Tuesday, August 13, 2019

Arctic Summer Has Been Too Much Like What We Normally Get

X marks the spot where the North Pole is on this map. Red box
points to where there was lightning recently. 
Time to check in once again to the not-so-Great White North, meaning the Arctic, which continues to have an extraordinarily hot summer.

You've seen some posts this summer noting how hot it is up there, but the news keeps coming. Alaska beach weather. Arctic wildfires. Summer thunderstorms rattling around the North Pole.

This in an area that is normally bleak and chilly despite the usual 24-hour a day sun in the first half of summer.

LIGHTNING NEAR NORTH POLE

Here in Vermont, we endured lightning strikes every summer.  That's just normal this time of year around here. But recently. lightning was also striking within 300 miles of the North Pole, which is really something.

In general, if you want a thunderstorm, it's fine to have cold, dry air aloft, but you need relatively warm, humid air near the surface.  We get that here in Vermont in the summer, so we have thunderstorms. As does pretty much everybody else in the mid-latitudes.

The Arctic has always had plenty of cold, dry air around. But warmth and humidity, at least compared to what it normally is up there, is usually scarce. Which means so are thunderstorms.

It's possible there has been lightning that far north before, but nobody that I've found knows of it. And one thunderstorm doesn't prove climate change. But this is odd. And warm.

It does make sense that lightning could become more common in the Arctic. There are signs it already is getting more frequent.  When the Arctic ocean is more ice covered, that stabilizes and chills the air, squelching any attempts at the billowing clouds that can produce lightning.

When there's open water, it can collect more heat, creating rising air currents and produce thunderstorms under the right conditions. Arctic sea ice is at its lowest level on record for this time of year, so it's kinda not surprising they had a weird thunderstorm up there.

The thunderstorms occurred in an area that was frozen over. But open water was just 150 miles away. The storms apparently got going there, over the open water, then moved north. 

ALASKA HEAT UPDATE

The ever helpful Category 6 weather and climate blog has given us a nice update on this summer in Alaska, which statewide, was the hottest on record.

The records are incredible, but the town that takes the cake in my opinion is Kotzebue, along the coast in northwestern Alaska. May, June and July there were the hottest on record. They have not had a single cooler than normal day since February 14! The last time Kotzebue had a cooler than normal month was two years ago.

That pretty much the entire state of Alaska was record warm in July is particularly incredible considering how vast it is. Superimpose Alaska on the Lower 48 and it covers the entire middle of the nation.

So far, the warm Alaska summer has extended through the first half of August.  Another heat ridge might build up there over the coming week or two, which would prolong the odd hot summer in Alaska.

SEA ICE AND OUR WINTERS

At least one new study suggests that melting sea ice is NOT
making our winter in Vermont more harsh. The debate continues....
As I've mentioned in previous blog posts here, some climate scientists have been wondering if the loss of Arctic sea ice have been making winters here in Vermont, elsewhere in the United States and in Europe harsher.

The theory is that the loss of sea ice makes the jet stream wavier and helps get it stuck,  causing cold air to plunge down on us from the north.

A new study questions this theory.  As ScienceDaily points out, the study says that although low winter Arctic ice levels and tough winters here often coincide, the low sea ice isn't having a big influence on these winters.

With or without climate change, Arctic sea ice levels fluctuate year to year. Sometimes there's not much ice, other times there's quite a bit. The overall trend is down for the ice, but it's not a steady drop over years and decades.

Atmospheric weather patterns tend to promote particularly relatively small amounts of sea ice in the Arctic during some winters. Those same weather patterns cause cold snowy winters in eastern North America and western Europe.

This won't be the final word on this issue. I'm sure the scientists will continue studying and debating this one.



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