GOVST-VCapital Hotel, Beijing, China, 13-17 Oct 2014Lecce, Italy, Feb 4-7, 2012

Coastal Oceans and Shelf Seas Task Team “Half-day” meeting

Pierre De Mey, LEGOS/U. ToulouseVilly Kourafalou, RSMAS/U. Miami

COSS-TT Meeting agenda

1330-1345 Overview of TT goals and activities

1345-1430 Strategy topic 1: Scientific support of the development of Coastal Ocean Forecasting Systems (COFS) and applications + discussion

1430-1500 Strategy topic 2: Integration between COFS and GOV systems + discussion

1500-1530 Coffee/tea break

1530-1600 Strategy topic 3: Linking with the regional and coastal altimetry community + discussion

1600-1630 Links with other TTs: presentations by members of other TTs on integration with COSS-TT welcome.

Short presentations (5’) by attendees are welcome in relation to the strategy topics. E.g. GOV groups are encouraged to briefly present their downscaling projects in topic 2 and links with OSEVal-TT, biogeochemical applications (MEAP-TT) or data assimilation (DAT-TT) are welcome in the “Links” session.

COSS-TTCOSS-TT

TT goals and activities

COSS-TT Task Teams in the GODAE OceanView organisation

COSS-TT Objectives of the Coastal Oceans and Shelf Seas Task Team

Mission Goal: Advance science in support of sustainable multidisciplinary downscaling and forecasting activities in the world coastal oceans.

Strategic goal: Help achieve a seamless framework from the global to the coastal/littoral scale.

Dual objectives as per current Work Plan:

• Establish community links between ongoing Coastal Ocean Forecasting Systems (COFS) in order to advance science in support of COFS

• Convene forums to discuss targeted science issues.

COSS-TT “Science in support of coastal forecasting”: science drivers

Priority areas where science can help the development of Coastal Ocean Forecasting Systems:

1. Monitoring of physical, geochemical and biological parameters in coastal regions

2. Development of fine-scale coastal ocean models

3. Integration: Downscaling the ocean estimation problem from large-scale to coastal-scale models, data and forcings, coastal data assimilation and prediction

4. Coastal-scale atmosphere-waves-ocean couplings

5. Ecosystem response to the physical drivers (added at ICW3)

6. Probabilistic approaches and risk assessment in the coastal ocean, including extreme events

COSS-TT

Examples of systems from Systems Information Table

I: Americas

II: Asia and Australia

III: Europe

 Acronym System Name Country Domain(s)

I 

ESTOFSExtratropical Surge and Tide Operational Forecast System

USAUS East, Gulf of Mexico and West Coasts, up to the Gulf of Alaska.

FKeyS-HYCOM

Florida Straits, South Florida and Keys Hybrid Coordinate Ocean Model

USAFlorida Straits and the South Florida coastal and shelf areas

NWPSNearshore Wave Prediction System

USACoastal Waters of all US territories

NYHOPSNew York Harbor Observing and Prediction System

USA

Coastal waters of the Middle Atlantic Bight on the East Coast of the US (<200m deep).

OFSOperational Forecast System

USAAll major estuaries and coastal systems of the US

P-Surge Probabilistic Surge USACoastal and overland areas of all US territories

REMOOceanographic modelling and observation network

BrazilWestern Equatorial and South Atlantic Ocean

SLGOSt. Lawrence Global Observatory

Canada Gulf of St. Lawrence

WCNRTWest Coast Near Real Time Data Assimilation System

USAWest U.S. Coast, California Current System

II

CGOFS

Chinese Global operational Oceanography Forecasting System

ChinaGlobal and Regional seas around China

ESROM_MOM Regional ocean modelling system

South Korea East Sea (Japan Sea)

eReefseReefs Marine Modelling

AustraliaAustralian coastal margins

MOVE/MRI

MRI Multivariate Ocean Variational Estimation System / MRI Community Ocean Model

Japan

Global, North Pacific, Western North Pacific, Coastal region around Japan

YS_ROMS Korea operational oceanography system

South KoreaYellow Sea and East China Sea

III

AFSAdriatic Forecasting System

ItalyAdriatic Sea and Northern Ionian Sea

COSYNACoastal Observation System for Northern and Arctic Seas

GermanyNorth Sea, German Bight, German Wadden Sea

MFSMediterranean Ocean Forecasting System

Italy Mediterranean Sea

NEMO-FOAMNEMO FOAM Operational Modelling

United KingdomEuropean Northwest continental shelf

POSEIDONRegional monitoring and forecasting system

GreeceAegean and Mediterranean Seas

PREVIMER PREVIMer Coastal observations and forecasts

France Bay of Biscay / English Channel / Northwestern Mediterranean Sea

COSS-TT TT members as of Oct, 2014

TT members

• COSS-TT is engaging the international Coastal Ocean and Shelf Seas modeling/forecasting community (COSS-COMM)

• International Coordination Workshops are open to the COSS-COMM

• > 100 people in COSS-COMM mailing list at the moment

Name Institution, City Country StatusBarth, Alexander U. Liège BelgiumChao, Yi RSS and UCLA, Los Angeles, CA USA

Chassé, Joël DFO, Mont-Joli, QC Canada (inactive)Choi, Byoung-Ju Kunsan National U. Korea New memberCirano, Mauro REMO, Rio de Janeiro BrazilDe Mey, Pierre CNRS / LEGOS, Toulouse FranceDumas, Franck IFREMER / Previmer, Brest France (inactive)He, Ruoying NCSU, Raleigh, NC USAHerzfeld, Mike CSIRO, Hobart AustraliaHirose, Naoki Kyushu U., Fukuoka Japan (inactive)Jianping, Gan Hong Kong U. of S&T ChinaKourafalou, Villy U. Miami / RSMAS, Miami, FL USAKurapov, Alexander Oregon State U. / COAS, Corvallis, OR USALiu, Guimei NMEFC, Beijing ChinaO’Dea, Enda UK Met Office, Exeter UKOddo, Paolo INGV, Bologna ItalyPinardi, Nadia U. Bologna ItalyPullen, Julie Stevens Institute of technology USA New memberRichman, Jim NRL, Stennis Space Ctr., MS USAStanev, Emil HZG, Hamburg Germany

Van der Westhuysen, André NOAA/NWS/NCEP USA New memberZhu, Jiang IAP, Beijing China

COSS-TT A few actitivies and achievements

ICW1, Miami, Jan 2012

ICW2, Lecce, Feb 2013ICW3, Puerto Rico, Jan 2014

• The Task Team acts as a link between the international Coastal Ocean Forecasting community and GODAE OceanView.

• A Coastal Systems Information Table is available (last update May 2014).

• Three International Coordination Workshops have been organized so far; these have been successfully embraced by the community as a much needed forum to discuss latest scientific advances, promote international networking and update strategic planning. (Next workshop: Lisbon, 1-4 Sep 2015.)

• Several special sessions have been sponsored by the Task Team at AGU and OSM over the years; these have consolidated the outcomes of the TT workshops and allowed exposure of TT goals and outcomes through outreach to the broader scientific community. The most recent session was in Hawai’i.

• Links have been established with other active international communities, such as the Coastal Altimetry community and EuroGOOS.

• Two synthetic COSS Community papers from the 2013 Symposium have been accepted for publication in JOO.

• A COSS Topical Collection of papers (32) has been launched in Oc. Dynamics

• A Science Strategy Plan in the works.

COSS-TT Puerto Rico workshop agenda (Jan 2014)

• Science sessions

– SCI1: Progress of coastal ocean forecasting systems, networks and applications 6 papers

– SCI2: Downscaling the ocean estimation problem and assimilating local data 6 papers

– SCI3: Towards fine-scale coastal ocean modelling 2 papers

– SCI4: Coastal-scale atmosphere-waves-ocean couplings 6 papers

– SCI5: Long-term monitoring, array design and OSSEs in coastal regions 5 papers

• Coordination topics

– Towards a COSS-TT Science Strategy Plan (SSP) Working Groups (// sessions)

– Exchanging information in the COSS Community update & discussion

– Update on the “COSS-TT Initiative” MoU

– Discussions on response to review, community paper, etc.

COSS-TT Lisbon workshop (Sept 2015)

• 1-4 September 2015

• Kindly hosted by MARETEC, Lisbon, Portugal

• 1st Announcement April 2014 (on GOV web site)

• Science program TBA

• Invite members of the GOVST and GOV Patrons Group to the workshop

– Discuss coastal interfaces

– Discuss coastal applications, targeted variables and ranges

– Discuss on case studies / pilot experiments to assess the quality of large-

scale products aimed at serving the downstream needs of COFS and

applications.

COSS-TT Known COSS involvement of GOV Patrons (as of Oct 2014)

• “COSS involvement ” examples– Run COFS– Fund science or observations in support of the development of COFS– Run or facilitate COFS applications

• Corrections welcome!

Organisation COSS involvement Is COSS-TT memberBoM ? CNES Yes ESA Yes EUMETSAT ? Ifremer Yes YesINCOIS Yes Mercator Ocean (Regional) Met Office Yes MRI-JMA Yes NASA Yes NERSC Yes? NMEFC Yes YesNOAA-CPO and NOAA-space Yes Yes

COSS-TT GOV review – 7 Nov 2013

• Panel :– Albert Fischer, Intergovernmental Oceanographic Commission, France– Shiro Imawaki, JAMSTEC, Japan– Ming Ji, NOAA Ocean Prediction Center, USA– Ralph Rayner, Centre for the Analysis of Time Series, London School of Economics, UK– Neville Smith, Bureau of Meteorology, Australia– Richard W. Spinrad, Oregon State University, USA (Chair)

• Chosen excerpts– “The Panel recommends the formal development […] of a strategic plan (with 5 and

10 year horizons)” (regarding GOV as a whole)– “Some Task Teams may require a tighter focus to their activities (e.g., the Coastal and

Shelf Seas Task Team)”– “Consistent with the GOV strategic plan, the challenges in this Task Team’s science

strategy document need to be prioritized by the ‘value add’ of collective action.”– “Focus should be on the interfaces between GOV systems and coastal models and

applications. ”– “This Task Team should develop a dialogue with other groups working on coastal

model development and applications (e.g., Delft Hydraulics, DHI, HR Wallingford, US Army Corps of Engineers, etc.).”

COSS-TTCOSS-TT

Strategy topic 1: Scientific support of the development of Coastal Ocean Forecasting Systems (COFS) and applications

Main goal:

Support research and development to advance coastal ocean forecasting, through the integration of observations and models in coastal areas and in synergy with larger scale observatories and modeling systems.

COSS-TT “Science in support of coastal forecasting”: science drivers

Priority areas where science can help the development of Coastal Ocean Forecasting Systems:

1. Monitoring of physical and biogeochemical parameters in coastal regions

2. Development of fine-scale coastal ocean models

3. Downscaling the ocean estimation problem from large-scale to coastal-scale models, data and forcings, coastal data assimilation and prediction (model/data integration)

4. Coastal-scale atmosphere-waves-ocean couplings

5. Ecosystem response to the physical drivers

6. Probabilistic approaches and risk assessment in the coastal ocean, including extreme events

(1) Monitoring of physical and biogeochemical parameters in coastal regions

Multi-platform and interdisciplinary Coastal Ocean Observing Systems

Coastal/regional array design: OSE/OSSEs, Representer Matrix Spectrum…

Monitoring needs in a variety of scales (mesoscale / sub-mesoscale; short to long term)

Fine scale modeling: seamless transition from large to shelf to coastal and estuarine scale

Integration of coastal observing systems and fine scale models

Advances in policy: establishment of regional observing systems

Advances in instruments and methods (CA, SWOT…)

Needs in boundary conditions, topography and forcing functions (see also Topic2)

NW PacificJapan Sea

Seto inland

NE PacificCalifornia coast

San Francisco Bay

(2) Development of fine-scale coastal ocean models

Kourafalou et al. (2014)

Provided by N. Usui (MRI-JMA)

COSS-TT

Downscaling methodologies

1. Dynamical downscaling

2. (Purely) Statistical downscaling

3. Dynamical downscaling with assimilation

(1 and 3 used to downscale COFS into LOFS)

(3)Downscaling the ocean estimation problem from large-scale to coastal-scale models, data and forcings, coastal data assimilation and prediction (model/data integration)

Ensure consistency in the fluxes that go between the various coupled models (atmosphere-to-ocean, atmosphere-to-wave, wave-to-ocean); example: sfc currents accounting for turbulence/fast response to wind

Reassess calibration strategies of individual models

Reassess parameterization of flux transfer between models

Observations needed at model interfaces

(4) Coastal-scale atmosphere-waves-ocean couplings

Coastal ocean coupled (wave-currents) model example: German Bight

German Bight: “normal” conditions German Bight: storm conditions

Kourafalou et al. (2014)

Coastal ocean coupled (biophysical) model example: Gulf of Mexico (offshore removal of Mississippi River plume waters under Loop Current influence)

Model simulated chl-aMonthly mean

MODIS observed chl-aMonthly mean

Provided by R. He (NCSU)

(5) Ecosystem response to the physical drivers

(6) Probabilistic approaches and risk assessment in the coastal ocean, including extreme events

Probabilistic forecasting: Forecast the (qualified) likelihood of occurrence of events.Still in early development, but with increasing need, esp. for management and decision support – important for extreme events and preparedness for climate change.

Alternative to the “classical” deterministic approach:

- Account for uncertainty in a dynamical system by generating a representative sample of the possible future states;

- Address possible growth of small initial state errors (or model parameterization issues) to significant forecast inaccuracies in time: perform multiple runs with either realistic perturbations of the initial state, or with different models (or model formulations).

Advantages:

- good approach when data are scarce for model initialization/forcing/validation (common in coastal areas)- preferable practice for management, facilitates decision making and crisis management

Examples:

Coastal flooding and sea-level surges, surface drift forecasting, extreme events, …

UTILITY OF COASTAL SYSTEMS

sustainably manage coastal and ocean areas portray the ocean state today, next week and for the next decade increase shipping efficiency mitigate storm damage and flooding of coastal areas sustain fisheries and fish stocks protect important ecosystems from degradation help decision-making in times of crisis improve climate forecasting in response to global change

Surface Oil Hazard (> 1 kg/km2 probability of oil presence)

June average

Kourafalou et al. (2014)

Application example: Southern Adriatic Sea

Ship Line DistributionJune average

COSS-TT Topic 1 as a Focus Area for annual activities?

• Types of annual activities– Workshops: sharing experience and best practices– COFS System Information Table (SIT)– Web site with tools inventory– Special issues and review articles on key tools/methods

• Expected outcomes– Supporting the science behind the development of COFS worldwide– Objectively assess certain monitoring designs (such as SWOT)

• Investment– Scientific support of the development of COFS worldwide– Sharing the scientific advancements through international collaboration – Exchange of best practices / Capacity building– Reaching out to coastal modeling efforts worldwide– Disseminate novel methodologies and scientific advancements in support

of COFS in international forums– Visibility of GOV in international coastal community

COSS-TT Next year’s activities (draft) – 1

• GOV review– “Consistent with the GOV strategic plan, the challenges in this Task Team

[…] need to be prioritized by the ‘value add’ of collective action.”– “Focus should be on the interfaces between GOV systems and coastal

models and applications. ”

• Focus area A: Scientific support of the development of COFS and applications– Sept. 2015 Lisbon workshop science topics TBD (usually 2-3 targeted

science topics & 1 applications topic)– Lisbon workshop new systems review– Oc.Dyn. COSS Topical Collection (deadline Feb 2015, 32 ms. announced)

COSS-TTCOSS-TT

Strategy topic 2: Integration between COFS and GOV systems

COSS-TT Objectives of the Coastal Oceans and Shelf Seas Task Team

Mission Goal: Advance science in support of sustainable multidisciplinary downscaling and forecasting activities in the world coastal oceans.

Strategic goal: Help achieve a seamless framework from the global to the coastal/littoral scale.

Dual objectives as per current Work Plan:

• Establish community links between ongoing Coastal Ocean Forecasting Systems (COFS) in order to advance science in support of COFS

• Convene forums to discuss targeted science issues.

COSS-TT(Herzfeld, CSIRO)

(EuroSITES)

(IOOS)

“Downscaling”

• Scales refinement – of all information sources: model, observations, forcings(lateral, rivers, atmosphere)

• Additional processes wrt large-scale solutions

• Enhanced representativity of local obs, of local forcings and couplings

• Added value wrt large-scale solutions, for both science and applications

COSS-TT Downscaling methodologies

1. Dynamical downscaling – e.g.:– AGRIF (Blayo/Debreu, 2002): Adaptive mesh refinement (+ optional 2D

coupling), within same model– Two-way coupling LRHR (e.g. Vandenbulcke et al., 2006)– “Spectral nudging”of HR model towards LR scales (e.g. Garreau et al., 2013

shown at Lecce workshop), models can differ

2. (Purely) Statistical downscaling– Use predictors LRHR – several types (e.g. Hessami et al., 2004)

3. Dynamical downscaling with assimilation– Considers LR solution as an imperfect source of information, just as local

observations and forcings (lateral, rivers, atm)– Models can differ– Simultaneous use of local observations– Requires validated LR error estimates– Can be extended to use several large-scale solutions (super-ensembles).

(1 and 3 used to downscale COFS into LOFS)

COSS-TT Dynamical downscaling with DA in the French AMICO project

• Bay of Biscay 3D hydrodynamical model– S26– Period: 07/11-06/12– Enhanced bathymetry product (LEGOS)– FES2012 tidal product (LEGOS)

• Open BCs– MERCATOR IBI/BISCAY36: SSH,T,S,U,V– 100-member LR ensemble (MyOcean2)

• DA– EnKF– Assimilate local obs and LR model solution– LR ensemble provides LR error estimate

Provided by N. Ayoub and P. De Mey (LEGOS)

COSS-TT Integration between COFS and LOFS systems – subtopics

• Subtopic 2.1: Practical integration through downscaling

– Science/numerics: space-time resolution of large-scale products, obc, bathymetry, forcings, transients, tides, wave-current interactions, IGW…

– Downscaling methodology

– Obs-related: consistent quality control, consistent “zeroes” (e.g. steric)

– DA-related

– …

• Subtopic 2.2: Demonstrating the added-value of downscaling

– Suitability (what do we mean by that?) of GOV products for downscaling

– Consistent reference data sets and metrics

– Choice of target variables (e.g. surface currents)

– Trade-offs (e.g. increased instability/noise while resolution increases)

– …

COSS-TT Topic 2 as a Focus Area for annual activities?

• Types of annual activities– R&D (Strategy Topic 1: workshops, tools sharing, scientific articles)– Pilot downscaling case studies associating voluntary GOV groups and

Regional/Coastal OFS• To be first discussed here in Beijing! Who, when, where, funding?• Lisbon workshop: discuss proposals.

• Expected outcomes– Scientific prototypes of integrated COFS, towards seamless integration– Identification of R&D areas for COFS: guide COFS development and product

definition– Guide definition of LOFS service to regional/coastal OFS community

• Investment– Active collaboration of some GOV groups with some COSS groups– Flag financial support for regional Pilot case studies in regions of interest

for Patrons– Time + travel/money to attend COSS workshops

COSS-TT Next year’s activities (draft) – 2

• Focus Area B: Integration between COFS and GOV systems– Update list of ongoing downscaling activities from GOV LOFS

• Intra- or inter-agencies• Research-level or operational• SIT + GOV-wide survey

– Lisbon workshop dedicated session, GOV LOFS invited• How do LOFS validate and qualify their products to service regional/coastal

ics/bcs?• What are COFS expectations regarding LOFS solutions?• Downscaling strategies and good practices: frequencies, variables, methods,

modelling choices (detiding, bathymetry transients, atm pressure, etc.)• Consistent validation of COFS and LOFS – common validation datasets (phy/bio)• Select pilot activities with above components, identify supplementary resources

needed• Downscaling WP?

COSS-TTCOSS-TT

Strategy topic 3: Linking with the regional and coastal altimetry community

Courtesy M. Cirano, C. Reinert Bulhões de Morais, R. Parkinson, C. Dufau

Courtesy C. Dufau

Courtesy C. Dufau

Courtesy C. Dufau

Courtesy N. Picot, C. Dufau

The SWOT small scales challenge to COFS: Tidal front and internal tides in the Iroise Sea (Bay of Biscay)

SWOT SDT meeting, Toulouse, June 2014

Courtesy Marié et al.

SWOT SDT meeting, Toulouse, June 2014

The SWOT surface velocities estimation challenge: total vs. geostrophic currents over the shelf

Courtesy Vervatis, De Mey, Testut, Ayoub

NEMO- BISCAY 1/36° 100-member ensemble(LEGOS/MERCATOR-Océan - MyOcean)

PEVR%: Posterior Ensemble Variance Reduction – NEA EnKFsea level zonal velocity

Observational networks assessment metrics (2004)

Complementarity between WSOA and tide gauges

Courtesy Mourre, De Mey, Le Provost

69,9

70,0

49,9

63,2

36,3

43,9

54,3

53,6

50,8

45,2

36,4

21,2

26,8

24,8

12,6

18,4

15,4

13,3

19,0

18,8

14,0

9,6

6,6

16,9

05 10 15 20 25 30 35 40 45 50 55 60 65 70 75

WSOA 10d + 20 tide gauges - 6h

AltiKa3 + 20 tide gauges - 6h

20 tide gauges - 12h

20 tide gauges - 6h

WSOA 10d

AltiKa3 (time lag)

6 Jason

5 Jason

4 Jason

3 Jason

2 Jason

Jason

COSS-TT Topic 3 as a Focus Area for annual activities?

• COSS-CA link can be FA; alternately CA community can be one of the bodies that GOV is committed to engage on annual basis

• Types of annual activities– Cross-attendance at workshops (specific sessions)– Specific joint workshop “Altimetry for Coastal Ocean Forecasting” (one-time

or recurrent, next to COSS workshop) – Start in 2015? Help from TAPAS?• Expected outcomes

– Help answer strategy questions from patrons (ESA, CNES, NASA, etc.)• E.g. added value of SAR mode• Use some COFS as test-beds for CA products and planned missions (e.g. SWOT)

– Review added value of integration of CA data sets in some COFS (e.g. ATOBA); feedback to CA data providers

• Investment– No additional work investment or funding (include existing projects)– Anything beyond simple linking would require backing/funding by Patrons– Time + travel/money to attend COSS and CA workshops

COSS-TT Next year’s activities (draft) – 3

• Focus Area C (or external link): Linking with the regional and coastal altimetry community– CAW’2014 via C. Dufau– Proposal of 2-day joint COSS/TAPAS workshop (Lisbon?): “Altimetry for

Regional/Coastal Ocean Forecasting”• Would complement CAWs (more engineering/data processing-minded).

COSS-TTCOSS-TT

Links with other TTs

COSS Links with other TTs

TASK TEAM FOR OBSERVING SYSTEM EVALUATION (OSEVAL-TT) – (1)

TASK TEAM FOR MARINE ECOSYSTEMS ANALYSIS AND PREDICTION (MEAP-TT) – (2)

TASK TEAM FOR DATA ASSIMILATION TECHNIQUES (DAT-TT) TBC – (3)

Impact Assessment: how does the Horizontal Profile Resolution influence

SSH? (RMS error)

• Assimilate AXCTDs to 1000 m depth• 0.5º vs. 1.0º horizontal resolution

(1) REGIONAL OSSE SYSTEM EXAMPLE: Gulf of Mexico (evaluate airborne profiles)

Halliwell et al. (2014)

Idealized airborne survey patterns • 0.5º grid (all points) • 1.0º grid (large points

only)

Decreasing horizontal resolution has a large impact on RMS errors of SSH

Higher-resolution profiling corrects variability with small horizontal scales that are not well constrained by satellite altimetry.

Deny all synthetic profiles

1.0° resolution

0.5° resolution

(2) Biogeochemical prediction in the coastal seas

Uncoupled ecosystem models: process-oriented studies on biogeochemical cycles, nutrient fluxes and

pathways;understanding of the effects of eutrophication / hypoxia / harmful algal

blooms (HABs)

Coupled three-dimensional hydrodynamic-ecosystem models:simulate the biogeochemistry of coastal ecosystems but also advance

knowledge on ecosystem functioningaddress the response of the marine ecosystems to the variability of physical

forcing.help establish the critical climatological, seasonal and interannual aspects of

ecosystem variabilityexplore alternate states under different management scenarios

COSS-TT

Specifics of data assimilation in coastal and shelf seas – 1 With respect to large-scale DA:• Usually smaller space scales, faster

time scales• Coastal models are free-surface

models, frequent inclusion of tides and response to HF atmospheric forcing

• NL couplings between physical processes such as coastal mesoscale processes, slope currents, tidal currents, coastal upwellings, internal waves/tides, storm surges, waves, thermohaline circulation, river runoff, …

• Presence of open boundaries, need to control them

T

z

(3) Coastal Data Assimilation in the coastal seas

COSS-TT Specifics of data assimilation in coastal and shelf seas – 2

• Superimposed/simultaneous observation of the various processes • More observation types: coastal HF radars, tide gauges, moored buoys,

wide-swath altimetry; enhanced representativity of observations• The nesting within a larger-scale model requires a downscaling strategy

to add the smaller scales while using the nested constraints on the larger scales

• Errors tend to be non-homogeneous, non-stationary (lateral/atm forcings), non-local, 3D (to the contrary of open ocean)

COSS-TTCoastal HF DA: Impact of including the surface atmospheric variables in the state vector

Assimilate 10-tg networkobs freq: 1 hourassim freq: 12 hours

NRMSE(SLA)

NRMSE(Ub)

November, 1999

No atm controlControl ps

Control ps and t

Normalized rms error (<1)

Lamouroux and De Mey, LEGOS, 2006

COSS-TTCOSS-TT

Additional slides