Saturday, 23 April 2016

Huge Springtime Arctic Warm-up to Crush Sea Ice; storms for Europe

Record Global Heat — Huge Springtime Arctic Warm-up to Crush Sea Ice, Drive Extreme Jet Stream Dip into Europe

22 April, 2016

We know now, as soon as the middle of April, that 2016 will be the hottest year on record. That not only will it be the hottest year, but that it will crush any other previous record hot year by a wide margin.

NASA GISS head — Gavin Schmidt — in a recent tweet estimated that 2016 would fall into a range near 1.32 C above the 1880-1899 average that NASA uses for its preindustrial baseline. By comparison, 2015 — which was the most recent hottest year on record after 2014 (three in a row!) — hit 1.07 C above the 1880-1899 average.

GISS Temperature Map First Quarter of 2016
(According to NASA, the first three months of 2016 were 1.25 C above the NASA 20th Century baseline and a ridiculous 1.47 C above the 1880 through 1899 preindustrial average. Image source: NASA GISS.)

As a result, 2016 will likely have jumped by about a quarter of a degree Celsius in a single year. If every year from 2016 on warmed up so fast the world would surpass the dreaded 2 C mark by 2019 and rocket to about +22 C above 19th Century averages by 2100. That’s not going to happen. Why? Because natural variability assisted greenhouse gas warming from fossil fuels to kick 2016 higher in the form of a serious heavyweight El Nino. But it’s a decent exercise to show how ridiculously fast the world is expected to warm from 2015 to 2016. And in the 2014-2016 string of three record warm years in a row we are basically expecting a 0.40 C jump above the then record warm year of 2010. Given that the world has warmed, on average by about 0.15 C to 0.20 C per decade since the late 1970s, what we’re expecting to see is about two decades worth of warming all cram-jammed into the past three years.

More Severe Arctic Heat is on the Way

But the Earth, as of this Earth Day, hasn’t warmed evenly. A far, far greater portion of that excess heat has stooped over the Arctic. During the first three months of 2016, the Arctic region above 66 degrees North Latitude has been fully 4.5 C hotter than the NASA 20th Century baseline. That’s a departure more than three times that of the rest of the Earth. And that’s bad news for anyone concerned about sea ice, or polar bears, or Arctic carbon feedbacks, or predictable seasons, or extreme droughts and floods, or the Jet Stream, or Greenland melt, or sea level rise, or … well, you get the picture.

One region, at the boundary between the Arctic Ocean and the Greenland Sea near Svalbard, has been particularly warm. So warm, in fact, that sea surfaces now devour slabs of Arctic Ocean ice blown into it by winds running out of the Arctic in a matter of days. It takes a lot of ocean warmth to have this kind of effect on sea ice. A particularly ferocious amount of heat for the ocean to exhibit so early on in the melt season.

Ice Devoured by Warm Greenland Sea
(Neven posted this excellent blog tracking a ferocious amount of heat in the region of the Greenland and Barents Sea. Arctic Sea Ice Forum commenter Andreas T provided this graphical representation of sea ice disintegration as it was blown into waters just to the north of Svalbard earlier this week.)

Perhaps the easiest way to illustrate how relatively hot the Arctic is now is the fact that sea ice in the region is melting fast. So fast that current extent measures by JAXA are at their lowest levels on record. It’s a precipitous rate of melt that’s about one week ahead of any of the previous fastest melt season. Or you could just look at the number of Arctic freezing degree days recorded at CIRES and find one more measure added to NASA or record low sea ice pointing toward the obvious fact that this year, for the Arctic, has been one of just absolutely ludicrous warmth.

As Winter progresses into Spring, temperatures typically moderate — closing in on baseline averages. And this year has been no exception. However, readings for the entire Arctic have tended to range between 1.5 and 2.5 C above average over the past two weeks. These are some seriously hot departures for Spring. Enough to keep Arctic heat in record ranges for 2016.
Three Powerful Warm Wind Events to Strike the Arctic in Concert

But over the coming five days, a series of south-to-north warm wind events is expected to push even these seasonally excessive readings higher.

Extreme Springtime warming in the Arctic
(GFS model forecasts predict Arctic temperatures to rise into a range between 3 and 5 C above normal for this time of year over the coming week. Such departures are in record ranges and will likely result in rapid snow and sea ice melt even as it drives a wedge of cold air out of the Arctic and over Europe — setting up a high risk of very severe weather events. Image source: Climate Reanalyzer.)

The first event is predicted to originate over the Yamal Peninsula of Russia during Saturday and Sunday — lasting on into Monday and Tuesday. There, temperatures are expected to rise into the (scorching for the Arctic at this time of year) mid 30s (F) as strong, warm winds blow over about 1,000 miles of western Russia and on up into the Kara and Laptev seas which are predicted to, likewise, experience near or above freezing temperatures. Over the entire region, temperatures are expected to range between 18 and 36 degrees F (10-20 C) above typical daily averages for this time of year. Snow and sea ice melt melt rates in this already rapidly thawing region will almost certainly pick up pace in the face of these obnoxiously unseasonable readings.

A second warm wind event is predicted to heat up Greenland, Baffin Bay, the mouth of Hudson Bay and a chunk of the Canadian Archipelago on Monday and Tuesday. A 1,500 mile synoptic southeast to northwest air flow is expected to originate in the Central North Atlantic. Running along the back of a high pressure system rooted between Iceland and Southeastern Greenland, these winds will ram a broad front of above-freezing airs over a rapidly melting Baffin Bay, dramatically warm the southern 2/3 of Greenland, and flush a comparable warm air pulse into the outlets of Hudson Bay. Temperatures in this broad zone are also expected to hit 18-36 F (10-20 C) above average readings. And its effects will likely be strong enough to initiate another strong early season melt spike for Greenland in addition to aiding in driving a quickening pace of melt for Baffin and Hudson bays.

Shattered Ice Beaufort and Chukchi
(Shattered sea ice over the Beaufort and Chukchi looks as if it’s been fractured from a blow from Thor’s mythical hammer Mjolnir. Open water and very thin ice openings stretch as wide as 60 miles in some sections. A warm wind event later this week is expected to provide still more melt pressure to this already greatly weakened sea ice. Image source: LANCE MODIS.)

A final warm wind event will be fed by a big warm up across Alaska predicted to settle in on Wednesday and Thursday. There, temperatures in Central Alaska are expected to rise into the lower 60s as two stalled out lows to the south pull warmer airs up from the Pacific Ocean. This heat is expected to invade the Chukchi and Beaufort seas driving temperatures to near or above freezing over Arctic Ocean surfaces that have already witnessed a great shattering of ice and an opening of dark, heat-venting open water holes. There the anomaly spike will be slightly milder — in the range of 15-32 F (8-18 C) above average. Such heat will provide melt stress to the fractured Beaufort, likely making more permanent the wide array of open water and thin ice spaces as the push toward Summer advances.

Mangled Jet Stream to Bring Storms to Europe

As all this heat bullies its way into the Arctic, a flood of cold air is expected to flee out of the region and on down a big dip in the Jet Stream — making a late-season invasion across the North Atlantic and into Europe. There, as we’ve seen previously during recent warm wind invasions of the Arctic during Fall, Winter and Spring, warm air from the south tends to cause cold to break out and then to dive down the trough lines. And there’s a huge trough predicted to dig in over Europe.
We should expect some rather severe weather to accompany this Springtime onrush of colder air — including potentially extreme thunderstorms, flooding, and even instances of late April snowfall over parts of Norway, Sweden, Scotland, the Alps, and sections of Germany.
Deep Trough Predicted for Europe
(A very deep Arctic trough is expected to dig into Europe and the Mediterranean later this week bringing with it the likelihood of some very severe weather. Image source:ECMWF/Severe Weather EU.)

Likely increased rates of sea ice melt, a severe blow to record low snow packs around the Arctic and a likely freakish cold air and severe weather invasion of Europe are all a result of this extreme Arctic heat playing havoc with typical weather and seasonality. By the middle of next week, temperature anomalies for the entire Arctic may rise to as high as 5 C above the already much warmer than normal 1981 to 2010 average. In such a case, we could hardly expect weather or climate conditions to be normal and there appears to be a big helping of weirdness and extreme effects coming down the pipe over the next seven days.

Hat Tip to DT Lange
Hat Tip to Andreas T

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