George Petihakis, Athanasia Iona, - PowerPoint PPT Presentation

Title: George Petihakis, Athanasia Iona,


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Development and Implementation of a Data
Integration System for Eutrophication Assessment
in Coastal Watersin the framework of INSEA
project CONTRACT Nº SST4-CT-2005-012336

• George Petihakis, Athanasia Iona,
• Gerassimos Korres, Pelopidas Karagevrekis,
• Dionisis Raitsos, and
• George Triantafyllou
• IMDIS-2008, Athens

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Agenda

• Description of the project
• Pagasitikos eutrophication problem
• Description of the Ecosystem Model
• Data Assimilation
• Data Management System

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Overall objective

• Building an integrated tool for coastal ecosystem
  assessment combining Models, Satellite Remote
  Sensing and in situ measurements.

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Strategy

• Build a consortium with the following
  tools/skills
• Models developed and operational,
• In situ Real-time measurement experience,
• Remote Sensing experience,
• Good data management capacities.
• Capacity for assessing the problem at a European
  scale.

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Consortium
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Data Flow
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Case Studies
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The eutrophication problem
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Field data
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Computational area
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Ecosystem model
ERSEM
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Assimilation into POM-ERSEM

• Model 1/100o Pagasitikos configuration with 25
  layers
• Downscaling from 1/30o Aegean, from 1/12o
  Mediterranean

Downscaling model solutions a problem of proper
OBCs (nesting) and initialization
Init
Init
Basin scale model (MED OPA 1/12)
Regional model (AEGEAN POM 1/30)
Coastal model (PAG POM 1/100)
OBCs
OBCs

• Interpolate coarse model solution and add
  constraints in order to dump spurious
  oscillations and propagating waves
• VIFOP (a variational
  initialization method, Auclair 1999)
• Nesting techniques developed within MFSPP, MFSTEP
  and POSEIDON projects

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Forcing Initial conditions

• ECMWF 6 hours data
• Wind stresses
• Temperature and air humidity
• Cloud cover
• Heat fluxes
• Solar radiation
• Precipitation Jaeger (horizontal resolution
  5?x2.5o)
• Initial conditions March analyzed fields

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Model results vs Obs
July Mean Circulation
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Model results
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Cost Functions
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The Low-Rank Kalman Filter(s)

• Singular Evolutive Kalman (SEEK) filters,
  low-rank (r) square-root KFs

Analysis
Forecast

• A collection of SEEK filters

• SEEK

• SEIK Ensemble variant

• SFEK

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Data Assimilation
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Data Assimilation
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Assimilation Experiments
TWIN EXPERIMENTS
FILTER ? rank OBSERVATIONS TYPE STATE VECTOR
SFEK 0.65 35 T,S PROFILES FULL
SEEK 0.65 35 T,S PROFILES FULL
SEIK 0.65 35 T,S PROFILES FULL
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Twin Experiments
SFEK, SEEK AND SEIK PERFORMANCE(35 modes, ?0.65)
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Assimilation into POM-ERSEM

• Observations SeaWiFS 2003 on a weekly basis
• SEEK Filter with rank 40
• Initialization EOFs computed from 2-days
  outputs of 2001-2002 model integration,
  explaining 95 of the variance
• Amplification factor 0.5

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Experiment Setup

• Model 1/100o Pagasitikos Gulf with 25 layers

2003
31/12/03
1996
2001
Spin up
EOFs
REF OBS
2 years
1 year
5 years

• Initialization starts from the state of
  31/12/2002
• Free-run run without assimilation starting from
  mean state
• Evaluation RMS misfit relative to the misfit
  from mean state

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Assimilation into ERSEM
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Hindcast Experiments 2003
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Hindcast Experiments 2003
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EXP4 Mean values of Chl and BIAS (model
Forecast and Analysis)
EXP4 SEEK, 7 mod, FF0.3, Er0.1
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Data for HNODC

• Hydrographic, Chemical and Biological data
• All the Pagasitikos gulf area, and
• Period April 1998 November 1999
• Parameters measured
• Temperature, Salinity, Density, Currents,
• Oxygen, Nitrate, Nitrite, Ammonium, Phosphate,
• Dissolved Organic Phosphate, Silicate,
• Chlorophyll-a, Bacteria, Phytoplankton, and
  Zooplankton.

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INSEA Common Data Index Metadata

• A total of 970 xml records from 23 cruises
  transmitted by HNODC to central INSEA CDI
  database (http//www.insea.info/cdi/)
• 413 xml records describing ADCP data
• 413 xml records describing CTD data
• 144 xml records describing Bottle data
• Validation scheme CDI_V1_04.xsd
• Produced by MIKADO Java Tool

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CONCLUSIONS

• A management tool for the ecosystem of
  Pagasitikos gulf has been developed and
  implemented successfully
• It consists of
• Hydrodynamic model
• Biogeochemical model
• Assimilation scheme
• Satellite data
• Model forecast is usually becoming different of
  the analysis which is an other indication of the
  systems strong variability requiring frequent
  observations
• Hindcast experiments show that the performance of
  the system requires
• Good quality of satellite observations
• The model exhibits biases since it produces the
  spring bloom a week before in relation to the
  satellite observations

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Thank You