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19990929: ECMWF data
- Subject: 19990929: ECMWF data
- Date: Wed, 29 Sep 1999 15:28:10 -0600
Brett,
You will see below that your Grid ID is defined as #255, and not
one of the known tile sectors 1 - 12 for the ecmwf grid IDs
that are used for the grids in the IDD.
The problem here is that by using a grid ID of 255, the GDS is used to
define the map projection- ie, it is not known ahead of time.
The GDS does not give you any information that the grid sector
is part of a larger grid area, and you cannot be guaranteed that
the next grid #255 is part of the same larger grid.
It would be possible to hard code in the values for this case in the
bd_gem_grid.f file and have the grid 255 define a 1.5x1.5 global grid-
but it would break if any ECMWF grid #255 was not part of the grid. For
instance,
the ECMWF defines a thinned grid as #255.
Steve Chiswell
Unidata User Support
>From: Brett Newkirk <address@hidden>
>Organization: .
>Keywords: 199909291858.MAA24041
>Hi Steve:
>I have 2 attachments below: TILE and TILE_NAGRIB. TILE has just some
>contents from a program gribdump which outputs GRIB header information-it
>has data from two separate files, the same variable, different tiles.
>TILE_NAGRIB has the data from tile C. If this data is not one of the ECMWF
>data already known, what data must I provide in regards to this data?
>****************
>TILE:
>-----------------------------------------------------
> Header : 1
> Originating Center : 98 (European Center for Medium-Range Weather
>Forecasts - Reading)
> Process : 193 (ECMWF model 193)
> Grid : 255
> points in grid : 3660
> Parameter : 2 (P_msl)
> Units : Pa
> Level Type : Mean Sea
> Reference Time : 1999/09/28:12:00
> Time Unit : Hour
> Time Range Indicator : Reference Time + P1
> Time 1 (P1) : 12
> Decimal Scale Factor : 0
> Binary Scale Factor : 0
> Reference Value : 99289.937500
> Minimum Value : 99289.94
> Number of Bits : 12
> BMS Included : FALSE
> GDS Included : TRUE
> IsInternationalGrid : FALSE
> GRIB Edition : 1
> Parameter Table Ver : 128
> GDS representation type : 0 (Latitude/Longitude)
> Number of columns : 60
> Number of rows : 61
> Number of points : 3660
> Kind of grid : rectangular
> GDS res/comp flag : 0x80
> GDS scan mode flag : 0
> GDS no. of vert. coords : 0
> GDS Ni : 60
> GDS Nj : 61
> GDS La1 : 90.000000
> GDS Lo1 : 136.500000
> GDS La2 : 0.000000
> GDS Lo2 : -135.000000
> GDS Di : 1.500000
> GDS Dj : 1.500000
>-----------------------------------------------------
> Header : 1
> Originating Center : 98 (European Center for Medium-Range Weather
>Forecasts - Reading)
> Process : 193 (ECMWF model 193)
> Grid : 255
> points in grid : 3660
> Parameter : 2 (P_msl)
> Units : Pa
> Level Type : Mean Sea
> Reference Time : 1999/09/28:12:00
> Time Unit : Hour
> Time Range Indicator : Reference Time + P1
> Time 1 (P1) : 0
> Decimal Scale Factor : 0
> Binary Scale Factor : 1
> Reference Value : 97862.687500
> Minimum Value : 97862.69
> Number of Bits : 12
> BMS Included : FALSE
> GDS Included : TRUE
> IsInternationalGrid : FALSE
> GRIB Edition : 1
> Parameter Table Ver : 128
> GDS representation type : 0 (Latitude/Longitude)
> Number of columns : 60
> Number of rows : 61
> Number of points : 3660
> Kind of grid : rectangular
> GDS res/comp flag : 0x80
> GDS scan mode flag : 0
> GDS no. of vert. coords : 0
> GDS Ni : 60
> GDS Nj : 61
> GDS La1 : 90.000000
> GDS Lo1 : -133.500000
> GDS La2 : 0.000000
> GDS Lo2 : -45.000000
> GDS Di : 1.500000
> GDS Dj : 1.500000
>**********
>TILE_NAGRIB
>
> IDS bytes 0 - 4 (GRIB msg id) = GRIB
> IDS bytes 5 - 7 (ids.msg_length) = 5574
> IDS byte 8 (ids.edition) = 1
> PDS bytes 1- 3 (pds.length) = 28
> PDS byte 4 (pds.version) = 128
> PDS byte 5 (pds.center) = 98
> PDS byte 6 (pds.process) = 193
> PDS byte 7 (pds.grid_id) = 255
> PDS byte 8 (pds.flag) = 128
> PDS byte 9 (pds.parameter) = 151
> PDS byte 10 (pds.vcoord) = 102
> PDS bytes 11 (pds.level_1) = 0
> PDS bytes 12 (pds.level_2) = 0
> PDS bytes 11-12 (pds.level) = 0
> PDS byte 13 (pds.year) = 99
> PDS byte 14 (pds.month) = 9
> PDS byte 15 (pds.day) = 28
> PDS byte 16 (pds.hour) = 12
> PDS byte 17 (pds.minute) = 0
> PDS byte 18 (pds.time_unit) = 1
> PDS byte 19 (pds.time_p1) = 12
> PDS byte 20 (pds.time_p2) = 0
> PDS byte 21 (pds.time_range) = 0
> PDS bytes 22-23 (pds.avg_num) = 0
> PDS byte 24 (pds.avg_miss) = 0
> PDS byte 25 (pds.century) = 20
> PDS byte 26 (pds.izero) = 0
> PDS bytes 27-28 (pds.dec_scale) = 0
> PDS EXT FLAG (1-app,0-nc,-1-rep) = 0
> PDS EXT STRING =
> GDS bytes 1 - 3 (gds.length) = 32
> GDS byte 4 (gds.NV) = 0
> GDS byte 5 (gds.PV) = 255
> GDS byte 6 (gds.grid_proj) = 0
> GDS bytes 7 - 8 (Nx) = 60
> GDS bytes 9 - 10 (Ny) = 61
> GDS bytes 11 - 13 (La1) = 90000
> GDS bytes 14 - 16 (Lo1) = 136500
> GDS byte 17 (flag) = 128
> GDS bytes 18 - 20 (La2) = 0
> GDS bytes 21 - 23 (Lo2) = -135000
> GDS bytes 24 - 25 (skipped)
> GDS bytes 26 - 27 (skipped)
> GDS byte 28 (mode) = 0
> GDS bytes 29 - 32 (skipped)
> GDS bytes 33 - 35 (skipped)
> GDS bytes 36 - 38 (skipped)
> GDS byte 39 (skipped)
> GDS bytes 40 - 42 (skipped)
> GDS bytes 43 - 45 (skipped)
> GDS bytes 46 - 48 (skipped)
> GDS byte 49 (skipped)
> GDS bytes 50 - 52 (skipped)
>
> MESG# NMCGRD# PRM# VCD# GEMPAK_TIME LEVL1 LEVL2 VCRD PARM
> 1 255 151 102 990928/1200F012 0 NONE PMSL
>
>
> 1 GRIB messages were read or scanned from the GRIB file:
> E00PC098E.grb
>
> Parameters requested:
>GBFILE,INDXFL,GDOUTF,PROJ,GRDAREA,KXKY,MAXGRD,CPYFIL,
> GAREA,OUTPUT,GBTBLS,GBDIAG.
>
>*************
>Thanks again-------Brett
>
>
>Brett Newkirk E-MAIL: address@hidden
>Office: ATG 424 Atmospheric Science/Geophysics Building
>Mailing Address: Department of Atmospheric Sciences, University of Washington
> Box 351640
> Seattle, WA 98195-1640
>Office Phone: (206) 685-2183
>
>
