Previously unknown underwater currents can severely impact the power of hurricanes, a new study suggests research that should improve the accuracy of storm system forecasts.
The discoveries were made thanks to measurements of the 2017 Category 5 storm Hurricane Maria, taken from a set of oceanographic instruments.
The analysis showed interactions between ocean islands and the hurricane that fueled the storm with increasing amounts of energy.
The researchers estimated that Hurricane Maria obtained up to 65% more potential intensity due to the sloping shelf patterns of the island shorelines, which resulted in currents that boosted and stabilized the various temperature bands of the ocean, Science alert reports.
Olivia Cheriton, an oceanographer of the US Geological Survey (USGS), said:
“We were surprised to find that the direction of the approaching hurricane winds relative to the coastline kept the ocean surface layer distinctly warmer compared to the colder waters below. This is important because warmer sea surface temperatures provided more energy for the storm.”
Sea-surface temperatures are one of the main factors that impact the energy of a hurricane. In the current case, the records say that waters around the coasts of the battered islands didn’t decrease in temperature until eleven or more hours after Hurricane Maria passed.
The stratification or layering of temperatures is a significant factor that impacts the cooling rates, meaning that warmer and cooler waters don’t mix.
The study data shows how a layer of warm water was trapped by increasing pressure beneath and strong ocean currents (provoked by the hurricane winds) of above.
Improving hurricane forecasting is a significant part of the work to try and decrease the impacts of hurricanes on society. They are typically very devastating and provoke both material and human losses. Knowing when and how intense a hurricane would improve the situation.
