We know from Carl-Gustav Rossby's 1930s theory of planetary waves that they should exist not only in the atmosphere
(where they are easily seen) but also in the oceans. However, until the advent of precise satellite altimetry in the
1990s, there was very scarce observational evidence. Altimetry has confirmed that these long-wavelength, westward-propagating
internal waves are common in the tropical and mid-latitude ocean, where they accompany the ubiquitous non-linear eddies,
and that they travel faster than expected – so theoreticians have had to make some adjustments to the theory. But then we
started looking in other global satellite-derived datasets (SST, ocean colour), and the signature of eddies and waves is also
clearly visible there - implying that these westward-propagating phenomena affect the heat balance and the biology. All these
new observations have opened a number of intriguing questions that are not only important for our full understanding of ocean
dynamics, but also linked to climate change and the carbon cycle.
In this talk, Dr Cipollini will review what we know, explain what are the many issues still open in this field of research,
that need to be tackled with an integrated, interdisciplinary effort, and provide an update on recent work carried out at the
National Oceanography Centre on this topic.
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