Upload
giacomo-watts
View
30
Download
0
Tags:
Embed Size (px)
DESCRIPTION
AMEN (NATL4 + AGRIF) A tlantic M ode water E xperiment using N emo/Agrif. Virginie Thierry, Sébastien Theetten, Jean-Marc Molines, Anne-Marie Tréguier, Carole Grit Drakkar Team, Nemo team, Agrif Team. Scientific Objectives. - PowerPoint PPT Presentation
Citation preview
25-26 January 2007 Drakkar Meeting - Grenoble
AMEN AMEN (NATL4 + AGRIF)(NATL4 + AGRIF)
AAtlantictlantic M Modeode waterwater E Experimentxperiment using using NNemo/Agrifemo/Agrif
Virginie Thierry, Sébastien Theetten, Jean-Marc Molines, Anne-Marie Tréguier,
Carole GritDrakkar Team, Nemo team, Agrif Team
25-26 January 2007 Drakkar Meeting - Grenoble
Scientific Objectives
Study mode water in the North-East Atlantic: formation, properties, subduction and variability
Identify formation area
Understand mechanisms that setup its properties
Determine the link between NAO index or other atmospheric indexes and mode water properties
Investigate the way mode water ventilates the ocean interior
Evaluate the ability of Drakkar model configurations to simulate correctly water masses and mode water in the eastern part of the North-Atlantic
25-26 January 2007 Drakkar Meeting - Grenoble
AMEN model configuration
AMEN : refinement in NATL4 in the North-East Atlantic NATL4: Atlantic ocean, 20°S-80°N Agrif zoom : 30°W-0°E, 31°N-55°N
25-26 January 2007 Drakkar Meeting - Grenoble
AMEN model configuration
• NATL4: ¼° resolution, eddy permitting, sea ice, closed boundaries, 486x529x64 grid points, time step: 2400S,
• Agrif zoom: 1/12°, eddy resolving, 383x397x64 grid points , time step: 720S,
• 64 grid points on the vertical:
– 36 levels within the first 1000 m, 6m at the surface, 50m at 500 m, 200 m at 5900 m
– Agreement with the NOC
• Bathymetry in Agrif zoom
– Identical to Mercator NATL12 bathymetry (for validation, exchanges purposes)
25-26 January 2007 Drakkar Meeting - Grenoble
AGRIF validation
►SALINITY
25-26 January 2007 Drakkar Meeting - Grenoble
AGRIF validation
Annual mean of EKE averaged along the western boundary
Low-resolution grid
High-resolution grid
25-26 January 2007 Drakkar Meeting - Grenoble
AGRIF validation
Annual mean of EKE averaged along the southern and northern boundary
Low-resolution grid
High-resolution grid
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
18°W – 44°NJuly 2001
Identify by PV < 6 10-11 m-1 s-1
Example of profile containing mode water
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
Density of the mode water core
1991 2001
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
Potential temperature of the mode water core
1991 2001
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
T/S diagram in the POMME area
In the POMME area, central water are fresher in ORCA025 than in the data
ORCA 1993 / ORCA 2000 / POMMEORCA 1993 / ORCA 2000 / POMME
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
Time series of the mode water properties at 18°W-44°N
Over the period 1991-2001, the mode water is getting warmer, saltier, lighter
Consistent with the observed warming of the cental water in the Bay of Biscay over 1992-2003 (Gonzalez-Pola et al 2005)
25-26 January 2007 Drakkar Meeting - Grenoble
Workplan2007• Finalize the configuration and run the simulation
– Resolve med water problem !• Validate the simulation with the large data set available in the area:
POMME, OVIDE, ARGO and historical data• Investigate mode water properties variability in using the model and
the data and mechanisms of this variability• Comparison with ORCA025-G70
2008• Use the Lagrangian tool Ariane to determine formation area,
ventilation area and ventilation processes• Comparison with NATL12• …
25-26 January 2007 Drakkar Meeting - Grenoble
Questions
• What forcing field shall we use ?
• The target period is 1980-2006
– Large data set in the 80’s (see J. Paillet thesis)
– Woce data in the 90’s
– POMME: 2000-2001
– OVIDE: 2002, 2004, 2006
25-26 January 2007 Drakkar Meeting - Grenoble
Thank you
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
Salinity of the mode water core
1991 2001
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
Potential vorticity of the mode water core
1991 2001
25-26 January 2007 Drakkar Meeting - Grenoble
Mode water in ORCA025-G70
Thickness of the mode water layer
1991 2001