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University of Bergen
Geophysical Institute

24 days of kitchen oceanography

Each day a new experiement will be posted here. Reveal what is hidden behind the windows by clicking on the arrows below.

Introduction
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Day 10
Day 11
Day 12
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Day 23
Day 24

Main content

Eddies

Day 11
11.12.2020

What are those pink curtains?

Virvler i et vannglass
Photo:
Mirjam Glessmer, GFI

Experiment 11:

We stir water in a cylindrical glass and then drip paint from the center radially outwards. This line of color gets deformed into a vortex, so that the resulting color curtain twists in itself. This is because the rotation of the water at the edge of the vessel is slowed down by friction. Gradually, this continues inward, causing shear within the vortex.

Chapter 11: Eddies

These eddies, rotating lenses of water, are called "meddies" (from Mediterranean and eddies) and can transport water (of certain temperature and salinity) over long distances. Eddies can also transport other properties, for example dissolved substances like gases or nutrients, but also plankton or plastic. Due to the fact that eddies rotate around their own axis, a shear flow is created by friction with surrounding water masses, which slowly mixes the inner and the outer bodies of water.

Rotating table

Check out more exiting experiments on rotation at Mirjam's blog. Here you can for example learn more about the Hadley cell and Rossby waves.