Kerguelen/Heard Island Simulation
This page describes a numerical simulation of gravity waves over Kerguelen/Heard Islands on June 17, 2024 for comparison with AWE swath 3234.
Computational Domain
The layout of the of the simulation is shown in the figure below. The origin is located at (49.3° S, 69.2° E).
The mesh is clustered in the horizontal direction over the islands Kerguelen/Heard with spacings of 500m/800m respectively. Stretching of ~2% is used between the uniform regions and to the boundaries. A uniform vertical spacing of 500m is used to 102 km where the sponge layer is imposed to the top of the domain at 112 km. Inviscid wall boundary conditions are used at the surface whereas characteristic (radiative) conditions are used in combination with a sponge layer at the lateral and top boundaries.
Wind Profiles
The background winds and temperature are fixed in space and time.
The plots below show representative profiles for point located at 49.5°S, 69.5°E. Winds taken by combining ERA5 and JAWARA data.
Forcing
In order to minimize starting transients, the mean winds are damped to zero
between the surface and 30 km. Forcing terms are then used to increase the
near-surface winds over a period of four
hours. The forcing terms follow a hyperbolic tangent function in time, which
results in very gentle accelerations near the beginning and end of the forcing
period. The maximum forcing rate is equivalent to that of a linear ramp
with a duration of one hour.Results
Animation of T' in a Gaussian Averaged xy plane
Animation of w' in a xy plane
Primary Breaking in an xz Plane at y=0
Comparison in Latitude Longitude Space
Other AWE Swaths on June 17, 2024
