The study looked at how waves breaking in the surf zone heat up the water. They used a method called Smoothed Particle Hydrodynamics to calculate the increase in energy and temperature of the water. When waves break, they create heat in the water. This heat is mainly found near where the waves break, and it's not a lot - just a tiny increase in temperature. The study also found that the heat generated by breaking waves can be carried away by underwater currents. Overall, breaking waves in the surf zone do warm up the water, but only by a very small amount.