A new study, conducted by scientists at the Department of Earth Science from University of California, in Santa Barbara, blatantly contradicts previous theories on the influence of the spread sheets of ice in the Northern hemisphere. The new model, analyzing data as old as 425,000 years, argues that sunlight plays a more important role in the formation of oceanic currents than the amount of melted water coming from the ice.
 

Thus far, theories said that only water coming from regions neighboring the North Pole was responsible for the way in which the large "loop" of water temperatures functions in the Atlantic. This loop takes place as warm water, carried by the Gulf Stream, reaches high latitudes, where it's cooled down by cool water, coming from glaciers and ice sheets.
 

Afterwards, the cooled water "dives" underneath the surface, at a depth of approximately 3,000 meters (about 10,000 feet), and rushes towards the Equator. The heat that is removed from warm water by fresh water is then spread across Europe, preventing ice from taking over the continent, as it did during ice ages, when glaciers covered all land stretching between the Pole and the Mediterranean Sea.
 

Unlike these old theories, the new one says that not only glaciers play a crucial part in keeping the loop running, and that sunlight is an important factor as well. "Because the ice sheets are so large, it was a nice simple story to say that they were having the predominant influence on all the parts of the climate system," said Lorraine Lisiecki, assistant professor at the Department and first author of the current study.
 

She added "[...] our study showed that this wasn't the only important part of the changes in climate. The distribution of sunlight is the controlling factor for North Atlantic deep water formation."
 

"The ocean does not always follow the climate; it exerts its own impact on climate processes. In other words, the ocean circulation doesn't just follow along with the rest of the climate, it actually changes in different ways than the ice sheets during glacial cycles," she concluded.