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Space varying wind and pressure input files (meteofiles)

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At present, for different wind meteo input files, different headers are used, which are read in different ways in the sourcecodesource code. Some effeort effort has been put to in making the files more self-descriptive, readible readable and to make the input of the different files more consistent. For three four wind-input options, a suggestion to standardise the headers is shown below. The suggestion is conform a possible transition to NetCDF format in the future. See NetCDF standard names for more information on the used standard NetCDF names. For Pseudo ArcInfo wind, wind meteo on the FLOW grid, meteo on an equidistant (rectilinear or spherical) grid, meteo on a separate curvi-linear curvilinear grid and Spiderweb wind three meteo on a Spiderweb grid, examples of input files are shown below.

• Keywords are case INsensitive.
• Comments are indicated by a #

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• .
• The keyword FileVersion (= 1.02) must be the first keyword, the order of the other keywords is free to choose.
• The pressure correction on boundaries using Paver and Pcorr, which used to be prescribed in the air pressure meteo file, has been moved to the MD-File. The correction is specified using the keyword:
  PavBnd (P average on Boundaries). This average pressure is applied on all boundaries to reduce pressure gradients there. The average pressure needs to be specified in Pascals.

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• Meteo on the FLOW grid:
  For meteo on the FLOW grid, the wind velocities and air pressure are specified in 1 file, using the keyword:
  Filwnd

Code Block
### START OF HEADER ### This file is created by Deltares FileVersion = 1.02

• Pseudo ArcInfo wind:

Code Block

### START OF HEADER ### This file is created by Deltares ### Additional commments meteotype = arcinfo # Type of meteo input file: curvi, arcinfo or spiderweb NODATA_value = -999.000 # Value used for undefined or missing data n_cols = 400 # Number of columns used for wind datafield n_rows = 16 # Version of meteo input file, to check if the newest file format is used filetype = meteo_on_flow_grid # Number of rows used for wind datafield grid_unit = degree # Type of meteo input file: meteo_on_flow_grid, meteo_on_equidistant_grid, meteo_on_curvilinear_grid or meteo_on_spiderweb_grid NODATA_value = -9.9900000E+02 # Unit of distances on the grid in both x- and y-direction #grid_unit # Value used for undefined =or missing mdata xn_llcornerquantity = -12.0003 # Xcoordinate of lower left corner of# gridNumber (inof unitsquantities specifiedprescribed in grid_unit) y_llcornerthe file quantity1 = 48.000x_wind # YcoordinateName of lowerquantity1 quantity2 left corner of grid (in= units specified in grid_unit) value_posy_wind = centre # Name of quantity2 quantity3 #= Location where the dataair_pressure is specified in a cell (centre or corner) #value_pos = corner # Name of quantity3 dxunit1 = = m s-1 0.12500 # GridUnit dimensions: dx and dy (in units specified in grid_unit) dyof quantity1 unit2 = m s-1 = 0.083333333 # Unit of n_quantityquantity2 unit3 = = 3 mbar # NumberUnit of quantitiesquantity3 ### prescribedEND inOF the fileHEADER quantity1TIME = 0 minutes =since 2008-01-08 00:00:00 x_wind+00:00 # Fixed format: <time> <time unit> "since" <date> <time> <time zone> 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 # Name0.0000000E+00 of quantity1 #quantity1 = y_wind # Name of quantity1 #quantity1 = air_pressure # Name of quantity1 unit1 = m s-1 0.0000000E+00 -9.9900000E+02 -9.9900000E+02 -8.6049000E+00 -1.0240000E+01 -5.4150000E+00 -1.8900000E+00 -2.9040000E+00 -9.9900000E+02 -9.9900000E+02 -9.9900000E+02 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 -1.0000000E+01 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 1.0000000E+03 TIME = 660 minutes since 2008-01-08 00:00:00 +00:00 # Fixed format: <time> <time unit> "since" <date> <time> <time zone> 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 0.0000000E+00 -9.9900000E+02 -9.9900000E+02 -2.3290000E+00 -9.0440000E+00 -1.3230000E+01 -8.3310000E+00 -6.9210000E+00 -9.9900000E+02 -9.9900000E+02 -9.9900000E+02 -1.0000000E+01 -1.1000000E+01 -1.2000000E+01 -1.5000000E+01 -1.8000000E+01 -1.4000000E+01 -1.2000000E+01 -0.8000000E+01 -1.2000000E+01 -1.6000000E+01 -1.2000000E+01 -1.0000000E+01 -0.7000000E+01 -0.4000000E+01 0.0000000E+00 -0.3000000E+01 1.0130000E+03 1.0140000E+03 1.0140000E+03 1.0160000E+03 1.0120000E+03 1.0120000E+03 1.0180000E+03 1.0200000E+03 1.0160000E+03 1.0140000E+03 1.0110000E+03 1.0130000E+03 1.0110000E+03 1.0180000E+03 1.0150000E+03 1.0130000E+03

• Meteo on an equidistant grid:
  For meteo on an equidistant grid, the wind velocities and air pressure are specified in 3 separate files using the keywords:
  Filwu
  Filwv
  Filwp
  and Filwr, Filwt, Filwc for relative humidity, air temperature and cloudiness respectively.

Code Block

### START OF HEADER ### This file is created by Deltares ### All text on a line behind the first # is parsed as commentary ### Additional commments FileVersion = 1.02 # Version of meteo input file, to check if the newest file format is used filetype = meteo_on_equidistant_grid # Type of meteo input file: meteo_on_flow_grid, meteo_on_equidistant_grid, meteo_on_curvilinear_grid or meteo_on_spiderweb_grid NODATA_value = -9999# Unit of quantity1 #unit1 = Pa # Unit of quantity1 ### END OF HEADER TIME = 0 minutes since 2007-10-08 15:24:00 -02:00 # Fixed format: time unit since date time time difference (time zone) 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 155.0000 346.2500 357.5000 8.750000 20.00000 31.25000 42.50000 53.75000 65.00000 76.25000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 time # Value =used for undefined 1440or minutes since 2007-10-08 15:24:00 -02:00missing data n_cols # Fixed= format: time unit since400 date time time difference (time zone) 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 # 2.435253Number of columns used for wind 2.435253datafield n_rows 2.435253 = 2.43525316 65.01978 75.11859 85.25320 95.45370 105.7529 116.1833 126.7762 # Number of rows 137.5612used for wind datafield grid_unit 148.5649 = 159.8090 degree 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544# Unit of distances on the grid 5298.544in both x- and y-direction: m 5298.544or degree x_llcorner 5298.544=

• Wind on a separate curvi-linear grid:

Code Block

### START OF HEADER ### This file is created by Deltares ### Additional commments meteotype-12.000 = curvi # Xcoordinate of lower left corner of grid (in units specified in grid_unit) y_llcorner = 48.000 # Type of meteo input file: curvi, arcinfo or spiderweb NODATA_value = -999.000 # Ycoordinate of lower left corner of grid (in units specified in grid_unit) value_pos # = Value usedcentre for undefined or missing data curvi_grid_file = hirlam.grd # Coordinates given in centre or corner #of Separate (curvi-linear) grid on which the wind can be specified first_data_value = grid_llcorner lower left cell? dx = 0.12500 # Options: grid_llcorner, grid_ul_corner, grid_lrcorner or grid_urcorner data_row # Grid dimensions: dx and dy =(in units specified in grid_rowunit) dy = 0.083333333 # Options: grid_row or grid_col. For switching rows and columns. n_quantity = 1 # Number of quantities prescribed in the file quantity1 = x_wind # Name of quantity1 #quantity1 (x_wind, y_wind or air_pressure) unit1 = y_wind m s-1 # NameUnit of quantity1 #quantity1 (m s-1 for velocities or Pa/mbar for = air_pressure) ### END OF HEADER TIME = 0 minutes since 2007-10-08 15:24:00 -02:00 # Fixed format: <time> <time # Name of quantity1 unit1 unit> "since" <date> <time> <time zone> 1.388999 1.388999 = m s-1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 # Unit of quantity1 #unit11.388999 2.388999 2.388999 = Pa 2.388999 2.388999 2.388999 2.388999 2.388999 2.388999 2.388999 # Unit2.388999 of quantity1 ### END OF HEADER TIME 3.388999 3.388999 = 3.388999 0 hours since 2006-01-01 00:00:00 -06:00 3.388999 3.388999 # Fixed format: time unit since date time time difference (time zone) 1 3.388999 3.388999 13.388999 13.388999 13.388999 TIME 1.388999 1.388999 = 1440 1.388999minutes since 2007-10-08 15:24:00 -02:00 1.388999 # Fixed 1.388999format: <time> <time unit> "since" <date> <time> 1.388999 <time zone> 1552.0000435253 3462.2500435253 3575.5000435253 81.750000435253 203.00000435253 314.25000435253 422.50000435253 532.75000557653 652.00000412253 762.25000435255 53001.000435253 53002.000435253 53001.000435253 53002.000435253 53001.000435253 53002.000435253 53001.000435253 53001.000435253 53002.000435253 53001.000435251 TIME 4.435253 4.435253 = 1.435253 1440 hours since 2006-01-01 00:00:00 -06:00 3.355253 3.456253 # Fixed format: time unit5.425253 since date time time difference (time zone) 2.435253 1.223453 25.435253523341 25.435253521246 23.435253255258 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 65.01978 75.11859 85.25320 95.45370 105.7529 116.1833

• Explanation of the data to grid conversion for meteo on an equidistant grid

For meteo on an equidistant grid the orientation of the data is the same as the grid (visually). The first data value is thus located at the grid at (1,nmax). A line is then read as a row on the grid and the second line in the dataset is row nmax-1 on the grid. See also figure 1.

Image Added
Figure 1: Data to grid conversion for meteo on an equidistant grid.

• Meteo on a separate curvilinear grid:
  For meteo on a separate curvilinear grid, the wind velocities and air pressure are specified in 3 separate files using the keywords:
  Fwndgu
  Fwndgv
  Fwndgp
  and Fwndgr, Fwndgt, Fwndgc for relative humidity, air temperature and cloudiness respectively.

Code Block

### START OF HEADER ### This file is created by Deltares ### All text on a line behind the first # is parsed as commentary ### Additional commments FileVersion = 1.02 126.7762 137.5612 148.5649 159.8090 5298.544 5298.544# Version of meteo input file, to 5298.544check if the newest file format 5298.544is used filetype 5298.544 = 5298.544meteo_on_curvilinear_grid 5298.544 5298.544 5298.544 # Type 5298.544of meteo input

• Spiderweb wind:

Code Block

### START OF HEADER ### This file is created by Deltares ### Additional commments meteotype = spiderwebfile: meteo_on_flow_grid, meteo_on_equidistant_grid, meteo_on_curvilinear_grid or meteo_on_spiderweb_grid NODATA_value = -999.999 # Value used for undefined or # Type of meteo input file: curvi, arcinfo or spiderweb NODATA_valuemissing data grid_file = -999hirlam.000grd # Separate (curvi-linear) #grid Valueon usedwhich forthe undefinedwind orcan missingbe specified first_data n_colsvalue = grid_llcorner = 400 # Options: grid_llcorner, grid_ul_corner, grid_lrcorner or grid_urcorner data_row = # Number ofgrid_row columns used for wind datafield n_rows = 16 # Options: grid_row or grid_col. For switching rows and columns. n_quantity = 1 # Number of rows used for wind datafield spw_radius = 600000.00 # Number of quantities prescribed in the file quantity1 # Radius= of spiderweb (in units specified in rad_unit) spw_rad_unit x_wind = m # Name of quantity1 (x_wind, y_wind, air_pressure, relative_humidity, air_temperature or cloudiness) unit1 # Unit of radius n_quantity = 3m s-1 # NumberUnit of quantitiesquantity1 prescribed in the file quantity1 = wind_speed (m s-1 for velocities, Pa/ mbar for air_pressure, % for relative_humidity or cloudiness and Celcius for air_temperature) ### END OF HEADER TIME = 0 hours since 2006-01-01 00:00:00 -06:00 # Fixed format: #<time> Name<time of quantity1 quantity2 =unit> "since" <date> <time> <time zone> 101530.000 wind_from_direction 101300.000 101600.000 101550.000 101500.000 101300.000 # Name of quantity2 quantity3 1013300.000 =101400.000 air_pressure_drop 101430.000 101500.000 101130.000 101320.000 101260.000 # Name of quantity3 unit1 101620.000 1013400.000 = 101520.000 m s-1 TIME = 1440 hours since 2006-01-01 00:00:00 -06:00 # Fixed format: <time> <time unit> "since" <date> <time> # Unit of quantity1 unit2<time zone> 101298.544 102108.102 = 101998.521 degree 101928.544 101721.314 101811.152 1013410.400 # Unit of quantity2 unit3101323.214 101430.000 101500.000 = 101130.000 Pa 101320.000 101260.000 101620.000 1013400.000 101520.000

• Explanation of the data to grid conversion for wind on a separate curvilinear grid.

The first_data_value keyword is used to determine the starting point on the grid. The first_data_value is the first value that is read in the meteo file, i.e. the upper left value in a data block. The keyword has 4 possible values:

grid_llcorner, meaning m = 1, n = 1 (on the curvilinear grid)
grid_lrcorner, meaning m = mmax, n = 1 ( " )
grid_ulcorner, meaning m = 1, n = nmax ( " )
grid_urcorner, meaning m = mmax, n = nmax ( " )

The data_row keyword is then used to determine the direction of placing the data on the grid, i.e. data_row = grid_column means that a row that is read in the meteo file becomes a column in the array on the grid (so fixed m, increasing n).

Example:

Code Block
first_data_value = grid_ll_corner data_row = grid_column

means:
The first read value (top left) of the meteofile coincides with the point (1,1) on the grid. The first row in the meteofile is then the first column on the grid, i.e. (1,1:nmax). The second row is then the second column (2,1:nmax) and so on. See also Figure 2.

Image Added
Figure 2: Data to grid conversion for wind on a separate curvilinear grid.

• Meteo on a Spiderweb grid:
  For meteo on a Spiderweb grid, the wind velocities and air pressure are specified in 1 file using the keyword:
  Filweb
  Meteo on a Spiderweb grid can be added to one of the other wind formats. Near and in the cyclone the winds are added using an averaging algorithm.

Code Block

### START OF HEADER ### This file is created by Deltares ### All text on a line behind the first # is parsed as commentary ### Additional commments FileVersion = 1.02 # Version of meteo input file, to check if the newest file format is used filetype = meteo_on_spiderweb_grid # Type of meteo input file: meteo_on_flow_grid, meteo_on_equidistant_grid, meteo_on_curvilinear_grid or meteo_on_spiderweb_grid NODATA_value = -999 # Unit of quantity3 ### END OF HEADER TIME = 0 minutes since 2004-01-03 11:02:00 +01:00 # Fixed format: time unit since date time time difference (time zone) x_spw_eye = 115.4 # Xcoordinate of cyclone eye (Spiderweb centre) at specified TIME y_spw_eye = 18.9 # Ycoordinate of cyclone eye (Spiderweb centre) at specified TIME p_drop_spw_eye = 5300 # Pressure drop at cyclone eye (Spiderweb centre) at specified TIME 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 155.0000 346.2500 357.5000 8.750000 20.00000 31.25000 42.50000 53.75000 65.00000 76.25000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 TIME # Value =used for undefined or 1440 minutes since 2004-01-03 11:02:00 +01:00missing data n_cols # Fixed= format: time unit since16 date time time difference (time zone) x_spw_eye = 114.4000 # Number of columns used for wind datafield n_rows # Xcoordinate of cyclone eye (Spiderweb centre)= at specified TIME y_spw_eye 400 = 18.90000 # Number of rows used for wind #datafield spw_radius Ycoordinate of cyclone eye (Spiderweb centre) at= specified TIME 600000.00 p_drop_spw_eye = 5300.000 # Radius of spiderweb (in units specified in rad_unit) spw_rad_unit = # Pressure dropm at cyclone eye (Spiderweb centre) at specified TIME 2.435253 2.435253 2.435253 2.435253# Unit of radius n_quantity 2.435253 = 2.435253 3 2.435253 2.435253 2.435253 2.435253 65.01978 75.11859 85.25320 # Number 95.45370of quantities prescribed in the file quantity1 105.7529 116.1833 126.7762 137.5612 148.5649 159.8090 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 = wind_speed # Name of quantity1 quantity2 = wind_from_direction # Name of quantity2 quantity3 = p_drop # Name of quantity3 unit1 = m s-1 # Unit of quantity1 unit2 = degree # Unit of quantity2 unit3 = Pa # Unit of quantity3 ### END OF HEADER TIME = 0 minutes since 2004-01-03 11:02:00 +01:00 # Fixed format: <time> <time unit> "since" <date> <time> <time zone> x_spw_eye = 115.4 # Xcoordinate of cyclone eye (Spiderweb centre) at specified TIME y_spw_eye = 18.9 # Ycoordinate of cyclone eye (Spiderweb centre) at specified TIME p_drop_spw_eye = 5300 # Pressure drop at cyclone eye (Spiderweb centre) at specified TIME 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 1.388999 155.0000 346.2500 357.5000 8.750000 20.00000 31.25000 42.50000 53.75000 65.00000 76.25000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 5300.000 TIME = 1440 minutes since 2004-01-03 11:02:00 +01:00 # Fixed format: <time> <time unit> "since" <date> <time> <time zone> x_spw_eye = 114.4000 # Xcoordinate of cyclone eye (Spiderweb centre) at specified TIME y_spw_eye = 18.90000 # Ycoordinate of cyclone eye (Spiderweb centre) at specified TIME p_drop_spw_eye = 5300.000 # Pressure drop at cyclone eye (Spiderweb centre) at specified TIME 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 2.435253 65.01978 75.11859 85.25320 95.45370 105.7529 116.1833 126.7762 137.5612 148.5649 159.8090 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544 5298.544

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• Explanation of the grid definition for wind on a Spiderweb grid.

The Spiderweb grid is defined using the number of rows 'n_rows' and the number of columns 'n_cols'.
The number of rows is used to divide the radius of the Spiderweb in small rings of width spw_radius/n_rows [m].
The number of columns is used to divide the circle in parts with angles of 2*pi/n_cols [rad].
The wind direction is defined according to the nautical convention, i.e. wind from the North has direction 0 degrees and the angle increases when turning clockwise.
If the grid_unit is 'degree' than the coordinates of the Spiderweb/cyclone eye are given in spherical coordinates using keywords 'x_spw_eye' and 'y_spw_eye'.
For each time of the time series, the coordinates of the Spiderweb eye and the pressure drop in the eye must be specified.