For a while, scientists have noticed the lull in the Earth's southern hemisphere, the part of the Earth that acts like a massive carbon sink. Now, scientists have discovered that the Antarctic Ocean pulls more carbon dioxide at an increased rate.

Scientists say that the increased trend should reduce concerns regarding the Antarctic Ocean's inability to clean-up CO2 and the slowdown that was thought to saturate this carbon sink.

The Antarctic Ocean absorbs almost 43 percent of the CO2 that human activities produce. This slows down the growth of greenhouse gases in the atmosphere.

However, scientists are still puzzled about the processes and factors governing CO2 uptake in the southern hemisphere. Further research would significantly improve the understanding on the Antarctic Ocean's response to global warming.

A team of scientists had reported that a slowdown occurred in between 1981 and 2004. It was the result of the combination of Antarctica's ozone hole and continued global warming, affecting the movement of westerly winds that prevail in the Antarctic Ocean.

More greenhouse gases will develop in the atmosphere if the slowdown in winds and CO2 uptake continued for a span of time.

With recent studies, the slowdown had appeared to have ended in 2002, and by 2012, the Antarctic Ocean's uptake has decreased to pre-slowdown levels.

Dr. Colm Sweeney, a researcher at the Research Laboratory of the National Oceanic and Atmospheric Administration's Earth System said that in 2002, the Antarctic Ocean's uptake of CO2 went from 2.5 billion tons to 2 billion tons.

One study published in Geophysical Research Letters showed that Drake Passage, an area in the southern hemisphere that expanses from South America to the West Antarctic Peninsula, has been increasing uptake of CO2 since 2002.

The coldest waters during winter absorb more CO2, and the deepest waters that has not had contact with the atmosphere has lower CO2 content than surface waters. This allows more absorption of CO2 than usual.

Another study published in the journal Science revealed differences in how water surface temperatures and water chemistry influenced uptake throughout the southern hemisphere. The researchers from ETH Zurich found that the differences could be related to the modes of climate variability in the Pacific and Atlantic.

Meanwhile, Jorge Sarmiento, a Princeton University professor believes that these results are 'still not rock-solid proof'. He concludes that a long-term monitoring program would be ideal but thinks that additional data would be a major achievement in understanding the Antarctic Ocean's carbon cycle.

Photo: David Stanley | Flickr