Tropical Rain’s Impact on Oceans

• A study by the University of Washington reveals that tropical rain doesn’t always make the ocean surface more buoyant.

• The study uses data from 22 buoys across the equatorial oceans to analyze over 31,000 hours of rainfall events.

• The buoyancy flux, which combines the effects of heat and freshwater, is analyzed.

• Light rain (0.2-4 mm/hr) often has a positive buoyancy flux, promoting mixing and destabilizing the ocean.

• Heavy rain, usually accompanied by stronger cold pools, tends to have a negative buoyancy flux, making the ocean surface more stable.

• The study also found that nighttime rainfall is more likely to cause instability.

• Geography also plays a role in the study, with a ‘cold rain zone’ in the western Pacific and Indian Oceans associated with more heat loss and a ‘hot rain zone’ in the central Pacific.