Interpolation of 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.
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%) | | |
| 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%)
| | |
| 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%) | | |
| 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%) | | |
| 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%) | | |
| 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%) | | |
| 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%) | | |
| 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%) | | |
| 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%) | | |
| 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%) | | |
