All posts tagged warm storms

Under the Arctic Dome — Brutish High Pressure System is Wrecking the Already Thinned Sea Ice

There’s a real atmospheric brute towering over the Arctic’s Beaufort Sea at this time. A high pressure system that would put shame to most other anti-cyclonic phenomena that bear the name. It is sending out a broad, clockwise pattern of winds. It is pulling up warm air from the Pacific to invade the Bering, Chukchi, East Siberian and Laptev Seas. And its torquing motion is shattering the already considerably thinned ice beneath it.

(A powerful high pressure system over the Beaufort Sea is predicted to further strengthen by late April 15. Image source: Earth Nullschool.)

Clocking in at 1046 mb of pressure, it makes typically strong 1030 mb high pressure systems seem weak by comparison. Over the next day it is expected to strengthen still — hitting 1048 mb by late April 15th (coming very close to an extraordinary 1050 mb system).

Shattered Sea Ice

This powerful and strengthening system has already been in place for about two weeks — slowly gaining momentum as its circulation has moved in mirror to the waters of the Beaufort Gyre that swirl beneath it. Masked only by a veil of sea ice considerably thinned by human-forced climate change, the waters of the Beaufort are now breaking through. Streaks of dark blue on white in an early break-up enabled both by a terrible Arctic warming and by this powerful spring weather system.

(Side-by-side images of Beaufort sea ice from April 4 [left frame] to April 13 [right frame]. Note the considerable and rapid advance of fracturing in a relatively short period. For reference, bottom edge of frame in both images is 500 miles. Image source: LANCE MODIS.)

Warm Storms

On the Siberian side of the Arctic, this massive high pressure dome is drawing in warm winds from the Pacific Ocean. Gust by gust and front by front, they come in the form of squalls that deliver above freezing temperatures and rains that blanket this thawing section of the Arctic. On Thursday, April 13, these warm winds had driven northward over 2,500 miles of Pacific waters to be drawn into storms that unleashed their fury — driving rains and gales through the already dispersed ice in the Bering Sea and shattering ice floes through the Chukchi. Today, April 14, these winds and rains drove northward to assault the ice of the East Siberian and Laptev seas.

(On April 13, above freezing temperatures, rains, and gale force winds ripped through the sea ice near Wrangle Island in the Chukchi Sea. Image source: Earth Nullschool.)

A Great Atmospheric Stack Drawing Heat into the Arctic

In the past, meteorologists like Stu Ostro envisioned that climate change would tend to produce towering high pressure systems — featuring increasingly strong storms roaring about their fierce outer boundaries. And the massive high lurking over the Arctic at this time is a good example of Ostro’s predictions coming to light in a region that is very sensitive to human-forced warming.

This great atmospheric stack appears to have had a considerable impact on the ice already — helping to push extent measures back into record low ranges by accelerating the melt trend. But these impacts are likely to spike over the coming week as this powerful high expected to remain in place through the next five days — continuing to draw warm air into the region.

(Global Forecast System models predict extreme warming over the Arctic Ocean throughout the next week resulting from the influence of a powerful high pressure system and very strong associated ridge in the Jet Stream. Image source: NCEP Global Forecast System Reanalysis.)

GFS model runs indicate that average temperatures over the Arctic Ocean region will hit a peak as high as 4 degrees Celsius above average by late next week. Meanwhile, the warmest zones are expected to be as much as 18-20 degrees Celsius above average. Such abnormal warmth at this time of year, if it emerges, will put a considerable damper on a freeze that should now be continuing in the High Arctic even as edge melt ramps up with the progression of spring.

This is particularly concerning due to the fact that temperature anomalies in the Arctic tend to fall off during spring and summer. In other words, such a powerful warming trend for the Arctic Ocean would be bad enough during winter — but it is an even more unusual event for spring. An ominous start to a melt season that could produce far-reaching regional and global consequences.

Links:

Earth Nullschool

LANCE MODIS

NCEP Global Forecast System Reanalysis

Stu Ostro

Climate Reanalyzer

Hat tip to Colorado Bob

Hat tip to Andy in San Diego

36 Comments

by robertscribbler on April 14, 2017 • Permalink

Posted in Climate Change

Tagged Arctic, climate change, global warming, high pressure system, Hothouse, Human Hothouse, record low sea ice, sea ice, Stu Ostro, warm storms, warm winds

Posted by robertscribbler on April 14, 2017

https://robertscribbler.wordpress.com/2017/04/14/under-the-arctic-dome-brutish-high-pressure-system-is-wrecking-the-already-thinned-sea-ice/

The Human World Has Never Experienced A Time When Global Sea Ice Was So Weak and Reduced

Neven — one of the world’s most beloved sea ice trackers — has again taken a break from his much-earned sabbatical to issue yet one more warning on the state of global sea ice.

His report, based on this month’s bombshell National Snow and Ice Data Center statement, can best be described as an urgent call for action on the part of the global community to redouble efforts aimed at reducing the wide-ranging and expanding harms caused by the terrible warming trend we have artificially forced upon our world.

Neven is a kind, honest, and open soul. He is also one of the smartest and decent fellow bloggers I have had the good fortune of encountering in my many travels during my last four years of covering the slow motion global train wreck caused by our widespread and vastly irresponsible burning of fossil fuels. In other words, the man, in my view, has the moral and intellectual authority that many lack. We should listen to him.

Before the World Warmed, This Would Have Been a 1 in 30 Billion Probability Event

For, sadly, on the crucial issue of sea ice, a general muting of the subject has tended to continue despite a jaw-dropping plunge in both the coverage and volume of a substance so crucial to maintaining a stable global climate:

(Global sea ice extent fell off a cliff during December of 2016. The measure has now bounced back a little. But the global average remains significantly below past record lows for this time of year. Loss of so much sea ice can be highly disruptive to the climate system and related atmospheric circulation and precipitation patterns. Image source: NSIDC.)

During December, global sea ice extent coverage fell to an amazing 4.4 million square kilometers below average. This is far, far outside the 2 standard deviation range — passing to fully 8 standard deviations beyond the typical yearly average.

Under past expectations of average, the statistical probability of such an event is approximately 1 in 30 billion. Of course, it’s pretty obvious at this time that a normal, natural variability is not the underlying cause of such a great loss of sea ice. That the warmth we added to the system has now greatly tipped the scales beyond anything representing what would have previously been considered a normal range. A range that since the year 2000 had already tended to dip below average more and more frequently. But one that has never seen so much ice lost.

Unprecedented Losses

This area of sea ice removed — enough to change how the face of our Earth looks from space — is approximately the size of two Greenlands (Note that sea ice loss does not directly contribute to sea level rise. But loss of protective sea ice can contribute to land ice melt — which does add to rates of sea level rise.). And it has been roughly split between the Arctic in the north and the Antarctic in the south.

If sea ice extent losses appear bleak, then sea ice volume losses seem even worse. Sea ice extent is a rough measure of the surface of the world covered by ice excluding gaps behind the leading ice edge. Sea ice volume, however, measures both the ice area — including gaps — and the ice thickness.

(Globally, we’ve lost about 1/3 of the total volume of sea ice since the 1980s. 2016’s record fall in the measure coincided with record hot global temperatures and an abnormal period of polar warming that continues on into 2017. Image source: Wipneus.)

Late 2016’s big drop included the approximate removal of 1/3 of the world’s sea ice volume when compared to 1981-2010 averages. In other words, 1/3 of all of the floating portion of the world’s cryosphere beyond the edge of anchored ice shelves had melted away during the period.

Record Global Temperatures as Prime Cause For North and South Pole Sea Ice Melt

In the north, extremely warm temperatures ranging from 2 to up to 7 degrees Celsius above average for the Arctic Ocean region have helped to drive these unprecedented fall and winter sea ice losses. In the south, warmer than normal surface conditions appear to have also helped to drive the amazing coordinate losses there. And overall, 2016 has shown warm to extremely warm conditions for both poles during a year in which global temperatures have spiked to around 1.2 degrees Celsius above 1880s averages.

(Extremely strong polar amplification during 2016 is the likely primary contributor to sea ice loss in both the northern and southern polar regions. Image source: NSIDC.)

Under polar amplification — a condition associated with the human-forced warming of our world — scientists expected that the polar regions would tend to warm faster than the rest of the Earth surface. And during 2016, this global warming related condition presented effects writ large. The damage to sea ice, so far, has been monumental. And these losses have continued into 2017 — even if they are somewhat less below the record low line than during their period of maximum departure this past December.

Albedo Losses and a Bad Set-up for Arctic Summer

Sea ice loss generates its own form of amplifying feedback — in which already prevalent polar warming can worsen further. Less ice coverage means that during summer more of the dark ocean surface is presented to absorb the sun’s rays. This replacement of a white, reflective surface with a dark blue, absorptive one means that still more heat will tend to be trapped in the polar environment. In addition, during winter, less ice cover means that the warmer ocean beneath will tend ventilate more heat and heat-trapping water vapor into the polar atmospheres. And it’s this kind of self-reinforcing cycle that can tend to lock in the dangerous changes like worsening severe weather, worsening heatwaves in the middle and lower latitudes, and the increasing rates of land glacier melt and sea level rise that scientists have been warning about for so long. And it’s this kind of disruptive longer term climate trend that we are being drawn into at this time.

(Freezing degree days for the crucial 80 N region have significantly departed into record low ranges. The less freezing degree days, the closer this region is to thawing. Image source: Tealight. Data Source: DMI.)

Nearer term, it appears that the polar heat which has already so greatly damaged the Arctic sea ice is set to stay. Over the next few days, the Arctic appears set to experience a powerful series of low pressure systems running in from the Barents side between Svalbard and Siberia. Neven warns that these storms will tend to push a considerable portion of the remaining thick ice out of the Arctic and through the Fram Strait. Over the next couple of weeks, global forecast models indicate that above freezing temperatures will tend to invade regions now covered by sea ice in Hudson Bay, Baffin Bay, and in the Chukchi Sea. Though the ice is trying to grow, such repeated insults will tend to keep ice coverage in record low ranges.

If this trend of warmth, storms and ice export continues through February, March and April — as it has during October, November, December and January — then the set up for the 2017 melt season would be about the worst we have ever seen. And that would tend to increase the likelihood of new record minimums being reached during September all while hastening the day when the Arctic experiences near ice free conditions. Lets hope that doesn’t happen. But, so far, the trends for the winter of 2016-2017, from pole to pole, have followed along the lines of a near worst case scenario.

Links:

Global Sea Ice Records Broken Again

National Snow and Ice Data Center Sea Ice News

Wipneus Sea Ice Graphs

NASA GISS Temperature Data

Polar Amplification

Tealight

DMI

Hat tip to Suzanne

Hat tip to Cate

Hat tip to Colorado Bob

235 Comments

by robertscribbler on January 13, 2017 • Permalink

Posted in Climate Change

Tagged Antarctic sea ice, arctic sea ice, climate change, environment, extreme weather, global warming, Human Hothouse, human warming, Neven, Neven Sea Ice, polar amplification, science, sea ice, sea ice melt, warm storms, weather

Posted by robertscribbler on January 13, 2017

https://robertscribbler.wordpress.com/2017/01/13/the-human-world-has-never-experienced-a-time-when-global-sea-ice-was-so-weak-and-reduced/

Warm Arctic Storms Aim to Unfreeze the North Pole Again — That’s 55 Degrees (F) Above Normal For January

It’s worth re-stating. The Starks were wrong. Winter isn’t coming. Winter, as we know it, is dying. Dying one tenth of a degree of global oceanic and atmospheric warming at a time. Steadily dying with each ton of heat-trapping greenhouse gasses emitted through our vastly irresponsible and terrifyingly massive burning of fossil fuels.

******

According to UCAR reanalysis, it’s something that’s only happened three times during December in the entire temperature record for the North Pole since the late 1940s. Four times now that a record warm surge of air hit that highest point of Northern Hemisphere Latitude during late December of 2015. An event that was influenced by the very destructive Winter Storm Frank. A combination of weather variables that, by themselves, was odd and rare enough. But what may be about to happen next week is even more rare. Because we’ve never, not once, seen this kind of heat set up at the North Pole during January.

(UCAR’s North Pole temperature data record since 1948 per Bob Henson shows no above freezing days at the North Pole during January through late April. But it could happen next week.)

Disturbingly, what we’re seeing now starting to take shape is another warm air invasion of the Arctic with the potential to bring above-freezing temperatures to the North Pole during the long polar night. An odd and highly abnormal event that may again take place this Winter in just a few more days. If it does happen it will be yet another case of a never-before-seen warming event occurring in a record hot world.

North Pole May Unfreeze A Second Time This Winter

According to Global Forecast Systems model reanalysis by Earth Nullschool, it appears that a record warm Earth atmosphere and ocean system is again taking aim at the High Arctic. Another synoptic daisy chain of storms funneling warm, south-to-north winds — dredging them up from the tropics, flinging them across thousands of miles of North Atlantic Ocean waters, driving them up over Svalbard and toward the North Pole — is predicted to set up by early morning Monday.

(Temperatures are predicted to warm into a new record range for the North Pole by late Tuesday. Readings that strike very close to freezing at the North Pole now appear in the most recent Global Forecast System model summary by Earth Nullschool. If temperatures in this region do hit above freezing, it will be an unprecedented event. Image source: Earth Nullschool. )

The anchor of these dervishes of Equator-to-Pole heat transfer is the very Winter Storm Jonas that just crippled the Eastern US with record snowfall amounts and storm surges that have beaten some of the highest seas seen during Superstorm Sandy. A second, hurricane force low in the range of 950 mb is predicted to set up between Iceland and Greenland. But the tip of this spear of record atmospheric heat pointed directly at the Arctic is a third, but somewhat milder 990 mb, storm.

And it is this northern low that will draw a leading edge of record warmth into the Arctic. An anomalous, ocean-originating heat front that will spread its pall of air warm enough to melt sea ice during Winter north of Svalbard tomorrow. A swath of near and above-freezing temperatures spreading inexorably Pole-ward. Reinforced by the supporting lows and the synoptic wave of warmth in train, this storm is predicted to drive near or slightly above freezing temperatures into the region of 90 North Latitude by late Tuesday or early Wednesday. An event that would be unprecedented, at least in modern meteorological reckoning. One that may well be unprecedented for the whole of the Holocene.

Conditions in Context — Another Summer-Type Heatwave For The Arctic During the Long Dark of Winter

(Another wave of extreme, above average temperatures for the Arctic is on the way. Image source: Climate Reanlyzer.)

To put such extraordinary temperatures into context, this predicted record polar warmth is in the range of 55 degrees (F) above normal for January. And for such a typically frigid region, these temperatures are more usual for June, July, or August. Or, to make another comparison, for Gaithersburg, Maryland it would be like seeing readings above 94 degrees (F) for the same Winter day. A summer heatwave in the midst of what should be a season of cold. That’s what’s predicted for a region that will not see a single ray of sunlight until April.

Heat trapping gasses with the ability to re-radiate the sun’s energy in the dark of night or in the depths of Winter are now having a profound impact on our world. It’s something that should really be keeping us up at night. At the very least, it’s something that on Tuesday may push the North Pole up above freezing on a, black as night, January day.

Links:

Warm Arctic Storm to Push Temps Above Freezing at North Pole During Winter

The Storm that Will Unfreeze the North Pole

Climate Reanlyzer

Earth Nullschool

Bob Henson

UCAR Climate Reanalysis

Hat Tip to Greg

188 Comments

by robertscribbler on January 24, 2016 • Permalink

Posted in Climate Change

Tagged Above Freezing at North Pole During Winter, Arctic heatwave, climate change, Extreme Arctic Heat, global warming, warm storms, Winter is Dying

Posted by robertscribbler on January 24, 2016

https://robertscribbler.wordpress.com/2016/01/24/warm-arctic-storms-aim-to-unfreeze-the-north-pole-again-thats-55-degrees-f-above-normal-for-january/

Arctic Sea Ice Bounce Wiped Out as 2015 Summer Tracks Third Lowest on Record

It’s been a rough summer for the Arctic sea ice. Extent values started off at record low levels during late spring, melt ponding and warming ramped up during early June, and July saw the ice pounded by intense high pressure cells located on the Greenland side.

(Abnormally hot water surrounds the Arctic sea ice on all sides. High sea surface temperature anomalies in this range tend to aid in the maintenance of late season melt momentum. Image source: DMI.)

Warm Waters and Airs

Anomalously warm water invaded from almost every side. The Kara saw extreme sea surface temperature warming after an early ice recession, a flood of warm water from rivers, and a powerful albedo flip to dark ocean from white ice. The Chukchi, Beaufort, and East Siberian seas saw a continued influx of anomalously warm waters from the Pacific side — this flow was fed by the powerful and persistent blobs of warm water in the Northeast Pacific. A heat invasion that has been ongoing for that region since at least Winter. And in North Baffin Bay a pool of anomalously hot water has combined with an extended period of warmer than usual air temperatures to deliver heat to the remaining thick ice along the Northern Greenland and Canadian Archipelago boundary.

Warm Storms Smashing the Old Ice

By August, a series of storms had invaded the Beaufort, Chukchi and East Siberian Seas. Kicking up 20-35 mile per hour winds, they pushed 2-7 foot swells out through an expanding shattered ice zone. Though the storms cooled the air, they tapped heat from the ocean itself through the process of surface churning and the larger dynamic of cyclonic Ekman pumping. All this motion and heat energy created a very unfavorable environment for sea ice — essentially melting the ice rafts out from the water line on up.

(Top [July 22] and bottom [August 4] comparison of the same Beaufort grid showing large rafts of multi-year ice gradually being smashed to finer and finer pieces. Image source: LANCE – MODIS.)

Large pieces of multi-year ice were smashed together like rocks in the late 20th Century video game — asteroids. The ice, ground into ever-finer bits by these storms, then felt the heat of the moving waters and suffered an ongoing dissipation.

The result is that the Beaufort ice is being steadily hollowed out. A bank of thicker ice floes is expanding into the warmer waters of the Chukchi and near-shore Beaufort as it melts. This leading ice edge, though frail, is denser than the interior ice for scores of miles where three large polynyas are in the process of joining into one. If this keeps up for too much longer, the next ten-to-twenty days will see the Beaufort ice and the Chukchi boundary ice practically wiped out.

Melt Invading Past 80 North

Meanwhile, thinned ice and open water is gradually invading the Central Arctic past the 80 North Latitude line.

(Arctic sea ice appears to be in a terrible state in the AMSR2 visible measure. Beaufort and Chukchi ice continues dramatic thinning. Central Basin ice is retreating in numerous places behind the 80 North line. And the fabled Northeast Passage is open to shipping. Image source: Uni Bremen.)

Heat from the Atlantic side is eating away at the ice edge there. Laptev melt is biting in beyond the 80 North line. And the Beaufort storms are basally melting and dispersing the Central Arctic boundary ice. As a result, the monitors are showing sea ice that looks to be in a very unhealthy state overall. The Northeast Passage is open and the Northwest Passage appears to be just a week or two behind.

The Rebound is Wiped out in all Major Monitors

As a result of all this punishment, the sea ice monitors are looking increasingly bleak. Japan’s JAXA extent monitor is showing sea ice boundary measures in the same range as third lowest year on record — 2011. The National Snow and Ice Data Center measure is not too far behind at just a hair above 2011 and 2010 — now tracking at 5th lowest extent on record (a loss of two places since last week). These extent measures are swiftly catching up to the Cryosphere Today area totals that are now also just a hair above 2011 at 4th lowest on record. The area measure is also interesting in that overall area is at 4.13 million square kilometers — which is now starting to dip below the 2005 line.

But perhaps most concerning of all is the fact that sea ice volume, which showed a brief bounce back from 2012 record lows during 2013 and 2014, is now re-entering decline. For According to PIOMAS, the ongoing punishment we have visibly seen in the form of high atmospheric temperatures north of the Canadian Archipelago and in remaining thick ice being swept into the billiards pool that is the Beaufort has pushed that volume measure well below the 2014 line and back toward recent record low years.

(PIOMAS volume measure takes a nose-dive in July. Continued losses at this rate would put sea ice volume in the range of lowest years recently observed. Image source: PIOMAS.)

It’s a steep nose dive. One that will start to challenge the upper boundary of record low years without a slowing in the rate of losses soon.

Storms, Ocean Surface Warmth, El Nino Heat Transport, and Beyond 80 North Melt Drive Late Season Loss Risk

With a month and a half of melt still to go, we could see a softening in this high rate of loss and an adjustment that brings use closer to 2014 for end season. Or we could see the steep rate of loss continue to challenge the 2011 boundary in some measures and possibly even break lower to challenge 2007. But given the melt momentum coming out of July, it is very unlikely that measures return to 2014 levels. As a result, it looks like the summer of 2015 is wiping out the post-2012 sea ice bounce which, given the massive pace of human-forced warming and failing to see large enough melt from Greenland to counter that trend in the Arctic, appears to have been inevitable.

Looking forward there appears to be four factors that will play out their final hands for 2015 melt. The first are those very warm sea surface temperatures we mentioned earlier. The second is the fact that this is an El Nino year featuring a very warm Northern Pacific and a strong northward heat transport through the Canadian Archipelago and Alaska. The third involves the weak sea ice and persistent storms in the Beaufort, Chukchi, and ESS. And the final major factor involves the strong advancement of melt into the Central Arctic and the higher likelihood that the below 80 North boundary ice will be wiped out in the coming weeks.

(The northward propagation of anomalously warm ocean surface waters is bad news for late season sea ice. Extremely warm Northeastern Pacific surface waters and an associated El Nino warming of the Eastern Pacific equatorial waters creates a pathway for warm air transport into the Arctic over Alaska and Canada during late summer. Such a situation may result in an extension of late season melt beyond the September 15 date. Image source: NOAA ESRL.)

Abnormally warm sea surface temperatures plus the atmospheric feedback of El Nino hint that more energy to melt ice may remain in the Arctic for longer than during a typical year. Current transport of that abnormally warm water into the Chukchi, East Siberian Sea, and the Beaufort will continue. And the El Nino tendency to push warm air up over Alaska and the Bering will be reinforced by the strong warming in the lower Chukchi. These factors will tend to extend late season melt. Over on the Atlantic side, a similar dynamic is starting to come into play. Warm waters in the Laptev and Barents are increasingly being driven against the edge ice past the 80 North boundary line by warm southerly winds and through the action of storm systems invading the upper North Atlantic. Over the past few days a pattern has emerged in the models indicating an influx of these storms past Iceland and into the Barents near Svalbard. Swell propagation and warm water driven north will have a deleterious effect on the ice there.

As storms rise up from the North Atlantic, storms are predicted to continue to plague the ice in the Beaufort, Chukchi and East Siberian seas. According to GFS model runs, this tendency continues through at least the next five days. And with warm air firmly in place over Alaska and the Chukchi, while cooler air sits over the Beaufort, the gradient necessary to fuel these storms will remain in play. Ocean state forecasts pick up seven foot swells in the East Siberian Sea tomorrow, nine foot swells in the Chukchi on Friday, and 3-4 foot swells ranging the thick ice billiard room in the Beaufort on Sunday. Swells in the Laptev open water are also predicted to hit 6-7 feet over the coming days.

Stepping back and looking at the overall distribution of the sea ice, we find that much of the beyond 80 North region is invaded by melt. A substantial amount of weak boundary ice remains in the Beaufort, the Chukchi, the East Siberian Sea, near the land regions of the Laptev, and within the waterways of the Canadian Archipelago. Ice in these outlier regions is traditionally more vulnerable to rapid melt and it is doubtful that much of it will remain by end season.

(Arctic Ocean sea ice extent measures are tracking in the range of 2012 according to the above graph by Wipneus. Low values that, entering final stage melt for August and September, may swing the overall measures lower come end season. Image source: Wipneus.)

Meanwhile, the beyond 80 North melt invasion is substantial to the point that we are now very close to the 2012 melt trend line in that key region. In fact, pretty much all the interior Arctic Ocean seas show extent values tracking near the 2012 record low line.

These low Arctic Ocean values imply a deeper vulnerability to hitting lower end season totals. A vulnerability the overall measures, so far have missed.

Links:

DMI

LANCE – MODIS

Uni Bremen

Arctic Sea Ice Graphs

by robertscribbler on August 5, 2015 • Permalink

Posted in Climate Change

Tagged Alaska, arctic sea ice melt, Beaufort, Bounce Wiped Out, Chukchi, climate change, Cyclones, Ekman Pumping, El Nino, environment, extreme weather, global warming, Poleward Heat Transport, science, sea ice, warm storms, weather

Posted by robertscribbler on August 5, 2015

https://robertscribbler.wordpress.com/2015/08/05/arctic-sea-ice-bounce-wiped-out-as-2015-summer-tracks-third-lowest-on-record/

Warm Storms Rage Through Barents as Arctic Sea Ice Enters 13th Day of Record Low Extent

On March 4, amidst a building polar heat amplification and a strong, thousands mile long, south to north wind and storm flow across the North Atlantic and into the Arctic, sea ice extent coverage for the northern polar region plunged to new record lows.

(26 foot wave heights [left frame] and 50-60 mph sustained southerly winds [right frame] in conjunction with warm storm near the ice edge at Svalbard on March 15, 2015. Storms of this kind have been raging up through the Barents delivering powerful, warm southerly winds and immense swells to the ice edge region for at least the past half month. This strong melt pressure and warm air delivery has contributed to record low sea ice extent totals continuing for the past 13 days running. Image source: Earth Nullschool. Data source: GFS.)

Human-forced heat continued to build throughout the Arctic as warm and intensely windy storms churned northward through the Barents, bringing with them powerful swells ranging from 15 to, at times, 40 feet in height. As these great swells ground away at the ice edge, temperatures hit daily anomalies greater than 4 C above the 1979-2000 average on Sunday, March 8 for the entire Arctic region. The next day, sea ice extent, according to NSIDC, plummeted to 14,273,000 square kilometers. A value 303,000 square kilometers, or an area about the size of Arizona, smaller than the previous record low value for the date set in 2006.

Ever since March 4, the Arctic has remained in new record low territory — a period that has now lasted 13 days. Though anomalous warmth has faded somewhat — dropping today to a range of 2.65 degrees Celsius above the 1979-2000 average — sea ice has only bounced back slightly. On March 15, the NSIDC extent measure had inched up to 14,333,000 square kilometers, still about 235,000 square kilometers below the previous record low for the date.

(Arctic sea ice extent as measured by NSIDC drops below previous record low values on March 4 of 2015 [bottom dark blue line] and has remained at record low levels ever since. For reference, previous record low years for March dates include 2006 [pink line], 2007 [light blue line], and 2011 [orange line]. The top dark blue line [1979] indicates how much sea ice extent has been lost during March over the past 36 years. Image source: NSIDC.)

Over the next week, however, these new record lows are more likely to continue to fade as warm Arctic surface temperature anomalies drop to around 1-2 C above average, the Arctic Oscillation shifts toward neutral or slightly negative, and the warm storm track through the Barents is interrupted by cold winds pushing south toward Scandinavia from the pole. Although mid-week warming forecast for Alaska and Baffin Bay may retard any potential rebound somewhat.

For the past two years, Arctic sea ice has experienced a bit of a rebound during the March through early April time-frame. This has appeared to coincide with a restrengthening of the polar Jet Stream as mid latitudes have warmed which, in turn, has weakened meridional patterns transporting heat into the Arctic during winter time. Low angle sunlight entering the Arctic at this time of year has also not yet gained enough momentum to significantly push the ice to melt. So we still have about a 2-3 week window for potential bounce-back before sunlight builds and begins to apply its steady heat forcing to the greatly diminished ice.

(Arctic Oscillation [AO] index forecast shows dip toward slightly negative or neutral AO status by end week after a rather extreme high in early March, with a return to mildly positive AO values by end month. Positive AO enhances edge melt of sea ice by encouraging storm formation at the ice edge and warm air invasions over the central ice. Image source: NOAA/CPC.)

That said, the ice is quite frail now, even with potential volume rebounds to mid 2000s levels. So even the slight addition of solar insolation may be enough to keep ice coverage values depressed in the neutral or moderately positive Arctic Oscillation regime that is predicted through the end of March. Extent measures maintaining near record lows along the 2006, 2007 and 2011 tracks, or just below, would establish a very low launching pad for a melt season that, lately, has tended to include precipitous declines in ice during the summer months.

The ongoing record low extent status, despite a return to weather patterns that are more favorable for rebound or maintenance, therefore, should be closely monitored.

Links:

by robertscribbler on March 16, 2015 • Permalink

Posted in Climate Change

Posted by robertscribbler on March 16, 2015

https://robertscribbler.wordpress.com/2015/03/16/warm-storms-rage-through-barents-as-arctic-sea-ice-enters-13th-day-of-record-low-extent/

Warm Winds Gather to Invade the Arctic: Summer Sea Ice Melt and The Storms of 2014

If there’s an aspect of global warming science that remains unsettled, it’s the general state of prediction and analysis over the fate of Northern Hemisphere sea ice. As is well known by now, model predictions greatly underestimated the pace of sea ice loss as a response to human-caused warming. Big melt years like 2007 and 2012 brought sea ice extent and area, by end 2012, to less than 50% of 1979 values. Sea ice volume for the same period was nearly 80% lower than 1979 measures. Such lows were generally not predicted to appear until the 2060s at the earliest.

Ice response to rapid human warming and polar amplification, in these cases, was, for lack of a better description, outrageously stunning. And the weather impacts of such amazing losses were increasingly dangerous and far-reaching. Climate systems inertia, in the case of sea ice, seemed to be no match at all for the strong and likely unprecedented warming forces we’d already unleashed.

Sifting through the sea ice tea leaves

Though much of what happened was and continues to be unexpected, a few overall patterns emerge in the data. Dynamic melt trends for area and extent were composed of massive melt years (2007 and 2012) followed by pseudo recovery years (2008, 2013) where the ice seemed to bounce back a little before inching again toward previous record lows (2009, 2010) or setting minor new melt records (2011 area) before the next big hit.

Sea ice volume measures were somewhat less messy with massive melt years (2007, 2010), more minor melt years (2011, 2012), one minor pseudo-recovery year (2008) and one major pseudo-recovery year (2013). In this set, one year (2009) stands out as neither showing a new record low volume nor showing pseudo-recovery as end season volume fell off slightly from the previous year. The fact that 2009 followed a pseudo-recovery year (2008) may or may not be instructive for the current melt season.

It is worth noting that in the volume progression, four out of seven years during the 2007 to 2013 period all showed new record lows.

(Graph of minimum Arctic sea ice volume as measured by PIOMAS since 1979 with various trend line projections. Data source: PIOMAS Image source: Wipneus.)

What one can read from these data points is that strong pseudo-recovery years (like 2013 and 2008) have typically been followed in recent years by a return to the decline trend but not to new record lows. So, statistically, this is what we would expect for 2014.

That said, keep in mind that though it remains extraordinarily difficult to predict end sea ice states for any single year, the overall trend of major and unprecedented melt is most likely to continue and the window for a total sea ice loss by end season before 2020 remains wide open. Further, statistical analysis will, in every case, bow to emerging conditions on and beneath the ice.

Evolution of the early 2014 melt season

For the 2014 melt season, the fickle Arctic does not at all disappoint. By late April and early May of 2014, an extraordinarily warm winter period had wiped out most of the 2013 recovery in sea ice volume measures. By mid April, PIOMAS was showing volume in the range of second or third lowest year on record for the date.

By today, May 12, sea ice area and extent measures were in the range of 4th to 5th lowest on record with both measures approximately mirroring 2007 values for the date.

Given the potential for very rapid melt during June and July, as displayed in recent melt years, these values are within striking distance of new record lows should the weather conditions for rapid melt emerge.

Observed conditions for early to mid May 2014

It is worth noting that May does not generally tend to be a predictive month for sea ice loss. In most cases, it is more a bottleneck period where values tend to crunch together as the sea ice softens up but generally shows few breaks toward the more rapid melt trends typically seen in June or toward a slower melt due to weather that is less favorable for ice degradation.

That said, a few currently ongoing conditions may provide some strong indicators for how the 2014 melt season could progress.

High amplitude Jet Stream waves through Eastern Siberia, the Bering Sea and Alaska. A doggedly persistent weakness in the polar Jet Stream along an arc from East Siberia to Western Canada has resulted in much warmer than usual conditions for the Bering Sea, the Chukchi Sea and regions of the Beaufort adjacent to the Alaskan and Canadian coasts. Warm air originating over a pool of much hotter than normal water in the Northern Pacific just south of Alaska has continued to flow up through the Bering Sea, into the Chukchi, and over Alaska and Western Canada and on into the Beaufort.

Tracking this warm air flow resulted in a bit of incredulity as day after day observation showed the air continuing on through the Beaufort, past the North Pole zone, down over Svalbard and the Fram Strait, into the North Atlantic and finally being swept east in the strong cross-ocean wind pattern toward England and Ireland. In this way, air from 40 North Latitude in the Pacific jumped the pole to end up in the Atlantic near England.

A persistence of this weather pattern would have numerous and potential critical impacts for the Arctic during the summer of 2014. First, it would result in a constant pressure of warmer than usual conditions for sea ice along an arc from the Mackenzie Delta and Adjacent Canadian Arctic Archipelago to the East Siberian Sea. Warm winds would assault the ice from launching pads over warmer land masses in this zone, resulting in increased and early ice erosions.

Already, we can see such conditions emerging in the following MODIS satellite shots provided by NASA:

(The Mackenzie Delta [upper left] and adjacent Canadian Archipelago waters. Image source: LANCE-MODIS.)

The above image shows the Mackenzie Delta and the Canadian Arctic Archipelago on May 11 of 2014. In these images, we can seen the result of continued warm winds from the south and near-or-above freezing temperatures. For the Mackenzie Delta, temperatures since early May have ranged between 23 and 42 F, or between 5 and 25 F above average for this time of year. The high temperatures have brought the snow melt line all the way to the coast very early and have resulted in both ice melt and retarded refreeze in the broken ice and large polynyas offshore in the nearby Beaufort. Note that an additional heat influx to these coastal waters will occur once the shallow Mackenzie River fully melts, likely resulting in the early break-up of land-fast ice near the delta.

(The Chukchi and Beaufort Seas on May 11, 2014 from the Bering Strait [upper left] to past Barrow, Alaska [lower center]. Image source: LANCE-MODIS.)

Further along the Canadian and Alaskan coasts, we find a continuation of sea ice weakness and break up in the off-shore regions north of Barrow Alaska and on into the Chukchi Sea. Large polynyas remain open throughout the region and exhibit no refreeze in the open water sections. Past the Bering Strait zone, Chukchi melt is very well advanced for early-to-mid May due to a combination of near constant warm southerly wind influx and an advancing warm water wedge through the Bering Strait.

This warm wind pattern through Eastern Siberia, Alaska and Canada and into the Arctic Ocean is reinforced by a combination of ongoing factors including a weakened polar Jet Stream which has tended to generate high amplitude ridges in this zone, a very warm pool of water in the Northern Pacific south of Alaska, and an emerging El Nino which historically has tended to push a high amplitude split in the Jet Stream up toward Alaska. These self-reinforcing factors make it likely that the overall pattern of warm southerly winds over the region will continue to persist and have an impact well into summer.

Finally, it is worth noting that the current and ongoing warm air influx through this region provides a constant source of energy for Arctic storm genesis, a factor that may well become more significant as melt season progresses. Forecasts for the next 24 hours show a storm pulling warm, above-freezing temperatures deep into the Beaufort as it begins a transition toward the northern polar zone. It is the second system to exhibit such anomalous warm air inflow and progression into the Central Arctic during the month of May.

(GFS model summary showing warm storm with associated above-freezing temperatures invading deep into the Beaufort Sea during late Monday and early Tuesday of this week. Image source: University of Maine.)

A third warm air invasion, this time from Eastern Siberia, and potential related storm development is also projected for late this week or early next week.

The Arctic dipole: storms over the Arctic Basin, high pressure over Greenland. Today, we track three Arctic low pressure systems — one emerging from the warm air influx over the Beaufort, one over the Laptev and one north and east of Svalbard. Greenland, meanwhile, shows a high pressure system centered almost directly over its large ice sheet. The net effect of these lows and highs is to funnel the warm wind streaming up from the Beaufort over the Northern polar zone near the Canadian Arctic Archipelago and out over the Fram Strait and Svalbard.

It is a dipole of high pressure over Greenland and low pressure over the Arctic Basin on the Central and Eastern Siberian side that has lasted for about two months through Northern Hemisphere Spring. This set-up creates a strong and consistent wind pressure providing transport of sea ice out of the Fram Strait. It is worth noting that Fram Strait export was one of the primary factors involved in the record low sea ice total seen during 2007, so a consistent dipole pattern of storms over the Arctic basin and highs over Greenland promoting ice export could well weigh heavily as melt season progresses.

Warming over Western Russia and Eastern Europe. A second zone showing consistent ridge development, polar Jet Stream weakness and coincident anomalous warming has emerged over western Russia and Eastern Europe. Such warming was seen during the weak El Nino of 2010 and resulted in severe heatwaves and wildfires for the region. A similar pattern has emerged in tandem with the rising and potentially far stronger 2014-2015 El Nino currently developing in the Eastern Pacific. Though it is too early to tell if this emerging hot zone will reach the extremes seen in 2010, this heat pool is likely to contribute warmth to sea ice zones in the Kara and Laptev Sea as the summer melt season progresses.

So far, Kara sea ice retreat has remained within usual boundaries for recent years. However, it is worth considering the potential strength of this developing warm air pool and how it may impact adjacent Arctic zones as May progresses into June. This week’s forecast now shows above-freezing temperatures predicted to progress into the Kara and 50 degree F readings predicted to push into estuaries bordering the Kara over the next few days.

Warm water upwelling, north wind flush, storm suction for Baffin Bay. Finally we come to Baffin Bay, a place many may well consider the Arctic Ocean’s red-headed stepchild. Over recent years, warm water up-welling, possibly driven in part by sea-bed methane release, in Northern Baffin Bay has resulted in an almost constant weakness and erosion of sea ice. This condition creates a bizarre circumstance in which Baffin is often surrounded by warmer waters north and south by late spring. This year is no exception. In addition, a north wind now appears to be flushing Baffin Bay sea ice toward the North Atlantic. The result is an expanding zone of ice-free water along the West Coast of Greenland pushing toward a widening gap in the north of Baffin Bay near the Nares Strait.

To the south, a persistent storm has developed near an anomalous cool zone in the North Atlantic waters off of Newfoundland. This cold pool is likely a residual of the continued dipole, hot-west, cold-east temperature anomaly over North America which has increasingly been squashed toward Newfoundland with the emergence of summer. The cold North Atlantic pool is also likely fed by a rising outflow of fresh, cold water from Greenland glaciers as well as the Baffin Bay ice export already described. A growing Gulf Stream weakening is also well established for the region.

The persistent storm is fed by high temperature differentials in the dipole zone. It is one of the remnant storm systems of this winter’s epic assault on the coasts of Great Britain — a possible precursor to even more vicious storms this coming winter.

But, today, the storm is simply providing added suction to drain ice out of Baffin Bay.

(Like a drain in a massive bathtub: storm off Greenland and Newfoundland on May 12 reinforces northerly wind flow pulling sea ice out of Baffin Bay. Image source: LANCE-MODIS.)

A final word on Storms and Warm Winds

During late April, we talked a bit about the impact of early season melt ponds on end-season sea ice levels. For recent scientific studies have found that early season melt pond formation has a high correlation with new record lows in sea ice area and extent.

But given the current very thin and broken state of sea ice, it’s worth considering whether the rules for sea ice loss aren’t in the process of changing.

Ever since the 2012 melt season’s close, the Arctic Ocean has exhibited a very battered sea ice state. One featuring widely disassociated packs of broken and brittle ice riddled with a long and pervasive spidering of leeds. For large melt pond systems to develop, the ice pack needs to be relatively contiguous. But the recent ice pack shows very little continuity and could, instead, be said to basically lack integrity. Such a state may well prevent a degree of melt pond formation in areas in which the ice is more and more highly disassociated into floes. And it is this disassociated ice state that may be the current and future norm as sea ice continues to thin and weaken.

In addition, rising temperatures in and around the Arctic have resulted in increased atmospheric water vapor content, increased cloud formation, and increased storm presence during summer periods. This progression toward storminess is consistent with paleoclimate studies showing that ice-free or near-ice-free Arctic states were much stormier than the current one. In the event of an expected stormier Arctic, melt pond formation may well result less from direct solar insolation through clear Arctic skies and more from an increasing number of rainfall and warm fog events over sea ice.

Cyclonic pumping of warmer waters from below the ice pack into surface water zones and the mixing of waters by waves generated by storm winds is also likely to have a far greater impact on sea ice melt than seen in recent years. It is likely we saw a prelude to just such an event during the great, late-season Arctic Cyclone of 2012 which sent waves the size of houses roaring across the Beaufort Sea to batter and disassemble the already weakened sea ice.

In this dynamic and changing system, warm winds are also likely to play a much greater role. Jet Stream erosion, in such a case, unleashes warm southerly winds on the sea ice. The winds, being warmer, hold a higher water vapor content than was typical for the Arctic prior to the human warming insult. Encountering ice and cold water, the water vapor in the winds condenses to form fog. The latent heat in the water vapor is thus released to do work melting the sea ice and warming the sea surface. In such cases, a kind of snow and ice eating mist develops from the warm wind — a blow torch for the sea ice.

Links:

LANCE-MODIS

Dual Ridges Form Sea Ice Achilles Heel for Summer 2014

Arctic Sea Ice Graphs

The Arctic Sea Ice Blog

The Storms of Arctic Warming