Harmonic analysis of sea surface elevation compared with satellite products and tide gauge observations.
Analysis Summary
Analyzed Constituents: K1, K2, M2, N2, O1, P1, Q1, S2
Analysis Date: 2026-10-10
Satellite Product: FES2014/TPXO9
Plots
Tide Gauge Station Map
GESLA tide gauge station locations
Year 2011
K₁ (lunar-solar diurnal) — model amplitude and phase
K₁ (lunar-solar diurnal) — amplitude/phase comparison with GESLA tide gauges
O₁ (principal lunar diurnal) — model amplitude and phase
O₁ (principal lunar diurnal) — amplitude/phase comparison with GESLA tide gauges
P₁ (principal solar diurnal) — model amplitude and phase
P₁ (principal solar diurnal) — amplitude/phase comparison with GESLA tide gauges
Q₁ (larger lunar elliptic diurnal) — model amplitude and phase
Q₁ (larger lunar elliptic diurnal) — amplitude/phase comparison with GESLA tide gauges
K₂ (lunar-solar semi-diurnal) — model amplitude and phase
K₂ (lunar-solar semi-diurnal) — amplitude/phase comparison with GESLA tide gauges
M₂ (principal lunar semi-diurnal) — model amplitude and phase
M₂ (principal lunar semi-diurnal) — amplitude/phase comparison with GESLA tide gauges
N₂ (larger lunar elliptic semi-diurnal) — model amplitude and phase
N₂ (larger lunar elliptic semi-diurnal) — amplitude/phase comparison with GESLA tide gauges
S₂ (principal solar semi-diurnal) — model amplitude and phase
S₂ (principal solar semi-diurnal) — amplitude/phase comparison with GESLA tide gauges
Station amplitude/phase comparison — diurnal constituents
Station amplitude/phase comparison — semi-diurnal constituents
Tide Gauge Station Comparison
Compared with 89 tide gauge stations.
Station Results (Sample)
| station | lat | lon | country | years_of_obs | constituent | model_amp | obs_amp | amp_diff | model_pha | obs_pha | pha_diff |
|---|---|---|---|---|---|---|---|---|---|---|---|
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | M2 | 1.673 | 2.695 | -1.022 | 164.480 | 142.046 | 22.433 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | S2 | 0.593 | 1.005 | -0.412 | -149.207 | -172.254 | 23.047 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | N2 | 0.336 | 0.533 | -0.197 | 145.097 | 123.796 | 21.301 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | K2 | 0.159 | 0.287 | -0.128 | -151.167 | -174.564 | 23.396 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | K1 | 0.070 | 0.082 | -0.013 | 107.919 | 82.046 | 25.873 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | O1 | 0.052 | 0.073 | -0.021 | -5.393 | -28.193 | 22.800 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | P1 | 0.022 | 0.028 | -0.005 | 106.514 | 72.698 | 33.816 |
| roscoff-54-fra-refmar | 48.718 | -3.966 | FRA | 53.000 | Q1 | 0.023 | 0.022 | 0.001 | -50.882 | -72.558 | 21.676 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | M2 | 2.311 | 3.674 | -1.363 | -163.028 | 177.534 | 19.439 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | S2 | 0.867 | 1.434 | -0.568 | -112.947 | -132.090 | 19.143 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | N2 | 0.459 | 0.717 | -0.257 | 178.830 | 161.366 | 17.465 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | K2 | 0.231 | 0.410 | -0.180 | -114.576 | -134.593 | 20.016 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | K1 | 0.084 | 0.095 | -0.011 | 121.084 | 95.529 | 25.555 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | O1 | 0.061 | 0.082 | -0.021 | 7.140 | -15.478 | 22.618 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | P1 | 0.029 | 0.035 | -0.005 | 120.998 | 87.756 | 33.242 |
| saint_malo-410-fra-refmar | 48.641 | -2.028 | FRA | 35.000 | Q1 | 0.025 | 0.024 | 0.001 | -35.705 | -57.656 | 21.951 |
| st_marys-stm-gbr-da_idh | 49.918 | -6.317 | GBR | 9.000 | M2 | 1.056 | 1.758 | -0.703 | 152.912 | 131.222 | 21.690 |
| st_marys-stm-gbr-da_idh | 49.918 | -6.317 | GBR | 9.000 | S2 | 0.331 | 0.603 | -0.272 | -164.243 | 172.192 | 23.565 |
| st_marys-stm-gbr-da_idh | 49.918 | -6.317 | GBR | 9.000 | N2 | 0.210 | 0.344 | -0.134 | 131.603 | 111.930 | 19.673 |
| st_marys-stm-gbr-da_idh | 49.918 | -6.317 | GBR | 9.000 | K2 | 0.090 | 0.172 | -0.082 | -166.040 | 169.735 | 24.226 |
Methodology
Harmonic Analysis
Tidal constituents extracted using UTide harmonic analysis package. Analysis performed on high-frequency model output (10-15 min resolution) over a minimum period of 60 days.
Satellite Comparison
Model results compared with satellite-derived tidal products:
- FES2014: Finite Element Solution 2014 (1/16° resolution)
- TPXO9: OSU Tidal Prediction Software (1/30° resolution)
Satellite data regridded to model grid using conservative interpolation.