Tides in Perth

Fluid mechanics - Swan River Model

Tide Generating Forces

Tide Generating Force:

Horizontal force:

Note: TGF = R-3

Spring and Neap tides

Lastquarter

FullMoon

NewMoon

Firstquarter

Sun

• The Moon, Sun and Earth in line

-the tidal forces of Sun and Moon are additive

-produces Spring tides: New Moon and Full Moon• Quadrature: when the moon is aligned at right angles to Sun

-first quarter and last quarter: Neap tides

Diurnal

Semi-diurnal

Diurnal inequality

Diurnal tides

Semi-diurnal

Diurnal

Predicted tides: Fremantle

diurnal

Semi-diurnal

Fremantle tides

Global distribution of tidal conditions

Tidal propagation in the Swan River

Tidal propagation in the Swan River