Massive Wildfires Follow Record-Shattering Heat-Wave in Alaska

Alaskan Wildfires

(Large fires in Alaska. Image source: Lance-Modis)

A week after a record heatwave set off highest ever temperatures in Alaska, massive forest fires are blanketing vast areas of wilderness.

More than 80 fires are now raging across the state. The largest include the Lime Hills Fire at 154,000 acres and the Moore Creek Fire at 126,00o acres. In total, nearly 400,000 acres have burned so far this summer. For reference, an average full fire season in the US results in around 3 million acres burned. So the 400,000 acres for Alaska alone represents an abnormally large area burned, especially so early in the fire season and for a region at or above the Arctic Circle.

Like Colorado, where blazes resulted in record damage during June, the largest of the Alaskan fires, Lime Hills, currently threatens a local community. As of Tuesday, the fire had moved to within a half mile of the town which is located on the upper Stoney River just west of Fairbanks. About 70 firefighters are working to ensure no structures are taken by the blaze.

Though not as hot as last week, temperatures still remain in the range of record heat for interior Alaska with some regions Tuesday showing temperatures near 80 degrees (Fahrenheit). Daily record highs for this area range in the high 70s for this time of year. So record-breaking temperatures have become a day-to-day event for this Arctic region.

Fires in Alaska are a direct result of the extreme record high temperatures there. And these temperatures are also linked to a long-period warming trend caused by human-spurred global warming. Increasing heat, dryness and wildfires in vulnerable regions are just one result of the climate change caused by an excessive and continuous burning of fossil fuels. May of 2013 was the 3rd hottest on record, according to NOAA’s National Climate Data Center. Overall, temperatures are about .8 degrees Celsius above temperatures when climate records started in the 1880s. This difference is equivalent to that caused by the Little Ice Age, but on the side of hot.

Also in May, global atmospheric CO2 levels hit a record 400 parts per million. This level of Greenhouse gas is enough to raise Earth’s temperatures another 2-3 degrees Celsius long-term or about half the difference between now and the last Ice Age, but also on the side of hot. Long term results of 400 ppm CO2 also include a 75 foot rise in sea level. Unfortunately, due to a failure by the world’s leaders to enact appropriate CO2 reduction policies, CO2 levels are set to rise to around 550 parts per million by mid-century, enough to bake in a total temperature increase of around 7 degrees Celsius long-term. A virtual fire age.

Between now and then, and without proper policy measures aimed at reducing the damage, we can expect gradual but continually increasing global temperatures with increasing instances of extreme weather events.

The current Arctic heatwave is just one example of the strange climate we are creating. Let us hope that policy makers have gotten the message. We need to get to work before we set off even more dangerous events.

Links:

Crews Battle Wildfires Across Alaska

US Wildfire Data

Heat Wave Sends Temperatures in Alaska to 94 Degrees

Unprecedented West Fork Fires Explode to 60,000 Acres

What Does a World at 400 PPM CO2 Look Like?

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PAC 2013, The Month-Long Arctic Cyclone: Transitioning to a Warm Storm?

PAC2013Jun21

(Image source: DMI)

Well, it’s official. PAC 2013 has yet to give up the ghost. After transitioning to the Canadian Archipelago, it has now formed a trough composing three low pressure centers that roughly straddles Greenland, Baffin Bay, and the thickest sea ice. At this point, the storm is nearly one month old (with a formation date around May 21-26). Lowest pressures appear to be around 990 mb, but the entire region is covered in rough weather and clouds.

A look at the heat map shows the storm pulling in warmer air from the Alaskan side of the Arctic and from regions around it. This extra energy has given it enough to fuel multiple lows for an extended period. As a by-product, many regions over the Central Arctic are now above freezing. Areas near the low pressure centers still show temperatures in the range of 0 to -3 Celsius. But a broad swath of above-freezing temperatures are now under the circulation of this, rather large, storm.

PAC2013TempJun21

(Image source: DMI)

On the map, we also notice areas of high heat concentration centered over Scandinavia, Central Siberia, Alaska, and just West of Hudson Bay. These regions of heat are both potential launching pads for more warm air invasions of the Arctic as well as feeding sources for our storm, should it continue.

And, according to forecasts, we can find that this storm isn’t done by a long-shot. ECMWF model runs show it forming troughs with numerous low pressure cells and chewing through large portions of the Arctic all the way through to July 1. Seems we were right to caution against an end to PAC 2013 in this earlier blog.

A very interesting example is the ECMWF forecast for June 27th when PAC 2013 forms a sprawling trough from the East Siberian Sea to Baffin Bay to Greenland to the Kara. It is a trough composed of not one, not two, but at least six separate low pressure cells. The forecast for tomorrow through much of the model run shows similar configurations with daisy chains of storms linked by a trough swirling along through the Arctic.

Six Lows PAC 2013

(Image source: ECMWF)

These model runs would seem to indication very stormy conditions not only for the Central Arctic, but for the periphery as well.

The ‘Warm’ Arctic Storm Begins to Emerge?

With temperatures rising to above freezing in the Central Arctic Basin and with storms projected to persist at least until July 1rst, we may receive an unwelcome glimpse of the ‘Warm’ Storm described here. Previously, I had speculated that ‘Warm’ Storm conditions would be present with moderate-to-strong cyclones persisting in the Central Arctic at a time when air temperatures ranged from 0 to 6 degrees Celsius. As we can see from the temperature map at the top of the post, we are not far off from that threshold now. And with heatwaves popping up around the Arctic there is more than enough warmth to push Central Arctic temperatures higher over the coming days and weeks.

Over at the Arctic Ice Blog (read it, join it, follow it, chat on it — you will learn boatloads), expert posters Wayne and R. Gates have noted that while clouds block direct sunlight, they can act to trap long-wave radiation. R. Gates had also linked a recent scientific study which showed that cloudy conditions from March to May enhanced rather than inhibited melt. The energy of this long-wave radiation would transfer directly to ice and ocean, so atmospheric temperatures would not be directly impacted. But more heat content in the waters and ice, overall, might be providing some of the extra kick that ECMWF appears to have missed. Another recent study by Edward Hanna found that low level clouds helped to increase the record Greenland ice sheet melt of 2012 (study here) by trapping heat near the ice. So the overall effect of clouds in cooling is less certain than one would think at first blush.

Another source of this extra heat may be via the ocean itself. As noted in previous posts, cyclonic action creates a kind of pumping force (Ekman), that can pull water up from the ocean’s depths. In the Arctic, the surface layer is cold. But underneath lies a layer of warm water fueled by the inflow from oceans surrounding the Arctic (primarily the Atlantic). As commenter Johnm33 noted, once a strong inflow of upwelling water is established, it is possible that yet more warm water is being drawn into the deep Arctic Ocean from the Atlantic. If this warmer inflow was pumped to the surface, it would add to atmospheric heat beneath the storm.

Lastly, the atmosphere, via high amplitude waves in the Jet Stream is now also providing its own source of heat by dredging deep into the lower latitudes and pulling warmer air up into the Arctic. So far this summer, we have seen record heat waves in both Scandinavia and Alaska. These heat waves were caused by persistent blocking patterns that injected heat into these Arctic locations. Scandinavia saw temperatures in the 80s, Alaska saw temperatures rocketing into the upper 90s. The Jet Stream configuration allowing for these hot air injections at these locations still persists and are plainly visible on the current Jet Stream map:

Mangled Jet Jun21

(Image source: California Regional Weather Service)

Note the large wave in the Jet Stream (and associated warmer air) now riding up over Alaska and deep into the Beaufort, Chukchi, and East Siberian Seas. Another pulse is visible lunging up through Scandinavia. A third, though less southwardly linked, pulse is also now rising over Eastern Siberia. These extraordinarily high amplitude waves all cross far beyond the Arctic Circle. An atmospheric condition that is anything but normal and one that is also continuing to supply warmer air to the Arctic environment, even one covered by a storm that would normally substantially cool the atmosphere there (for more information on how snow and ice melt in the Arctic is enabling these high amplitude Jet Stream waves, take a look at some of the work of Dr Jennifer Francis). Instead, as the discrepancy with ECMWF predictions and surface observations shows, we have temperatures that are only .5 to 1 degree C cooler than average under the storm (they should be about 3-7 C cooler) and much, much warmer conditions surrounding it.

A Warm Storm persisting in the Central Arctic for long periods is a potential nightmare scenario for sea ice melt. Currently, we have warming conditions in the Central Arctic, a spate of record heat-waves at the periphery in places like Alaska and Scandinavia, a mangled Jet Stream that keeps pumping warmer air into the Arctic, and a storm that is now projected to persist until at least July 1rst. So we now have to consider at least the temporary emergence of the Warm Storm to be a possibility going forward.

Impacts to Sea Ice Still Ongoing, Likely to Ramp Up

A substantial thinning and chopping up of the sea ice is now apparent in all visible (when you can see through the clouds), concentration, and thickness monitors. Now, a wasteland of thinned, shattered and broken ice is visible in a swath from Svalbard all the way to Wrangle Island near the Bering Strait. A comprehensive graphic summary of these impacts is provided below:

PAC2013USNavyJun21Thinner

(Image source: US Navy)

The current image, provided by the US Navy is a stark contrast to conditions seen at the end of May. This thickness measure shows a long ‘claw’ of much thinner ice reaching all the way in to the Central Arctic and encompassing the North Pole. This graphic reveals very poor Central Ice thickness conditions for mid-to-late June.

USNAVYConcentrationPAC2013

(Image source: US Navy)

The US Navy surface concentration graphic also reveals very broken conditions for the Central Arctic in mid-to-late June.

UniBremanPAC2013

(Image source: Uni Bremen)

Uni-Bremen has been providing consistent confirmation of ice damage and fragmentation due to the Ongoing Arctic Storm for nearly two weeks now. Here’s the most recent concentration monitor showing the broad swath of broken ice.

Cryosphere Today PAC2013

(Image source: Cryosphere Today)

And Cryosphere Today, which is less sensitive than the other monitors shows low ice concentrations stretching from Svalbard to Wrangle Island.

Overall, should PAC 2013 continue to warm even as it persists, it should have ever-greater deleterious effects on the Central Arctic sea ice as mid-to-late June transitions into July. The US Navy thickness forecast shows ongoing thinning and fracturing in this region all the way through June 28th. One interesting feature of note in this forecast is that it appears a substantial section of ice will be separated from the main pack and stranded in the Kara Sea if current trends continue through early July.

PACUSNAVYforecastJun28

(Image source: US Navy)

The Storm That Just Won’t Quit

So, apparently against all odds, PAC 2013 continues and, even worse, shows risk of beginning a transition to a ‘Warm’ Storm in the Central Arctic. Should this trend remain in effect, increasingly visible damage to the central ice is likely to become ever more apparent as June turns to July.

Links:

DMI

ECMWF

US Navy

Cryosphere Today

Uni Bremen

Neven’s Arctic Ice Blog

California Regional Weather Service

Jennifer Francis Explains How Sea Ice and Snow Melt impact the Jet Stream

The Warm Arctic Storm

The Arctic Heatwave: Greenland, Alaska, Scandinavia, Heat Domes and a Mangled Jet Stream

Over the past year, we’ve now experienced three major heatwaves north of the Arctic Circle. Greenland melted under a freakish blanket of heat-trapping clouds, Scandinavia saw an early June heatwave that sent temperatures into the 80s, 30 to 40 degrees hotter than normal, and just this week Alaska experienced record heat that sent temperatures there into the upper 90s, probably the hottest temperatures ever recorded there.

Now, a combination of new research reveals changes to the Jet Stream that enable warm air to enter the Arctic even as a thickening atmosphere sets in place conditions where powerful ‘heat domes’ are more likely to form.

Unprecedented Heat, Melt In Greenland

Our story begins in Greenland during July of 2012. At that time, a powerful blocking pattern enabled a strong high pressure system to form over that frozen land. An upward swing in the jet stream pumped ever-warmer air over its vast ice sheets. Finally, record temperatures were reached both along the coast-line and even at the center of its three kilometer high glaciers. Temperatures in the Greenland interior rocketed to 60 degrees.

Greenland Melt 2012

(Image source: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory)

Within only a few days, almost the entire ice sheet was experiencing some kind of melt. A record 90% of the ice sheet succumbed, far out-pacing the previous record of 52 percent set just two years before in 2010.

Draped over top of this melt was a freakish layer of low clouds. Clouds are, generally, thought to block heat from the sun. But, in this case, it appeared the clouds had locked heat in, recirculating it and keeping it close to the ice, forming a heat-trapping blanket over Greenland.

Far above this low cloud layer, the atmosphere was growing ever thicker. A towering high pressure system known as a heat dome was sucking in the warmer air from around and beneath it, trapping it in a denser and denser layer. From the south, a long-period, very persistent blocking pattern fed warmer, moister air into this heat dome. Meanwhile, the sea ice, which had tended to insulate Greenland from direct assaults of heat in the past, had retreated far behind its usual summer lines of defense.

As a result, Greenland baked.

In the media, contrarians did their best to down-play what was clearly a catastrophic event. They retreated to their usual ‘natural variability’ claims. But the closest event bearing any similarity to the 2012 event happened in the 19th Century and it didn’t occur at the end of a long string of worsening melt. Context formed a mire which contrarians were having ever-greater difficulties extracting themselves from.

The Scandinavian Heat Wave

But context was coming back to haunt us yet again as June 2013 rolled around. This time, another blocking pattern had emerged — creating a strange whirl in the Jet Stream. The path of atmospheric current followed a course much like a river bends through a marsh. It coiled, snake-like, bending back on itself, forming cut off circles.

This punch of colder air extended from Greenland all the way into central Europe. This extrusion of Arctic atmosphere resulted in one of the most extreme winter/spring periods Europe has ever experienced. Record snows were followed by record floods. By June, some water gauges on Europe’s largest rivers recorded the highest levels since the 1500s. It was the third 1,000 year flood to occur within the last 13 years.

But the colder, stormier air didn’t penetrate any deeper than Eastern Europe. There, it doubled back on itself, heading up and back into the North Atlantic. In front of this coil of air, this blocking pattern that had persisted over Europe since winter, rose a burst of heat. This pulse flowed into Scandinavia where it stagnated. Heat pooled in this region and, in a few days, records were being shattered across such improbable Arctic regions as Finland. 80 degree temperatures reigned in a region that usually experienced 40 degree weather this time of year.

In about a week, the Scandinavian Heat Wave had backed off, but temperatures remained well above average into mid-June.

The Alaskan Heat Wave

But heat was, again, about to re-emerge just two weeks later in another improbable region of the Arctic.

This time, a blocking high pressure system that had created a high amplitude wave in the Jet Stream over the Pacific Ocean just south of Alaska and west of British Columbia was about to preform an exotic trick. Alaska, resting just north of this blocking ridge had lain beneath a front of cold air for much of May. So while areas of California, Nevada, Arizona, Washington, Oregon, and British Columbia were experiencing abnormally warm conditions, Alaska experienced temperatures that had plunged into record low territory for many cities.

Contrarians proclaimed the end of global warming for Alaska. But the heat was coming and they only had to wait one month. By June, the blocking pattern which had kept cold air to the north and warmer air to the south began to edge into Alaska. Temperatures flipped from the 20s to the 70s for many regions. Barrow, which had experienced a warmer than average winter and spring, saw temperatures rise into what, for it, was the balmy 40s.

But this pulse of warmer than average air wasn’t finished. The current of Jet Stream cut off, giving this warm high pressure system an encapsulating band of winds. Conditions were now right for the formation of another heat dome. And form it did. By Monday of this week, temperatures had rocketed to 98 degrees in some places of the Alaska interior, possibly breaking the all-time record high for the hottest temperature ever recorded, at any time, in Alaska.

Today, temperatures for Barrow, one of the coldest cities on Earth, are projected to hit 70 degrees, about 31 degrees above the average high for this time of year.

Greenland, Scandinavia, Alaska, three record heat waves above the Arctic Circle all in the last year. What in the world had happened to the weather?

Enter the Experts…

A number of climate scientists and meteorologists have begun to grapple with the new, unstable regime of weather gripping the Arctic. These include Dr. Jennifer Francis of Rutgers University, Stu Ostro of The Weather Channel, and Dr. Edward Hanna of the University of Sheffield.

Dr. Francis, last year, provided compelling scientific evidence that the erosion of Arctic sea ice and the rapid melt of Northern Hemisphere snow cover during the summer time resulted in changes to the Jet Stream. This erosion of sea ice and land snow resulted in less of the Arctic’s cold air being trapped within the Arctic. It also resulted in more floods of warmer air coming up from the south. This north-south motion of air masses had the net effect of reducing the temperature difference between the Arctic and the mid-lattitudes. As a result, the river of air surrounding the pole known as the Jet Stream began to slow down, forming large dips and bulges.

As these dips formed and the air slowed, the Jet Stream had more of a tendency to become stuck. This sticking in place created ‘blocking patterns’ in which a given set of weather was more likely to persist over long periods of time. Recent examples of these blocking patterns and their related weather include Europe’s extreme winter and spring of 2012-2013 and the 2012 US Heatwave and related 2012-2013 drought. Further, without the collision of Arctic and Tropical air masses enabled by a massive dip and up-swing in the polar Jet Stream near the US East Coast, it is doubtful that the Hybrid Superstom Sandy would have ever formed.

Dr. Francis notes an increased frequency of such extreme, blocking pattern spawned, events and the picture she paints provides us with a much better understanding of how climate change is impacting our weather.

Recently, Dr. Francis spoke on the subject of climate change in an event entitled “The Alarming Science Behind Climate Change’s Increasingly Wild Weather”  with the weather Channel’s Stu Ostro. Stu brings a different yet complimentary set of knowledge to the new observations presented by Dr. Francis. Over the past couple of decades, Stu has noted what appears to be a ‘thickening’ of the atmosphere. He equates it to a cake batter which, when heated, tends to rise. This rising atmosphere, according to Stu, has led to the formation of powerful, persistent high pressure systems. As Stu noted in a recent article in Mother Jones:

“The frequency of these really strong ridges of high pressure aloft, these anomalous high pressures aloft are increasing.”

And the result is some rather alarming consequences.

A recent paper headed by Dr. Edward Hanna at the University of Sheffield implicates both the mangled Jet Stream and a powerfully thickened high pressure system in the record 2012 melt in Greenland. According to the paper:

Our analysis allows us to assess the relative contributions of these two key influences to both the extreme melt event and ongoing climate change. In 2012, as in recent warm summers since 2007, a blocking high pressure feature, associated with negative NAO conditions, was present in the mid-troposphere over Greenland for much of the summer. This circulation pattern advected relatively warm southerly winds over the western flank of the ice sheet, forming a ‘heat dome’ over Greenland that led to the widespread surface melting.

Dr. Hanna’s paper pointed out the movement of warmer air over Greenland via a strong blocking pattern in the Jet Stream and the building up of a powerful ‘heat dome’ and blocking high pressure system over the ice sheets. Hanna also added the contribution that lower level clouds enhanced, rather than inhibited, melt.

Together, this research points toward how receding sea ice and a warming climate are setting in place conditions that are causing these Arctic heat waves. And the recent heatwaves in Greenland, Scandinavia, and Alaska provide excellent illustrations of the kind of events we can expect with greater frequency in the future.

Links:

Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory

Dr. Jennifer Francis: Understanding the Jet Stream

One Meteorologist’s Come to Jesus Moment on Climate Change

‘Heat Dome’ Melted Ice Sheet in 2012

Atmospheric and Oceanic Climate Forcing of the Exceptional Greenland Ice Sheet Surface Melt in Summer 2012

Heatwave Sends Temperatures in Alaska to 94 Degrees

Human Climate Change is Wrecking the Jet Stream: UK Met Office Calls Emergency Meeting

Arctic Sea Ice Melt, Methane Release Shows Amplifying Feedbacks From Human-Caused Climate Change

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