Design Review Climatology in GFE

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Design ReviewClimatology in GFE

• Tom LeFebvre
• November 10, 2005

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Climatology in GFE

• Requirements Review
• Engineer the architecture to add climatology data
  sets from NCDC to GFE display, smart tools, and
  formatters. Allow these data sets to be used as
  part of the gridded forecast process.

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NCDC Grids

• How are NCDC grids created?
• Start with 1961-1990 atlas grids produced by
  PRISM
• Create 1971-2000 distance-weighted average grids
• Calculate the difference, preserving the detail
  in the original PRISM data set

61-90 Atlas
71-00 Obs
71-00 Climo grid
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Climatology in GFE

• NDCD Gridded Climatology Grids
• Binary
• Projected on a lat/lon grid
• 2 minutes / grid point (nominally 4 km)
• 12 Monthly Normals
• Max Temp.
• Min Temp.
• Precipitation

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Processing NCDC Grids

• To be used in GFE, NCDC grids must be
• Remapped to local map projection
• Clipped to local spatial domain
• Converted to local spatial resolution
• Solution Use built in functions in ifpServer
• Convert NCDC grids to AWIPS model data format
• ifpServer will remap, clip, and convert
  resolution automatically

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Processing NCDC Grids
010101000101101011110010101010101 1010101001010101
11010101010100010 01010001110100101010100101010101
1 010010101010110101010101000101010 10100101010101
1010101010101011101 001011011100011010101010101110
101 101010010101010110101010101010101 100101010101
010100101010110010100 1010101000011110101010101110
01101 101010010101010110101010101010101 1001010101
01010100101010110010100 10101010000111101010101011
1001101 100101010101010100101010110010100 10101010
0001111010101010111001101 101010010101010110101010
101010101 100101010101010100101010110010100 101010
100001111010101010111001101

• netcdf 20050101_0000
• dimensions
• record UNLIMITED // (12 currently)
• n_valtimes 12
• data_variables 2
• charsPerLevel 11
• namelen 132
• x 1601
• y 505
• levels_1 1
• variables
• float mnt(record, levels_1, y, x)

NCDC Binary file
AWIPS model netCDF file
This processing is done one time at GSD
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Climatology in GFE
Remapping, clipping, resolution
conversion performed inside ifpServer
Climatology netCDF file
ifpServer
ifpServer reads Climatology netCDF file
ifpServer makes Climatology grids available to
all GFEs
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Climatology in GFE

• Once netCDF file is installed, one line in the a
  configuration file makes it available to the
  ifpServer.
• To install climatology in GFE
• Install climatology netCDF file
• Add one line to configuration file
• Install smart tool

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Smart Tool PopulateFromClimo

• User selects
• Time period on GFE
• User selects element MinT or MaxT
• User selects data source (PRISM or NCDC)

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Smart Tool PopulateFromClimo

• Retrieves grids from ifpServer
• Performs spline calculations at each grid point
• Creates climatology grid for each selected day

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Cubic Spline

• 2 phases
• Calculates coefficients based on monthly grids
• Uses coefficients to calculate grids in between
  (in time) monthly grids
• All monthly grids are centered on the middle of
  the month (all months 15th, February 14th)