Siberian Heatwave Wrecks Sea Ice as Greenland High Settles In

We’ve never seen Arctic sea ice extents that are as low as they are now in early June. And with Arctic heatwaves, warm winds, warm storms, and a Greenland High all settling in, something had better change soon or otherwise the ice cap over the northern Polar Ocean is basically screwed.

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On the shores of the Arctic Ocean’s East Siberian Sea (ESS), near the town of Logashinko, temperatures today are expected to rise to near 80 degrees Fahrenheit. Readings that are about 40 to 50 degrees (F) above normal for this near-polar region during this time of year.

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(Welcome to increasingly ludicrous climates. Temperatures near 80 F at Logashinko, Russia are at least 40 degrees F above average for this time of year. A place well north of the Arctic Circle, but whose temperatures are predicted today to match those of St. Martin Island in the tropics. Image source: Earth Nullschool.)

We would have never expected temperatures to have risen so high near typically frozen Logashinko during early June sans the heating effect of atmospheric CO2 levels that have this year peaked near 407.5 parts per million. The highest levels seen on Earth in about 15 million years. These scorching polar temperatures were driven north by a powerful high amplitude ridge in the Jet Stream that has dominated Eastern Russia for much of 2016 Spring. This expansive ridge enabled extreme wildfires popping up all over the region even as it today drives 80 degree weather all the way to Arctic Ocean shores — enforcing a regime of rapid sea ice melt over the East Siberian Sea.

ESS, Laptev Get Ripped Up

As the warm winds drive northward across ice-clogged Arctic Ocean waters, temperatures rapidly fall into 35 to 41 degree (F) ranges. And though that may sound cool to the casual observer, for the East Siberian Sea zone during early June, that’s scorching hot — topping out at more than 10 degrees above average for some areas. A pretty extreme variation for late Spring when temperatures over the Arctic Ocean only typically depart from average by about 3 or 4 degrees at most.

East Siberian Sea Melting

(The Laptev and East Siberian Sea Ice is getting ripped up by extreme Arctic warmth. The blue tint to ice in the above image indicates melt ponds, while dark blue indicates open water. Zooming in closer reveals the brown flush of warm waters issuing from heated Siberian rivers. Image source: LANCE MODIS.)

All across this Arctic Ocean region, melt ponds and widening polynyas now abound in the ridiculously warm airs. In the satellite shot above, the tell-tale bluish tint of the ice reveals a plethora of these ponds expanding northward through the ESS and on toward the pole. A flush of hot water running into the Arctic Ocean from East Siberia’s rivers is melting the near shore ice. And a giant 80 mile wide gap of open water has now been torn into the ice of the Laptev Sea.

Record Extent Lows Continue to Worsen

The sudden Arctic heatwave and rapid related melt involvement of the ESS and Laptev is just the most recent melt spike in a polar ocean that sees ice extent levels hitting new record lows with each passing day. As of June 2nd, the expanse of Arctic Sea ice only measured 10.37 million square kilometers. This is about 430,000 square kilometers below the previous daily record low set just last year and fully ten days ahead of the record sea ice melt year of 2012.

Arctic sea ice extent new record lows

(Arctic sea ice extent record lows continue for this time of year and threaten to plunge deeply below the 2012 line in coming days. Image source: JAXA.)

A coverage of sea ice that is now 42 days and 2.1 million square kilometers of sea ice loss ahead of an average melt year during the 1980s.

Here Comes the Greenland High

Extreme heat building into the Siberian side of the Arctic and record low sea ice extent measures are today being joined by yet another disturbing Arctic feature. For as of yesterday, a strong ridge of high pressure began to form over Greenland, the Canadian Archipelago and Iceland.

Greenland highs tend to increase temperatures over the enormous glaciers of that frozen island even as the clockwise circulation pattern of an anticyclone tends to shove sea ice out into the Barents and North Atlantic. The dominance of a Greenland High during both 2012 and 2007 is thought to have heavily influenced record end season sea ice melts during those years as well as the extreme Greenland surface melt spike during 2012.

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(A high pressure ridge emerging over Greenland, Iceland and the Canadian Archipelago today is expected to strengthen this week — generating a high pressure gradient between warm storms developing over the Arctic Ocean and winds that threaten to increase the rate of ice transport out of the High Arctic and into regions of warmer water. Image source: Earth Nullschool.)

This week’s predicted ridge formation is not expected to bring with it a severe surface melt of Greenland. However, the clockwise winds driving sea ice transport may serve as yet one more heavy blow to the already greatly weakened ocean ice. Pressures later this week are expected to rise to 1040 mb over Greenland. And strong winds running between powerful warm storms expected to form in the Kara and Central Arctic are predicted to rise to near gale force north of Greenland — generating a risk of a very vigorous ice loss from the near polar zone as floes are driven into warm Barents and North Atlantic waters.

In context, the combined severe record sea ice lows and emerging weather conditions represent a seriously bad state for Arctic sea ice. One with a high risk of continued further extreme losses and new daily record lows for at least the next seven days.

Links:

Earth Nullschool

LANCE MODIS

JAXA

Arctic Sea Ice Graphs

The Arctic Ice Blog

Hat tip to Greg

Hat tip to Cate

Hat tip to DT Lange

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June Snow Melt Brings July Arctic Sea Ice Drop-off

It’s a pretty well established theory. If snow over the Northern Hemisphere land and sea ice masses substantially melts during May and June, it can tend to set up a general weather pattern that is conducive to large-scale reductions of the Arctic sea ice come July, August and September.

Arctic Sea Ice in ragged condition during mid July

(Arctic sea ice in very ragged condition by July 19, 2015. A situation born of a continuous Greenland and Central Arctic high pressure ridge setting up warm air build-ups and a sea ice-flushing dipole weather pattern. Image source: LANCE-MODIS.)

Arctic High Pressure, Heat, Collapsing the Sea Ice

And, during June, we saw just this kind of trend emerge. Arctic heatwaves over both the Continental land masses and the Arctic sea ice resulted in a rapid melting of snow cover. Heatwaves fed by massive bulges in the Northern Hemisphere Jet Stream, particularly along the now-famous Ridiculously Resilient Ridge over what is today an amazing (horrific) hot zone of Northeastern Pacific surface waters. El Nino and Positive PDO played their role too, kicking up the hot zones and the ridge to ever greater intensity. An atmospheric and ocean synergy in a 1 C hotter than 1880s context that kept hurling more and more heat into the Arctic environs. Melting more snow and setting the stage for a potential sea ice massacre to come.

By early July there were indications that just such an event may be on the way. A ‘heat dome’ type high pressure system had become well established over the Greenland side of the High Arctic. And for the past three weeks now, this high has remained entrenched. A persistent weather pattern that has allowed more sunlight to hit the sea ice during periods of peak insolation, a pattern that compacts sea ice in the Central Arctic, a pattern that draws storms into the Siberian side of the Arctic to chew away at the ice edge, and a pattern, that overall, drives the ice inexorably toward its Atlantic Ocean flush valve in the Fram Strait.

Arctic Heat

(Hot to record hot conditions have remained in place over the Arctic Ocean throughout July. Image source: NSIDC)

All this extra heat, transport, compaction and storms chewing away at the sea ice edge has finally started to take a very serious toll. As of today, sea ice extent measures had dropped from 7th to 10th lowest on record to 6th to 7th lowest. Area has remained at 4th to 5th lowest on record for the date. Meanwhile volume in the DMI measure has dropped to 2nd lowest on record.

Most charts now are starting to show a steep ‘cliff’ type rate of decline indicative of rapid sea ice collapse. This is particularly true in NSIDC’s Charctic and Cryosphere Today’s sea ice graphs which now show both extent and area lines plunging at rates that will rapidly cross new thresholds if they continue over the coming days.

Sea Ice Concentration in a Rough State

But perhaps most disturbing of all are the indicators that are now showing up in nearly all of the visual concentration monitors. Uni Bremen sea ice concentration continues to look like a massacre on the Pacific side. NSIDC doesn’t appear to be much better. But Cryosphere Today takes the cake for an overall display of sea ice weakness that, on the 19th (updated as the CT measure used earlier ended up being a bit off), looked nearly as bad as on the same day during the record melt year of 2012:

2012 to 2015 Comparison

(Comparison of July 19, 2015 and July 19, 2012 shows 2015 looking nearly as bad as 2012 in the concentration measure. Image source: Cryosphere Today.)

Comparing the left frame image with the MODIS satellite shot at the top of this post, we find confirmation of an overall, very weak sea ice state. Concentration throughout the Arctic appears low. This is especially true on the Beaufort, Chukchi and East Siberian Sea side (see MODIS shot at bottom of post). But extensive weakness and low concentration appears to pervade the entire ice mass. Zooming in on the sea ice surface, we find that some of this low concentration is possible to confirm. The entire Arctic is now full of broken floes, polynya and melt ponds.

Though it is also possible that this extensive melt ponding (also a feature that weakens sea ice) may have kicked the Crysosphere Today concentration sensor a bit into the extreme scale (corrected during the past 24 hours), the 2012-to-2015 comparison above is still apples to apples. And what’s a bit disturbing about this comparison is the fact that much of the concentration in red (55 to 70 percent) in the 2012 measure completely melted out at the ocean surface by mid September of that year. More notably, perhaps, is the fact that the Cryosphere Today concentration measure is, at least in part, confirmed by the US Navy ARCc Concentration model which has now begun to pick up some of the earlier predicted rapid melt in the observational ensemble:

US Navy Concentration

US Navy Concentration Forecast

(Sea ice massacre starting to show up in the US Navy ARCc model daily observations [top frame] and continues to be predicted in the 30 day history and 7 day forecast [bottom frame]. Image source: US Navy.)

Above, we see very low sea ice concentration practically anywhere outside the 80 degree North Latitude line. Most notably, concentration is very thin and rapidly weakening in the Beaufort, Chukchi, East Siberian, and Laptev Seas. And the seven day forecast shows very rapid melt throughout all these regions with the low concentration bulge beginning to invade north of the 80 degree line on the Laptev and ESS side in particularly troubling fashion.

Forecast — Continued Rapid Melt, Some Records May be Threatened

So the question, going forward, is — what next? And it appears that the sea ice is being prepped for continued rapid to accelerating melt over at least the next 7-10 days. Seven day forecasts show the ridge remaining on the Greenland side of the Arctic throughout the period. A position that will continue the current melt, transport and ice weakening regime. Longer range, ten day, ECMWF forecasts find the high shifting more toward a strong ‘heat dome’ located in the Central Arctic with a somewhat weaker high remaining over Greenland — a minor variation of the current ice-weakening state that may slow down ice export but leave compaction, melt ponding, heat build-up, and ice edge weakening due to storms in tact.

Very weak sea ice

(Sea ice throughout the Beaufort, Chukchi, ESS and Laptev is very weak. Can it survive another 10 days of the Greenland/Central Arctic heat dome? Image source: LANCE-MODIS.)

Due to this weather forecast and due to some observations beginning to come in line with ARCc model runs, we cannot rule out a very rapid melt and recession of sea ice along a broad arc running all the way from the Canadian side to East-Central Siberia. The sea ice is visibly very weak there. Perhaps the weakest we’ve ever seen it for this time of year. Ice that will continue to be pulled poleward by the highs that are forecast to remain in place. Ice that will run into weakened, melt pond invaded ice — a paltry respite for its retreat. And ice that will continue to be harried by edge storms and an influx of much hotter than normal air and water from the Pacific Ocean side. It’s a rapid melt risk that calls into effect the potential that some old sea ice area, extent, and volume records may be challenged or broken — probably not 2012’s all time low marks, but more possibly 2011 or 2007.

It’s, overall, a very tenuous situation for sea ice, one that is continuing to be fed by a growing El Nino and still firmly entrenched RRR to the south. So the evolution of sea ice melt over the next few weeks will likely be a critical game-maker for the state of Arctic Sea ice melt and the overall story of Arctic Sea Ice decline in this sad age of human-forced climate change.

UPDATED JULY 21, 2015

Links:

LANCE-MODIS

NSIDC

US Navy

Cryosphere Today

Uni Bremen

June Arctic Heatwave Takes Down Northern Hemisphere Snow Cover

Halfway to 2 C

Arctic Heatwave Pummels Sea Ice in Early July

See Beaufort and Northwest Passage Melt Progress Over at The Arctic Sea Ice Blog

(Please support public, non-special interest based science like the work conducted by the national snow and sea ice monitors, NOAA and NASA. Without their ongoing work, this analysis and commentary would not be possible.)

2012 Record Challenged as 40% of Greenland Ice Sheet Surface Melts on June 17th

Yesterday, 40% of the surface of Greenland melted.

It was still mid-June, yet a month before melt values typically peak. But a persistent high pressure system over Greenland, a rapidly melting Baffin Bay and warm winds riding up the west coast were enough to spur a surface melting event that shoved melt coverage firmly above the two standard deviation threshold and into record range.

greenland_melt_area_plot_tmb

(Greenland Melt Extent as of June 17, 2014. Image source: NSIDC.)

Temperatures along the west coast of Greenland and on through the southern ice-covered tip ranged between 30 and 55 degrees Fahrenheit, while 30-43 degree readings surrounded much of the periphery. Warm winds and rain to mixed precipitation accompanied a moisture-laden storm emerging from Baffin Bay and passing over the western ice sheet to add further and extreme early season melt pressure.

The warm storm and rains compounded already rapid melt pond formation along Greenland’s southwestern coasts. Large blue ponds varying between .5 to 3 kilometers in width had already formed over southern and western sections of the ice sheet by June 16, before they were covered in clouds and squally wet weather on June 17th. By today, the clouds cleared as the passing storm moved on to reveal melt ponds further swelled by a combination of warmth and wet weather:

West Greenland Melt Ponds June 18

(Large expanse of melt ponds near the outlet to the Jacobshavn Glacier on June 18, 2014. The smallest blue dots represent glacial melt ponds of about 300 meters in width. The largest exceed 3 kilometers at the widest point. Image source: LANCE-MODIS.)

Melt ponds add heat amplification to the glacier surface by reducing albedo even as they provide melt drainage to the glacial base. Floods of water from melt ponds add to glacier speed and buoyancy by reducing friction at a moving glacier’s base and by flooding geographic low points beneath the glacier. Melt ponds also reduce overall ice sheet integrity by permeating the ice with holes and fractures.

The Jacobshavn Glacier in the satellite shot above is Greenland’s fastest. It is now involved in a very rapid rush toward the ocean at a rate of 46 meters per day. A rush that has been facilitated in recent years by a major proliferation of melt ponds during summer time.

During extreme events, melt ponds can combine and over-top or break ice dams in dangerous glacial outburst floods. It is worth noting that Greenland melt pond proliferation has not yet reached a threshold for high risk of such events. But the now decade-long proliferation of melt ponds over the ice sheet surface during summer time remains a troubling occurrence.

40% melt coverage in mid June is an extraordinarily high number. Last year, melt coverage peaked at 47% in late July with June values approaching the high 20s in late June. July of 2012 saw a 97% melt coverage — an event last seen about 120 years ago and one that is, unfortunately, likely to be repeated soon under current human heat forcing. It is worth noting, however, that the record year of 2012 saw Greenland melt coverages periodically exceeding 40% from mid-to-late June.

Greenland melt June 17 2014

(Greenland melt coverage on June 17 of 2014. Image source: NSIDC.)

Early melt and proliferation of melt ponds along with persistent high pressure systems over Greenland tend to have a compounding effect that amplifies over-all melt coverage. Low mists and clouds tend to form during such conditions, trapping heat near the ice surface even as albedo over the ice sheet falls due to wide-scale melt pond formation.

Though yesterday’s melt coverage is an early challenge to melt levels seen during 2012, current conditions would have to both persist and intensify for the broad extent of melt seen during late June and through July of 2012 to show a rough repeat. That said, a 40% melt coverage on this date is a record-challenging level that bears watching.

Links:

NSIDC

LANCE-MODIS

Greenland Undergoing Record 120 Year Melt

The Glacial Megaflood: Growing Glacial Outburst Flood Risk

Hat tip to Andy from San Diego

Blocking Pattern Serves up Nor’Easter One Week After Sandy as More and More Scientists Affirm Climate Change Made Superstorm Worse

 

A Nor’Easter that could  trouble the New Jersey, New York, Connecticut, Rhode Island and Massachusetts coasts with 50 mph wind gusts is in the process of forming today. A deep trough produced by a powerful blocking pattern and worsened by eroding Arctic Sea Ice is channeling a low pressure system that is likely to deepen off Cape Hatteras later tonight.

Models show the potential for a 990 mb low pressure forming off the Northeast coast come Wednesday. The result is that tropical storm force winds may bring 7-8 foot water rises (2-3 foot storm surges on top of high tides) to areas already devastated by Hurricane Sandy. Normally, a water rise of this level would result in light to moderate tidal flooding. However, in areas where dunes have been wiped out, sea walls and board walks beaten to bits, this rather moderate storm surge may re-flood some communities still reeling from last week’s disaster.

Tropical storm force winds may again knock out power in some areas still struggling to repair damage from Sandy. 1.3 million homes and businesses remain without power following the storm, down from 8.5 million a week ago. In addition, 1-2 inches of rain along the coast and snowfall in a region from Pennsylvania to Maine may cause further difficulty — especially for those still without power.

Though this storm is likely to be nothing like Sandy, it is a reminder of a new and ominous weather pattern taking shape this winter. According to numerous Arctic researchers, this year’s record sea ice melt is contributing to a powerful negative Arctic Oscillation. This weather condition has produced a strong trough swooping down from the Arctic and through the Eastern United States. The trough is producing numerous storms — one which combined with Hurricane Sandy to form a powerful superstorm. This week, the trough is bringing an early-season Nor’Easter. An odd second-week appearance of a storm that usually forms during winter.

These weather events may well be harbingers for very stormy conditions throughout the winter of 2012 for the US East Coast and Northeast. Jennifer Francis, an Arctic researcher at Rutgers University warned only just a few weeks ago that human climate change and sea ice loss was resulting in a situation that would likely produce a succession of powerful storms this fall and winter.

As the new storm forms off the East Coast, more scientists are affirming climate change’s role in both making Sandy worse and in producing a general climate of increasingly extreme weather. An article written by Dr. Jeff Masters, Dr. Bob Corell, and Dr. Kevin Trenberth entitled Did climate change contribute to Sandy? Yes published in Politico and Reuters yesterday. The article clearly stated that climate change made Sandy worse and warned that unless human carbon emissions are dramatically reduced more and more severe weather is to follow.

Climate scientists broadly agree that the extreme weather we’ve seen over the past few years is exactly what we’d expect to see in a changing climate. And it’s not just Sandy; we’re on track to have the hottest year in more than a century of record-keeping in the continental United States, the country has suffered one of the most crippling droughts in history, as well as one of the worst wildfire years in history. Last year, when Hurricane Irene hit the United States, meteorologists called it “unprecedented,” yet Sandy has already outpaced the damage from Irene.

We’ll probably never know the exact point when the weather stopped being entirely natural. But we should consider Sandy—and other recent extreme weather events – an early taste of a climate-changed world, and a grim preview of the even worse to come, particularly if we continue to pump more carbon pollution from smokestacks and tailpipes up into the atmosphere.

Jeff Masters is a meteorologist and former Hurricane Hunter, he now directs the climate blog WeatherUnderground. Bob Corell is an American climate scientist. Kevin Trenberth is the head of the US National Center for Atmospheric Research. Together, they represent over 150 years of climate science and meteorological experience.

Links:

http://www.politico.com/news/stories/1112/83335.html

http://www.wunderground.com/blog/JeffMasters/show.html

Hurricane Sandy, The Storm that Climate Change Wrought; How Global Warming Made Sandy Far, Far Worse

(Earth. See that massive swirl of clouds with arms stretching up into the Arctic and back across the Atlantic Ocean? Yes, that’s Sandy.)

This year was already the worst extreme weather year ever recorded. Fires, heatwaves, a monster Derecho and a devastating drought together would have made 2012 one for the record books. The one saving grace, it seemed, was that hurricane season hadn’t significantly added to an already severe problem. That was before Hurricane Sandy slammed into the US Northeast causing what many think will be in the range of 10-20 billion dollars in damage. If total damage estimates exceed 20 billion, Sandy will be one of the five most costly hurricanes in US history.

Sandy was nothing if not unprecedented. Never has the Northeast seen this kind of storm so late in the season. Never has New York and New Jersey been subject to such a high level of ocean flooding over such a broad area. According to CNN’s chief meteorologist: “There’s no one that’s not 300 years old that has seen anything like this.” That’s just a finer way of saying that there is no record for a storm like Sandy ever occurring in this region of the country. And, in many cases, there’s no record for a storm like Sandy occurring period.

What made Sandy so unique? In two words: climate change. We’ve seen northeastern Atlantic Ocean storms where powerful troughs combine with hurricanes in ways that create a much stronger storm. The last time such a thing happened was during the 1991 ‘Perfect Storm.’ But that storm formed over the open waters of the Atlantic and only caused damage as it brushed New England with the powerful squall lines and heavy surf it cast off. In the case of Sandy, the Perfect Storm came ashore far further south and west than is usually possible.

Sandy’s Global Warming Ingredients

Since 1991, atmospheric changes and alterations to the Earth’s physical characteristics have been taking place that make storms like Sandy more and more possible. These ‘ingredients’ include increasing ocean temperatures, changes in the jet stream, and the receding boundary of Arctic Sea Ice.

To understand how these changes made it possible for a storm like Sandy to have such a devastating effect on the US Northeast and Mid-Atlantic so late in the season, it helps to follow the life of the storm that became Sandy…

Like so many other hurricanes, Sandy was born of the tropical Atlantic. She started as a pulse of thunderous rain storms swirling off the coast of Africa. This tropical wave slowly gathered energy from the hot tropical Atlantic as she moved west, gradually twisting into the classic coma shape as she entered the central Caribbean.

(GOES weather satellite Image of Sandy from October 22. Sandy is already large for a tropical system. But Sandy will soon grow even larger by combining with other storms to the north.)

Ocean heat content for the South Atlantic and Caribbean was abnormally high this year. Most of this added heat content came from human caused global warming. In many regions, temperatures were 2-3 degrees above average. This meant that, for a storm like Sandy, these waters were about as warm as they would have been two to three weeks earlier during a typical season of the 20th century. This added energy increased the likelihood that the storm would form in the first place. It also gave the storm more capacity to strengthen even in an environment of increased wind shear.

As Sandy tracked northward, she plowed through Jamaica and hopped over the eastern tip of Cuba. Maintaining significant strength as a category two storm, Sandy grew to a large size, boasting a tropical storm wind field in excess of five hundred miles in diameter. Hovering off the coast of Florida, Sandy was about to enter the second stage of her development.

Two systems to the north would play key roles in Sandy’s growth and path. Both were products of new ‘blocking patterns’ that have emerged as regular weather events during the past decade. ‘Blocking patterns’ occur when the jet stream makes deep swoops down from the Arctic and into the mid and lower latitudes. These swoops make giant wave-like patterns in the jet stream. They also create a huge amount of atmospheric inertia. The result is that weather patterns tend to be more persistent. In the under-belly of a blocking pattern, one can expect abnormally hot and dry conditions to persist over long periods of time. In the frontal down-slope of the blocking pattern, one can expect abnormally cool, wet, and stormy conditions. The peaks of these blocking patterns tap the tropics and the troughs tap the Arctic.

According to Dr. Jennifer Francis, these blocking patterns have emerged as a result of sea ice loss in the Arctic. The receding edge of the sea ice pulls air northward changing the shape of the jet stream from that of a rippling halo to that of a circle of sine waves.

The new blocking pattern that had established itself over the central US allowed a powerful cold front to sweep southward, both lending energy to Sandy via strong temperature and pressure gradients and steering Sandy first northward, then pulling her in toward the Mid-Atlantic coast. A second aspect of the blocking pattern emerged in the form of a new high pressure system that has tended to form recently over Greenland. This particular high pressure system blocked the path of Sandy northeastward, shoving Sandy back up against the frontal trough that ended up lending her so much strength.

(A visible satellite shot of Sandy beginning to combine with a powerful Arctic cold front. The massive trough of cold air is outlined in blue. Sandy is in the red circle. To the northeast is a blocking high backing in over Newfoundland. Note the extraordinary size of the combined trough and Sandy.)

As Sandy began to touch the trough’s strong, cooler winds, her tropical storm wind field spread out, eventually reaching 900 miles in diameter. In addition, Sandy found herself cloaked in the trough’s rain shield. This shield helped to prevent the worst effects of wind shear which, at times, was powerful enough to rip a normal storm apart.

Sandy’s encounter with the Arctic-born cold-air trough caused her to explode in size and as she moved north, she pummeled the Outer Banks of North Carolina and Coastal Virginia from 300 miles off shore. What strength she lost at her core was multiplied manifold in the expanding reach of her effect. North Carolina and Virginia coasts experienced impacts usually reserved for those in the direct path of a Hurricane — powerful winds, heavy rains, and storm surge flooding. Roads were washed out, dunes were breached, homes were flooded. Water rises exceeded seven feet in some places.

(Sandy taps hotter than normal Atlantic Ocean water in final rush to the coast. At this point, Sandy is the largest tropical cyclone ever recorded in the Atlantic Ocean.)

Yet Sandy was still hundreds of miles away, biding her time for the final rush to shore. And in this critical time period, global warming again played its hand. Sandy was now moving parallel to the Virginia coast. In normal years, water temperatures would begin to drop off here, sucking energy from the storm. This year, though, water temperatures had heated to 5 degrees Fahrenheit above normal through, the year after year, heat trapping effects of human emitted greenhouse gasses. Sandy drank deep from this added heat and, as the Arctic-born trough began to pull Sandy in to shore, she intensified.

Maximum sustained winds reached 90 mph, tropical storm force wind diameter reached 1000 miles, hurricane force wind diameter reached 200 miles, and the pressure fell to an unprecedented 940 millibars. Sandy was now a storm for the record books. A storm that was the largest tropical cyclone ever to form in the Atlantic. A storm never seen before in this region of the world. A storm powerful enough to push ocean water nearly a mile inland up and down the Jersey coast. A storm mighty enough to create a nearly 14 foot water rise in New York City.

Without climate change, the storm may not have formed in the first place, the storm probably wouldn’t have reached category 2 strength or grown to such a large size, the storm would have not combined with such a powerful trough sweeping so far south, the storm would have not been blocked from going out to sea by the new Greenland/Newfoundland high pressure, the storm would not have strengthened so far north over abnormally hot waters, and the storm would have not been pulled into the coastline by the powerful blocking pattern caused by melting sea ice.

Sandy was, in all ways, the storm that climate change wrought. And since the pattern is now established for this kind of storm to happen now, it is likely that this kind of ‘300 year storm’ will happen again. Almost certainly with growing force and almost certainly within the next decade or two.

I’ll leave you with the following quote from Time Magazine:

“Perhaps, if you are in your 60s or 70s or 80s, Sandy’s destructive forces are a once in your lifetime event. But younger generations—those of us in our fifties, and our children—will likely be looking at flooded coastal cities, devastated infrastructure, blownout power, and storm surges for the rest of our lives.”

(Graffiti scrawled on the side of a house flooded by Sandy. Image credit: here.)

Links:

http://science.time.com/2012/10/30/climate-change-and-sandy-why-we-need-to-prepare-for-a-warmer-world/

http://www.newyorker.com/online/blogs/newsdesk/2012/10/watching-hurricane-sandy-ignoring-climate-change.html

http://blogs.scientificamerican.com/observations/2012/10/30/did-climate-change-cause-hurricane-sandy/

http://www.huffingtonpost.com/sunita-narain/sandy-climate-change_b_2044339.html

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