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Interpolation of the surface winds at 10m is affected by the changes to:

the land sea-mask processing
the default interpolation method
the distance computation and selection of nearest points
the handling of the interpolation at the polar latitudes

HRES - O1280

The 10u and 10v components of wind have been interpolated from the O1280 octahedral reduced Gaussian target grid to regular lat-lon grids at different target resolutions using EMOSLIB and MIR.

Large differences are seen for the values at the polar latitude line (90N and 90S).
Neglecting the differences at the polar latitudes, differences between MIR and EMOSLIB generally lie between +/- 4.0m/s
In general, more than 98.5% points differ by less than +/- 0.1m/s
The largest differences occur close to the coasts and in areas where the gradient of the fields changes most rapidly

The plots show the differences with the contours chosen on a logarithmic scale to enhance the smaller differences. Differences smaller than 0.1% 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. The line of slightly larger differences visible in all plots to the north west of the United Kingdom and Ireland is due to a stationary front with a strong south-westerly flow to the south east.

Target resolution	Parameter	Statistics of differences (excluding 90N and 90S)	Histogram of differences (excluding 90N and 90S)
0.1x0.1	10u	Maximum difference = 2.655655 Minimum difference = -3.279892 Mean absolute difference = 0.010699 Median absolute difference = 0.002548 Standard deviation = 0.036172 RMS of differences = 0.036173 Percentage of points with absolute difference < 0.10 = 98.578% < 0.25 = 99.663% < 0.50 = 99.917% < 1.00 = 99.989%	-3.5 : -3.0 - 3 ( 0.000046%) -3.0 : -2.5 - 3 ( 0.000046%) -2.5 : -2.0 - 21 ( 0.000324%) -2.0 : -1.5 - 66 ( 0.001018%) -1.5 : -1.0 - 312 ( 0.004812%) -1.0 : -0.5 - 2603 ( 0.040147%) -0.5 : 0.0 - 3093830 ( 47.717780%) 0.0 : 0.5 - 3384416 ( 52.199642%) 0.5 : 1.0 - 2056 ( 0.031711%) 1.0 : 1.5 - 236 ( 0.003640%) 1.5 : 2.0 - 41 ( 0.000632%) 2.0 : 2.5 - 11 ( 0.000170%) 2.5 : 3.0 - 2 ( 0.000031%) 3.0 : 3.5 - 0 ( 0.000000%)
0.1x0.1	10v	Maximum difference = 2.242844 Minimum difference = -3.879227 Mean absolute difference = 0.010432 Median absolute difference = 0.002609 Standard deviation = 0.035247 RMS of differences = 0.035247 Percentage of points with absolute difference < 0.10 = 98.638% < 0.25 = 99.673% < 0.50 = 99.915% < 1.00 = 99.991%	-4.0 : -3.5 - 2 ( 0.000031%) -3.5 : -3.0 - 0 ( 0.000000%) -3.0 : -2.5 - 1 ( 0.000015%) -2.5 : -2.0 - 3 ( 0.000046%) -2.0 : -1.5 - 27 ( 0.000416%) -1.5 : -1.0 - 269 ( 0.004149%) -1.0 : -0.5 - 2393 ( 0.036909%) -0.5 : 0.0 - 3468253 ( 53.492705%) 0.0 : 0.5 - 3009813 ( 46.421942%) 0.5 : 1.0 - 2569 ( 0.039623%) 1.0 : 1.5 - 244 ( 0.003763%) 1.5 : 2.0 - 24 ( 0.000370%) 2.0 : 2.5 - 2 ( 0.000031%) 2.5 : 3.0 - 0 ( 0.000000%) 3.0 : 3.5 - 0 ( 0.000000%) 3.5 : 4.0 - 0 ( 0.000000%)
0.125x0.125	10u	Maximum difference = 2.742874 Minimum difference = -3.841110 Mean absolute difference = 0.010641 Median absolute difference = 0.002640 Standard deviation = 0.035974 RMS of differences = 0.035975 Percentage of points with absolute difference < 0.10 = 98.599% < 0.25 = 99.663% < 0.50 = 99.918% < 1.00 = 99.990%	-4.0 : -3.5 - 1 ( 0.000024%) -3.5 : -3.0 - 3 ( 0.000072%) -3.0 : -2.5 - 7 ( 0.000169%) -2.5 : -2.0 - 8 ( 0.000193%) -2.0 : -1.5 - 31 ( 0.000747%) -1.5 : -1.0 - 198 ( 0.004771%) -1.0 : -0.5 - 1668 ( 0.040192%) -0.5 : 0.0 - 2236285 ( 53.885347%) 0.0 : 0.5 - 1910412 ( 46.033137%) 0.5 : 1.0 - 1280 ( 0.030843%) 1.0 : 1.5 - 153 ( 0.003687%) 1.5 : 2.0 - 24 ( 0.000578%) 2.0 : 2.5 - 8 ( 0.000193%) 2.5 : 3.0 - 2 ( 0.000048%) 3.0 : 3.5 - 0 ( 0.000000%) 3.5 : 4.0 - 0 ( 0.000000%)
0.125x0.125	10v	Maximum difference = 2.211929 Minimum difference = -4.150375 Mean absolute difference = 0.010332 Median absolute difference = 0.002914 Standard deviation = 0.035219 RMS of differences = 0.035219 Percentage of points with absolute difference < 0.10 = 98.662% < 0.25 = 99.674% < 0.50 = 99.915% < 1.00 = 99.991%	-4.5 : -4.0 - 1 ( 0.000024%) -4.0 : -3.5 - 1 ( 0.000024%) -3.5 : -3.0 - 0 ( 0.000000%) -3.0 : -2.5 - 1 ( 0.000024%) -2.5 : -2.0 - 2 ( 0.000048%) -2.0 : -1.5 - 17 ( 0.000410%) -1.5 : -1.0 - 176 ( 0.004241%) -1.0 : -0.5 - 1507 ( 0.036313%) -0.5 : 0.0 - 1688708 ( 40.690975%) 0.0 : 0.5 - 2457843 ( 59.223991%) 0.5 : 1.0 - 1642 ( 0.039566%) 1.0 : 1.5 - 168 ( 0.004048%) 1.5 : 2.0 - 12 ( 0.000289%) 2.0 : 2.5 - 2 ( 0.000048%) 2.5 : 3.0 - 0 ( 0.000000%) 3.0 : 3.5 - 0 ( 0.000000%) 3.5 : 4.0 - 0 ( 0.000000%) 4.0 : 4.5 - 0 ( 0.000000%)
0.25x0.25	10u	Maximum difference = 2.006119 Minimum difference = -3.840561 Mean absolute difference = 0.010868 Median absolute difference = 0.002670 Standard deviation = 0.038290 RMS of differences = 0.038291 Percentage of points with absolute difference < 0.10 = 98.533% < 0.25 = 99.614% < 0.50 = 99.899% < 1.00 = 99.986%	-4.0 : -3.5 - 1 ( 0.000096%) -3.5 : -3.0 - 0 ( 0.000000%) -3.0 : -2.5 - 2 ( 0.000193%) -2.5 : -2.0 - 2 ( 0.000193%) -2.0 : -1.5 - 9 ( 0.000867%) -1.5 : -1.0 - 79 ( 0.007609%) -1.0 : -0.5 - 527 ( 0.050759%) -0.5 : 0.0 - 465868 ( 44.870935%) 0.0 : 0.5 - 571323 ( 55.028028%) 0.5 : 1.0 - 379 ( 0.036504%) 1.0 : 1.5 - 41 ( 0.003949%) 1.5 : 2.0 - 8 ( 0.000771%) 2.0 : 2.5 - 1 ( 0.000096%) 2.5 : 3.0 - 0 ( 0.000000%) 3.0 : 3.5 - 0 ( 0.000000%) 3.5 : 4.0 - 0 ( 0.000000%)
0.25x0.25	10v	Maximum difference = 1.868179 Minimum difference = -2.262680 Mean absolute difference = 0.010483 Median absolute difference = 0.002914 Standard deviation = 0.036397 RMS of differences = 0.036397 Percentage of points with absolute difference < 0.10 = 98.594% < 0.25 = 99.633% < 0.50 = 99.907% < 1.00 = 99.991%	-2.5 : -2.0 - 2 ( 0.000193%) -2.0 : -1.5 - 6 ( 0.000578%) -1.5 : -1.0 - 41 ( 0.003949%) -1.0 : -0.5 - 398 ( 0.038334%) -0.5 : 0.0 - 415556 ( 40.025042%) 0.0 : 0.5 - 621719 ( 59.882012%) 0.5 : 1.0 - 476 ( 0.045847%) 1.0 : 1.5 - 37 ( 0.003564%) 1.5 : 2.0 - 5 ( 0.000482%) 2.0 : 2.5 - 0 ( 0.000000%)
0.5x0.5	10u	Maximum difference = 2.465591 Minimum difference = -2.399643 Mean absolute difference = 0.011799 Median absolute difference = 0.002701 Standard deviation = 0.045343 RMS of differences = 0.045343 Percentage of points with absolute difference < 0.10 = 98.207% < 0.25 = 99.449% < 0.50 = 99.845% < 1.00 = 99.978%	-2.5 : -2.0 - 3 ( 0.001154%) -2.0 : -1.5 - 5 ( 0.001924%) -1.5 : -1.0 - 29 ( 0.011157%) -1.0 : -0.5 - 180 ( 0.069252%) -0.5 : 0.0 - 144921 ( 55.756002%) 0.0 : 0.5 - 114595 ( 44.088566%) 0.5 : 1.0 - 166 ( 0.063866%) 1.0 : 1.5 - 17 ( 0.006540%) 1.5 : 2.0 - 2 ( 0.000769%) 2.0 : 2.5 - 2 ( 0.000769%)
0.5x0.5	10v	Maximum difference = 1.750687 Minimum difference = -1.841110 Mean absolute difference = 0.011405 Median absolute difference = 0.002640 Standard deviation = 0.042246 RMS of differences = 0.042246 Percentage of points with absolute difference < 0.10 = 98.289% < 0.25 = 99.493% < 0.50 = 99.861% < 1.00 = 99.982%	-2.0 : -1.5 - 2 ( 0.000769%) -1.5 : -1.0 - 20 ( 0.007695%) -1.0 : -0.5 - 148 ( 0.056941%) -0.5 : 0.0 - 141343 ( 54.379424%) 0.0 : 0.5 - 118216 ( 45.481687%) 0.5 : 1.0 - 166 ( 0.063866%) 1.0 : 1.5 - 24 ( 0.009234%) 1.5 : 2.0 - 1 ( 0.000385%)
1.0x1.0	10u	Maximum difference = 2.465393 Minimum difference = -2.399841 Mean absolute difference = 0.011716 Median absolute difference = 0.002380 Standard deviation = 0.047399 RMS of differences = 0.047399 Percentage of points with absolute difference < 0.10 = 98.171% < 0.25 = 99.429% < 0.50 = 99.840% < 1.00 = 99.975%	-2.5 : -2.0 - 2 ( 0.003069%) -2.0 : -1.5 - 2 ( 0.003069%) -1.5 : -1.0 - 7 ( 0.010743%) -1.0 : -0.5 - 46 ( 0.070595%) -0.5 : 0.0 - 33182 ( 50.923880%) 0.0 : 0.5 - 31874 ( 48.916513%) 0.5 : 1.0 - 42 ( 0.064457% 1.0 : 1.5 - 3 ( 0.004604%) 1.5 : 2.0 - 1 ( 0.001535%) 2.0 : 2.5 - 1 ( 0.001535%)
1.0x1.0	10v	Maximum difference = 1.342804 Minimum difference = -1.771454 Mean absolute difference = 0.011245 Median absolute difference = 0.001984 Standard deviation = 0.042607 RMS of differences = 0.042607 Percentage of points with absolute difference < 0.10 = 98.194% < 0.25 = 99.471% < 0.50 = 99.859% < 1.00 = 99.980%	-2.0 : -1.5 - 1 ( 0.001535%) -1.5 : -1.0 - 7 ( 0.010743%) -1.0 : -0.5 - 36 ( 0.055249%) -0.5 : 0.0 - 24291 ( 37.279006%) 0.0 : 0.5 - 40777 ( 62.579804%) 0.5 : 1.0 - 43 ( 0.065991%) 1.0 : 1.5 - 5 ( 0.007673%) 1.5 : 2.0 - 0 ( 0.000000%)