"Warm" Arctic- Cold Continents Theory Based on Sea Ice Loss

[blizzard1024]

I was wondering what folks on this forum thought of this. Was it a knee-jerk reaction of scientists

to the severe winters of 2009-10 and 2010-11 in the U.S? Last winter, there was warmer than normal

conditions in the Arctic and cold in Asia and Europe. The U.S/Canada were the only main midlatitude areas

that were warm in the NH last winter. See 850 mb temp anomalies below.

Basically for those new to this idea...loss of sea ice leads to more heating of Arctic Ocean

and disrupts the jet stream patterns favoring more blocking and more negative phase AO

and NAO patterns. BUT...I remember in the 1990s the studies were saying that, with global

warming from GHG increases, the NAO/AO would be more positive. Of course, this was after

a string of a positive NAO/AO winters. So you can see my skepticism. The basic concept

of less sea ice and more blocking seems on target. One thing of note was seen, especially in winter

2009-2010. We had record low NAO values and yet winter in the northeast was snowy yes..

but not exceptionally cold. One of my colleagues said that this was a severe winter in a

global warming world!! Based on the indices, that winter should have been as cold as some

of the historically cold winters in the northeast like 1976-77 and it was nowhere near that.

Maybe we do see more colder or at least snowy than normal winters for a while at least...but not as cold as it was?

Again, I am skeptical on this idea. Anyone else have some thoughts or recent research they know of?

Please share. Thanks!

Here is some reference material on this topic....if proven true or even favoring more negative

NAO/AO winters...it could be an interesting run in the transition to a warmer climate by the

end of this century....

http://www.arctic.no..._continent.html

http://voices.washin...arctic-col.html

http://climatesignal...-to-u-s-europe/

¹Honda, M., J. Inoue, and S. Yamane (2009): Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters. Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.

²Strey, S.T., W. Chapman, and J. Walsh (2009): Effects Of An Extreme Arctic Sea Ice Minimum On the Northern Hemisphere Atmosphere During Late Autumn and Early Winter:, Eos Trans. Eos Trans. AGU, 90(52), Fall Meet. Suppl., Abstract C41A-0421.

³Francis, J.A., W. Chan, D.J. Leathers, J.R. Miller, and D.E. Veron (2009), Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent, Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274.

⁴ Budikova, D. (2009): Role of Arctic sea ice in global atmospheric circulation: A review. Global Planet. Change, 68(3), 149–163.

⁵ Petoukhov, V., and V. Semenov (2010): A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents. J. Geophys. Res.-Atmos., ISSN 0148-0227.

⁶Serreze, M. C., A. P. Barrett, and J. J. Cassano (2011), Circulation and surface controls on the lower tropospheric air temperature field of the Arctic,J. Geophys. Res., 116, D07104, doi:10.1029/2010JD015127.

⁷ Overland, J.E., K.R. Wood, and M. Wang (2011): Warm Arctic–cold continents: Impacts of the newly open Arctic Sea. Polar Res., 30, 15787, doi: 10.3402/polar.v30i0.15787. [PDF Version]

⁸ Jiping Liu, Judith A. Curry, Huijun Wang, Mirong Song, and Radley M. Horton (2012). Impact of declining Arctic sea ice on winter snowfall PNAS 2012 ; published ahead of print February 27, 2012, doi:10.1073/pnas.1114910109

⁹ Francis, J. A. and S. J. Vavrus (2012), Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophys. Res. Lett., 39, L06801, doi:10.1029/2012GL051000.

[nzucker]

It's definitely an interesting idea about low sea ice correlating to a blocking pattern, but we have a small sample size. However, I must disagree with the assertion that Winter 09-10 should have been as cold in the CONUS as Winter 76-77, and that the difference was due to global warming. There was a distinct difference in the 500mb patterns that led to one winter being colder, and one winter being snowier.

Winter 76-77 had an ideally positioned block for cold weather in the CONUS, with a large ridge situated north of Alaska and stretching back into Siberia. This pattern allows Siberian cold, the most extreme stuff in our hemisphere, to spill towards NW Canada, and the ridge positioned north of AK over the Beaufort and Chukchi Seas allows this displaced Siberian cold to be pumped southward as the high creates persistent north winds over these areas. There was also no troughing over the Pacific which could have injected maritime air into the continent. Our coldest airmasses in the US come from the source regions of eastern AK, the Yukon, and the Northwest Territories. This map shows a beautiful pattern for putting Siberian air into those source regions, and then pumping it southward on the front side of that North Pacific/West Coast high:

Winter 09-10 had a general -AO/Arctic block, but the ridge was positioned much closer to Greenland with more normal heights in Alaska, the Beaufort Sea, and off the Pacific coast. The coldest air in the US rarely comes from Greenland and Hudson Bay, and the pattern is 09-10 is much more likely to create extreme cold in Europe compared to North America. You also had troughing over the West Coast and into the Central Pacific, which allowed maritime air to flood the CONUS occasionally, especially in January:

The one bitterly cold month in Winter 09-10 was December, which had the Alaska/Pacific blocking pattern similar to 76-77:

This double blocking pattern (-NAO/-EPO) resulted in a memorably cold December for much of the Plains and Northern Rockies with -10F anomalies, and extreme cold in Europe:

[Entropy]

The basic concept of less sea ice and more blocking seems on target. One thing of note was seen, especially in winter

2009-2010. We had record low NAO values and yet winter in the northeast was snowy yes..

but not exceptionally cold. One of my colleagues said that this was a severe winter in a

global warming world!! Based on the indices, that winter should have been as cold as some

of the historically cold winters in the northeast like 1976-77 and it was nowhere near that.

This is a good point. Although 2009-10 was a quite snowy winter, it wasn't particularly cold in my neck of the woods. The local records show a mean temperature just 0.3F below the 1971-2000 normal. Even more noteworthy, the lowest minimum temperature of the winter was just +1F, which is actually unusually warm. From 1960 to 1989, there were only two winters that failed to drop below zero. I do think the cold temperatures were more pronounced in the southeast though.

As for the sea ice theory, with the current record low extent, this winter should provide a good test of its validity. There's always seemed to be a reticence in the meteorological community to use climate change effects as a basis for a long-range forecast, so it will be interesting to see whether any forecasters adopt this theory in formulating seasonal outlooks this year.

[blizzard1024]

It's definitely an interesting idea about low sea ice correlating to a blocking pattern, but we have a small sample size. However, I must disagree with the assertion that Winter 09-10 should have been as cold in the CONUS as Winter 76-77, and that the difference was due to global warming. There was a distinct difference in the 500mb patterns that led to one winter being colder, and one winter being snowier.

Winter 76-77 had an ideally positioned block for cold weather in the CONUS, with a large ridge situated north of Alaska and stretching back into Siberia. This pattern allows Siberian cold, the most extreme stuff in our hemisphere, to spill towards NW Canada, and the ridge positioned north of AK over the Beaufort and Chukchi Seas allows this displaced Siberian cold to be pumped southward as the high creates persistent north winds over these areas. There was also no troughing over the Pacific which could have injected maritime air into the continent. Our coldest airmasses in the US come from the source regions of eastern AK, the Yukon, and the Northwest Territories. This map shows a beautiful pattern for putting Siberian air into those source regions, and then pumping it southward on the front side of that North Pacific/West Coast high:

Winter 09-10 had a general -AO/Arctic block, but the ridge was positioned much closer to Greenland with more normal heights in Alaska, the Beaufort Sea, and off the Pacific coast. The coldest air in the US rarely comes from Greenland and Hudson Bay, and the pattern is 09-10 is much more likely to create extreme cold in Europe compared to North America. You also had troughing over the West Coast and into the Central Pacific, which allowed maritime air to flood the CONUS occasionally, especially in January:

The one bitterly cold month in Winter 09-10 was December, which had the Alaska/Pacific blocking pattern similar to 76-77:

This double blocking pattern (-NAO/-EPO) resulted in a memorably cold December for much of the Plains and Northern Rockies with -10F anomalies, and extreme cold in Europe:

Yeah....it was just a comment and seemed to make sense. But 1976-77 as you point was far different in other circulation aspects so I have to agree

with you.

[ORH_wxman]

It's definitely an interesting idea about low sea ice correlating to a blocking pattern, but we have a small sample size. However, I must disagree with the assertion that Winter 09-10 should have been as cold in the CONUS as Winter 76-77, and that the difference was due to global warming. There was a distinct difference in the 500mb patterns that led to one winter being colder, and one winter being snowier.

Winter 76-77 had an ideally positioned block for cold weather in the CONUS, with a large ridge situated north of Alaska and stretching back into Siberia. This pattern allows Siberian cold, the most extreme stuff in our hemisphere, to spill towards NW Canada, and the ridge positioned north of AK over the Beaufort and Chukchi Seas allows this displaced Siberian cold to be pumped southward as the high creates persistent north winds over these areas. There was also no troughing over the Pacific which could have injected maritime air into the continent. Our coldest airmasses in the US come from the source regions of eastern AK, the Yukon, and the Northwest Territories. This map shows a beautiful pattern for putting Siberian air into those source regions, and then pumping it southward on the front side of that North Pacific/West Coast high:

Winter 09-10 had a general -AO/Arctic block, but the ridge was positioned much closer to Greenland with more normal heights in Alaska, the Beaufort Sea, and off the Pacific coast. The coldest air in the US rarely comes from Greenland and Hudson Bay, and the pattern is 09-10 is much more likely to create extreme cold in Europe compared to North America. You also had troughing over the West Coast and into the Central Pacific, which allowed maritime air to flood the CONUS occasionally, especially in January:

The one bitterly cold month in Winter 09-10 was December, which had the Alaska/Pacific blocking pattern similar to 76-77:

This double blocking pattern (-NAO/-EPO) resulted in a memorably cold December for much of the Plains and Northern Rockies with -10F anomalies, and extreme cold in Europe:

That Dec '09 map is weird...it has the first couple shades of yellow as still below average.

A better "visual" for that month is this:

And I agree that the pattern later that winter wasn't ideal for frigid cold here....we actually got cut off from our best source region.

December 2000 is also a good example of a good looking arctic for extreme cold over most of the CONUS

[tacoman25]

Yes, as others have pointed out there were some key differences between 1976-77 and 2009-10 that led to different outcomes around the country.

Another way to look at the pattern differences is not just the difference in the -NAO component, but also 1976-77 had a very strong +PDO pattern in the Pacific, which led to much greater heights along the West coast of the U.S./Canada. This combined with the -NAO to produce a very cold winter for the eastern 2/3 of the nation that winter. The blocking on the Pacific side wasn't nearly as good for cold in the eastern U.S. in 2009-10.

[nzucker]

You can see that sometimes these epic cold patterns have the ridge displaced north of Alaska towards the Siberian side, with the highest heights in the polar regions of the Beaufort and into the Chukchi and East Siberian...both Dec '00 and Winter 76-77 exhibited the displaced -EPO block leading to extreme cold in the CONUS.

[GaWx]

Although 2009-10 wasn't as cold as 1976-7, the coldest winter on record here in Atlanta, it was still the 9th coldest on record here as well as the coldest since 1977-8 and was the coldest non-weak Nino on record. There was absolutely no underforming here in the SE US imho coldwise. Records go back to 1878-9. One thing I will say about Nino's in the E US is that the weak variety has been the coldest on average by far. I feel that one can argue that had 2009-10 been a weak Nino, it could have been a good bit colder, especially up in the NE US.

[bluewave]

Although 2009-10 wasn't as cold as 1976-7, the coldest winter on record here in Atlanta, it was still the 9th coldest on record here as well as the coldest since 1977-8 and was the coldest non-weak Nino on record. There was absolutely no underforming here in the SE US imho coldwise. Records go back to 1878-9. One thing I will say about Nino's in the E US is that the weak variety has been the coldest on average by far. I feel that one can argue that had 2009-10 been a weak Nino, it could have been a good bit colder, especially up in the NE US.

The Southeast warming hole is allowing your area have winter cold outbreaks that are close to or even exceed your

coldest winter temps.The Winter of 2010 ranked #6 in the Southeast vs #15 for the us on a whole. You can see that winters

have not been warming over the Southeast compared to the warming trend for the US on the whole. December 2010

is also a very strong example of this with the coldest on record for Georgia and Florida.

Southeast winters

US winters

December 2010 record cold

Recent decade

[Jonger]

Looks like the SE balances out the rest of the country. Interesting how Friz complains about St. Louis and it was only .1 to .2 over the 30 year average.

[nzucker]

You can see that winters have not been warming over the Southeast compared to the warming trend for the US on the whole. December 2010

is also a very strong example of this with the coldest on record for Georgia and Florida.

You can also see that the polar vortex has generally been located over Eurasia, particularly over Siberia, in the last 10 winters. While global warming may be one reason for the decrease in "extreme" cold in the United States, such as the lows below 0F in NYC/Central Park, the position of the PV also plays a huge factor in who receives the brunt of the vodka cold airmasses. Even with a good blocking pattern that brings cold and snow to the US (09-10 for example), you're not going to get the extreme temperatures of winters like 76-77 or 70-71 with the PV sitting over Central Asia.