Extreme Weather – The Arctic Connection
When it comes to science, climate change and weather, it is always a tricky business to try to definitively establish cause and effect. Separating the real cause from a mere coincidence, and then connecting the dots between the extreme meteorological events that we witness on our television news and identifying their specific cause is - to say the least - challenging.
Enter scientists like Dr. Eddy Carmack. Dr. Carmack is a Scientist Emeritus with Fisheries and Oceans Canada and for much of his career was a climate oceanographer with the department. His primary focus was on the Arctic and the northern ocean and he has interesting things to say about the changes he sees going on there, and their impact on the rest of the world.
He too is quick to point out that his work, and that of other scientists, is not carried out to prove cause and effect. And that it is quite a leap to go from climate-related studies and pin them specifically on a single meteorological event like Hurricane Sandy. That said, for the last two decades he has attempted to find linkages between what's going on in the Arctic Ocean with what is transpiring in its neighbouring subarctic, Atlantic and Pacific Oceans. It is the connectivity of processes that fascinates him and it has been a theme that has run through much of his research.
He has been very well placed to examine those processes since he led Canada’s Three Oceans (C3O) project from 2007 to 2011. C3O, an International Polar Year project, was comprised of a large international team of scientists who set out to gather integrated, multidisciplinary and baseline information on the physical, chemical and biological structure of subarctic and Arctic waters around Canada. Among other things, their studies documented the ice/ocean physics at play, and how it might be linked to the Arctic atmosphere and changing weather further south.
And since 2003, the international Joint Ocean Ice Studies (JOIS), co-led with Drs. Fiona McLaughlin and Bill Williams, and which includes the work of many DFO scientists, has carried out an annual expedition to the Canada Basin. Dr. Carmack: "The Canada Basin study is the premier Arctic monitoring activity in the world in terms of temporal, spatial and disciplinary breadth. The Canada Basin is in fact, ground zero for Arctic climate change. We didn't design this study ahead of time - to observe the abrupt collapse of summer ice and the warming of the ocean – or to document changes to the Polar Vortex – rather they just sort of happened in the middle of our study."
Those changes have been considerable. In recent years scientists have witnessed an alarming decline in summer ice coverage in the Arctic. 2007 was a watershed year in summer ice retreat and thinning. Since then the ice fields have fluctuated from year to year but have remained distressingly low.
With so much open water in the summer, heat is absorbed into the ocean as never before. When winter comes, the Arctic re-freezes – but not as thickly as it used to - and in so doing it first has to give that heat up that has been absorbed in the upper 10 to 40 metres of the water. That relinquished heat in turn warms the overlying atmosphere and weakens the Polar Vortex, which is a large-scale region of air that is contained by a strong west-to-east jet stream that circles the polar region.
Dr. Carmack: "Heating the polar vortex causes it to rotate slower. When it rotates slower its outward boundary - which is the polar jet stream - starts to become unstable. And wiggle. It develops large meandering waves and they move slower around the earth and they tend to "block". Blocking means that weather patterns tend to remain longer in a given spot. So a heat wave, or drought, or hurricane might last uncomfortably longer in a given place."
He adds, "At both the higher atmospheric levels and closer to the water surface, conditions in the Arctic set the scene for Arctic air masses to destabilize and shift south - to interact with hot, wet air from farther south. This means we can expect more frequent large-scale extreme weather events in the southerly regions of Canada and the United States, when Arctic and sub-tropical air masses clash, such as with Hurricane Sandy."
Dr. Carmack cautions however, that these are general characteristics. On the other hand, he underscores the undeniable set of cascading linkages. He points out that if the Arctic ice thins - which it is - and if more heat is stored in the surface during summer and if this weakens the Polar Vortex - which is exactly what is happening - and if in response the Polar jet stream develops large meanders - which does happen - then there are connections to the storms we have been seeing over the past few years. The leap, he suggests, comes by suggesting that one particular meteorological event, like Hurricane Sandy, that took place over a period of 4 to 8 days was absolutely connected to all of this.
He also likens the linkages to falling dominoes. It took us a long time to tip over that first domino - to get the ice thinning in the summer to have an impact on atmospheric events. But there are other dominoes, all banging into each other. Rising water temperatures, ocean acidification, changes to the structure of the food web, changes to the basic patterns of primary food production - to name but a few.
He points out that the climate process is a two-way street. "The perception is that the Arctic is some kind of victim," he notes. "We produce the carbon dioxide down here and it gets all the punches up there. I think that what people ought to realize is that the Arctic is not going to take this lying down. As we are seeing it's going to send some pretty drastic changes to the comfort zone that we live in - whether we are talking about changes in our weather patterns, our rainfall patterns, our temperatures, the length of extreme events, like droughts and cold snaps, and so on. There are indeed going to be consequences to what we are doing to change our connectivity with the Arctic."
So, have we reached a tipping point? It probably depends a little on what you call normal, or have come to accept as a new normal.
Dr. Carmack: "We are increasingly living in a nonlinear and unpredictable world. It is a complex and chaotic system that – with our help – is changing very quickly. In the Arctic that nonlinear unpredictable future has arrived already. By studying and understanding the processes that are taking place there, we in fact have a chance to look into the future. Doing so will allow us to come up with better climate policies down here before the kind of massive changes that we are seeing north of us trickle down and take over our domain where we live, breathe and feed ourselves."
Wherever anyone comes down on the climate debate, one thing is certain. It can only be in our own best interests to understand how things are connected and try to come up with policy responses and adaptations that will work. The Arctic has provided us with a glimpse into the future. It is up to all of us to heed its warnings, take them to heart, and ask our decision makers to come up with mitigating strategies to prevent the possible from becoming the inevitable.
The Boy Scouts said it best, "Be Prepared".
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