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M2O1K1P1Q1K2N2S2 NNAMELONGLATALTPROGAMPLPHASEAMPLPHASEAMPLPHASEAMPLPHASEAMPLPHASEAMPLPHASEAMPLPHASEAMPLPHASE 113NEWLYN-5.5550.1013 ATLANTIDA 12.94760.8810.658194.960.96782.8170.32291.9310.246254.951.06216.1962.49681.2284.12320.902 LOAD07 12.87161.0650.657195.010.96382.7960.32291.8880.246254.891.05616.4112.49081.3564.10421.094 DIF 0.076-0.1846E-04-0.0470.0040.0213E-040.0433E-040.0620.006-0.2150.006-0.1280.019-0.192 114 REDRUTH -5.2350.23113 ATTLANTIDA 12.68357.6980.645193.280.95081.5160.31790.6460.241253.721.04411.8352.43277.984.04316.768 LOAD07 12.64257.690.644193.240.94681.4840.31790.6050.241253.721.04011.8232.43177.9334.03616.736 DIF 0.0410.0088E-040.0440.0040.0324E-040.0415E-045.E-040.0040.0128E-040.0470.0070.032 329 MONTIERNEU -0.9545.8810 ATTLANTIDA 8.20783.9430.468207.440.62893.4370.210102.740.176263.290.71851.6411.752103.622.75953.552 LOAD07 8.26583.9860.472207.510.62893.3680.211102.750.177263.340.72451.6621.770103.662.78653.581 DIF -0.058-0.043-0.004-0.0677E-050.069-0.001-0.010-9E-04-0.049-0.006-0.021-0.018-0.039-0.027-0.029 404SANTADER-3.8143.4725 ATTLANTIDA 9.03794.4560.526216.840.71099.6790.234108.960.195270.370.78563.5131.941114.273.02265.188 LOAD07 9.10494.4710.531216.890.71199.6520.235108.990.196270.390.79163.4951.960114.283.05065.173 DIF -0.067-0.015-0.005-0.054-0.0010.027-6E-04-0.032-0.001-0.016-0.0060.018-0.019-0.014-0.0280.015 423LA CORUNA-8.4243.370 ATTLANTIDA 10.751107.620.654223.40.931105.110.302114.360.232277.710.92778.1722.320127.763.57679.569 LOAD07 10.813107.640.659223.420.932105.110.304114.400.233277.740.93278.162.336127.793.60179.562 DIF -0.062-0.018-0.005-0.018-0.002 -0.036-0.001-0.027-0.0050.012-0.016-0.027-0.0250.007 427SANTIAGO/L-8.5442.88250 ATTLANTIDA 10.011109.940.619224.820.887106.080.288115.320.220279.250.86381.4032.171129.963.33382.644 LOAD07 9.832109.850.608224.730.874105.820.284115.060.216279.240.84881.3402.134129.883.27382.578 DIF 0.1790.0950.0110.0870.0130.2570.0040.2570.0040.0100.0150.0630.0370.0830.0600.066 434OVIEDO F. C-5.8543.35246 ATTLANTIDA 8.27099.7260.502218.990.722100.650.237109.750.187273.870.70969.6701.782119.742.74171.203 LOAD07 8.23099.7180.499218.940.721100.570.237109.650.186273.940.70569.6491.773119.742.72671.183 DIF 0.0400.0080.0030.0550.0010.0844.E-040.0967.E-04-0.0660.0040.0210.009-0.0030.0150.020 480PORTO-8.6741.080 ATTLANTIDA 9.7047117.280.612229.990.876111.30.282120.650.211284.490.85090.9352.118136.743.26791.840 LOAD07 9.679117.290.612229.980.871111.20.282120.610.211284.540.84890.9422.117136.763.26291.851 DIF 0.0257-0.0122E-040.0080.0050.1033E-040.0453E-04-0.0490.002-0.0079E-04-0.0180.005-0.011 481 COIMBRA -8.4340.2050 ATTLANTIDA 8.816119.390.561231.710.808112.570.261121.930.194286.430.78894.0861.929138.482.98794.857 LOAD07 8.857119.450.564231.730.809112.560.262121.980.195286.510.78394.1181.941138.543.00594.896 DIF -0.041-0.057-0.003-0.021-8.E-040.013-0.001-0.048-7.E-04-0.0800.005-0.032-0.012-0.062-0.018-0.039 482LISBONNE-9.1938.710 ATTLANTIDA 9.874127.180.629236.410.894118.300.288127.830.212291.530.893103.082.161145.513.408103.74 LOAD07 9.842127.180.628236.400.888118.190.287127.780.211291.580.890103.092.159145.533.400103.75 DIF 0.032-0.0029.E-040.0070.0060.1138.E-040.0545.E-04-0.0470.003-0.0060.002-0.0160.008-0.011 TABLE 1 Fig. 1. The ATLANTIDA 3.0 interface The program calculates: the effect of the direct Newtonian attraction of water masses, the ocean load effect, and their sum. It is possible to make calculations for either a point or for nods of a grid. The kinds of the program from LOAD87 of ETERNA package are: 1) Calculations for different models of Earths structure; 2) Absence of necessity of the local area. The amplitudes and phases of the ocean loading effect in the gravimetric data measured close to the coast of Europe are shown in Figs. 2 and 3. The amplitude exhibits an overall trend of a moderate increase in its gradient from south northwards. For example, as the coastline is approached from inland near the Moroccan coast off the mouth of Gibraltar, the amplitude increases, on average, from 4.5 to 7.0 gal over a distance of 100 km. However, the amplitude near the western coasts of Portugal and France increases over the same distance from 6 to 10 gal. Farther north, at Cape Saint Mathieu at the extremity of Brittany and at the Land's End headland of the Cornwall Peninsula in Northern England, the effect changes from 7 to 12.5 gal as the coast is approached. The southwesterly increase in Western Ireland is from 6 to 11 gal, and near the northeastern coast of Great Britain the effect in the coastal zone attains 5 gal. Some specificity in the behavior of amplitude against the ambient background is also observed in the English Channel slightly west of Calais. It is interesting that in the nearby Solent Straight, the tidal flow rates are very high (up to 10 km per hour). As far as the phase in concerned, here, the nodular features in Fig. 3 near Le Havre and in the eastern part of the Irish Sea and north of Scotland, close to the Orkney and Shetland Islands are remarkable. The differences in amplitudes of the total oceanic effect calculated by the ATLANTIDA3.0 and LOAD87 programs for the M2 wave are presented in Fig. 4. Just as the amplitudes themselves and their gradients, these differences increase from the south towards the north; however, they nowhere exceed 0.2 gal in absolute value and vanish 50--100 km offshore. At the same time, along the coastline up to 45N, these differences are not larger than 0.05-0.074 gal. The differences increase up to 0.1 gal in the approach to the Cornwall Peninsula where they attain 0.1--0.2 gal. Similar values are also observed in local areas near Le Havre and on the western coast of Great Britain. It is worth noting that overall, the amplitude differences (in percentage) do not exceed 0.5--1% over the major part of the coastline of Western Europe. This value is half the relative error of tidal height determination in the CSR3.0 oceanic model. The maximal phase differences are also revealed near the Cornwall Peninsula, on the French coast of the English Channel, and on the western coast of Great Britain. Instead of the phase differences themselves, Fig. 5 shows the sine of the phase difference times the amplitude. Overall, contribution of the phase differences to the studied signal along the coast of Europe does not typically exceed 0.01 gal except for the narrow zones mentioned above, i.e., the phase mismatch is, generally, substantially smaller than the amplitude difference. This is also true for other tidal waves. Dissipation causes the variation in the amplitude immediately close to the coastline, which does not typically exceed 0.1 gal. This is clearly seen in Fig. 6, where the difference in amplitudes between the reference periods of 12 h and 1 s is shown for the PREM model. Slightly higher values (up to 0.2 gal) are only observed close to the Saint Mathieu Cape and Land's End Cape projecting into the ocean. Here again, the specific features of the variations in the Irish Sea and English Channel are remarkable. The phase discrepancies normally lie within hundredths of a degree and attain a few degrees only in the mentioned particular zones. The differences in the structure of the crust and upper mantle cause somewhat higher discrepancies in the amplitudes and phases of the ocean gravimetric effect. The differences between the amplitudes calculated by the IASP91 and PREM models are presented in Fig. 7. The discrepancies between the models attain 0.1 gal near the Moroccan coast and increase to 0.3 gal at the western coasts of Portugal and France. The maximum phase differences here are at most 0.1 . However, near the tip of Cape Cornwall and close to the Irish seaboard, the region of Le Havre and Calais, the amplitudes differ by 0.35--0.4 gal and the phases, by 5-7 . The total result of the above-discussed effects associated with the differences in the structure of the Earth's crust and the upper mantle and dissipation is shown in Fig. 8. We have also studied the total effect caused by rotation and anisotropy from the data in (Pagiatakis, 1990). This effect turned out to be very small. In conclusion, we summarize in Table 1 the amplitudes and phases of the total oceanic gravimetric effect calculated by the ATLANTIDA 3.0 and LOAD87 programs at 10 ICET points. Only those points where the amplitude of the effect in the M2 wave exceeds 7 gal are included in the table. The calculations do not take into account dissipation for the PREM and CSR3.0 models.