Hotter Oceans Bring Dangers as El Nino Approaches: Weather Watch

Here’s what’s on Bloomberg Green’s weather radar today.

(Bloomberg) —

The world’s oceans are hot. Surface sea temperatures, the metric commonly used by researchers and referred to as SSTs, have collectively reached their highest levels in the 1981 to 2023 dataset, said Boyin Huang, an oceanographer with the US National Centers for Environmental Information. 

Part of the reason for the jump in temperatures is the shift away from three years of La Nina in the Pacific, he said. La Nina is when the equatorial Pacific cools and the atmosphere above it reacts to the change. That area has been warming, raising the overall average of sea surface temperatures.

That’s only part of the puzzle.

“The other reason is that there is a long-term warming trend in SST, which is associated with so-called Global Warming,” Huang said over email. “We believe that these two reasons result in the current record-breaking SST.”

The world’s oceans have a huge say in what happens on land. For instance, along with the Pacific warming, there are indications the western Indian Ocean will also heat up, which could trigger a positive phase of the Indian Ocean Dipole — that basin’s El Nino cycle. The last time El Nino and the positive Indian Ocean Dipole occurred, Australia was wracked by drought and wildfires. This can also lead to an increase in cyclones — another name for hurricanes — striking Mozambique and east Africa.

Already the Indian Ocean has produced some monster storms, including Ilsa that struck western Australia last month, and Freddy that took five weeks to travel the length of the basin becoming the longest-lasting tropical cyclone on record.

In other news today: 

Japan: A powerful 6.5-magnitude earthquake and a series of strong aftershocks struck Ishikawa Prefecture on Japan’s west coast, but there was not tsunami threat. 

Europe: The continent will remain split next week between slightly cooler than previously expected conditions in the Northeast and higher-than-usual temperatures in Iberia.

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