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?
25
July, 2014
(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 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:
(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 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.
(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:
Song
of Flood and Fire Refrain: Epic Canadian Floods Wreck 5.5 Million
Acres of Cropland
For
the Northwest Territory of Canada, the story this summer has been one
of record-setting wildfires. Fires casting away smoke plumes the size
of thunderstorms, fires that burn regions of tundra the size of small
states. Fires that just burn and burn and burn for weeks on end.
But
to the south and east in Saskatchewan and Manitoba, the story is
drastically different. For over the past month, unprecedented
flooding in this region has wrecked untold damage to Canada’s
farmlands.
(Powerful storms over Manitoba and Saskatchewan on July 23rd, 2014. Image source:LANCE-MODIS)
This
situation is the result of an odd and wreckage-inducing tangle in the
Jet Stream. For hot air has been funneling up over the Northwest
Territory for the better part of two months now, pushing temperatures
in this Arctic region into an unprecedented range topping the 70s,
80s, and even 90s on some days. This high amplitude ridge in the Jet
Stream has been reinforced and locked in place, a result some
scientists attribute to the loss of Arctic sea ice during recent
years, setting up a hot weather pattern favorable to wildfires.
As
the massive Arctic wildfires ignited and burned, they cast off giant
streams of smoke, burdening the down-wind atmosphere with aerosol
particles — an abundance of condensation nuclei for cloud
formation. These smoke streams fell into a trough flowing down over
Manitoba and Saskatchewan. The deep trough, often extending far into
the Central US formed a kind of trap for storms and, like the fixed
ridge over the Northwest Territory, it has remained in place for
months on end.
Given
this mangled positioning of atmospheric heat and moisture flows, it
was only a matter of time before massive rainstorms erupted in the
wake of the large-scale Canadian fires. And the result was an
unprecedented flooding. The offspring of an unprecedentedly powerful
and persistent atmospheric pattern set off by human warming.
Major
Floods Wreck Canadian Crops
For
some local farmers, the past couple of days have seen 48 hour rain
totals in excess of 10 inches. A 100 year rain event at a scale few
farmers in the region have ever seen. And the recent floods are just
the latest in a series of heavy rainfalls that have been ongoing ever
since early July. Flood follows flood follows flood. A progression
that has left most farms swimming in inches to feet of water and mud.
In
total, farmland encompassing 3 million acres in Saskatchewan and 2.5
million acres in Manitoba are now under water and are unlikely to
produce any crops this year. As a result, wheat plantings are
expected to decline by 9.8 percent from last year, canola is expected
to decline by 5.8 percent from the June forecast, and oat is expected
to decline by 6 percent, according to estimates from Bloomberg.
July
flooding in these regions has so far resulted in over 1 billion
dollars in damages to farmers. As much as half of these losses may
not be covered as insurers are still reeling from severe moisture
damages during 2011, just two years ago. As a result of the ongoing
parade of storm casualties, insurers have also raised deductibles,
leaving farmers more vulnerable to the odd and powerful new weather
coming down the pipe.
The
Part Played By Climate Change and a Mangled Jet Stream
We
often hear of the expanding droughts of human-caused climate change
wrecking croplands. But the upshot of expanding drought in one region
is record downpours in another. And downpours, if they are intense
enough, can have a negative impact on crops as well.
The
cause of this is as simple as warming’s enhanced ability to
evaporate water. For
it is estimated by climate scientists that each degree C in
temperature increase amplifies the global hydrological cycle by 7-8
percent. That means that current warming of about 0.8 C since the
1880s has resulted in about a 6% increase in both evaporation and
precipitation. At the level of weather, this translates into more
intense droughts under dry, hot weather, and more intense rainfall
events under wetter, cooler weather.
(High amplitude Jet Stream wave pattern fueling wildfires in the Northwest Territory and record floods in Manitoba and Saskatchewan. Note the extreme northward projection of the Jet over the Northwest Territory and the strong, deep, trough back-flowing from Hudson Bay into Manitoba, Saskatchewan and the northern tier of the Central US. Image source: University of Maine.)
One
mechanism that has tended to amplify drought and rain events during
recent years has been a weakening and intensifying waviness of the
Northern Hemisphere Jet Stream. This weakening has been attributed by
some scientists to a large-scale recession of Arctic snow cover and
sea ice. For since 2007, not one day has seen an average sea ice
extent and the range has typically fallen into a zone between 20-50
percent below levels seen during the 1970s and 1980s. New major
record low years in 2007 and 2012 have also fueled speculation that
sea ice may completely melt away during one summer between now and
2030, 2025, or even 2020 — 50-100 years ahead of model predictions.
As
the sea ice serves as a haven for cold air masses, its loss is bound
to impact the resiliency of these systems and since a solid pool of
cold air to the north is a major driver of Northern Hemisphere upper
air currents, the weakening of this cold pool has had dramatic
impacts on climates
(Extreme dipole hot/cold pattern associated with Jet Stream mangled by climate change. Image is for July 14, a match to the above Jet Stream shot. Note the extreme heat in the ridge and the much cooler air in the trough. This is exactly the kind of pattern we would associate with sea ice retreat and Jet Stream weakening. Image source: University of Maine)
For
this year, the ridge over Canada’s Northwest territory was a direct
upshot in a northward retreat of the Jet Stream over Canada and, at
times, into the Arctic Ocean. This set the stage for severe wildfires
in the zone of warmth underneath this ridge pattern. To the east, a
powerful downsloping trough pulled cooler air into Saskatchewan and
Manitoba as well as over the Central and Eastern US. This set the
pattern up for cooler than average conditions as well as for strong
rainstorms.
The
crop-shattering events of July were a direct result of this climate
change induced ‘Song
of Flood and Fire.’ A pattern we’ve seen repeat again and
again over the past few years and one that may well intensify as both
time and human-caused warming advance.
Links:
Hat-tip
to Colorado Bob.
Is
This the Compost Bomb’s Smoking Gun? Second Mysterious Hole Found
in Yamal Russia
24
July, 2014
Is This the Compost Bomb’s Smoking Gun? Second Mysterious Hole Found in Yamal Russia
Yamal,
Russia — a stretch of tundra flats and peat bogs stretching as far
as the eye can see before terminating into the chill waters of the
Kara. A rather stark and desolate place, one that was mostly unknown
until a massive and strange hole appeared in the earth there last
week. Since that time, the strange hole has been the butt of every
kind of wild speculation and controversy.
(MODIS satellite shot of Yamal Siberia — the peninsula located in center frame and recent site of mysterious holes that may have been caused by the catastrophic destabilization of thawing methane gas embedded in the permafrost. Image source: LANCE-MODIS.)
The
hole itself was an alien feature. “We haven’t seen anything like
this before,” would be an entirely accurate statement. All about
the hole was a large pile of debris — overturned earth, huge chunks
of soil piled up in a signature very familiar to the ejecta of a
meteor impact crater.
Approaching
the hole edge, we came to a gradual slope that proceeded downward for
about 40 feet at about a 35 degree incline. Along the surface of this
incline, both the unfrozen soil cap and the frozen permafrost were
visible.
But
it wasn’t until we hit the bottom edge of this incline that we
encountered the strangest feature of all — a sheer cliff, rounded
in a shape like the smooth bore of a gun, and plunging straight down
through icy permafrost for about another hundred and twenty feet
before revealing a basement cavern slowly filling with melt.
It’s
a combination of features that appears to be one half impact crater
and one half sink hole.
(The freakish combination of features including apparent ejecta piled around a crater with a sheer tunnel coring 220 feet down. Image source: The Siberian Times)
The
Compost Bomb
Key
to the second theory is that thawing permafrost contains vast stores
of volatile methane at various depths. The methane is either trapped
in pockets encased in ice and soil or locked in a water lattice
structure forming what is called methane hydrate. Both forms are
unstable, though they are often buried beneath tens to hundreds of
meters of permafrost. Researchers have remained unsure how rapidly
this methane would release and its rate of release is key to how fast
the world will warm this century in response to human-caused
greenhouse gas heat forcing.
Over
1,400 gigatons of carbon are sequestered in the permafrost. Much of
this immense store is biological material buried over the 2 million
year span of below-freezing conditions dominating much of the Arctic
region of our planet. During this time, gradual glacial advance and
retreat froze and refroze the earth in layers entombing a vast load
of the stuff. Now, human warming is beginning to unlock it.
Permafrost
spans much of the Arctic, under-girding Siberia, far Northern Europe,
the northern tiers of Canada, and most of Alaska. It also rests
beneath a flooded zone called the East Siberian Arctic Shelf. Initial
reports and research from these regions indicate an ongoing release
of millions of tons of methane and CO2 annually. Bubbling seabed
stores from the shallow East Siberian Arctic Shelf have caused some
to speculate that releases of 1 billion tons to 50 billion tons of
methane could be possible during the coming years and decades.
(Is a sleeping dragon awakening in the Arctic? Map of wide expanse of permafrost containing 1,400 gigatons of carbon. Image provided by NASA’s CARVE methane research experiment which is now under the aegis of ABOVE.
Peter
Wadhams, in an article for Nature last year, attempted to bracket the
potential impacts of such large releases. In the article, Wadhams
estimated that a 50 gigaton emission from the Arctic methane store
over the next two decades would increase global temperatures by about
0.6 C above the current rate of warming and force temperatures
through the 2 C barrier by 2035 (ironically,
Michael Mann comes to the same conclusion without implicit inclusion
of a powerful methane release). The costs in human lives and
economic damage from such a release would be immense and it would
risk further outbursts from the large and vulnerable carbon store.
And
though the potential for such very large releases remain highly
controversial among scientists, the massive pile of thawing
permafrost carbon is an ominously large and unstable store facing off
against an initial human warming that is more than six times
faster than at any time during the geological past.
In
the shadow of this emerging and hard to gauge threat, a term emerged
to encapsulate the vast warming potential stored in permafrost,
should it release and hit the atmosphere. The term — compost
bomb — alludes to the
risk involved in pushing the two-million-year-old Northern Hemisphere
permafrost stores into rapid thaw.
Mystery
Hole — A Smoking Gun?
With
the spontaneous emergence of a strange hole that Russian scientists
are linking to destabilized gas pockets within the permafrost due to
thaw, it became possible that, yet one more, explosive mechanism for
release had presented itself. And now, today, a second and similar
hole has been discovered:
According
to the Moscow Times:
“Global
warming, causing an alarming melt in the ice under
the soil, released gas causing an effect like the popping
of a Champagne cork,” the news report said, citing
an expert at the Subarctic Scientific Research Center.
The first
hole is estimated to be about 50 meters wide and 70 meters
deep, with water from melting permafrost cascading down its
sides into the icy deposit below.
The second
hole is “exactly” like the first one,
but “much smaller,” local lawmaker Mikhail Lapsui told
the Interfax-Ural news agency. “Inside the crater itself,
snow can be seen. (emphasis added)”
And
so, in the course of just one week, we have two very strange holes
that Russian scientists are linking to destabilizing gas pockets
beneath the thawing tundra. Smoking barrel of the compost bomb? Or as
a commenter here called Colorado Bob puts it:
We’re
going to see the tundra breaking out in these things like zits on a
teenager.
Let’s
hope these are mere sink-holes from collapsing ice pockets in the
permafrost. Let’s hope there’s another explanation for what
appears to be ejecta piled around these holes. Let’s hope that
these ‘zits’ showing up in the Yamal permafrost remain local to
the area. And let’s hope we don’t start seeing similar explosive
outbursts from tundra in other regions, or worse, along the seabed of
the East Siberian Arctic Shelf.
Lastly,
let’s hope that any outbursts remain small in size and do not lift
very large sections of land or submerged sea bed.
In
any case, these initial reports are not promising and it appears we
may both have a compost bomb smoking gun and a potential mechanism
for rapid destabilization and explosive release of gas pockets deeply
embedded in the frozen tundra all wrapped into one. Not very
reassuring to say the least.
Links:
Hat
tip to todaysguestis
Hat
tip to Colorado Bob
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