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HRES T1279

  • Differences between EMOSLIB and MIR are due to
    1. Use by MIR of an  intermediate full (regular) Gaussian grid at a resolution corresponding to the target lat-lon resolution for the spectral to grid transformation followed by grid-to-grid interpolation
    2. MIR uses a more accurate truncation of the spectral series to correspond target grid resolution to avoid ripples from aliasing effects
  • For transformations to high resolution target grids for which no spectral truncation occurs
    • differences are at most +/-3K
    • differences are smaller than +/-1K for more than 99% of grid points
  • For transformations to lower resolution target grids
    • the maximum and minimum differences are significantly larger.
    • differences are smaller than +/-2K for more than 99% of grid points
    • larger differences are due to sub-optimal default truncation of the spectral series used by EMOSLIB:
      • EMOSLIB truncation=T799 for 0.25x0.25 where theoretical  ideal used by MIR is truncation=T719
      • EMOSLIB truncation= T319 for 0.5x0.5 where theoretical  ideal used by MIR is truncation=T359
      • EMOSLIB truncation=T213 for 1.0x1.0 where theoretical  ideal used by MIR is truncation=T179
      Consequently, fields produced by EMOSLIB are more affected by 'aliasing'
  • The use of the intermediate grid with MIR generally produces smoother fields.


Target resolutionStatistics of differencesHistogram of differencesGlobalEurope
0.1x0.1

Maximum difference = 1.693253
Minimum difference = -1.505966
Average difference = 0.000041
Mean difference = 0.000041
Median difference = -0.000107
Standard deviation = 0.047950
Variance = 0.002299
RMS of differences = 0.047950

-1.693253 : -1.354602 -         28 (  0.000432%)
-1.354602 : -1.015952 -        127 (  0.001959%)
-1.015952 : -0.677301 -        905 (  0.013958%)
-0.677301 : -0.338651 -       8284 (  0.127769%)
-0.338651 : 0.000000 -    3432007 ( 52.933663%)
  0.000000 : 0.338651 -    3033555 ( 46.788127%)
  0.338651 : 0.677301 -       7733 (  0.119270%)
  0.677301 : 1.015952 -        771 (  0.011892%)
  1.015952 : 1.354602 -        140 (  0.002159%)
  1.354602 : 1.693253 -         50 (  0.000771%)

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0.125x0.125

Maximum difference = 2.510147
Minimum difference = -2.505478
Average difference = 0.000059
Mean difference = 0.000059
Median difference = 0.000381
Standard deviation = 0.072670
Variance = 0.005281
RMS of differences = 0.072670

-2.510147 : -2.008118 -         22 (  0.000530%)
-2.008118 : -1.506088 -        115 (  0.002771%)
-1.506088 : -1.004059 -        621 (  0.014964%)
-1.004059 : -0.502029 -       5551 (  0.133756%)
-0.502029 : 0.000000 -    2018900 ( 48.647255%)
  0.000000 : 0.502029 -    2118984 ( 51.058871%)
  0.502029 : 1.004059 -       5228 (  0.125973%)
  1.004059 : 1.506088 -        515 (  0.012409%)
  1.506088 : 2.008118 -        122 (  0.002940%)
  2.008118 : 2.510147 -         22 (  0.000530%)

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0.25x0.25

Maximum difference = 8.004074
Minimum difference = -7.327957
Average difference = -0.000261
Mean difference = -0.000261
Median difference = 0.000168
Standard deviation = 0.244372
Variance = 0.059717
RMS of differences = 0.244372

-8.004074 : -6.403259 -          1 (  0.000096%)
-6.403259 : -4.802444 -         18 (  0.001734%)
-4.802444 : -3.201630 -        169 (  0.016278%)
-3.201630 : -1.600815 -       1595 (  0.153625%)
-1.600815 : 0.000000 -     514518 ( 49.556750%)
  0.000000 : 1.600815 -     520200 ( 50.104022%)
  1.600815 : 3.201630 -       1527 (  0.147076%)
  3.201630 : 4.802444 -        168 (  0.016181%)
  4.802444 : 6.403259 -         35 (  0.003371%)
  6.403259 : 8.004074 -          9 (  0.000867%)

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0.5x0.5

Maximum difference = 13.379105
Minimum difference = -9.935349
Average difference = -0.002242
Mean difference = -0.002242
Median difference = -0.001755
Standard deviation = 0.414993
Variance = 0.172219
RMS of differences = 0.414999

-13.379105 : -10.703284 -          0 (  0.000000%)
-10.703284 : -8.027463 -          5 (  0.001924%)
  -8.027463 : -5.351642 -         49 (  0.018852%)
  -5.351642 : -2.675821 -        412 (  0.158510%)
  -2.675821 : 0.000000 -     130551 ( 50.227378%)
    0.000000 : 2.675821 -     128490 ( 49.434441%)
    2.675821 : 5.351642 -        366 (  0.140813%)
    5.351642 : 8.027463 -         38 (  0.014620%)
    8.027463 : 10.703284 -          6 (  0.002308%)
  10.703284 : 13.379105 -          3 (  0.001154%)

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1.0x1.0

Maximum difference = 9.762299
Minimum difference = -10.036530
Average difference = -0.006566
Mean difference = -0.006566
Median difference = -0.002350
Standard deviation = 0.635313
Variance = 0.403623
RMS of differences = 0.635347

-10.036530 : -8.029224 -         14 (  0.021486%)
  -8.029224 : -6.021918 -         20 (  0.030694%)
  -6.021918 : -4.014612 -         81 (  0.124309%)
  -4.014612 : -2.007306 -        462 (  0.709024%)
  -2.007306 : 0.000000 -      32208 ( 49.429098%)
    0.000000 : 2.007306 -      31834 ( 48.855126%)
    2.007306 : 4.014612 -        438 (  0.672192%)
    4.014612 : 6.021918 -         68 (  0.104359%)
    6.021918 : 8.029224 -         24 (  0.036832%)
    8.029224 : 10.036530 -         11 (  0.016882%)

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