Here is some hard to understand (or reconcile) research (on the surface anyway) about the ice sheet covering Antarctica and its potential future melting. Scientists from the Potsdam Institute for Climate Impact Research claim that more snowfall on the continent of Antarctica counter-intuitively leads to MORE ice loss at the edges. In fact they say that future ice loss will be 3 times greater because of increased snowfall upon the continent. Doesn’t sound right, does it? Especially since the ice sheet around Antarctica is growing and breaking records for it’s extent into the ocean. It would appear that right now, increased snowfall on Antarctica IS leading to more ice. And, isn’t that how the ice sheets (and glaciers) build up in the first place? With more snowfall? They certainly didn’t get that way by less snowfall and melting.
The key to unravelling this paradox is to think about the near future. If the oceans continue to warm, then the ice could melt faster than the build-up due to snow in the interior of Antarctica. Less ice floating around in the sea around Antarctica would mean the glaciers and ice sheets on the continent would have less resistance flowing into the ocean. The increased snow could exert more pressure on the flowing ice pushing it into a warmer sea, thus causing more melting. The key trend will be whether the increased snowfall (and build-up of ice sheets) will outpace the melting at the edges. Here is some additional reading about the opposite ice trends in the Arctic and Antarctic plus some additional theory as to the mechanism by which the Antarctic ice sheet has grown.
By the way, on the subject of Antarctica, Lake Vostok is a story I have been following for a few years (another good post here) - the Russians apparently DID break through to Lake Vostok earlier this year. So far there are no signs of life, but more investigations are coming. I think it would be neat if some new form of life was discovered, something that has had no contact with the earth’s surface for hundreds of thousands of years. As long as it did not turn into a situation like “The Thing” (which is a good thriller movie – not terribly gory either).
Also, on the subject of ice, have you ever wondered how many molecules of water it takes to form an ice crystal? It is not just two. Due to the shape and forces (intermolecular hydrogen bonds) within water molecules, if you put just 2 water molecules in jar and chilled it down below freezing, the molecules would not come together to form ice. Maybe 10? Surely 10 molecules of water could maneuver into a particular arrangement, stick to each other and form a real ice crystal, right? Not quite. According to this recent research, it takes approximately 275 molecules of water before a legitimate standard ice crystal will form. Now you have some weekend trivia with which to stump your friends.
Have a nice Friday! Meteorologist Justin Loew.
This post was written by jloew on December 14, 2012