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VANIMEDAT project : Decadal and interdecadal sea-level variability in the Mediterranean sea and northeastern Atlantic ocean. A. Pascual 1 , M. Marcos 2 , S. Ruiz 1 , D. Gomis 1 , S. Monserrat 1 , E. Alvarez 3 , B. Pérez 3 , M. G. Sotillo 3 , G. Larnicol 4 , M. N. Tsimplis 2 - PowerPoint PPT Presentation
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VANIMEDAT project:Decadal and interdecadal sea-level variability in the Mediterranean sea and northeastern Atlantic ocean
A. Pascual1, M. Marcos2, S. Ruiz1, D. Gomis1, S. Monserrat1, E. Alvarez3, B. Pérez3, M. G. Sotillo3, G. Larnicol4, M. N. Tsimplis2
e-mail: [email protected] IMEDEA (CSIC-UIB), Balears, SPAIN, 2 NOC, National Oceanographic Center, Southampton, UK3 Puertos del Estado, Madrid, SPAIN4 CLS Space Oceanography Division, Toulouse, FRANCE
1. Objectives of VANIMEDAT project
GENERAL OBJECTIVE: Study of decadal and interdecadal sea-level
variability in the seas surrounding the Iberian peninsula. (Project funded by the Spanish Ministry of Science and Education)
SPECIFIC OBJECTIVES:a) Characterization of the spatial and temporal sea-
level variability.b) Quantification, at a regional scale, of the different
mechanisms that drive sea-level variability.c) Estimation of ocean mass increase.
Tide gauge data: Hourly and monthly data. Period:(~1900-2006).Tides are filtered and atmospheric correction(IB/MOG2D/HAMSOM) is applied.
Barotropic sea level models: HAMSOMMOG2D
Baroclinic model: to be run in the framework of VANIMEDAT project.
2. Data and models
3. Preliminary results
GRACE GOCE
MODEL INTERCOMPARISON (1993-2001)
mean = 5.63 mm/yr mean = 2.90 mm/yr
Configuration of the barotropic
models.
SEA LEVEL TRENDS FROM ALTIMETRY
TIDE GAUGES VS ALTIMETRY (1993-2001)
4. Ongoing and future work
ZONE
HAMSOM
MOG2D
ALL 19.33 12.03ATL 27.64 5.83WMED
22.87 14.44
ADR 8.29 12.72
ZONE
HAMSOM
MOG2D
ALL 23.67 0.53ATL 33.21 3.24WMED
31.30 6.02
ADR 8.43 -9.95
ZONE
HAMSOM
MOG2D
ALL 19.10 22.28ATL 25.35 7.93WMED
28.1 33.98
ADR 0.69 13.38
mean = 5.39 mm/yr mean = 5.48 mm/yr
Barotropic sea level variance from each model.
HAMSOM
MOG2D
Ratio of variance reduction at tide gauges ([Var(TG-IB)-Var(TG-model)]/Var(TG-IB), in %, for all frequencies (left), LF (>20 days, centre) and HF (<20 days, right).
ZONE
HAMSOM(%)
MOG2D(%)
ALL 1.54 1.53ATL 17.42 3.11WMED
-0.79 0.63
ADR -6.69 1.89Left: Dubrovnik tide gauge (blue) and altimetry (red) time series corrected by HAMSOM (top) and MOG2D (bottom). Right: Ratio of variance reduction of the differences between altimetry and tide gauge ([Var(TG-alti)|model-Var(TG-alti)|]/Var(TG-alti)|IB.
HAMSOM MOG2DSpatial
Res.1/6º lat1/4º lon
20-200 km
Temp Res
1 h 6 h
Period 1958-2001
1993-present
Region Med/NEAtl GlobalAtmosph. Forcing
REMO (NCEP/NCAR)
6 h
ECMWF6 h
TIDE GAUGE VARIANCE REDUCTION (1993-2001)
ALTI_MOG2D 1993-2001
ALTI_MOG2D1993-2006
ALTI_HAMSOM
1993-2001
ALTI_IB1993-2001
MOG2D
HAMSOM
TP
Altimetry data: • Along-track processing:
Atmospheric correction: (IB/MOG2D/HAMSOM) Usual other corrections
• Objective analysis: Long wavelength error corrected. Weekly maps, 1/4º. Period: 1993-present
(Top) Position of gauges (hourly data) used for the comparison with altimetry.
Jason
ERS-1/2
ENVISAT
• Combination of tide gauge and altimetry data to reconstruct sea level in the last century.• Characterization of heat fluxes from REMO.• To run a baroclinic numerical model to extract the steric component. • Use of GRACE and GOCE data to extract the mass component.
