Wednesday, July 17, 2013

Boiling Under That "Heat Dome"? You Can Thank Global Warming!

Comparison images of Arctic (top) and Antarctic sea ice changes for summer minimum and wniter maximums. (From National Snow and Ice Data Center)

Tens of millions will be baking today with "thermatures" that approach 110 degrees F in some cities, such as Philadelphia. The official meteorological patter is that it's due to a "heat dome".  But most won't go the next step and track it to what it really is: global warming reaching a new dramatic level on this planet.  Why the hesitance? Who knows? But as physicist Michio Kaku noted this morning: "this could be part of a larger trend."

What do we know? As Kaku observed, one single heat dome event can't be pinned on global warming, but the trend or statistical average disclosing enhanced temperatures over larger regions, can. And the fact is that the statistical trend discloses many more such heat dome incidents, over larger and larger areas and lasting longer. As he pointed out this morning, this translates to longer and longer summers, hotter ones and more elderly likely dying because of heat waves - as well as increased strain on limited power supplies.

Now, let's get down to cases. As I noted in previous blogs, e.g. Oct. 21, 2012, Arctic sea ice is more important for Earth's energy balance because when it melts the albedo more rapidly decreases, exposing dark terrain which absorbs more solar radiation which is then trapped by the CO2 blanket. Meanwhile, the melting of Antarctic sea ice each summer largely leaves the energy balance unchanged. I also noted that there is a net loss of sea ice of some 74-75 gigatons per year.

Now,  let's move to the behavior of the Jet Stream in relation to Arctic thermal balance. Dr. Jennifer Francis of Rutgers University last year,  provided cogent scientific evidence that the erosion of Arctic sea ice and land snow resulted in less of the Arctic's cold air being trapped within the Arctic. This means there is less cold air available within the jet stream, at the same time more warm and moist air intrudes from the south. As a direct result of the temperature difference being reduced between the Arctic and mid-latitudes, the Jet Stream has formed large dips and bulges - many of them occurring during the summers and with the dips northward lasting longer - creating your "high pressure heat domes".

Again, no one heat dome points to global warming, but a succession of them over years, emerging as a higher temperature trend, does. Add to this that as the dips form and the affected air is repeatedly slowed, the Jet Stream has a greater tendency to become "stuck".  This sticking in place creates blocking patterns in which heat domes are likely to form with the inevitable heat waves occurring over extended periods of time.

To her credit, Dr. Francis has also pointed to an increased frequency of such blocking patterns, which also show how climate change is impacting our weather.  That such anomalous high pressure domes are increasing ought to therefore terrify every man, woman and child impacted each year. Because as Kaku observed, they will get worse - something first pointed out by David Suzuki in a 1991 book ('It's A Matter Of Survival')  on global warming.

Suzuki observed that extended heat periods would increase in frequency eventually leading to the first "year of no seasons" by which time there'd be no cooler respite at all. He estimated it as beginning from 2040, but the increasing length of summers, the increasing heat dome events and Arctic melting suggest if may arrive as early as 2020.

If people can barely handle it now, what will they do when actual temperatures hit 110F daily and only are down to 95-100F at night, even without humidity factored it? What will they do when so many want to keep cool at any cost that they drain the power grid to a crashing halt? What will happen when the water mains also break, as they have threatened to do in Prince William County,  Maryland (forcing a 5-day shutdown), because our people and politicos pay more attention to an artificial DOW than they do to their own water mains and other corroding infrastructure?

These are questions that remain to be answered.  The problem is we may not like the answers we will soon get!

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