Greenland Ice Melt
We in Canada like to think we have a lock on the world’s fresh water, that we have lots to spare. And if you live in the eastern half of Canada, from Winnipeg eastwards, you have an argument for that case, at this soggy summer. And it has been one to remember, though the coming few weeks may yet resuscitate a return to beachwear.
But since we are talking about water, it would behoove us to have a small diversion to the frozen island, so happily named by Eric the Red some 1,000 years ago, hoping to make it an emigration destination, Greenland. This almost one-million-square-mile island, about the total area of Quebec and Ontario combined, has the distinction of being covered with glacial ice with an average thickness of mile and half. That makes it the second largest repository of fresh water in the world. About 10 per cent of the entire fresh water of the world is tied up in those Greenland glaciers. The only ice sheet larger is the Eastern Antarctic ice sheet of the antipodes.
Over the past decade researchers have been measuring the summer melt we get off this massive ice sheet. Its a complicated business and not all that easy to do, but its related to the flow and speed of the glaciers, measured used radar imaging, lasers, satellites and other fancy high tech gear. But the results were reported, verified and subject to peer review, and hold up. The ice sheet was and is melting faster than previously had been measured.
Back in the mid 1990s that flow was in the neighbourhood of 10 cubic miles. It had been stable and predictable for the previous few decades. But about ten years ago researchers who studied the flow, the temperature of the north Atlantic, the Gulf Stream and other related topics, noticed it jumped an order of magnitude. The melt was now over 100 cubic miles a year and it was increasing. This was news. The ice cap was melting, the average temperature had skyrocketed way past even the worst estimates the IPCC had projected. Modeling suggested that much cold fresh water would have a substantial impact on the heat flow the Northeastern coast of North America and North Western Europe receive from the Gulf Stream.
The cold water water off of Greenland is less dense than the very saline and warm water coming up from the southern Atlantic. About 25 per cent of our heat energy comes from that massive flow of water. Just a couple of hundred kilometres off the coast the water is close to 20 degrees celsius, even in the winter. And it has a huge impact on our weather systems.
With that much cold water coming off Greenland, it has the ability to cap the warm water from the Caribbean and keep the heat in the ocean. We wind up getting very little of the heat benefits from the Gulf Stream. As a result we get wet cold winters, and protracted wet springs and summers. Which is what we have had so far this summer season.
How long will this go on? How many years can we expect to get soggy summers. The Greenland melt is being monitored closely and it appears that each year the melt is increasing. Historical data tells us that as long as the cold water is there to cap the Gulf Stream we can expect this soggy inclement weather to continue. A short, back of the envelop calculation tells us there is enough ice for this to continue a long long time, at least until most of the ice has melted.
And the surprising thing is that as we experienced one of the wettest, least sunny and soggiest June and July on record, June was the warmest June ever recorded on this pale blue orb. Food for thought?
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