Australian researchers assert that wind patterns play a crucial role in causing severe coral bleaching events at the Great Barrier Reef in Australia.
In a recent study, scientists from Monash University in Melbourne discovered that wind patterns are a key factor contributing to rising ocean temperatures, leading to the recent mass coral bleaching events at the world’s largest coral reef.
Coral on the Great Barrier Reef around Lizard Island, Australia bleached on April 5, 2024. (Photo: AFP/TTXVN).
Coral bleaching occurs when sea temperatures rise too high, causing thermal stress to the corals and expelling the symbiotic algae from their tissues, resulting in a bleached appearance. Although not all corals that experience bleaching die immediately, they are at risk of starvation and may take up to 10 years to recover.
Since 2016, the Great Barrier Reef has undergone 5 mass bleaching events, raising concerns about the long-term health of this unique ecosystem. The research team analyzed weather data from the past 30 years and found that trade winds from the east play an important role in regulating ocean temperatures in the reef area.
Dr. Lara Richards – the lead researcher – stated that the decline of trade winds in 2022 significantly altered the sea surface temperature prior to the bleaching event, affecting 91% of the reef area.
Dr. Richards explained: “Within 3 weeks, we observed ocean temperatures increase by nearly 2 degrees Celsius, reaching 30.5 degrees Celsius due to the absence of trade winds, which reduced cloud cover, increased solar radiation, and diminished cooling efficiency from evaporation.” When the trade winds returned, ocean temperatures dropped sharply by 1 degree Celsius within 48 hours, thanks to a threefold increase in evaporative cooling.
Previously, rising ocean temperatures causing bleaching were often linked to the El Niño phase of the El Niño-Southern Oscillation (ENSO), a global climate phenomenon driven by changes in wind and sea surface temperature in the tropical Pacific region. However, the 2022 bleaching event was the first to occur during the La Niña phase of ENSO, which is typically characterized by lower temperatures and higher rainfall across much of Australia.
