People don't usually associate sea ice together with the Earth's orbit. A study though is looking into the relationship between sea ice and the Earth's orbit. Sea ice and the Earth's orbit might be linked in some way, as the study contends.
The Earth always had an Ice Age. Scientists have seen that the Earth had been into a number of Ice Ages which were broken by interglacial periods. Scientists say that the Earth right now is in an interglacial period.
The Ice Ages and the interglacial periods have been on a 100,000-year cycle. A team of researchers say that a variation in the Earth's orbit might cause sea ice in the Southern Hemisphere to expand. This would then let sunlight be reflected back into space, which would cause global cooling.
Jung-Eun Lee is the lead author of the study and an assistant professor at Brown University's Department of Earth, Environmental and Planetary Studies. She said that sea ice has been important in the Southern Hemisphere. If this is combined with the Earth's orbit having variations, at some points in time these two come together that would result in an Ice Age.
Serbian scientist Milutin Milankovitch first proposed of the recurring changes in the Earth's orbit in the 1930s. He observed that these changes have a pattern, and that the cycle can go to a 100,000-year period to a 21,000-year period. These changes can also occur when the Earth's tilt is changed a bit, which can occur within the 21,000-year period, according to Brown University's site.
The change in the Earth's tilt is called precession. When this happens, the Earth's tilt could cause the Southern Hemisphere's summers to be cooler as the area is tilted much farther away from the Sun. In itself this would not be much, but each hemisphere has a different capacity to grow sea ice as well, as Science Daily reports.
The Southern Hemisphere is more likely to grow more sea ice, as compared to the Northern Hemisphere. There isn't much room for sea ice to grow in the Northern Hemisphere because the ocean's area there is much smaller than that in the Southern Hemisphere. Sea ice then can expand more if ever the Earth's tilt moves the region away from the Sun.
Sea ice expansion could be felt even more so if the Earth is within the time for another Ice Age. This could happen if it is near a 100,000-year period of Ice Age. Another Ice Age though is hard to predict, as Lee has said. This is because human activity has contributed much to climate change, which could have an effect on the Ice Age timing period.
The Earth is said to be due for another Ice Age though. Sea ice and the Earth's orbit might be linked to produce it. Astronomers also speculate that methane gas warmed early Mars.
