The scientists who have been working feverishly to understand the mystery behind expanding Antarctic sea amid global rise in temperatures may have a lead.
While the sea ice has been disappearing globally at a staggering rate of about 13,500 square miles every year, Antarctic Sea has recorded an unbelievable expansion until reaching a record high of 7.78 million square miles in 2014. According to a recent study published in Nature Geoscience, the answer to this mystery phenomenon is not available in Southern Ocean but in Pacific.
Researchers at the National Center for Atmospheric Researcher in Boulder, Colorado, along with researchers in Australia and Seattle, discovered that Antarctic Sea expansion started at the turn of 21st century, roughly coinciding with Interdecadal Pacific Oscillation (IPO), an extended variation of atmospheric pressure that impacts the temperatures in sea waters, cooling the ocean surface in Pacific and shifts temperatures in to negative phase, causing global consequences.
"When you get changes in [sea surface temperatures] in some areas of the tropics, you affect precipitation, that affects the amount of energy released in the atmosphere," Gerald Meehl, the study's lead author and a climate scientist with NCAR, told The Washington Post.
"That starts affecting, through this kind of chain reaction process, circulation at great distances away."
IPO was taken into consideration by few climate change models that can precisely forecast the expansion of Antarctic sea ice, as well as global warming slow down in the beginning of 2000s. Out of "262 realizations of 20th century climate, 10 of those got this observed slowdown of global warming happening at about the same time as in the observations, at the same magnitude," Dr. Meehl told The Washington Post. "And for those 10, there was the negative phase of the IPO, and it also has the signature of Antarctic sea ice."
