Oceanic Tidal Angular Momentum

U Seiler, Periodic changes of the angular momentum budget due to the tides of the world ocean, J. Geophys. Res., 96, 10287, 1991.

This model of the ocean tides is a purely numerical one; no tidal observations were used in its solution. Seiler solved Laplace's tidal equations on a global finite-difference grid using time-stepping methods. Dissipation was effected by quadratic bottom drag and a turbulent eddy viscosity.

These angular momentum data are extracted directly from the above reference. Amplitude and Greenwich phase lag are given for major tidal constituents. The (x,y,z) Cartesian components of angular momentum refer to the (Greenwich, 90°E, North) axes. Momentum components are decomposed into those due to tidal oceanic heights, which perturb the inertia tensor, and tidal currents, which effect relative momentum exchanges between ocean and mantle.

Units of momentum amplitude are 10²⁵ kg m²/s. Units of phase are degrees.

                   X               Y               Z
 Tides         amp    pha      amp    pha      amp    pha

M2 Heights    0.824  327.8    0.264  300.8    0.824   96.5
M2 Currents   1.241  201.1    2.139  149.5    3.056  311.9

S2 Heights    0.282   26.5    0.402  328.9    0.792  130.3
S2 Currents   1.085  274.5    1.545  188.7    1.866  338.2

N2 Heights    0.189  307.0    0.045   94.7    0.019   67.5
N2 Currents   0.098  167.0    0.274  158.3    0.543  320.0

K1 Heights    0.637  358.2    1.134  221.4    0.076  124.9
K1 Currents   0.182  234.2    0.380  201.6    0.653  143.3

O1 Heights    0.489   13.6    1.533  217.1    0.516  106.6
O1 Currents   0.204  262.2    0.185  111.7    0.851  114.2

P1 Heights    0.251  351.1    0.371  228.3    0.047  183.0
P1 Currents   0.037  275.2    0.169  213.3    0.240  144.7
 
 

The following long-period constituents are in the same format, except the amplitude units are 10²⁴ kg m²/s.

                   X               Y               Z
 Tides         amp    pha      amp    pha      amp    pha

Mf Heights    0.093  118.3    0.112   24.5    3.324   15.8
Mf Currents   0.127  332.8    0.092    0.0    0.286   97.7

Mm Heights    0.043   58.2    0.059  339.5    1.945   10.7
Mm Currents   0.062  315.3    0.037  326.0    0.074   91.3

Ssa Heights   0.026    6.2    0.012  258.6    1.851    2.0
Ssa Currents  0.011  278.3    0.007  279.9    0.009   88.9