Dissemination products

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Dissemination requirements

Transmission of Products

The dissemination supports products which can be represented as fields of values of single parameters over a defined area. The data are represented in FM 92 GRIB code, and the optional bitmap section of GRIB is used to designate the land-sea mask, indicating which points are present and which are missing with respect to the total area.

Data are also available in the form of rectangular "hollow boxes" to provide boundary conditions for limited area models. Such products take the form of a strip of points around the boundary of a rectangular area; the width of the strip is specified as a number of points from the boundary. Where such points are land points, they are omitted. The bitmap section of such products indicates which values are present and which are missing with respect to the total area. Member States may also specify bitmaps of required points. These are modified according to the land-sea mask to generate products containing data restricted to the points requested, provided that such points are indeed sea points. Again, the resulting GRIB products will be accompanied by bitmap sections indicating which points contain data with respect to the total area.

Data are available at any multiple of the basic grid of the generating model and for any user-defined sub-area.

A new GRIB ECMWF local Code Table 2, version 140 is used for wave model data. The parameters supported are listed in the Table 6.1 below.

Table 6.1 (ECMWF GRIB Code table 2, version 140)

FIELD CODE	MARS ABBREV.	FIELD NAME	UNITS	NO. OF BITS/VAL.
215	UST	U-component stokes drift	m**s-1	16
216	VST	V-component stokes drift	m**s-1	16
220	MP1	Mean wave period based on first moment	s	16
221	MP2	Mean wave period based on second moment	s	16
222	WDW	Wave spectral directional width	-	16
223	P1WW	Mean wave period based on first moment for wind waves	s	16
224	P2WW	Mean wave period based on second moment for wind waves	s	16
225	DWWW	Wave spectral directional width for wind waves	-	16
226	P1PS	Mean wave period based on first moment for swell	s	16
227	P2PS	Mean wave period based on second moment for swell	s	16
228	DWPS	Wave spectral directional width for swell	-	16
229	SWH	Significant wave height	m	16
230	MWD	Mean wave direction	degree	16
231	PP1D	Peak period 1D-spectra	s	16
232	MWP	Mean wave period	s	16
233	CDWW	Coefficient of drag with waves Significant	-	16
234	SHWW	Height of wind waves	m	16
235	MDWW	Mean direction of wind waves	degree	16
236	MPWW	Mean period of wind waves	s	16
237	SHTS	Significant height of total swell	m	16
238	MDTS	Mean direction of total swell	degree	16
239	MPTS	Mean period of total swell	s	16
244	MSQS	Mean Square Slope	-	16
245	WIND	10 Meter Wind Speed	m/s	16
246	AWH	Altimeter wave height	m	16
247	ACWH	Altimeter corrected wave height	m	16
248	ARRC	Altimeter range relative correction	-	16
251	2DFD	2 Dimensional spectra	m2srad-1	16
252	WSK	Wave spectral kurtosis	-	16
253	BFI	Benjamin-Feir index	-	16
254	WSP	Wave spectral peakedness	s**-1	16

The two-dimensional wave spectra field is available with the same combinations of resolution, sub-area, box boundaries, and bit-map selected points as for other wave data.

Global Wave Model products

Parameters available in dissemination are listed in the Table 6.1.

Horizontal resolution

- 0.25 x 0.25 degrees latitude-longitude grid, or multiples thereof

- any sub-area

Verifying times

- T+0 to T+144 at 3 hour interval

- T+150 to T+240 at 6 hour interval

- 2-D spectra field is available from T+0 to T+120 at 6 hour interval

The two-dimensional wave spectra field is available for 36 frequencies starting at 0.0345 Hz with 10% increments, and for 36 directions with 10 degree separation, at each point, where the first direction starts at 5 degrees (all information about the spectral discretisation is available in the grid headers)

Mediterranean/Baltic Wave Model products

Mediterranean/Baltic wave forecast model covers the area 900 North/980 West/90 North/420 East. The part of the land-sea mask used by the model is plotted on the Figure 1.3. Parameters available in dissemination are listed in the Table 6.1.

Horizontal resolution

- 0.125 x 0.125 degrees latitude-longitude grid, or multiples thereof

- any sub-area

Verifying times

- T+0 to T+120 at 6 hour interval

- 2-D spectra field is available from T+0 to T+120 at 6 hour interval

The two-dimensional wave spectra field is available for 36 frequencies starting at 0.04177 Hz with 10% increments, and for 36 directions with 10 degree separation, at each point, where the first direction starts at 5 degrees (all information about the spectral discretisation is available in the grid headers)

18-01-2011