The Pacific depths have actually been getting colder. Image Credit: CC BY-SA 2.0 contri
Despite global warming, the bottom of the Pacific Ocean is still cooling thanks to a centuries-old cold spell.
In a new study, researchers from Harvard University and the Woods Hole Oceanographic Institution have revealed that the temperature changes found in the depths of the Pacific appear to be lagging behind those found nearer to the surface by several hundred years.
In other words - it takes a surprisingly long time for the surface water to circulate to the lowest depths.
Because of this, the effects of a cold period known as the Little Ice Age, which began around 700 years ago, have only now managed to filter their way to the bottom.
"These waters are so old and haven't been near the surface in so long, they still 'remember' what was going on hundreds of years ago when Europe experienced some of its coldest winters in history," said study lead author and physical oceanographer Jake Gebbie.
It is believed that during the 20th century, the depths of the Pacific cooled by somewhere between 0.02 and 0.08 degrees Celsius despite the effects of climate change.
The cooling effect of the Little Ice Age however won't be enough to offset modern global warming.
Im not sure if i buy thier logic. So the temperatures are lagging down there and take hundreds of years to catch up to the surface? Who was down there monitoring the temperature changes of different depths 700 years ago?
Thank you good relevant info. Still no mention of how they came to the conclusion that the cooling is caused by a little ice age 700 years ago. Is that the only reason the depths could cool? Or is there less sunlight getting down because the waters murky? Thats just a random idea but who decided that the water "remembers" what happened 700 years ago as the article put it. They made it sound silly.
You take the temperature of newly-formed deep water in places like the North Atlantic as the current temperature. Then just measure the temperature in different currents on the ocean bottoms. The temps between the places where deep water is formed and those where it rises back to the surface are a record of past surface temps. The speed of the currents tells you how long along the deep water was formed. Doug
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