Overview of Mercator Ocean Cal/Val activities

1
Overview of Mercator Ocean Cal/Val activities

1. Operational assessment of the real time Mercator
   ocean analyses and forecast
2. Scientific qualification of the systems and
   qualification of reanalyses products
3. Trace the history of the quality of the
   production systems
4. RD validation targeted studies

2
1. Operational assessment of the real-time
mercator ocean analyses and forecasts

• Verbrugge Nathalie2, Pene Nicolas2, Greiner
  Eric2, Drévillon Marie1, Lellouche Jean-Michel1,
  Benkiran Mounir2, Hernandez Fabrice1, Nouel
  Lucas1, Vinay Gaëtan1
• 1 Mercator-Ocean, Toulouse, France
• 2 CLS, Toulouse, France

3
Real-time Mercator-Ocean products

• Since April 2008, Mercator runs a global ocean
  configuration at ¼ horizontal resolution and a
  North Atlantic and Mediterranean zoom at 1/12.
• The real time operation of these systems produces
  each week realistic 3-dimensional oceanic
  conditions including a hindcast and forecast.
• Moreover, the regional zoom is operated daily to
  produce 7 day forecast with daily updates of the
  atmospheric ECMWF forcing.
• To fulfil the operational assessment of the
  quality of the system outputs, more than 1300
  graphics per week are produced and visualised by
  an team of operators through web pages. A
  step-by-step document guides them through the
  validation process. It contains expected nominal
  values, description of oceanographic
  structures/water masses

4
Assimilation performance

• The assimilation performance is monitored in the
  observations space (in situ Coriolis profiles, ½
  SST RTG, and altimeters) and the delivery quality
  of the input data sets is supervised.

5
Calibration/Validation procedure

• Before the distribution of its real-time
  products, Mercator-Ocean checks the quality with
  a Calibration/Validation procedure. This
  assessment procedure is operated automatically
• Outputs are compared to independent observations
  (Cersat Sea Ice concentration and drifts, Odyssea
  High resolution SST, Coriolis drifters, T/S
  climatology, historical data sets).
• Hindcast, nowcast and forecasts are
  inter-compared to check the consistency of the
  production.
• Some MERSEA metrics (mooring points and 2D
  oceanic sections) are also used.

6
Comparisons of zonal velocities with some
drifters from the CORIOLIS Database
Drifters vs ¼ Hindcast Global system 2D map
and dispersion diagram
Drifters vs SURCOUF
SURCOUF CLS analysed gridded velocity products
from altimetry and drifters
7
Sea Ice
Cersat Sea Ice Concentration
Hindcast Sea Ice Concentration from ¼ Global
system
28-05-2008
8
Work in progress

• Qualification of meso scale processes
• Qualification of nesting zones
• Qualification of biological variables
• Qualification of IBI system for coastal
  downstream applications
• Routine intercomparisons of systems
  (quality/performance)

Charly régnier1, Bruno Levier1, Abdelali El
Moussaoui1, Claire Maraldi2, Fabrice
Hernandez1 1. Mercator-Ocean 2. Mercator/LEGOS
9
2. Qualification of reanalysis products example
of GLORYS1V1

• Nicolas Ferry1, Laurent parent1, Eric Greiner2,
  Marie Drévillon1, Elisabeth Rémy3
• 1 Mercator-Ocean, Toulouse, France
• 2 CLS, Toulouse, France
• 3 CERFACS, Toulouse, France

10
Scientific qualification process

• Check at least over a one year experiment
• the statistics
• Data assimilation statistics (mainly misfit
  average and RMS)
• Comparisons with independent data (drifters, tide
  gauges)
• Etc
• The physics
• Seasonal and interannual signals
• High frequencies and analysis jumps
• Equatorial waves
• Volume transports
• Etc..
• Try to analyze
• The systematic biases
• The modes and tendencies

11
SLA assimilation scores
12
In situ average innovations/residuals
GLORYS
PSY3V2R2

• Example SSS in 2007
• Real time data for PSY3V2R2
• reprocessed data for GLORYS

13
Processes example convection in the Labrador Sea
Same diagnostic in GLORYS
Seasonal-to-interannual development of potential
temperature () in the central Labrador Sea
(Figure from Enhanced production of Labrador Sea
Water in 2008, Igor Yashayaev and John W. Loder,
GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L01606,
doi10.1029/2008GL036162, 2009).
14
Ideas for routine monitoring of the GOOS

• Edit a quartely bulletin including
• Black lists, grey lists
• Record of data status
• Record of geographical gaps
• Sensitivity studies in reanalysis mode (see
  Elisabeth Remy in session 3)

15
3. Trace the history of the quality of the
production system - quarterly bulletin (in
progress)4. RD validation targeted studies -
process studies - OSE/OSSE etc