MERCATOR OCEAN JOURNA: 
SEPTEMBER 2021 
3. The IBI-MFC wave forecast/analysis/reanalysis 
component: 
The IBI-MFC provides a short term (10-days) high- 
resolution wave forecast product for the IBI area. The IBI 
Wave system, based on the MF-WAM model, is today run 
twice-a-day on a 1/20° grid, forced with the ECMWF hourly 
wind data. The system assimilates significant wave height 
(SWH) altimeter data, and it is off-line coupled with surface 
currents provided by the IBI NRT ocean forecasts system. 
The IBI WAV NRT forecast product, in operations since 
December 2016, has been continuously upgraded with: 
evolution of the model application (MFWAM model 
upgraded in March 2019), 
-enhancement of horizontal resolution (from the 
ariginal 1/10° to 1/20°, changed in December 2019) 
and extension of forecast horizon (up to 10 days 
ahead since December 2020), 
Iimprovements of bathymetry and atmospheric forcing 
{since December 2019 using hourly winds, instead of 
the original 3-hourly ones). 
The first IBI WAV analysis product was delivered in July 
2020, with applied the data assimilation of SWH altimetric 
observations. Finally, IBI-MFC has made progress on the 
wave-ocean coupling of their NRT PHY and WAV forecast 
products. Thus, the impact of surface currents on waves 
Was activated in July 2020, whereas the wave contributions 
(Stokes drift and stress modification) in the IBI forecasted 
5cean currents was included later, in December 2020. 
The IBI wave forecasts are reliable and accurate, and the 
product quality, as well as the potential enhancements, 
are assessed by comparing IBI wave outputs (for 
significant wave height, mean period and wave direction) 
to observations, from both in-situ moorings and satellite 
remote sensed products (Toledano et al., 2021). Figure 3 
shows an example of accuracy level of the IBI WAV NRT 
product when compared with the independent (non 
assimilated) HY2A altimetric observations. 
a) BI NRT WAV Validation {comparison with HY2A SWH (2014-2019)}) 
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b) 1BI MY WAV Validation (comparison with in-situ observations) 
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‚igure 3: Top panels: Validation of IBI WAV NRT forecast product for SWH with the (non-assimilated) HY2A SWH Altimetry observations (Maps 
of scatter index and bias, together with a scatter plot are shown). Bottom panels: Validation of IBI WAV MY reanalysis product with in-sitı 
ıbservations: SWH RMSD at moored buoys; Taylor diagram showing comparison of the present IBI MY product (currently delivered through 
che Copernicus Marine Service cataloaue) and the previous IBI wave reanalysis product released.