Interpolation of upper air u and v components of wind is affected by the changes to:
HRES - O1280
xxxx has been interpolated from the xxx target grid to regular lat-lon grids at different resolutions using EMOSLIB and MIR.
winds at 1000 hPa affected by::
- MIR using 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
- MIR using a more accurate truncation of the spectral series corresponding to the target grid resolution to avoid ripples from aliasing effects
HRES T1279
- For transformations to high resolution target grids (0.1x0.1 and 0.125x0.125) for which no spectral truncation occurs
- differences are at most +/-3.5m/s
- differences are smaller than +/-0.5m/s for more than 99% of grid points
These differences are due to MIR making the spectral transformation to an intermediate Gaussian grid followed by grid-to-grid interpolation to the regular lat-lon grid whereas EMOSLIB transforms directly to the lat-lon target grid. - For transformations to lower resolution target grids:
- the maximum and minimum differences are significantly larger.
- differences are smaller than 1 m/s for more than 80% of grid points
- larger differences are due to sub-optimal default truncation of the spectral series used by EMOSLIB:
- EMOSLIB uses truncation=T799 for a 0.25x0.25 target grid compared to the theoretical ideal used by MIR of truncation=T719
- EMOSLIB uses truncation=T319 for a 0.5x0.5 target grid compared to the theoretical ideal used by MIR of truncation=T359
- EMOSLIB uses truncation=T213 for a 1.0x1.0 target grid compared to the theoretical ideal used by MIR of truncation=T179
Consequently, fields produced by EMOSLIB are more affected by 'aliasing' than those produced by MIR.
- Generally, the use of the intermediate grid with MIR produces smoother fields.
- For the cases shown here, differences between MIR and EMOSLIB generally lie between xxx
- In general, more than xxxx of points differ by less than xxx
- The largest differences occur close to the coasts and in areas of steep orography where the gradient of the field changes most rapidly
The plots show the differences with the contours chosen on a logarithmic scale to enhance the smaller differences. Differences smaller than 0.5% of the field range are not shown. Grid points where the absolute difference is greater than 25% of the maximum absolute difference are indicated with red (EMOSLIB greater than MIR) and blue (EMOSLIB less than MIR) filled circles.
| Target resolution | Parameter | Statistics of differences | Histogram of differences | Global | Europe |
|---|
| 0.1x0.1 | u | Maximum difference = 2.019257
Minimum difference = -1.974884
Mean absolute difference = 0.040151
Median absolute difference = 0.022186
Standard deviation = 0.070667
RMS of differences = 0.070667 Percentage of points with absolute difference < 0.10 = 91.262%
< 0.25 = 98.637%
< 0.50 = 99.817%
< 1.00 = 99.991% | -2.5 : -2.0 - 0 ( 0.000000%) 0 ( 0.000000%)
-2.0 : -1.5 - 17 ( 0.000262%) 17 ( 0.000262%)
-1.5 : -1.0 - 226 ( 0.003486%) 226 ( 0.003486%)
-1.0 : -0.5 - 5381 ( 0.082994%) 5381 ( 0.082994%)
-0.5 : 0.0 - 3248347 ( 50.100978%) 3165179 ( 48.818234%)
0.0 : 0.5 - 3223408 ( 49.716330%) 3132650 ( 48.316522%)
0.5 : 1.0 - 5850 ( 0.090228%) 5850 ( 0.090228%)
1.0 : 1.5 - 350 ( 0.005398%) 350 ( 0.005398%)
1.5 : 2.0 - 20 ( 0.000308%) 20 ( 0.000308%)
2.0 : 2.5 - 1 ( 0.000015%) 1 ( 0.000015%) |  Image Added
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| v | Maximum difference = 1.914169
Minimum difference = -1.721573
Mean absolute difference = 0.046585
Median absolute difference = 0.026260
Standard deviation = 0.078025
RMS of differences = 0.078025 Percentage of points with absolute difference < 0.10 = 88.455%
< 0.25 = 98.182%
< 0.50 = 99.827%
< 1.00 = 99.996% | -2.0 : -1.5 - 10 ( 0.000154%)
-1.5 : -1.0 - 125 ( 0.001928%)
-1.0 : -0.5 - 5388 ( 0.083102%)
-0.5 : 0.0 - 3203002 ( 49.401598%)
0.0 : 0.5 - 3269394 ( 50.425597%)
0.5 : 1.0 - 5532 ( 0.085323%)
1.0 : 1.5 - 134 ( 0.002067%)
1.5 : 2.0 - 15 ( 0.000231%)
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| 0.125x0.125 | u | Maximum difference = 2.638397
Minimum difference = -3.040314
Mean absolute difference = 0.059515
Median absolute difference = 0.031952
Standard deviation = 0.106560
RMS of differences = 0.106560 Percentage of points with absolute difference < 0.10 = 84.039%
< 0.25 = 96.518%
< 0.50 = 99.352%
< 1.00 = 99.933% | -3.5 : -3.0 - 1 ( 0.000024%) 1 ( 0.000024%)
-3.0 : -2.5 - 1 ( 0.000024%) 1 ( 0.000024%)
-2.5 : -2.0 - 32 ( 0.000771%) 32 ( 0.000771%)
-2.0 : -1.5 - 118 ( 0.002843%) 118 ( 0.002843%)
-1.5 : -1.0 - 1033 ( 0.024891%) 1033 ( 0.024891%)
-1.0 : -0.5 - 12236 ( 0.294838%) 12236 ( 0.294838%)
-0.5 : 0.0 - 2066135 ( 49.785426%) 2027359 ( 48.851082%)
0.0 : 0.5 - 2057047 ( 49.566442%) 2013191 ( 48.509691%)
0.5 : 1.0 - 11895 ( 0.286621%) 11895 ( 0.286621%)
1.0 : 1.5 - 1363 ( 0.032843%) 1363 ( 0.032843%)
1.5 : 2.0 - 163 ( 0.003928%) 163 ( 0.003928%)
2.0 : 2.5 - 48 ( 0.001157%) 48 ( 0.001157%)
2.5 : 3.0 - 8 ( 0.000193%) 8 ( 0.000193%)
3.0 : 3.5 - 0 ( 0.000000%) 0 ( 0.000000%) |  Image Added
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| v | Maximum difference = 2.837143
Minimum difference = -2.504654
Mean absolute difference = 0.069448
Median absolute difference = 0.038315
Standard deviation = 0.117622
RMS of differences = 0.117622 Percentage of points with absolute difference < 0.10 = 79.683%
< 0.25 = 95.303%
< 0.50 = 99.193%
< 1.00 = 99.951% | -3.0 : -2.5 - 1 ( 0.000024%)
-2.5 : -2.0 - 16 ( 0.000386%)
-2.0 : -1.5 - 69 ( 0.001663%)
-1.5 : -1.0 - 907 ( 0.021855%)
-1.0 : -0.5 - 15802 ( 0.380764%)
-0.5 : 0.0 - 2045563 ( 49.289725%)
0.0 : 0.5 - 2071008 ( 49.902845%)
0.5 : 1.0 - 15693 ( 0.378137%)
1.0 : 1.5 - 913 ( 0.022000%)
1.5 : 2.0 - 90 ( 0.002169%)
2.0 : 2.5 - 10 ( 0.000241%)
2.5 : 3.0 - 8 ( 0.000193%) |  Image Added
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| 0.25x0.25 | u | Maximum difference = 7.823715
Minimum difference = -6.886246
Mean absolute difference = 0.206354
Median absolute difference = 0.107925
Standard deviation = 0.368593
RMS of differences = 0.368593 Percentage of points with absolute difference < 0.10 = 47.241%
< 0.25 = 76.027%
< 0.50 = 90.373%
< 1.00 = 97.323% | -8.0 : -7.0 - 0 ( 0.000000%)
-7.0 : -6.0 - 12 ( 0.001156%)
-6.0 : -5.0 - 13 ( 0.001252%)
-5.0 : -4.0 - 76 ( 0.007320%)
-4.0 : -3.0 - 370 ( 0.035637%)
-3.0 : -2.0 - 1636 ( 0.157574%)
-2.0 : -1.0 - 11706 ( 1.127485%)
-1.0 : 0.0 - 503796 ( 48.524041%)
0.0 : 1.0 - 506646 ( 48.798544%)
1.0 : 2.0 - 11704 ( 1.127292%)
2.0 : 3.0 - 1689 ( 0.162679%)
3.0 : 4.0 - 408 ( 0.039297%)
4.0 : 5.0 - 135 ( 0.013003%)
5.0 : 6.0 - 33 ( 0.003178%)
6.0 : 7.0 - 12 ( 0.001156%)
7.0 : 8.0 - 4 ( 0.000385%) |  Image Added
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| v | Maximum difference = 9.905029
Minimum difference = -7.118408
Mean absolute difference = 0.214605
Median absolute difference = 0.116943
Standard deviation = 0.366808
RMS of differences = 0.366808 Percentage of points with absolute difference < 0.10 = 44.908%
< 0.25 = 74.036%
< 0.50 = 89.647%
< 1.00 = 97.294% | -10.0 : -9.0 - 0 ( 0.000000%)
-9.0 : -8.0 - 0 ( 0.000000%)
-8.0 : -7.0 - 1 ( 0.000096%)
-7.0 : -6.0 - 5 ( 0.000482%)
-6.0 : -5.0 - 14 ( 0.001348%)
-5.0 : -4.0 - 74 ( 0.007127%)
-4.0 : -3.0 - 268 ( 0.025813%)
-3.0 : -2.0 - 1461 ( 0.140719%)
-2.0 : -1.0 - 12227 ( 1.177666%)
-1.0 : 0.0 - 503768 ( 48.521344%)
0.0 : 1.0 - 506380 ( 48.772923%)
1.0 : 2.0 - 12235 ( 1.178437%)
2.0 : 3.0 - 1475 ( 0.142067%)
3.0 : 4.0 - 263 ( 0.025331%)
4.0 : 5.0 - 56 ( 0.005394%)
5.0 : 6.0 - 7 ( 0.000674%)
6.0 : 7.0 - 2 ( 0.000193%)
7.0 : 8.0 - 1 ( 0.000096%)
8.0 : 9.0 - 2 ( 0.000193%)
9.0 : 10.0 - 1 ( 0.000096%) |  Image Added
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| 0.5x0.5 | u | Maximum difference = 10.179855
Minimum difference = -9.166824
Mean absolute difference = 0.365231
Median absolute difference = 0.206863
Standard deviation = 0.622578
RMS of differences = 0.622578 Percentage of points with absolute difference < 0.10 = 28.037%
< 0.25 = 56.549%
< 0.50 = 78.538%
< 1.00 = 92.510% | -11.0 : -10.0 - 0 ( 0.000000%)
-10.0 : -9.0 - 1 ( 0.000385%)
-9.0 : -8.0 - 6 ( 0.002308%)
-8.0 : -7.0 - 12 ( 0.004617%)
-7.0 : -6.0 - 35 ( 0.013466%)
-6.0 : -5.0 - 57 ( 0.021930%)
-5.0 : -4.0 - 151 ( 0.058095%)
-4.0 : -3.0 - 425 ( 0.163512%)
-3.0 : -2.0 - 1506 ( 0.579409%)
-2.0 : -1.0 - 7510 ( 2.889351%)
-1.0 : 0.0 - 119503 ( 45.976839%)
0.0 : 1.0 - 120948 ( 46.532779%)
1.0 : 2.0 - 7476 ( 2.876270%)
2.0 : 3.0 - 1527 ( 0.587488%)
3.0 : 4.0 - 445 ( 0.171207%)
4.0 : 5.0 - 177 ( 0.068098%)
5.0 : 6.0 - 88 ( 0.033857%)
6.0 : 7.0 - 27 ( 0.010388%)
7.0 : 8.0 - 15 ( 0.005771%)
8.0 : 9.0 - 5 ( 0.001924%)
9.0 : 10.0 - 5 ( 0.001924%)
10.0 : 11.0 - 1 ( 0.000385%) |  Image Added
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| v | Maximum difference = 11.994492
Minimum difference = -10.408829
Mean absolute difference = 0.368936
Median absolute difference = 0.218124
Standard deviation = 0.607771
RMS of differences = 0.607773 Percentage of points with absolute difference < 0.10 = 26.601%
< 0.25 = 54.811%
< 0.50 = 77.828%
< 1.00 = 92.495% | -12.0 : -11.0 - 0 ( 0.000000%) -11.0 : -10.0 - 1 ( 0.000385%) -10.0 : -9.0 - 4 ( 0.001539%)
-9.0 : -8.0 - 2 ( 0.000769%)
-8.0 : -7.0 - 11 ( 0.004232%)
-7.0 : -6.0 - 25 ( 0.009618%)
-6.0 : -5.0 - 45 ( 0.017313%)
-5.0 : -4.0 - 119 ( 0.045783%)
-4.0 : -3.0 - 409 ( 0.157356%)
-3.0 : -2.0 - 1460 ( 0.561711%)
-2.0 : -1.0 - 7676 ( 2.953216%)
-1.0 : 0.0 - 120111 ( 46.210757%)
0.0 : 1.0 - 120302 ( 46.284241%)
1.0 : 2.0 - 7701 ( 2.962835%)
2.0 : 3.0 - 1473 ( 0.566713%)
3.0 : 4.0 - 357 ( 0.137350%)
4.0 : 5.0 - 137 ( 0.052709%)
5.0 : 6.0 - 52 ( 0.020006%)
6.0 : 7.0 - 24 ( 0.009234%)
7.0 : 8.0 - 7 ( 0.002693%)
8.0 : 9.0 - 2 ( 0.000769%)
9.0 : 10.0 - 0 ( 0.000000%)
10.0 : 11.0 - 1 ( 0.000385%)
11.0 : 12.0 - 1 ( 0.000385%) |  Image Added
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| 1.0x1.0 | u | Maximum difference = 12.553375
Minimum difference = -11.167328
Mean absolute difference = 0.576833
Median absolute difference = 0.346344
Standard deviation = 0.950006
RMS of differences = 0.950007 Percentage of points with absolute difference < 0.10 = 17.397%
< 0.25 = 38.972%
< 0.50 = 63.338%
< 1.00 = 84.401% | -13.0 : -12.0 - 0 ( 0.000000%)
-12.0 : -11.0 - 2 ( 0.003069%)
-11.0 : -10.0 - 0 ( 0.000000%) -10.0 : -9.0 - 4 ( 0.006139%)
-9.0 : -8.0 - 8 ( 0.012277%)
-8.0 : -7.0 - 18 ( 0.027624%)
-7.0 : -6.0 - 29 ( 0.044506%)
-6.0 : -5.0 - 57 ( 0.087477%)
-5.0 : -4.0 - 152 ( 0.233272%)
-4.0 : -3.0 - 300 ( 0.460405%)
-3.0 : -2.0 - 862 ( 1.322897%)
-2.0 : -1.0 - 3648 ( 5.598527%)
-1.0 : 0.0 - 27096 ( 41.583794%)
0.0 : 1.0 - 27900 ( 42.817680%)
1.0 : 2.0 - 3625 ( 5.563229%)
2.0 : 3.0 - 870 ( 1.335175%)
3.0 : 4.0 - 323 ( 0.495703%)
4.0 : 5.0 - 120 ( 0.184162%)
5.0 : 6.0 - 72 ( 0.110497%)
6.0 : 7.0 - 31 ( 0.047575%)
7.0 : 8.0 - 14 ( 0.021486%)
8.0 : 9.0 - 12 ( 0.018416%)
9.0 : 10.0 - 9 ( 0.013812%)
10.0 : 11.0 - 6 ( 0.009208%)
11.0 : 12.0 - 0 ( 0.000000%)
12.0 : 13.0 - 2 ( 0.003069%) |  Image Added
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| v | Maximum difference = 11.211227
Minimum difference = -15.431351
Mean absolute difference = 0.569787
Median absolute difference = 0.359665
Standard deviation = 0.903314
RMS of differences = 0.903316 Percentage of points with absolute difference < 0.10 = 16.687%
< 0.25 = 37.482%
< 0.50 = 62.307%
< 1.00 = 84.652% | -16.0 : -15.0 - 1 ( 0.001535%)
-15.0 : -14.0 - 0 ( 0.000000%)
-14.0 : -13.0 - 0 ( 0.000000%)
-13.0 : -12.0 - 2 ( 0.003069%)
-12.0 : -11.0 - 0 ( 0.000000%)
-11.0 : -10.0 - 3 ( 0.004604%)
-10.0 : -9.0 - 3 ( 0.004604%)
-9.0 : -8.0 - 5 ( 0.007673%)
-8.0 : -7.0 - 7 ( 0.010743%)
-7.0 : -6.0 - 22 ( 0.033763%)
-6.0 : -5.0 - 59 ( 0.090546%)
-5.0 : -4.0 - 114 ( 0.174954%)
-4.0 : -3.0 - 258 ( 0.395948%)
-3.0 : -2.0 - 822 ( 1.261510%)
-2.0 : -1.0 - 3659 ( 5.615408%)
-1.0 : 0.0 - 27178 ( 41.709638%)
0.0 : 1.0 - 27981 ( 42.941989%)
1.0 : 2.0 - 3719 ( 5.707489%)
2.0 : 3.0 - 824 ( 1.264579%)
3.0 : 4.0 - 309 ( 0.474217%)
4.0 : 5.0 - 108 ( 0.165746%)
5.0 : 6.0 - 47 ( 0.072130%)
6.0 : 7.0 - 21 ( 0.032228%)
7.0 : 8.0 - 9 ( 0.013812%)
8.0 : 9.0 - 4 ( 0.006139%)
9.0 : 10.0 - 2 ( 0.003069%)
10.0 : 11.0 - 2 ( 0.003069%)
11.0 : 12.0 - 1 ( 0.001535%)
12.0 : 13.0 - 0 ( 0.000000%)
13.0 : 14.0 - 0 ( 0.000000%)
14.0 : 15.0 - 0 ( 0.000000%)
15.0 : 16.0 - 0 ( 0.000000%) |  Image Added
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