The Southern Indian Ocean Is Losing Salt at an “Astonishing” Rate
Summary
A significant area of the Southern Indian Ocean is experiencing rapid freshening, impacting seawater salinity, ocean layering, heat distribution, and nutrient accessibility. This phenomenon poses potential implications for marine ecosystems and global climate patterns, as highlighted by the authors.
Key Insights
What does 'freshening' mean in the context of ocean salinity?
Freshening refers to a decrease in seawater salinity, where the water becomes less salty due to the influx of fresher water, altering ocean density and layering in the Southern Indian Ocean off western Australia.
Why is the Southern Indian Ocean freshening, and what are the main impacts?
The freshening is driven by climate change-induced shifts in global wind patterns over the Indian and tropical Pacific Oceans, which redirect fresher water from the Indo-Pacific pool into the region, reducing the salty seawater area by 30% over 60 years. This disrupts ocean layering, vertical mixing, heat distribution, nutrient upwelling, and marine ecosystems like plankton and seagrass, with potential effects on global circulation and climate.