All posts tagged sea ice loss

NOAA’s 2017 Arctic Report Card Shows Transition Toward Not-Normal Polar Environment Continues

The Arctic shows no sign of returning to the reliably frozen region of recent past decades. — NOAA

Reading this [Arctic Report Card], I feel physically sick. I feel so anxious. I’m not sure how many more years or months I’m going to be able to work daily on climate change. — Eric Holthaus

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During 2017, the Arctic experienced much warmer than normal winter and fall temperatures. Meanwhile, according to NOAA’s 2017 Arctic Report Card, somewhat cool late spring and early summer temperatures did little to abate a larger ongoing warming trend.

NOAA notes:

The average surface air temperature for the year ending September 2017 is the 2nd warmest since 1900; however, cooler spring and summer temperatures contributed to a rebound in snow cover in the Eurasian Arctic, slower summer sea ice loss, and below-average melt extent for the Greenland ice sheet.

(NOAA’s Arctic Report Card shows a Polar environment experiencing serious and harmful changes.)

This warming trend was evidenced by continued systemic long term sea ice losses with NOAA stating that sea ice cover has continued to thin even as older, thicker ice comprised only 21 percent of Arctic Ocean coverage compared to 45 percent during 1985.  NOAA noted very slow Chukchi and Barents sea ice re-freeze during fall of 2017 — which was a feature of much warmer than typical sea surface temperatures during late August. Temperatures which ranged up to 4 C above average for this time of year and that created a kind of heat barrier to typical fall ice cover expansion.

Sea ice is a primary indicator of Arctic health. But losses over recent decades have been quite precipitious as indicated by the graph below:

Sea Ice Coverage Loss

(Arctic sea ice loss since 1978 during September [red] and March [black]. Image source: NOAA.)

NOAA also found evidence of ongoing increases in ocean productivity in the far north — which tends to be triggered by increasing temperature and rising ocean carbon uptake (also a driver of acidification).

Other observations of systemic warming came as permafrost temperatures hit record levels during 2016.  Decadal rates of permafrost warming as measured at Dead Horse along the North Slope of Alaska proceeded at a rate of 0.21 to 0.66 degrees Celsius every ten years.

(Changes in Arctic ground temperature [20 meter depth] at varying locations shows widespread movement toward permafrost thaw. Image source: NOAA.)

Tundra greening trends also continued over broad regions:

Long-term trends (1982-2016) show greening on the North Slope of Alaska, the southern Canadian tundra, and in the central Siberian tundra; tundra browning is found in western Alaska (Yukon-Kuskokwim Delta), the higher-Arctic Canadian Archipelago, and western Siberian tundra.

Rapid warming of the Arctic, loss of sea ice, permafrost thaw, greening tundra, changes in ocean productivity and other factors are all starting to seriously impact the people of the Arctic. Coastal towns have been forced to move inland due to erosion and sea level rise. And a number of communities have lost access to key food sources due to sea ice loss or migration of local species away from warming regions. Subsidence has generated harmful impacts to infrastructure. Meanwhile, the increased incidence of Arctic wildfires presents a rising hazard to Northern Communities:

High latitude fire regimes appear to be responding rapidly to environmental changes associated with a warming climate; although highly variable, area burned has increased over the past several decades in much of Boreal North America. Most acreage burned in high latitude systems occurs during sporadic periods when lightning ignitions coincide with warm and dry weather that cures vegetation and elevates fire danger. Under a range of climate change scenarios, analyses using multiple approaches project significant increases (up to four-fold) in area burned in high latitude ecosystems by the end of the 21st century.

Taken together this is tough news — a technical report written in the lingo of science but that, in broad brush, describes evidence of a world fundamentally changed. For those of us with sensitive hearts, it’s a rough thing to write about:

Overall, NOAA calls for increased efforts to adapt to climate change in the far north. In addition, the need for mitigating harms from climate change by speeding a transfer to renewable energy could help to preserve cryosystems and ecosystems that are now under increasingly severe threat.

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by robertscribbler on December 12, 2017  •  Permalink
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Posted by robertscribbler on December 12, 2017

https://robertscribbler.wordpress.com/2017/12/12/noaas-2017-arctic-report-card-shows-transition-toward-not-normal-polar-environment-continues/

Southern California Fires Expand to Over 255,000 Acres as Conditions Worsen

On Sunday, driven by above normal temperatures and fanned by warm winds, the Thomas Fire in Ventura County, California rapidly expanded. This resulted in a loss of containment as the blaze jumped fire breaks — placing parts of Santa Barbara under seige.

(Smoke plumes from the Thomas fire as seen by a webcam located atop Santa Ynez Peak, a 4300′ mountain 17 miles northwest of downtown Santa Barbara.)

This single fire, as of Monday morning, covered 230,000 acres. At that time, it was the fifth largest fire in California history. It was burning in December. And, at the time, the fire was continuing to swiftly grow.

Five other fires burning in Southern California together cover an additional 25,000+ acres. As a result, approximately 255,000 acres are now burning in this region of the state.

The 6,000 firefighters now engaged in battling these blazes had hoped that predicted milder Santa Ana winds would afford them a chance to gain an advantage over these fires this weekend. But this didn’t happen. The western high pressure ridge strengthened. Local temperatures increased to well above the seasonal average. And though winds subsided somewhat, very dry conditions dominated.

Due to the worsening situation, 25,000 structures are now threatened by the fires — up from 20,000 earlier this week. More than 790 structures have been burned or destroyed. More than 95,000 people remain under evacuation orders. And more than 85,000 people are without power. Tragically, the fires have now claimed their first human life as well.

Unfortunately, warmer than normal, dry and windy conditions are expected to continue through at least Friday, December 15th. Resulting in a long running period of heightened fire danger. These climate change related features are driven by a very persistent high pressure ridge over the North American west. A feature that has been linked to loss of sea ice and a warming Arctic in some climate studies.

Overall, climate change is worsening fire danger out west. During summer, hotter and drier conditions are intensifying the California fire season. And during fall through winter, the climate change associated warming, drying and strengthening of the Santa Ana winds is enabling the eruption of very large city-threatening fires during the winter months.

(UPDATED)

CREDITS:

Hat tip to Colorado Bob

Hat tip to Eric Holthaus

Hat tip to Wili

Hat tip to Titania Baildon

14 Comments
by robertscribbler on December 11, 2017  •  Permalink
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Posted by robertscribbler on December 11, 2017

https://robertscribbler.wordpress.com/2017/12/11/southern-california-fires-expand-to-over-255000-acres-as-conditions-worsen/

Weird Polar Warming Appears to Have Made February of 2017 the Second Hottest Ever Recorded 

I think the scientific consensus will be that February probably should not have been so darn hot. But it was. And that’s pretty amazingly weird.

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Clocking in at 1.32 C above 1880s averages, the month was oddly and disturbingly warm. The strong equatorial Pacific Ocean surface warming that was the El Nino of 2015-2016 had long since passed. The effects of a weak La Nina cooling of the same waters during late 2016 still lingered. And the Pacific Decadal Oscillation (PDO) — a measure of ocean surface temperature oscillation in the Pacific that tends to help drive natural variability based warming and cooling cycles — showed a meager warming bias value of 0.08 (or barely positive).

All these factors pointed toward a climate system that should have been pulling the world into a cyclical short term cooling during 2017 and 2018 (relative to 2016 record warmth). Global temperatures under such conditions would have been expected to recede about 0.1 to 0.2 C off highs hit during 2016 of 1.2 C hotter than 1880s temperatures. Averaging in a still disturbingly warm range near 1 C above 1880s values but waiting for the next El Nino cycle for a run at new global record warmth.

Heat Heads Toward the Poles

But, so far, the expected cyclical cooling isn’t happening. Instead, January of 2017 showed up as 1.14 C hotter than 1880s while February was 1.32 C hotter. The combined average of these two months was 1.23 C warmer than the preindustrial baseline — or a hair warmer that the 2016 average. This shouldn’t have happened. But it did. And now there is some risk that 2017 may be yet another record hot year. The fourth in a row consecutively.

So what was the cause?

(February saw highest above average temperature readings centered near the poles — a signal that polar warming was the primary factor driving near record heat for the month. Image source: NASA.)

According to NASA, both polar zones experienced considerable above average temperatures during the month of February. Lower latitude temperatures were also well above average, but the highest temperature spikes appeared in the far north and the far south. At the 80 to 90 north and south latitude zones, temperatures were 4.5 and 2 C above average respectively. And the heat was particularly intense in the Northern Hemisphere Arctic and near Arctic between 60 and 90 north latitude with temperatures ranging from 3 to 4.5 C above average.

Polar Amplification Appears to Drive Weird 2017 Warmth

Such strong warming at the poles is indicative of a global warming related condition called polar amplification. The causes of polar amplification include increasing water vapor at the poles, high greenhouse gas overburdens in the Arctic, a darkening of the polar ice from particulates (wildfire and human-produced smoke), intensification of transport of heat from the lower and middle latitudes toward the poles, warming oceans and changes in ocean circulation, and loss of snow and ice cover at the poles. To this final point, sea ice coverage has been consistently at or near record lows for both the northern and southern polar regions.

(Global sea ice extent at record lows likely helped to contribute to extremely warm conditions at the poles during February of 2017. Less sea ice means more water vapor evaporating from oceans in the polar regions. Water vapor is a powerful greenhouse gas. In addition, warmth from the ocean can more readily ventilate into local atmospheres which aids in heat transport to the polar regions as the skein of sea ice retracts. Image source: Wipneus. Data Source: NSIDC.)

Polar amplification is not typically cited as a climate event that can overcome the transient cooling signal of a post El Nino period. However, given a first look at the evidence, this appears to be exactly what happened during early 2017. If this is the case, it is cause for serious concern. It is an indicator that a global tipping point has been reached in that warming at the poles (which is an upshot of the ridiculously high greenhouse gas levels we now see globally) is strong enough to drown out some of the traditional ENSO and PDO signals.

Links:

NASA

NSIDC

Polar Amplification

Pacific Decadal Oscillation

Hat tip to Colorado Bob

73 Comments
by robertscribbler on March 16, 2017  •  Permalink
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Posted by robertscribbler on March 16, 2017

https://robertscribbler.wordpress.com/2017/03/16/weird-polar-warming-appears-to-have-made-february-of-2017-the-second-hottest-ever-recorded/

Big Arctic Warm-Up Predicted For This Week: Melt to Speed Up, Or Sea Ice to Show Resiliency Due to Variability, Strength of Negative Feedbacks?

Rate of Sea ice volume decline for all months

(Rate of Arctic sea ice volume decline with trend lines for all months in the PIOMAS measure. Updated through June of 2014. Image source: Wipneus.)

What it really all comes down to is heat energy balance. Beneath a warming, moistening Arctic atmosphere, sea ice loses resiliency due to slow attrition of the ice surface, due to loss of albedo as ice melts, and due to slower rates of refreeze during winter. Atop a warming Arctic Ocean, sea ice loses bottom resiliency, tends to be thinner and more broken, and shows greater vulnerability to anything that churns the ocean surface to mix it with the warming deeper layers — storms, strong winds, powerful high pressure systems.

It is this powerful set of dynamics under human caused climate change that has dragged the Arctic sea ice into what has been called a ‘Death Spiral.’ A seemingly inexorable plunge to zero or near zero ice coverage far sooner than was previously anticipated.

But in the backdrop of what are obviously massive Arctic sea ice declines and a trend line, that if followed, leads to near zero ice coverage sometime between next year and 2030, lurk a few little details throwing a bit of chaos into an otherwise clear and, rather chilling, picture of Arctic sea ice decline.

The Fresh Water Negative Feedback

One of these details involves the greatly increasing flow of fresh water into the Arctic Ocean. For as the Arctic heats, it moistens and rainfall rates over Arctic rivers increase. This results in much greater volumes of fresh river water flushing into the Arctic Ocean and freshening its surface. Another source of new fresh water flow for the Arctic is an increasing rate of Greenland melt outflow. The volumes, that in recent years, ranged from 300 to 600 cubic kilometers, can, year-on-year, add 1-2% to the total fresh water coverage in the Arctic Basin and North Atlantic. These combined flows mean that fresh water accumulates more rapidly at the surface, resulting in an overall increase in fresh water volume.

Change in salinity

(Change in Arctic Ocean Salinity between the mid 1990s and mid 2000s. Image source: Benjamin Rabe, Alfred Wegener Institute via Science Daily.)

Since 1990, we have observed just such an accumulation. For a recent study in 2011 showed that since 1992, Arctic Ocean surface fresh water content had increased by 20%. A remarkable increase due to the changing conditions that included greatly increased river outflows into the Arctic Ocean as well as a ramping ice melt from Greenland and the Canadian Archipelago Islands.

Fresh water is less dense than salt water and will tend to float at the surface. The physical properties of fresh water are such that it acts as a heat insulator, deflecting warmer, saltier ocean water toward the bottom. As such, it interrupts the heat flow from deeper, warmer Arctic Ocean waters to the sea surface and into the atmosphere.

As an added benefit to the ice, fresher water freezes at higher temperatures. So as the Arctic Ocean freshens, it creates a bit of wiggle room for the sea ice, giving it about a 0.5 to 1 C boost so it can sometimes even form during conditions that were warmer than those seen in the past.

In this manner, an expanding fresh water zone acts as a kind of last refuge for sea ice in a warming world. A zone in which sea ice may even periodically stage comebacks in the backdrop of rampant human warming. We may be seeing such a comeback in the Antarctic sea ice, which has shown anomalous growth and even contributed to an expanding cool atmospheric zone in the Southern Ocean, despite ongoing global warming. The freshwater and iceberg feeds from the vast Antarctic ice sheets have grown powerful indeed due to warm water rising up to melt the ice sheets from below, letting loose an expanding surface zone of ice and fresh water. This process will necessarily strengthen as more and more human heating hits the deep ocean and the submerged bases of ice sheets. An effect that will dramatically and dangerously reverberate through the ocean layers, setting the stage for a horrible stratification.

But today, we won’t talk about that. Today is for negative feedbacks due to fresh water flows from increasing polar precipitation and through ice sheet melt.

In the end, human warming dooms Arctic sea ice to an eventual final melt. But before that happens the increasing volume of fresh water from river flows and the potentially more powerful negative feedback coming from a growing ice and fresh water release from Greenland and the Canadian Archipelago will inevitably play their hands.

The Slower Than Terrible 2014 Melt Season

And so we arrive at the 2014 sea ice melt season for the Arctic. As with 2013, the melt got off to a relatively rapid start and then slowed through July as weather conditions grew less favorable for ice melt. Above freezing temperatures hit the ice above 80 degrees North about one week later than average, also providing some resiliency to the central ice — a condition that historically leads to higher end-season sea ice values in about 80 percent of the record.

The high pressure systems of early June gave way to weak storms and overall cloudy conditions. This shut down the cycle of strong melt, compaction, and transport of ice out of the Arctic that may have put 2014 on track for new records and another horrible slide down the Arctic sea ice death spiral. Instead, conditions set up for slower melt. Ice was retained and backed up through the Fram Strait, and the ice spread out, taking advantage of the thickened fresh water layer to slow its summer decline.

This is in marked contrast to the terrible 2007 and 2012 melt seasons which severely damaged the ice, making a total Arctic Basin ice melt all more likely in the near future. And it was also cutting against the 2010 to 2012 trend in which sea ice volume measures continued to plunge despite ambiguous numbers in sea ice area and extent (no new record lows) during 2010 and 2011. For this year, sea ice volume is now, merely, ‘only’ 4th lowest on record, according to the PIOMAS measure.

The fact that we are looking at a 4th lowest year as another bounce-back year is a clear indication of how terrible things became since 2010. And so far, this year’s melt has, like 2013, simply not been so terrible and terrifying. A wag back toward 2000s levels that is likely due to the inherent negative feedback of freshening surface water and to a swing in natural weather variability that, during any other year and in any other climate, would have pushed summer ice levels quite high indeed.

If the storms had been strong enough to draw a large enough pulse of warm water to the surface, the story might have been different. But, as it stands, this summer of weak Arctic weather hasn’t activated any major melt mechanism to push the ice into new record low territory. And so in many major monitors we are now above 2013 melt levels for this day.

Cryosphere Today shows sea ice area at 5.22 million square kilometers, above 2013 and just slightly above 2011 while ranging below 2008 for the date. Overall, the area measure is at 6th lowest on record for the date. Meanwhile, NSIDC shows sea ice extent at 7.74 million square kilometers or just above 2013 values for the same day but remaining below 2008 and 2009 by a substantial margin. Overall, also a sixth lowest value for the date:

Sea ice july 2014 v2

(NSIDC chart comparing sea ice melt years 2012 [dashed green line], 2008 [maroon line], the 1981 to 2010 average [solid line] and 2013 [pink line]. Image source NSIDC.)

So in the sea ice butcher board tally, with the negative feedback of fresh water floods and glacial melt moderately in play and with weather that is highly unfavorable for melt, we currently stand at 4th lowest in the volume record, 6th lowest in the extent record, and 6th lowest in the area record.

And now, things may just be about to get interesting…

Forecast Shows Arctic Heatwaves on the Way

GFS and ECMWF model runs show two warm ridges of high pressure developing over the Arctic this week. And the emergence of these warm and moist air flows into the Arctic may well have an impact by pushing the Arctic back toward melt-favorable conditions.

The first ridge is already expanding across the Canadian Archipelago. Yesterday it brought 80 degree temperatures to Victoria Island which still sits between wide channels clogged with sea ice. Smoke from wildfires is being entrained in this ridge and swept north and east over the remaining Archipelago sea ice and, today, the Greenland Ice Sheet.

While the smoke aerosol from fires blocks some of the incoming solar short wave radiation, it absorbs and re-radiates it as long-wave radiation. Many studies have shown this albedo-reducing darkening of the cloud layer by black and brown carbon aerosols has a net positive warming effect. In addition, the soot falls over both land and sea ice where it reduces reflectivity medium to long-term (Dark Snow).

Smoke streaming over Canadian Archipelago and Northwestern Greenland

(Smoke associated with record wildfires in the Northwest Territory streaming over the Canadian Archipelago, Northern Baffin Bay, and Northwestern Greenland beneath a dome of record heat. Image source: LANCE-MODIS.)

The ridge is expected to expand east over the next few days until it finally settles in as a moderate-strength high pressure system over Greenland. There it is predicted to juxtapose a set of low pressure systems that will slowly slide south and east over Svalbard. The conjoined counterclockwise cyclonic wind pattern of the lows and the clockwise anti-cyclone of the high over Greenland in the models runs over the Fram Strait. And so, for at least 4-5 days, the models predict a situation where sea ice transport out of the Arctic may be enhanced.

Meanwhile, on the other side of the Arctic, a series of high pressure systems are predicted to back up over the Pacific Ocean section of Irkutsk and Northeast Siberia. This ridge is expected to dominate coastal Siberia along the Laptev and East Siberian Seas. Temperatures along the coast are expected to reach 15-20 C above average, while temperatures over the waters are expected to rise to melt enhancing levels of 1 to 5 C.

Ahead of the ridge runs a warm frontal boundary that is heavily laden with moisture and storms. So a liquid and mixed precipitation band is likely to form over the East Siberian and Beaufort Sea ice as the ridge advances.

The ridge is projected to drive surface winds running from the south over the East Siberian Sea, across the polar region, and into the Greenland and Barents Seas. This cross-polar flow of warm, moist air will also enhance the potential for ice transport.

Melt Pattern

(Pattern more favorable for sea ice melt and transport emerging over the next seven days. This Climate Reanalyzer snapshot is at the 120 hour mark. Note Arctic positive temperature anomalies at +1.18 C. Will the pattern override potential negative feedbacks such as high fresh water content in the Arctic and unfavorable weather likely produced by the late emergence of temperatures above 0 C in the 80 North Latitude zone? Image source: University of Maine.)

Overall, it is a weather pattern that shows promise to increase melt, especially in the regions of the Canadian Archipelago and the East Siberia Sea, and to speed ice mobility and transport. Persistent lows near the central Arctic for the first half of this period and shifting toward Svalbard during the latter half will continue to disperse sea ice which may lend one potential ice resiliency feature to a pattern that is, otherwise, favorable for ice loss.

Negative Feedbacks and Weather Unfavorable For Melt

If the melt pattern described above comes to impact the ice and push greater rates of sea ice loss over the coming days and weeks, it’s likely that end season 2014 will end up with sea ice measures below those of 2013, but above the previous record lows seen during past years. This would likely put 2014 well within the range of the post 2007 era at 3rd to 5th lowest on record for most monitors. Not a new record year, but still well within the grips of the death spiral.

If, however, the weather predicted does not emerge or the sea ice retains resiliency through it, then 2014 stands a chance of pushing above final levels seen in 2013. In such an event, end season area and extent measures may challenge levels last seen during 2005 while sea ice volume maintains between 4th and 5th lowest.

If this happens, we may need to start asking this question:

Are negative feedbacks, in the form of greatly increased freshwater flows from rivers and glaciers, starting to pull the Arctic sea ice out of a high angle nose dive and are they beginning to soften the rate of decline? Or is this just a year when weather again wagged the dog as natural variability played a trump card for the summer of 2014 but further drives for new records will follow come 2015, 2016, or 2017?

In any case, near-term sea ice forecasts remain somewhat murky, as they should given the high instability of the current situation.

Links:

Science Daily

Now Melts the Arctic

The Arctic Ice Blog

NSIDC

LANCE-MODIS

University of Maine

PIOMAS

Cryosphere Today

Dark Snow

 

 

 

 

154 Comments
by robertscribbler on July 25, 2014  •  Permalink
Posted in Climate Change
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Posted by robertscribbler on July 25, 2014

https://robertscribbler.wordpress.com/2014/07/25/big-arctic-ocean-warm-up-predicted-for-this-week-melt-to-speed-up-or-sea-ice-to-show-resiliency-due-to-variability-strength-of-negative-feedbacks/

Summer 2014 Melt Season to Ramp up in Early May Heat Wave: Fixed Jet Stream, Dual Ridges Form Sea Ice Achilles Heel

For many months the weather pattern has been essentially fixed. A ridge over China and Eastern Russia combined with warm air flows over Central Asia to amplify heat from Siberia and on into the Arctic Ocean. On the other side of the Pacific, a harmonic pattern involving warm southerly air flows over Alaska and Western Canada has also transported an inordinate amount of highly anomalous heat into the Arctic.

These warm ridges have been consistently reinforced by high amplitude Jet Stream waves. During the Winter of 2013-2014, these same atmospheric heat transport engines collapsed the polar vortex, causing melt, avalanches, and 60 degree F temperatures for Alaska in January all while pulling Arctic air down over the Eastern United States throughout the winter months.

For Alaska, Western Canada and the Eastern US, it is a general pattern that has now lasted nearly 14 months. A blocking pattern that weather historians everywhere should take note of as a general evidence of atmospheric changes resulting from human-caused warming and a validation in observation to the findings of Dr. Jennifer Francis.

Early Season Melt in the Bering Sea

This warm air flow also severely retarded sea ice formation in the Bering Sea between Alaska and far Eastern Russia throughout winter. Now, this poorly formed ice is rapidly melting out as a barrage of storms and continued warm, southerly air flows result in ongoing degradation. Recent observations show a rather extreme loss of sea ice in this region over the past 18 days:

Bering and Chukchi Seas April 10Bering and Chukchi Seas April 27

(LANCE-MODIS comparison of Bering and Chukchi Sea Ice on April 10 [left image] and April 27 [right image]. Image source: LANCE MODIS. Hat Tip to Arctic Sea Ice Forums Poster Frivolousz21.)

As we can clearly see in the two images above, both snow cover and sea ice have experienced severe losses in this region from April 10 to April 27. Warm southerly winds have continued to push ice northward enhancing melt as temperatures typically remained near or above -2 C (the temperature at which sea ice begins to melt) in most regions. Snow losses amplified warmer than freezing water flows into adjacent ocean basins, also enhancing sea ice losses as land masses continued to warm.

Heat Pulse for Bering, Chukchi, East Siberian and Beaufort Seas

Over the next six days, this general warming trend is expected to spike, bringing with it a front of much hotter than usual temperatures extending along a broad zone of the Arctic Ocean north of Canada, Alaska and East Siberia and nearly reaching the North Pole at maximum extent.

The pulse is expected to bring 18-32 F above average temperatures for this region, pushing daily highs into the mid 30s to mid 40s over the Arctic Ocean and to nearly 50 F over waters directly adjacent to the Alaskan coast. GFS model runs for May 2, 2014 show this powerful warm air invasion, indicated by the wave of green on the map below, extending well into the Arctic Ocean with extraordinarily warm temperatures in the mid-to-upper 60s over a broad swath of Central Alaska:

Arctic Heatwave Friday May 2

(GFS temperature model for May 2, 2014. Image source: University of Maine.)

Such an intense warm pulse will greatly involve the Bering, the Chukchi, the East Siberian and Beaufort Seas. It will likely most significantly impact sea ice in regions of the Bering Sea and near-shore zones of the Chukchi and Beaufort. The early season heat wave may also enhance the ice weakening process throughout the affected zone by softening the sea ice and by creating the potential for melt pond formation.

The Major Impact of Early Season Melt Pond Formation

During May and June, early melt pond formation can have a dramatic impact on sea ice melt much later in the season as the darker pools reduce ice sheet albedo serving as a kind of heat lens that bores down through the ice surface. Eventually, the melt ponds connect, forming larger and larger volumes over the ice face until the sea ice is almost completely overwhelmed. In the last phase, melt breaks down through the ice surface to contact the ocean. At this point, the sea ice is typically splintered into much smaller and disassociated fragments.

A recent paper in the journal Nature has found that a multiplication of such early season melt ponds may well be a predictive indicator of end season sea ice extent, area and volume values come September.

The paper notes:

Our simulations show that melt ponds start to form in May, a maximum extent of 18% is reached in the climatological mean at mid-July, and there are hardly any exposed ponds left by mid-August. The strong interannual variability and the positive trend are striking. Whereas in 1996, the year with the highest September ice extent since 1979, the maximum pond fraction reaches only 11%, in 2012, the year with the lowest September ice extent, up to 34% of the sea ice is covered by ponds.

Neven over at the Arctic Ice Blog recently provided an excellent assessment of the impact of melt ponds which is available here.

Massive interconnection of sea ice melt ponds

(Major expanse of dark sea ice melt ponds in the Chukchi Sea during June of 2010. Image source: The Polaris Project.)

Achilles Heel For the Arctic During the Summer of 2014

The most recent hot pulse for this region may just be the first of many as the spring and summer melt season progresses. Jet Stream patterns continue to remain fixed, delivering much hotter than normal temperatures throughout the Western Canadian, Alaskan, and East Siberian regions. Furthermore, snow cover losses for these regions are particularly well advanced further enhancing the likelihood of warm air invasions from these rapidly heating continental zones. Anomalously large and extreme early season fires may also result in a degree of albedo loss as smoke and soot is drawn northward to darken both remaining snow cover and sea ice.

As such, this zone represents a kind of sea ice Achilles heel as the 2014 melt season progresses. If we do see major losses and a progression toward record melt, it will likely come as a result of extreme weather patterns emerging from the continental zones spanning East Siberia, Alaska and Western Canada.

Links:

LANCE MODIS

Arctic Sea Ice Forums

University of Maine

Global Forecast System Model

More on Melt Ponds

September Sea Ice Minimum Predicted By Sea Ice Melt Pond Fraction

 

 

17 Comments
by robertscribbler on April 29, 2014  •  Permalink
Posted in Climate Change
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Posted by robertscribbler on April 29, 2014

https://robertscribbler.wordpress.com/2014/04/29/summer-2014-melt-season-to-ramp-up-in-early-may-heat-wave-fixed-jet-stream-dual-ridges-create-sea-ice-achilles-heel/

Heavy, Early-Season Blow to Arctic Ice Cap: Powerful, Warm Storm Disintegrates Barents Sea Ice

A vast swath of sea ice that painstakingly formed as somewhat cooler conditions had finally settled in near Svalbard and Frans Joseph Land in the Barents Sea was shattered yesterday as a powerful, heat-laden Arctic cyclone screamed up out of a rapidly warming extreme North Atlantic.

The storm originated west of the Norway coastline where, in recent years, a repository of exceptionally warm water has collected. This near-Arctic and Barents Sea warm pool has resulted in numerous effects including a forced recession of sea ice by hundreds of miles during winter time as well as providing impetus for various anomalous heat waves in Scandinavia in recent years.

This time, the heat pool was the genesis for a powerful storm that delivered an intense package of early season warmth to a section of sea ice drifting in the North Barents Sea region.

Warm Storm Impacts

April 16, pre-storm

In the above image, provided by NASA’s  LANCE-MODIS sensor, we can see a 250 mile section of sea ice that had extended out into the Barents Sea over the past few weeks during a cooler period as warmer conditions shifted to the Laptev, East Siberian, and Beaufort Seas. The date of this shot is April 16. To the lower left is the tip of Svalbard. Upper left is the far edge of Frans Joseph Land. Another few hundred miles to the right of far right frame is Northern Norway.

The storm, for now is off frame.

Storm April 17

Now on April 17, we can see the storm center in the far left frame near the tip of Svalbard. At this point, the storm has bombed out to an extraordinarily powerful 950 mb low, packing 60+ mph winds. In its upper quadrant, it carried with it temperatures ranging from 10 to 20 C above typical seasonal averages. Perhaps more importantly, through cyclonic forces it pumped waters that were up to 5 C above average temperature up from the depths and into the ice pack. This kind of cyclonic Ekman Pumping, in recent years, has had an increased potential to rapidly reduce sea ice due to warmer surrounding water conditions and warmer waters at depth.

Note that rapid sea ice disintegration is already involved in the wake of this severe Arctic Cyclone.

Aftermath -- Near Zero Contiguous Ice

Now, today, on April 18, we can see that in the aftermath of this powerful Arctic Cyclone there is very little contiguous sea ice left. What remains is what in sea ice parlance can be termed nilas — very thin and diffuse ice of 0-10 centimeters in thickness. Note that the entire 250 mile zone is completely involved in this very visible ice loss and that such losses continue on past Frans Joseph Land and into the Kara Sea.

Further Implications for the 2014 Melt Season

Melt season in the Arctic is now well involved. In addition, we have numerous weaknesses in the Northern Hemisphere Jet Stream that continue to funnel much warmer than average air over the Arctic Sea Ice. Alaska, Siberia and the Barents all continue to see strong warm air impulses that progress well into the zone covered by sea ice.

Today, according to GFS model measures for the zero hour, average Arctic temperatures are 2.24 C above the, already warmer than normal, 1979 to 2000 average. This is a rather high spike for spring, when Arctic temperatures typically start to settle back down after seeing high levels of global warming associated heat amplification during winter time.

The excess heat had already pushed Arctic sea ice extent measures down to near record lows as of April 17. According to NSIDC, extent measures had fallen to 13.9 million square kilometers yesterday, the second lowest level in the measure. With full effect from the recent intense storm not yet fully realized, it is possible that impacts in this region alone could reduce total values by at least 100,000 square kilometers.

arcticice_nsidc apr 17

(Arctic Sea Ice Extent Second Lowest on Record for April 17. Data Source: NSIDC. Image Source: Pogoda i Klimat.)

Yet one more major blow to sea ice from a powerful warm storm type system. And, in this case, with melt season progressing rapidly and with so much heat already shifting into the Arctic, it is highly unlikely that this zone of newly dispersed ice will see much in the way of recovery over the coming weeks.

 

Links:

LANCE-MODIS

NSIDC

Pogoda i Klimat

Global Forecast Systems Model

Persistent Arctic Cyclone and the Warm Storm of 2013

 

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by robertscribbler on April 18, 2014  •  Permalink
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Posted by robertscribbler on April 18, 2014

https://robertscribbler.wordpress.com/2014/04/18/heavy-early-season-blow-to-arctic-ice-cap-powerful-warm-storm-disintegrates-barents-sea-ice/

Climate Change and Jet Stream Erosion Again: Epic European Floods Drive Thousands From Homes

According to news reports, a broad swath of central Europe is suffering severe impacts from major flooding.

In the Czech Republic, over 3,000 people have been forced to flee their homes as raging flood waters threatened both lives and property. Officials in Prague shut down the subway system and erected flood barriers to protect valuable historic districts from waters that were still rising as of Tuesday. In Germany, at least 10,000 were forced to evacuate as 1,700 soldiers were called up to manage major water rises. The German Chancellor noted that damage from this week’s floods appeared likely to exceed the devastation experienced in 2002, Germany’s worst flood in modern memory.  In Passau, where the Danube reached 12.2 meters above flood stage, the historic city center was under water higher than any level recorded since 1501, the year flood records began. Austria also suffered severe impacts as all three countries remain crippled with road, rail and river service suspended due to immense flooding.

The 2002 flood was called a ‘millennial flood’ because this kind of event is supposed to happen only once every thousand years. Yet flood levels have rivaled that of the 2002 flood at least on one occasion with the most recent flood already exceeding 2002 levels in a number of locations. Unfortunately, human-caused climate change has resulting in 1,000 year floods happening about twice a decade in Europe. And as greenhouse gas emissions continue to ramp up, the situation is likely to grow worse.

This year, extreme weather induced by just this kind of climate change has continued to persist. A major dip in the jet stream plunging down over Greenland and invading Britain and Europe resulted in severe weather throughout this winter and spring. Germany so far has received nearly double the amount of rain of a normal spring. Britain has suffered its wettest spring on record, while Italy saw its wettest conditions in 150 years. Since the early 2000s, four record floods have impacted Europe causing between $1 billion and $40 billion dollars in damages. The current event is likely to rival the most damaging of these floods.

Increasingly, scientists are showing that loss of Arctic sea ice caused by human warming is a primary contributor to these extreme weather events. Sea ice volume is down as much as 80% since 1979. This major erosion, scientists note, results in a slowing of the polar Jet Stream. This slowing, in turn, creates a higher frequency of blocking patterns that cause weather conditions to persist for long periods over a given area. In Europe, the northwest-southeast dip in the Jet Stream has resulted in cooler, stormier conditions to persist through southern and central regions since winter. It is a pattern that has been stuck in the same mode for months, bringing storm after storm to the region.

Back in April, the UK Met Office held an emergency meeting to discuss the impacts of climate change on the Jet Stream and attempted to plan for the severe weather now in store. Earlier this spring, the European Environmental Agency warned of the potential for record flooding. Now these predictions appear to be born out.

Links:

Record Floods Inundate Central Europe

Historic Flooding in Central Europe

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by robertscribbler on June 4, 2013  •  Permalink
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Posted by robertscribbler on June 4, 2013

https://robertscribbler.wordpress.com/2013/06/04/climate-change-and-jet-stream-erosion-again-epic-european-floods-drive-thousands-from-homes/

Sea Ice Melt: When 2040 Predictions Could Happen Tomorrow

ncar_seaice_2040.jpg.CROP.original-original

(NCAR sea ice predictions for 2040)

The above image shows NCAR’s 2006 prediction for potential sea ice losses by 2040, but current rates of sea ice loss could result in such conditions within 1-6 years.

Sea ice melt. It’s something we should all be concerned about. That protective cap of ice over the northern polar region provides a number of beneficial services. Its white, reflective layer cools the Earth, reflecting sun into space. As such it is a haven for Earth’s cold air stores. It also rests above a shallow sea filled with sequestered carbon. The cold cap locks these stores in, keeping them out of the Earth’s atmosphere.

Such a large cap of cold ice also has powerful regional influences. Over the past 10,000 years, it has ensured the health of adjacent land tundra which also sequesters massive volumes of carbon locked in organic material. Sea ice and tundra form an insulator that protects Greenland’s massive ice sheets from melt even as they establish a regional climate system that benefits Earth’s life by providing stability in temperatures and weather patterns.

They also form a first line of defense against runaway global warming.

Yet this system — its cold air, its glaciers, its tundra, and its sea ice — is in increasing jeopardy. Sea ice, which is a primary insulator keeping cold air in the Arctic, has declined about 55% by area and 80% by volume since 1979. This loss of ice reduces reflectivity during summer months and enables greater ocean heat uptake, further hastening melt. It also results in warmer seas during winter time, which helps to keep air temperatures much warmer during the coldest season. This one, two punch has the net effect of pushing melt at ever more rapid paces. Now, yearly volume losses are enough, if sustained, to bring the Arctic Ocean to a nearly ice-free state by 2016 plus or minus three years.

For context, take a look at the above NCAR picture again and then take a look at this picture of end summer sea ice in 2012.

arctic-seaice-colorsep15

(Image source: Cryosphere Today)

Not too different, are they?

Another single year loss equivalent to 2012 would push sea ice to a state comparable to the NCAR prediction for 2040. And such a loss could happen this year, or next year, or the following. Unless current trends reverse (an unlikely event given an increasing CO2 forcing), then NCAR’s 2040 prediction will almost certainly happen before 2020.

We are losing the northern polar sea ice. And we are losing it far more rapidly than previously anticipated. With it, we are losing all the beneficial services sea ice provides. So as the sea ice recedes more sunlight will be absorbed by the Earth’s northern oceans. As this happens, oceans will warm faster, melting tundra. Together, warmer seas and warmer tundra will release more methane into the atmosphere. Over time, this will produce more warming. All the added heat will push Greenland to melt at an increasing rate. The flushes of fresh, cold water from Greenland together with loss of sea ice will play havoc with northern hemisphere weather as cold and hot air build up and battle in places where they hadn’t before. Europe and portions of North America will see especially severe impacts from this whip-sawing climate. But the impacts of ice melt and polar amplification will be global, creating weather that is likely to make a mess of the world’s growing seasons, resulting in potentially severe impacts to the world’s food security. Lastly, a more rapidly melting Greenland will increase the rate of sea level rise.

This is why sea ice isn’t just an image on a map or a number on a chart. This is why loss of sea ice is much, much more than an opportunity to drill in the Arctic. An ‘opportunity’ that will only serve to make a growing problem worse.

If Earth were a space ship, its captains and crew would consider the sea ice one of its key human life support systems. Its health and stability would be a primary contributor to the safety of passengers and crew members. Loss of sea ice, in this case, would mean a loss of a vital life support and climate stability system. After loss of sea ice, life on space ship Earth becomes more difficult and the risk of harm to its passengers grows.

This is why we should all be concerned about the dramatic sea ice losses we are now witnessing. This is why we should view the cynical Arctic profiteering of the oil companies with dread. And this is why we should do our very best to slow and halt the human-caused changes that are robbing us of that vital, protective layer of ice over our northern oceans.

Links:

The Arctic Ice “Death Spiral”

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by robertscribbler on May 29, 2013  •  Permalink
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Posted by robertscribbler on May 29, 2013

https://robertscribbler.wordpress.com/2013/05/29/sea-ice-melt-when-2040-predictions-could-happen-tomorrow/

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