssAssume you want to compute the model spatial covariance at time T

( )

( ) ( , ) ( , ) ( )0 0

0

T

t

T t T T t T=s R R sλ

144444424444443

STEP 2) run TL-ROMS forced with ( )0tλ

STEP 3) multiply by and take expected value( )T Ts

( ) ( , ) ( )0 0Tt T t T=R sλ

STEP 1) AD-ROMS

µ( , ) ( ,) ( ))( 0 0T Tt T T tT T = ºR Rss R

Page 42: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR ( )( ) T TT= ss

model to model covariance

Page 43: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR ( )( ) T TT= ss

µ ( , ') ( '', )( ', '')0

TT

tt t t t tt t dº ò R RR ( ') ( '')Tt t= ss

model to model covariance

model to model covariance most general form

Page 44: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR ( )( ) T TT= ss

model to model covariance

Page 45: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR ( )( ) T TT= ss

model to model covariance

µ ( ') ( , ') ' ( ', ) ( ') '0 0

0 0

T TT T

t tt t t dt t t t dtº ò òI R HR H R

data to data covariance

ˆˆ T= dd

if we sample at observation locations through ( ') '0

( )T

tt dtò H

Page 46: The Inverse Regional Ocean Modeling System:

Representer Matrix

µ ( , ) ( , )0 0Tt T T tº R RR ( )( ) T TT= ss

model to model covariance

µ ( ') ( , ') ' ( ', ) ( ') '0 0

0 0

T TT T

t tt t t dt t t t dtº ò òI R HR H R

µ ( ') ( , ') ' ( ', ) ( ') '0 0

0 0

T TT T

t tt t t dt t t t dtº ò òP R HR H R

data to data covariance

ˆˆ T= dd

if we sample at observation locations through ( ') '0

( )T

tt dtò H

if we introduce a non-diagonal initial condition covariance

preconditioned data to data covariance

Page 47: The Inverse Regional Ocean Modeling System:

… back to the system to invert ….

Page 48: The Inverse Regional Ocean Modeling System:

( ) ˆ

ˆ

1 10

1 0T T - - -+ - =G G G CeP dC

H14444444244444443

( )( ) ˆ

ˆ0

1

n

T T

-+ =dGP CG eGP

P β14444442444444314444244443

4DVAR inversion

IOM representer-based inversion

Hessian Matrix

Stabilized Representer Matrix

Representer Coefficients

µ TºR GPG

Representer Matrix

( ') ( , ') '0

0

T

tt t t dt=òG H R

def:STRONG CONSTRAINT

Page 49: The Inverse Regional Ocean Modeling System:

4DVAR inversion

IOM representer-based inversion

Hessian Matrix

Stabilized Representer Matrix

Representer Coefficients

µ (( ') (', '') ' '''')0 0

TT T

t tt dt ttt t d

é ùº +ê úë ûò òR GCG C

Representer Matrix

ˆ

( ') ( '') ˆ' ''( ' (, '') ( ' ' '(, '' ))) '' ''0 0 0 0

1

T TT T T T

t t t t

n

t t t dt t tdt dt dt t tt

-é ù é ù+ =ê ú ê úë û ë ûò ò ò ò

P

G dCG GC C e

β14444444444444444444244444444444444444443 1444444444444444442444444444444444443

( ')( ) ( ( ˆ', ')') ( )

ˆ ( , ')0

1 1 1 0T TT

tt ttt t dt t

t t

- - -é ù+ - =ê úë ûò eC CG dG CG

H144444444444424444444444443 ( ) ( ') ( , ') '

T

tt t t t dt=òG H R

def:WEAK CONSTRAINT

Page 50: The Inverse Regional Ocean Modeling System:

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

ˆ

ˆ( ') ( ', '') ( '') ' '' ( ', '') ( '') ) ' ''( '0 0 0 0

1

T T T T

T T

t t t t

n

t t t t dt dt t t t dt dtt

-é ù é ù+ =ê ú ê úë û ë ûò ò ò ò

P

G C G C C deG

β14444444444444444444244444444444444444443 1444444444444444442444444444444444443

WEAK CONSTRAINT

How to solve for corrections ? Method of solution in IROMS

( )te

Page 51: The Inverse Regional Ocean Modeling System:

Stabilized Representer Matrix

Representer Coefficients

ˆ

( ') ( ', '') ( '') ˆ' '( ', ' (' ')' '' ' ( '' ))0 00 0

1

TT T

t

T TT

t t t

n

dt dtt t t t dt dt tt t t

-é ù+ê ú é ù =êë úû ë ûò òò ò

P

G e dG C CG C

β144444444444444444442444444444444444444 144444444444444444244444444444444444343

WEAK CONSTRAINT

How to solve for corrections ? Method of solution in IROMS

( )te

IOM representer-based inversion

''( , '') ( ', '') ( '( ) ') ' '

0

T

T T

t

tn

tt t t t dt tt dt = òò C R He β

Page 52: The Inverse Regional Ocean Modeling System:

IOM representer-based inversion

Stabilized Representer Matrix

Representer Coefficients

ˆ

( ') ( '') ˆ' ''( ' (, '') ( ' ' '(, '' ))) '' ''0 0 0 0

1

T TT T T T

t t t t

n

t t t dt t tdt dt dt t tt

-é ù é ù+ =ê ú ê úë û ë ûò ò ò ò

P

G dCG GC C e

β14444444444444444444244444444444444444443 1444444444444444442444444444444444443

WEAK CONSTRAINT

How to solve for corrections ? Method of solution in IROMS

( )te

nβP̂ x ˆ = d

''( , '') ( ', '') ( '( ) ') ' '

0

T

T T

t

tn

tt t t t dt tt dt = òò C R He β

Page 53: The Inverse Regional Ocean Modeling System:

Method of solution in IROMS

''( , '') ( ', '') ( '( ) ') ' '

0

T

T T

t

tn

tt t t t dt tt dt = òò C R He β

STEP 1) Produce background state using nonlinear model starting from initial guess.

ˆ( ) [ , ( ), , ]0 0B t t t t=u Nu F

[ ]ˆ( ) ( , ) ( ', ) ( ) ( ') '0

00 0

t

F Bt

t t t t t N t dt= + +òu R u R u F

ˆ ˆ( ') ( ) '0

Tn

tt t dt= - òd d H u

ˆˆ n =dPβ

[ ]ˆ ˆ( ) ( , ) ( ( ')', ) ( ) ( ') ' ( ', ) '0 0

0 0

t tn

Bt t

t t t t t N t dt t dtt t= + + +ò òu R u R u F eR

STEP 2) Run REP-ROMS linearized around background state to generate first estimate of model trajectory

STEP 3) Compute model-data misfit

do 0n N= ®ˆ ( ) ( )0 0

Ft t=u u

STEP 4) Solve for Representer Coeficients

STEP 5) Compute corrections

STEP 6) Update model state using REP-ROMS

outer loop

Page 54: The Inverse Regional Ocean Modeling System:

Method of solution in IROMS

''( , '') ( ', '') ( '( ) ') ' '

0

T

T T

t

tn

tt t t t dt tt dt = òò C R He β

STEP 1) Produce background state using nonlinear model starting from initial guess.

ˆ( ) [ , ( ), , ]0 0B t t t t=u Nu F

[ ]ˆ( ) ( , ) ( ', ) ( ) ( ') '0

00 0

t

F Bt

t t t t t N t dt= + +òu R u R u F

ˆ ˆ( ') ( ) '0

Tn

tt t dt= - òd d H u

ˆˆ n =dPβ

[ ]ˆ ˆ( ) ( , ) ( ( ')', ) ( ) ( ') ' ( ', ) '0 0

0 0

t tn

Bt t

t t t t t N t dt t dtt t= + + +ò òu R u R u F eR

STEP 2) Run REP-ROMS linearized around background state to generate first estimate of model trajectory

STEP 3) Compute model-data misfit

do 0n N= ®ˆ ( ) ( )0 0

Ft t=u u

STEP 4) Solve for Representer Coeficients

STEP 5) Compute corrections

STEP 6) Update model state using REP-ROMS

outer loop

inner loop

Page 55: The Inverse Regional Ocean Modeling System:

µˆ

''

ˆ

( '')

( ')

( )

ˆ ˆ( ) ( ', ) ( ', '') ( , '') ( ) '' '0 0

Adjoint Solution

Convolution of Adjoint Solution

Ta

t T TT T

t t t

t

t

t

t t t t t t t t dt dt dt= ò ò ò

f

P H R C R H

λ

τ

ψ ψ) ) )

144444444444244444444444314444444444444444442444444444444444444434

ˆ

( ')

( )

ˆ0

ngent Linear model forced with

Sampling of Tangent Linear solution

T

t

t

t

dtò

f

τ

1444444444444444444444444424444444444444444444444444434144444444444444444444444444444424444444444444444444444444444 3

+Cεψ

444444

How to evaluate the action of the stabilized Representer Matrix µP

Page 56: The Inverse Regional Ocean Modeling System:

Baroclinic Jet Example -

Page 57: The Inverse Regional Ocean Modeling System:

… end

Page 58: The Inverse Regional Ocean Modeling System:

µˆ

''

ˆ

( '')

( ')

( )

ˆ ˆ( ) ( ', ) ( ', '') ( , '') ( ) '' '0 0

Adjoint Solution

Convolution of Adjoint Solution

Ta

t T TT T

t t t

t

t

t

t t t t t t t t dt dt dt= ò ò ò

f

P H R C R H

λ

τ

ψ ψ) ) )

144444444444244444444444314444444444444444442444444444444444444434

ˆ

( ')

( )

ˆ0

ngent Linear model forced with

Sampling of Tangent Linear solution

T

t

t

t

dtò

f

τ

1444444444444444444444444424444444444444444444444444434144444444444444444444444444444424444444444444444444444444444 3

+Cεψ

444444

µˆ

ˆ

( ')

( ) ( ')

ˆ ˆ ˆ( ) ( ', ) ( ', '') ( '') '' '0 0 0

Convolution of Adjoint Solution

Tangent Linear model forced with

Sa

T t T

t t t

t

t

t

t t t t t t dt dt dt=ò ò òf

f

P H R C

τ

ψ λ144444444424444444443

14444444444444444442444444444444444444434

ˆ( ) mpling of Tangent Linear solution t

+Cε

τ

ψ

14444444444444444444444442444444444444444444444444434

µˆ

ˆ

ˆ

( ) ( ')

( )

ˆ ˆ ˆ( ) ( ', ) ( ') '0 0

Tangent Linear model forced with

Sampling of Tangent Linear solution

T t

t t

t

t

t

t t t t dt dt= +ò òf

P H R f Cε

τ

τ

ψ ψ1444444442444444443

144444444444444444444244444444444444444444434

Page 59: The Inverse Regional Ocean Modeling System:

µ

ˆ( )

ˆ ˆ ˆ( ) ( )0

Sampling of Tangent Linear solution

T

t

t

t t dt= +òP H Cε

τ

ψ τ ψ144444424444443