MARCOOS/ESPreSSO ROMSRU Coastal Ocean Modeling and Prediction group

John Wilkin, Gordon Zhang, Julia Levin, Naomi Fleming, Javier Zavala-Garay, Hernan Arango

5 km resolution for assimilation

1 km resolution for forecast

NCEP NAM 3-hour meteorology

1-day average USGS gauge river flow

Open boundaries: ROMS MAB-GoM nested within GODAE-HyCOM operational N. Atlantic (He/NCSU)

> OPeNDAP data portal

> Assimilation experiments in 2006 (4DVar)

> Glider observation analysis (Representers)

Assimilation and observing system design experiments in 2006 (LaTTE and SW06)

> LaTTE subdomain

RU CODAR (with tides)

All glider CTD

All moored T/S

> SW06/MARCOOS/ESPreSSO

Now: Climatology (Hydrobase); AVISO altimetry in Slope Sea; SST (AVHRR/MODIS/GOES

blended from PFEL CoastWatch)

Soon: regional climatology; glider; VOS/XBT; Argo

Future: coastal along-track altimetry; in situ and satellite optics and ocean color

> Glider observing system design

use representers to analyse information content of MARCOOS glider tracks

X_afterDAforecast_skill = 1

X_beforeDA

2X = MSE, MB , 2 (1 CC)m oS S

Forecast skill improvement with assimilation of CODAR60-day ensemble of all analyses/forecasts

u “along-shelf” component

forecast windowanalysis forecast windowanalysis

after assimilating CODAR data

(Oke, et al, 2002)

2 2MSE = MB SDE 2 (1 CC)m oS S MB ( )m o SDE m oS S

0

1

0

1no assimilation of CODAR data

X_afterDAforecast_skill = 1

X_beforeDA

2X = MSE, MB , 2 (1 CC)m oS S

Forecast skill improvement with assimilation of CODAR60-day ensemble of all analyses/forecasts

v “across-shelf” component

forecast windowanalysis forecast windowanalysis

after assimilating CODAR data

(Oke, et al, 2002)

2 2MSE = MB SDE 2 (1 CC)m oS S MB ( )m o SDE m oS S

0

1

0

1no assimilation of CODAR data

The “Representer” (Bennett) is a measure of the covariance/correlation between ocean state variables and a pattern of observations

Method: integrate the adjoint model backwards forced at observational locations, then the tangent linear model forward to carry “information” to analysis/forecast times

Cost function:

Covariance between J and temperature,

, reflects the

influence of glider observation

2

1

2 2

2 1

1( ) ( )

( )

t

t L

J T T S S dLdtL t t

cov( , ( , , , ))J T x y z t

At time = finish of glider mission

At time = 5 days after finish of glider mission

Cost function:

Covariance between J and temperature,

, reflects the

influence of glider observation

2

1

2 2

2 1

1( ) ( )

( )

t

t L

J T T S S dLdtL t t

cov( , ( , , , ))J T x y z t