MyOcean2 First Annual Meeting – 17-18 April 2013

WP 12

THEMATIC & ASSEMBLYCENTRE for Sea Level

MyOcean2 First Annual Meeting – Cork /16-17 April 2013

Work Package Main Objectives

MyOcean2 First Annual Meeting – 17-18 April 2013

Scientific objectives are Improve the quality of current SL TAC products (along track products, gridded

products) thanks to the feedbacks coming from MyOcean Users (external , intenal) and from WP17 (calval) & WP18 (multiyear assessment) activities

Finalize the development of new products. New generation for assimilation (TAPAS). Collaboration with MFCs needed

Technical objectives are Improve and consolidate the processing chains (both for NRT and DT/REP

products) New version of the system more configurable to manage global and regional

processing

Operational objectives are Continue to operate the system with integration of evolution (new algo, new

products) Handle the constellation events, new missions (AltiKa, Sentinel-3, Jason3) Improve the product latency Do and enrich the Service to EEA (new climate indicators)

Partnership

MyOcean2 First Annual Meeting – 17-18 April 2013

Coordination CLS

CLS IMEDEA DTU LEGOS

Development Maintenance

Operation

System Engineering

Service

Cal/Val

R&D

Cal/Val Cal/Val Cal/Val

R&D R&D R&D

19981998…… …….2012…From the idea to the transition to operations

System Evolution

10 versions of the system installed

between V2 and V3

System Evolution

MyOcean2 First Annual Meeting – 17-18 April 2013

Objectives were New version of the system more configurable to manage global and

regional processing

Main achievements are System entirely redeveloped (python). Big effort done this year Day to day management of the constellation changes

Constellation is getting old=> requires effort to maintain the level of quality

Main difficulties encountered Visualisation of Sea Level products (along track) is not possible today.

This should be possible in V4 Difficult to manage main Myocean Version (3&4) and the daily constraints

(constellation)

J1N

March/April 2012: loss of EnvisatJason-1 gap

March/April 2013: Jason-1 gap (15 days)Jason-2 gap (12 days)Þ No reference mission early april

Cryosat

Jason-2

Jason-1 Geodetic

Impact on SL-TAC products quality: Error increase

Envisat

System Evolution

Error (% of variance)

Mean Contribution (%)

June 2012

February 2013

The SL-TAC product quality depends on the health of the altimetry constellation.The constellation is getting old: Jason-1 is 12 yr old, Jason-2 had its first unavailibility this

month after almost five years of operationWe are very lucky to have Cryosat-2 in the system

Success story Myo1

SLA measured by Cryosat-2 in the Arctic region during the historical minimum of sea ice coverage on the 15th septembre 2012

Gridded SLA map computed from Jason-1 & 2

Along track SLA data from Cryosat (CNES processor)

Sea ice boundary from Myocean

Cryosat-2 integration was one of the sucess story of Myocean-1

Jason-2/ HY2A SLA map (demo)Legeais et al 2012

System Evolution

• New satellites have to be used

• Altika has been launched on 25th of February this year. Currently in Calval phase. It will be integrated in the DUACS/SL-TAC system in the 2nd half of the year

• HY2A has the technical capability of measuring good Sea Level (payload). Preliminary assessment has proved the interest of these data. Fine assessment of the product still in progress.

=>Sentinel-3 is needed ! Importance of Myocean interface/coordination with space component (Level 2)

System Evolution

MyOcean2 First Annual Meeting – 17-18 April 2013

Objectives were New version of the system

Main achievements are System entirely redeveloped (python) more configurable to manage

global and regional processing Management of the constellation changes

Constellation is getting old=> requires effort to maintain the level of quality

Main difficulties encountered Visualisation of Sea Level products (along track) is not possible today.

This should be possible in V4 Difficult to manage main Myocean Version (3&4) and the daily constraints

(constellation)

Production Evolution

MyOcean2 First Annual Meeting – 17-18 April 2013

Objectives were Improve SL products and develop innovative products

Main achievements are Increase of the delivery rate: Since Feb 2013, The SLTAC process “on

the fly” the altimetry products and thus deliver new products every 1 hours => Up to 24h of additional data depending on the running time start of the model available for global product for J1and J2 (C2 coming soon)

Definition of the Tapas products Preparation of the Reprocessing activity Provision of Mean Sea Level trend to EEA for the European region

Main difficulties encountered DGF parametrization for “on the fly” products Manage users from AVISO/Myocean: we have to handle users from both

sides

1 day ago today

Assimilation system

21 days ago 2 days ago

Near Real time DUACS processing Real time processing

Daily delivery Delivery every 1H

=> Up to 24h of additional data depending on the running time start of the model

V3 « On the fly » processing available since February

Production Evolution

Production Evolution

MyOcean2 First Annual Meeting – 17-18 April 2013

Objectives were Improve SL products and develop innovative products

Main achievements are Increase of the delivery rate: Since Feb 2013, The SLTAC process “on

the fly” the altimetry products and thus deliver new products every 1 hours => Up to 24h of additional data depending on the running time start of the model available for global product for J1and J2 (C2 coming soon)

Definition of the Tapas products (foreseen for June) Preparation of the Reprocessing activity Provision of Mean Sea Level trend to EEA for the European region

Main difficulties encountered DGF parametrization for “on the fly” products Manage users from AVISO/Myocean: we have to handle users from both

sides

Production Evolution

TAPAS Experiment• Tailored Product for Assimilation• 2nd workshop in June in Barcelona

-0.4 0.40.0 0.4

Mean salinity misfit (psu)RMS salinity misfit (psu)

Model/Insitu Misfit with assimilation of conventional product

Model/Insitu Misfit with assimilation of TAPAS product - no filter and not corrected from atmospheric effect (DAC)

• Performance of Tapas products have been estimated using the regional IBI Mercator model

Better consistency between the model and in situ data for salinity => promising resultOperational delivery of Tapas product for Med MFC foresee mid 2013

Conventional altimetry limitation

• All existing altimeters present high spectral energy below 100 km which is explained by the large LRM footprint

• At 70km error represent 50% of the signal energy (spatial limit)

SAR processing is very promising

• Cryosat-2 measures some specific regions in SAR mode => we observe clean SSHA spectrum down to 50 km and spatial limit seems to be close to 30 km

• SAR processing is very promising to improve the along track resolution of altimetry products and pave the way for high resolution altimetry (Sentinel 3)

50 km 30 km

Theorical Linear energy decrease

Production EvolutionSLA Spectrum (m2.km) using high rate altimetry data (20Hz) over a small Pacific area (From Boy et al 2012)

103 102 10 1 10-1

km

Jason-2 LRMCryosat-2 SAR

100 km

Production Evolution

MyOcean2 First Annual Meeting – 17-18 April 2013

Objectives were Improve the data latency

Main achievements are Increase of the delivery rate: Since Feb 2013, The SLTAC process “on

the fly” the altimetry products and thus deliver new products every 1 hours => Up to 24h of additional data depending on the running time start of the model available for global product for J1and J2 (C2 coming soon)

Definition of the Tapas products Preparation of the Reprocessing activity (foreseen for V4) Provision of Mean Sea Level trend to EEA for the European region

Main difficulties encountered DGF parametrization for “on the fly” products Manage users from AVISO/Myocean: we have to handle users from both

sides

A 20 year period precise altimetry time series: more than 60 years of cumulated data from 10 sensors

New altimeters standards : New GDR ESA & CNES reprocessing (ENVISAT GDR2.1, Jason-2 GDR-D, REAPER…)

Improvement of the mapping technic New merging tuning : Better continuity between missions, new filtering

wavelenght for along-track data, new correlation scales

MyOcean2 First Annual Meeting – 17-18 April 2013

SLA contours and ocean color on 20/11/2011

Production Evolution

The eddies are better reproduced with the new version of the correlation scales

A 20 year period precise altimetry time series: more than 60 years of cumulated data from 10 sensors

New altimeters standards : New GDR ESA & CNES reprocessing (ENVISAT GDR2.1, Jason-2 GDR-D, REAPER…)

Improvement of the mapping technic New merging tuning : Better continuity between missions, new filtering

wavelenght for along-track data, new correlation scales 2 –steps mapping and bathymetry constraint

MyOcean2 First Annual Meeting – 17-18 April 2013

Production Evolution

Wavenumber spectral slopes obtained from the new satellite-derived fields reveal a more realistic cascade of eddy energy.

From Escudier et

al 2012

Along track

Grid

Grid HR

Grid HR+ Bathy

New reference priod : SLA, MSS and MDT referenced to the [1993,2012] period instead of current [1993, 1999] period.

Fig: SLA along a meridional section crossing the the Kuroshio in December 2011. The reference change will impact the mean of the

SLA at regional scales

Changing the reference period can modify the SLA instantaneous signature of the specifics structures of the global surface circulation. It does not modify the Absolute Dynamic Topography.

20-y reference [1993, 2012]7-y reference [1993,1999]3-y reference [1993,1995]

cm

Production Evolution

Production Evolution

MyOcean2 First Annual Meeting – 17-18 April 2013

Objectives were Improve the data latency

Main achievements are Increase of the delivery rate: Since Feb 2013, The SLTAC process “on

the fly” the altimetry products and thus deliver new products every 1 hours => Up to 24h of additional data depending on the running time start of the model available for global product for J1and J2 (C2 coming soon)

Definition of the Tapas products Preparation of the Reprocessing activity Provision of Mean Sea Level trend (SPC) to EEA for the European region

Main difficulties encountered DGF parametrization for “on the fly” products Manage users from AVISO/Myocean: we have to handle users from both

sides

Products assessment Assessment of SL TAC regional products

Focus on Arctic and Mediterranean sea

Development of new diagnosis to assess Sea level product performances Developpment of Lagrangian algorithm

Exemple of Finite size Lyapounov Exponents (FSLE) maps computed from Global and regional altimetry data

for the January 2003 Navidad event (From

Dussurget et al)

First period summary and next steps

MyOcean2 First Annual Meeting – 17-18 April 2013

Several improvement for SL TAC system and product New system allowing a better latency of the product Big work in the management of the constellation events Definition of new Tapas products that will fullfill the MFC need

Good perspectives in the near future Integration of Altika data in the system (and maybe HY2A) A New generation of product in V4 A complete reprocessing of the entire altimetry series (20 years) in

V4

Nex steps: toward high resolution altimetry SAR altimetry data seems to have the potential to detect small scale structures

(30 to 50 km) on instantaneous observations Work has to continue to prepare future missions (Sentinel-3 and Jason-CS)

END

MyOcean2 First Annual Meeting – 17-18 April 2013