EMOSLIB does not apply any land sea-mask processing when interpolating the mean sea-level pressure so differences arise only from the different interpolation method and selection of nearest points used by MIR

HRES O1280

Mean sea-level pressure has been interpolated from the O1280 octahedral reduced Gaussian grid to regular lat-lon grids at different target resolutions using EMOSLIB and MIR. 

  • The differences for more than 99% of grid points are less than 20Pa and in the cases presented here all differences are less than 1 hPa.
  • The largest differences occur in regions of high orography with the field gradient changes most rapidly.
  • Larger differences are also seen in the lower resolution target grids (0.5ºx0.5º and 1.0ºx1.0º) at the polar latitudes (90ºN and 90ºS) which arise from the different handling of the interpolation at the poles.

The plots show the differences with the contours chosen on a logarithmic scale to enhance the smaller differences. Differences smaller than 0.1% of the field range are not shown. Grid points where the absolute difference is greater than 50% of the maximum absolute difference are indicated with red (EMOSLIB greater than MIR) and blue (EMOSLIB less than MIR) filled circles.


Target resolutionStatistics of differencesHistogram of differencesGlobalEurope
0.1x0.1

Maximum difference = 68.125000
Minimum difference = -91.375000
Mean absolute difference = 0.312304
Median absolute difference = 0.125000
Standard deviation = 1.072257
RMS of differences = 1.072257

Percentage of points with absolute difference

        < 1.0 = 95.306%
        < 2.0 = 97.828%
        < 10.0 = 99.743%

-100.0 : -90.0 -          1 (  0.000015%)
  -90.0 : -80.0 -          0 (  0.000000%)
  -80.0 : -70.0 -          1 (  0.000015%)
  -70.0 : -60.0 -          5 (  0.000077%)
  -60.0 : -50.0 -         12 (  0.000185%)
  -50.0 : -40.0 -         36 (  0.000555%)
  -40.0 : -30.0 -        153 (  0.002360%)
  -30.0 : -20.0 -        638 (  0.009840%)
  -20.0 : -10.0 -       7583 (  0.116957%)
  -10.0 : 0.0 -    3294855 ( 50.818295%)
      0.0 : 10.0 -    3172050 ( 48.924209%)
  10.0 : 20.0 -       7478 (  0.115337%)
  20.0 : 30.0 -        603 (  0.009300%)
  30.0 : 40.0 -        121 (  0.001866%)
  40.0 : 50.0 -         49 (  0.000756%)
  50.0 : 60.0 -         13 (  0.000201%)
  60.0 : 70.0 -          2 (  0.000031%)
  70.0 : 80.0 -          0 (  0.000000%)
  80.0 : 90.0 -          0 (  0.000000%)
  90.0 : 100.0 -          0 (  0.000000%)

0.125x0.125

Maximum difference = 92.937500
Minimum difference = -80.062500
Mean absolute difference = 0.297040
Median absolute difference = 0.062500
Standard deviation = 1.112258
RMS of differences = 1.112258

Percentage of points with absolute difference

        < 1.0 = 95.244%
        < 2.0 = 97.784%
        < 10.0 = 99.717%

-100.0 : -90.0 -          0 (  0.000000%)
  -90.0 : -80.0 -          1 (  0.000024%)
  -80.0 : -70.0 -          3 (  0.000072%)
  -70.0 : -60.0 -         10 (  0.000241%)
  -60.0 : -50.0 -          7 (  0.000169%)
  -50.0 : -40.0 -         26 (  0.000626%)
  -40.0 : -30.0 -         84 (  0.002024%)
  -30.0 : -20.0 -        387 (  0.009325%)
  -20.0 : -10.0 -       5446 (  0.131226%)
  -10.0 : 0.0 -    2862191 ( 68.967128%)
      0.0 : 10.0 -    1276136 ( 30.749672%)
   10.0 : 20.0 -       5303 (  0.127781%)
   20.0 : 30.0 -        362 (  0.008723%)
   30.0 : 40.0 -         81 (  0.001952%)
   40.0 : 50.0 -         28 (  0.000675%)
    50.0 : 60.0 -          9 (  0.000217%)
    60.0 : 70.0 -          2 (  0.000048%)
    70.0 : 80.0 -          3 (  0.000072%)
    80.0 : 90.0 -          0 (  0.000000%)
    90.0 : 100.0 -          1 (  0.000024%)

0.25x0.25

Maximum difference = 92.875000
Minimum difference = -61.875000
Mean absolute difference = 0.338583
Median absolute difference = 0.125000
Standard deviation = 1.266861
RMS of differences = 1.266861

Percentage of points with absolute difference

        < 1.0 = 95.149%
        < 2.0 = 97.663%
        < 10.0 = 99.580%

-100.0 : -90.0 -          0 (  0.000000%)
  -90.0 : -80.0 -          0 (  0.000000%)
  -80.0 : -70.0 -          0 (  0.000000%)
  -70.0 : -60.0 -          4 (  0.000385%)
  -60.0 : -50.0 -          4 (  0.000385%)
  -50.0 : -40.0 -          6 (  0.000578%)
  -40.0 : -30.0 -         15 (  0.001445%)
  -30.0 : -20.0 -        101 (  0.009728%)
  -20.0 : -10.0 -       2043 (  0.196775%)
  -10.0 : 0.0 -     527362 ( 50.793843%)
      0.0 : 10.0 -     506516 ( 48.786022%)
   10.0 : 20.0 -       2066 (  0.198991%)
   20.0 : 30.0 -         93 (  0.008957%)
   30.0 : 40.0 -         19 (  0.001830%)
  40.0 : 50.0 -          6 (  0.000578%)
  50.0 : 60.0 -          2 (  0.000193%)
  60.0 : 70.0 -          1 (  0.000096%)
  70.0 : 80.0 -          1 (  0.000096%)
  80.0 : 90.0 -          0 (  0.000000%)
  90.0 : 100.0 -          1 (  0.000096%)

0.5x0.5

Maximum difference = 51.000000
Minimum difference = -61.000000
Mean absolute difference = 0.309541
Median absolute difference = 0.000000
Standard deviation = 1.523147
RMS of differences = 1.523153

Percentage of points with absolute difference

        < 1.0 = 94.304%
        < 2.0 = 97.268%
        < 10.0 = 99.306%

-70.0 : -60.0 -          2 (  0.000769%)
-60.0 : -50.0 -          1 (  0.000385%)
-50.0 : -40.0 -          1 (  0.000385%)
-40.0 : -30.0 -          3 (  0.001154%)
-30.0 : -20.0 -         21 (  0.008079%)
-20.0 : -10.0 -        855 (  0.328947%)
-10.0 : 0.0 -      41886 ( 16.114958%)
    0.0 : 10.0 -     216238 ( 83.194060%)
 10.0 : 20.0 -        871 (  0.335103%)
 20.0 : 30.0 -         33 (  0.012696%)
 30.0 : 40.0 -          6 (  0.002308%) 
 40.0 : 50.0 -          2 (  0.000769%)
  50.0 : 60.0 -          1 (  0.000385%)
  60.0 : 70.0 -          0 (  0.000000%)

1.0x1.0

Maximum difference = 50.937500
Minimum difference = -60.812500
Mean absolute difference = 0.437874
Median absolute difference = 0.062500
Standard deviation = 1.932739
RMS of differences = 1.932777

 Percentage of points with absolute difference

        < 1.0 = 94.672%
        < 2.0 = 96.980%
        < 10.0 = 98.766%

-70.0 : -60.0 -          1 (  0.001535%)
-60.0 : -50.0 -          0 (  0.000000%)
-50.0 : -40.0 -          0 (  0.000000%)
-40.0 : -30.0 -          0 (  0.000000%)
-30.0 : -20.0 -          2 (  0.003069%)
-20.0 : -10.0 -        389 (  0.596992%)
-10.0 : 0.0 -      44619 ( 68.476059%)
    0.0 : 10.0 -      19737 ( 30.290055%)
 10.0 : 20.0 -        401 (  0.615408%)
 20.0 : 30.0 -          9 (  0.013812%)
 30.0 : 40.0 -          1 (  0.001535%)
 40.0 : 50.0 -          0 (  0.000000%)
 50.0 : 60.0 -          1 (  0.001535%)
 60.0 : 70.0 -          0 (  0.000000%)