Tides & Ocean Math: Harmonic Constituents, Tide Tables & Wave Calculations

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• For the fictional harbour of Port Halden you turn the M2 period into an angular speed, model 24 hours of water level with a cosine and find the time of the first high water.
• Add the solar S2 tide to M2, calculate the spring-neap period, compute the tidal range for 16 days and chart the spring-neap cycle.
• From 25 hourly modelled heights you read the highest and lowest water, the time of high water and how many hours boats can cross the marina sill.
• Estimate the rising tide hour by hour with the sailors' rule of twelfths, compare it with a cosine model of the same tide and measure the largest gap.
• Calculate today's tidal range, interpolate the maximum tidal stream between neaps and springs and estimate the tidal prism and mean current through a lagoon inlet.
• For eight swells you calculate the deep-water wavelength and speed, the wavelength and speed at the local depth and classify each wave as deep, intermediate or shallow.
• For six sea states you calculate the wave energy per square metre and the wave power per metre of crest, then the time-weighted mean power and the annual energy resource of a stretch of coast.
• From 30 years of annual mean sea level at a fictional tide gauge you calculate the linear trend in mm per year and cm per century, chart it with a trendline and extend the line to 2050.