The generation and development of the long term Mediterranean

SSR products

The aims are:

1. to identify and develop of an optimal algorithm for the Mediterranean sea to produce high quality ocean color datasets for the region.

2. to provide an accurate and consistent stream of ocean colour data at a resolution and format compatible with operational forecasting of the Marine Environment.

The SeaWiFS reanalysis from 1997 to 2004

A new regional algorithm for Chlorophyll retrieval

Bio-optical measurements: (143 chl/opt measurement points) to define the Mediterranean regional algorithm

In situ chlorophyll-a data: (944 chl profiles) to validate SeaWiFS, Polder, MODIS, MERIS chlorophyll products and merged level 3 binned data produced by Mersea

Mediterranean Ocean Color CAL/VAL DATA SETS

10 Mediterranean cruises:from 1998 up to now were organized by ISAC in the framework of Italian National Projects

Bio-optical stations

)( 44

33

221010 RbRbRbRbbC

MEDOC4 : R is log10 of either the 443/560 or the 490/555 or the 510/555 band reflectance ratios. The switch from one band ratio to another one is based on the chlorophyll concentration itself (the Maximum is Chosen)

THE NEW MEDITERRANEAN ALGORITHM

a

b

AlgorithmsALL N = 137 OWP < 0.4 N = 84 OWP > 0.4 N= 53

r RPD APD r RPD APD r RPD APD

MedOC4 0.91 0.0 29.2 0.88 7.8 25.9 0.83 -12.3 34.5

SeaBAM N=1174Mediterranean N=137

Optical characteristics: Mediterranean vs Global

1. Low Chlorophyll: Med Band Ration < Global Band Ratio

2. Max Ratio choice similar for Med and Global

3. Is the Med Sea Greener or less Blue then the Global Ocean?

Is the Med Sea Greener or less Blue then the Global Ocean?

Chl < 0.1 : -blue (30%); +Green (15%)

0.1<Chl < 0.3 :+blue (12%); +Green (10%); Global generally use 443 for ratio – Med use 443 50% of the cases 490 50%.

Chl >0.3 : Med and Global tend to converge

Mediterranean Algorithm Validation

Satellite-in situ match-up stations

AlgorithmsALL N = 290 OWP < 0.4 N = 223

r RPD APD r RPD APD

Oc4v4 0.79 110.6 122.4 0.78 145.7 145.9

Bricaud 0.80 38.4 59.6 0.81 51.8 64.2

D'Ortenzio 0.76 18.5 49.4 0.7333.1

49.2

MedOC4 0.77 16.9 42.6 0.82 1.3 39.0

RPDA lgi OWPiOWPi

i1

N

1

N100%

APDA lgi OWPiOWPii1

N

1

N100%

Conclusions

• The analysis confirms that OC4v4 presents a remarkably bias in the oligotrophic chlorophyll range (>100%).

• The two regional algorithms (BRIC and DORMA) behave generally better the global OC4v4.

• A new Mediterranean algorithm (MedOC4) was developed. The algorithm has and percent MBE around zero in the entire range of Mediterranean conditions.

• The validation of the SeaWiFS products demonstrate the improvement obtained in SeaWiFS chlorophyll retrieval when the new MedOC4 is used in the processing chain. The SeaWiFS MedOC4 error is always less the 20% for chlorophyll values > 0.05 mg m-3

The SeaWiFS reanalysis from 1997 to 2004: reprocessing of the entire Mediterranean Sea L1A archive using MedOC4

Algorithm

Input Data

• SeaWiFS L1A data from HROM

• Add other station: HSPZ, HDUN,….

• Add M_LAC for missing

• Total number of pass L1A data 6127 pass

The DATA PROCESSING

L1A………

L1A

For SeaWiFS one day passesover the Mediterranean Sea

L2………L2

n-L3………

n-L3

L2bin………

L2bin

22 L3 products for each L2 file

chlor_al2_flagschl_medoc4K_490parsenz

Rrs_412Rrs_443Rrs_490Rrs_510Rrs_555Rrs_670Rrs_765Rrs_865

taua_412taua_443taua_490taua_510taua_555taua_670taua_765taua_865

L3bin

1km 1km

1km

2km

2km

Top of AtmosphereReflectances

Atmospherically correctedproducts

Mappedproducts

Mosaicked and Merged Passes over the Mediterranean Sea

WHY GRID?It is an innovative solution for the data access and exchange

Increased exploitation of available resources

It enables new classes of large-scale, high-power applications (e.s. reprocessing of large data volumes)

It is a model for future European EO Ground Segment…

It enables interconnection between science computing centers

It enables International cooperation in EO applications

It enables the production of EO multi sensor merged products for data assimilation

DATA PROCESSING ON GRID

UI CE

SE

WN:Node01.. ….Node16

WN:Node01.. ….Node16

Gridtest03.esrin.esa.int Grid0007.esrin.esa.int

Se0.artov.rm.cnr.it

1) Globus-job-submit

2) Globus-job-status3) Globus-job-get-output

Globus-url-copy Globus-url-copy

UI=User Interface

SE=Storage element

CE=Computer Element

WN=Worker node

The processing cost

N° pass= 6127

CPU time/pass= 15 min

Total processing time

~ 64 days

N° pass= 6127

WN CPU time/pass= 14 min

N° WN =16

Total processing time

~ 4 days

GOS infrastructure ESA-CNR GRID infrastructure

SeaWiFS dataset from 1997 to 2004

- 93 % Disc space exploitation

Input Data: 164 GB on SE for the whole L1A datasetOutput Data: 320 GB on SE for the whole L3 datasets

Previous algorithm NEW algorithm Difference OLD-NEW

OC4.V4 Med OC4 (OC4.V4) – (Med OC4)0-0.1 0.2

0.01 50.01 5

2 July 2004

The GRID products output

Previous algorithm NEW algorithm Difference OLD-NEW

OC4.V4 Med OC4 (OC4.V4) – (Med OC4)

0-0.80 0.30.01 5 0.01 5

21 April 2004

Med OC4

(OC4.V4) – (Med OC4)

1999 Monthly maps

OC4.V4

APRIL

Med OC4

(OC4.V4) – (Med OC4)

1999 Monthly maps

OC4.V4

JULY

OC4.V4 Med OC4

(OC4.V4) – (Med OC4)

1999 yearly average

A regional approachfor

the Mediterranean SeaPrimary Production

Introduction

Antoine et al.,1995WEST MED: 197 gC m-2 y-1

EST MED: 137 gC m-2 y-1

Bosc et al.,2004WEST MED: 155-172 gC m-2 y-1

EST MED: 114-125 gC m-2 y-1

Sa

telli

te

Published valuesEST MED: 55-97 gC m-2 y-1

WEST MED: 78-158 gC m-2 y-1

Oth

er

De

pth

(m

)

Chlorophyll (mg m-3)

De

pth

(m

)

Chlorophyll (mg m-3)

d Ze

maxμ,max dzdtdtzxftzPURzChla=PP0 0

700

400

* )),((),,()(12

Introductiond= day length

Ze= euphotic depth PAR(Ze)=1% PAR(0)

PUR= f(PAR,Ts)

CsatZpd

Ze

Ze Ctot Ctot Csat

From global in situ profiles

Trophic states

PP Model Adjustment to Mediterranean Conditions

1. Develop a regional algorithm for satellite chlorophyll retrieval (DORMA, MED_OC4)

2. Develop new relation for the euphotic depth (Ze) as function of Ctot (total chlorophyll within the euphotic layer)

3. Develop a new relation between Ctot and Csat

4. Define the new trophic states for the Mediterranean Sea

Model adjustments

Ze Ctot Model adjustments

Ctot=40.6 Csat0.459

Ctot=45.03 Csat0.595

Morel and Berthon (1989)

This study

Ctot Csat

Model adjustments

Ranges of Morel and Berthon: 0-0.05, 0.05-0.15, 0.15-0.3,0.3-0.45, 0.45-1.5, 1.5-5, >5 mg m-3

Model adjustments

This study

Morel and Berthon

(1989)

MED_OC4 SeaWiFS Chlorophyll from 1998 to 2004

New Ranges: 0-0.05, 0.05-0.1, 0.1-0.15, 0.15-0.4, 0.4-1.5, 1.5-5

AVHRR OISST from 1998 to 2004

SeaWiFS PAR from 1998 to 2004

INPUT DATA

7-14 April 2001 7-14 April 2001

7-14 April 2001

Model IntecomparisonBosc et al. (2004)

April ‘99 December ‘99

Comparison

Impact of chl algorithm on PP

Weekly mean of Mediterranean basin PP

MedOC4

Bricaud

OC4

Antoine et al.,1995WEST MED: 197 gC m-2 y-1

EST MED: 137 gC m-2 y-1

Bosc et al.,2004WEST MED: 155-172 gC m-2 y-1

EST MED: 114-125 gC m-2 y-1

Sa

telli

te

This WorkEST MED: 79-86 gC m-2 y-1

WEST MED: 102-125 gC m-2 y-1

ou

r

Published valuesEST MED: 55-97 gC m-2 y-1

WEST MED: 78-158 gC m-2 y-1

Oth

er