Wednesday, April 29, 2015

On The Origin of Tornadoes - 6

Fig. 1 A cold mini-vortex is calved
I. Introduction

March was the warmest month on record for the global average.

The quarter (Jan., Feb. Mar.) was likewise the warmest quarter in recorded weather history for the globe we call the Earth.

More to the point, "This marks the highest March temperature in the 136-year period of record, surpassing the previous record of 2010 by 0.05°C (0.09°F)" (NOAA, Global Analysis - March 2015).

In other words, there was an acceleration in global warming.

People in the North East U.S. probably missed the heat since they were repeatedly blasted with polar air from the polar vortex.

People in the western U.S. experienced record highs as their fellow citizens in the eastern U.S. experienced the cold polar vortex sections breaking off and floating southward.

Yesterday, and the day before, a small hurricane-looking section of a vortex of cold air, 25 deg. below normal (45 deg. low and lower) floated over Texas and headed east (see Fig. 1).

II. One Abrupt Change Goes Almost Unnoticed

As I pointed out in the last post, I expected the tornado count to drop in 2014.

Tornadoes had been, and still are, taking an abrupt drop in numbers from the ongoing trend:
It’s the great depression for tornado activity in the U.S.

At least 400 fewer tornadoes than average have touched down in the U.S. this year, making it one of the quietest years on record for twisters, according to the National Weather Service (NWS).

Whereas an average of 1,260 tornadoes form each year in records dating to the early 1950s, only 823 have occurred in 2014 through November, says Greg Carbin, warning coordination meteorologist at the NWS Storm Prediction Center, in Norman, Okla.
(U.S. Tornado Numbers Among Lowest In Recorded History in 2014). The unique conditions in the U.S. that produce 75% of the world's tornadoes here have changed.

III. What Is Up With That?

Cold air from the polar vortex, i.e., spinning off and calving little vortexes that travel south, inhibit tornado formation:
Under normal climate conditions, cold air is confined to the Arctic by the polar vortex winds, which circle counter-clockwise around the North Pole. As sea ice coverage decreases, the Arctic warms, high pressure builds, and the polar vortex weakens, sending cold air spilling southward into the mid-latitudes, bringing record cold and fierce snowstorms. At the same time, warm air will flow into the Arctic to replace the cold air spilling south, which drives more sea ice loss.
(Wunderground, emphasis added). The laws of fluid dynamics tell us that "Heat flows from hot to cold ... The first statement of the 2nd law of thermodynamics - heat flows spontaneously from a hot to a cold body - tells us that an ice cube must melt on a hot day, rather than becoming colder" (Univ. Winnipeg).

In the video at the bottom of this post, beginning at 11:05, the Arctic scientist explains that as ice cover melts away heat from the water enters the atmosphere and breaks up the polar vortex the same way it breaks up ice.

IV. What Is To Be Expected RE: Tornadoes?

In the near term the decrease in the number of tornadoes is welcome, but what does this abrupt climate change portend?

Not only is there a source of warm air flowing in forcing cold air out, there is a source of warm water too, as explained in Section V, Fig. 2, below.

These changes in the Arctic are producing strange phenomena that can be considered a type of feedback loop:
As the sea ice covering the Arctic continues to shrink under the influence of greenhouse gas-induced warming, it’s causing a host of other changes in the region, including the growth of large waves in the previously iced-over areas. Those waves could potentially reinforce and hasten the demise of sea ice, leading to further changes in the fragile polar realm.

Changes brought on by global warming in the Arctic region have been well documented. Temperatures there have risen twice as fast as the global average. That rise is tied to a decline in Arctic sea ice, which has seen its seasonal minimum area shrink by nearly 14 percent per decade since the late 1970s. Those changes could be influencing weather patterns in lower latitudes of the world, though that’s an area of continuing research for scientists.

And in the latest sign of more changes afoot, according to a recent study published in the journal Geophysical Research Letters, waves are swelling to heights never before seen in the Arctic Ocean — a shift that’s tied to the loss of sea ice and could further exacerbate it.
(Swelling Waves Could Hasten Demise of Arctic Sea Ice). Thus, when the ice has all melted and the cold air mass has been replaced or modified with warmer air, it is likely that the tornado count will increase as the vortex diminishes.

V. What About Sea Level Rise (SLR)?

The Greenland Ice Sheet, especially along the coast, is sure to feel the warmth if warmer
Fig. 2 Source of warm water for Arctic
air and warmer water incursion into the Arctic generates additional ocean currents.

The normal pattern is for that to happen as follows:

1) warm water will flow up through the Gulf of Alaska from "The Blob" into and through the Bering Strait; 2) It will make its way into the Chukchi Sea; 3) Then if will flow across into and through the Fram Strait; and 4) Finally it will then flow around both sides of the coast of Greenland (The Arctic: Ocean Circulation).

The ice sheet areas of Greenland will likely see an acceleration of melt in the coastal zone there (see "IV. The Melt Zones" @ What Do You Mean - World Civilization? - 2).

VI. When Will There Be SLR Impact?

That depends, first, on acceleration of melt of the Arctic ice that is floating on the ocean.

The diminishing of ice extent will not be a factor in SLR because that ice has already done its displacement, however, as it melts the reflective power it has goes away.

Then the darker ocean will be impacted by absorbing more and more sunlight instead of reflecting it.

That means more warm water flowing through the Fram Strait, and then around Greenland.

Increased Greenland ice melt will follow, which means an acceleration of SLR (The Question Is: How Much Acceleration Is Involved In SLR?, 2, 3).

VII. Conclusion

"The toe bone's connected to the foot bone, The foot bone's connected to the ankle bone, The ankle bone's connected to the leg bone" (Dem Bones).

And so forth.

The global climate system is like that too, so "The Blob" over at the "Garbage Patch" (see link @ Fig. 2) can have an impact on Greenland in unexpected ways.

Not to mention having an impact on civilization's energy infrastructure that will be worse than tornadoes (FERC Plan To Limit Overpopulation?, Sea Level Rise: Impact on Energy Infrastructure).

The previous post in this series is here.

2011 Tedx Video featuring long-time Arctic scientist:

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