We have been studying Earth-like planets for some time now, with many scientists believing that we are not alone in the universe. Now, according to new research, it has been found that the salt levels in the oceans on these planets may have a significant effect on their climates.
Researchers from the Centre for Ocean and Atmospheric Sciences at the University of East Anglia have revealed that the circulation of extremely salty or fresh water in these extra-terrestrial seas would influence their temperatures, adding that this could, in fact, make for more habitable conditions for alien life.
Computer simulations of Earth-like planets on their habitable climates have focused mainly on their atmospheres. However, the researchers believe that it is vital to study their oceans to gain a better understanding of its climate stability and habitability.
The scientists also mention that this is the first time researchers have considered that the seas on Earth-like planets may not be similar to ours, they could prove to be significantly more or less salty than the oceans here on Earth.
Prof. David Stevens from UEA’s School of Mathematics said in a statement:
“The number of planets being discovered outside our solar system is rapidly increasing. Our research helps to answer whether or not these planets could sustain alien life.
“We think that many planets may be uninhabitable because they are either too close or too far from their sun. A planet’s habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water.
“Oceans play a vital role in sustaining life and also have an immense capacity to control climate. But previous studies on ocean circulation on other planets have made the assumption that fundamental ocean properties — such as the salinity and depth of water — would be similar to that on Earth.
“We wanted to find out what might be happening on other planets, which might appear superficially similar to Earth, but where conditions such as salinity are radically different to our own planet.”
The research team used computer models of ocean circulation on exoplanets to see what would happen when their oceans had different salinity levels to Earth. They considered oceans with very low salinity (similar to freshwater), salinity similar to the average value of Earth’s oceans, and high salinity (similar levels to the Dead Sea), according to University of East Anglia.
Dr. Manoj Joshi from UEA’s School of Environmental Sciences, said:
“On Earth, we have a circulation where warm water moves toward the poles at the surface, before being cooled, then sinking at high latitudes, and traveling toward the equator at depth.
“Our research shows that oceans on other planets with a much higher salinity could circulate in the opposite direction — with polar water flowing toward the equator at the surface, sinking in the tropics, and traveling back toward the poles at depth. We also found a similar pattern emerging for freshwater oceans.
“These circulation patterns are the opposite of what happens on Earth, and would result in a dramatic warming in the polar regions.
“Such a circulation scenario might extend the planet’s range of habitability.”
Jodie Cullum from UEA’s School of Mathematics, said:
“Of course, on any given exoplanet, many other properties are likely to differ from their Earth-like values, some of which may also have a significant influence on ocean circulation — such as tidal forces, planetary rotation, ocean depth, and the location of continents.
“But this is important work which will help us better-understand the habitability of distant planets in more accurate detail than ever before.”
A study titled: “Importance of ocean salinity for climate and habitability” was published in the Proceedings of the National Academy of Sciences (PNAS).
Learn more about Kepler-186f with NASA’s Ames Research Center: