28 April 2023

Professor Jim Thomas’ recent publication in the Journal of Fluid Mechanics, Upscale transfer of waves in one-dimensional rotating shallow water, has been selected as a featured publication by the journal. A special highlighted article about the paper was published in the Focus on Fluids section of the journal. Jim is an ICTS joint faculty with the Centre for Applicable Mathematics, Tata Institute of Fundamental Research, Bengaluru.

Focus on Fluids (FoF) articles highlight particular papers published by the journal which have the potential to make a significant mark and explain their context and importance to a wider scientific audience. Publications covered by FoF articles are more widely read and featured in a dedicated section on the journal’s website.

Jim studies the dynamics of fluids and is especially interested in the atmosphere and oceans. He explained that the atmosphere and the oceans have a lot of waves, which transfer energy from large length scales to small length scales. For instance, winds blowing over the oceans excite waves at 1000-kilometre scales, which break up into smaller waves and cause the oceans to mix at millimetre scales. The ocean mixing is responsible for ocean currents, which carry heat from the poles towards the equator.

A thirty-year-old theory argues that the inverse phenomenon is also possible. That is, energy can be transferred from small lengths to larger scales. In the featured publication, Jim and his colleague at the University of California studied this inverse phenomenon. With the help of numerical calculations, they were able to validate the theory as well as provide critical corrections.

Atmospheric scientists, oceanographers, and climate scientists are interested in understanding how the waves interact and transfer energy across scales. “Our work implies that atmosphere-ocean climate models will need to keep track of large-scale waves as well, which they don’t do now,” said Jim. Studies like theirs will help make better weather and climate predictions, he hopes.

ICTS congratulates Jim for the feature and wishes him more success.