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How climate change impacts the Indian Ocean dipole, leading to severe droughts and floods

Phys.org/news (JANUARY 4, 2023)

With a new analysis of long-term climate data, researchers say they now have a much better understanding of how climate change can impact and cause sea water temperatures on one side of the Indian Ocean to be so much warmer or cooler than the temperatures on the other

Titre : How climate change impacts the Indian Ocean dipole, leading to severe droughts and floods

With a new analysis of long-term climate data, researchers say they now have a much better understanding of how climate change can impact and cause sea water temperatures on one side of the Indian Ocean to be so much warmer or cooler than the temperatures on the other—a phenomenon that can lead to sometimes deadly weather-related events like megadroughts in East Africa and severe flooding in Indonesia.

Phys.org/news (JANUARY 4, 2023)

Présentation
The analysis, described in a new study in Science Advances by an international team of scientists led by researchers from Brown University, compares 10,000 years of past climate conditions reconstructed from different sets of geological records to simulations from an advanced climate model.

The findings show that about 18,000 to 15,000 years ago, as a result of melted freshwater from the massive glacier that once covered much of North America pouring into the North Atlantic, ocean currents that kept the Atlantic Ocean warm weakened, setting off a chain of events in response. The weakening of the system ultimately led to the strengthening of an atmospheric loop in the Indian Ocean that keeps warmer water on one side and cooler water on the other.

This extreme weather pattern, known as a dipole, prompts one side (either east or west) to have higher-than-average rainfall and the other to have widespread drought. The researchers saw examples of this pattern in both the historical data they studied and the model’s simulation. They say the findings can help scientists not only better understand the mechanisms behind the east-west dipole in the Indian Ocean, but can one day help to produce more effective forecasts of drought and flood in the region.

Source  : Brown University

Annonce (Phys.org/news)

Page publiée le 13 janvier 2023