Super El Nino Likely as Huge Warm Water Wave Hits West Coast, Extreme Marine Die Off Developing

by Climate Change SOS, Daily Kos, April 30, 2015

attribution: NASA MODIS

Three tropical cyclones churned the waters around Australia on March 11, 2015, including Pam, which reached category 5 and devastated the south Pacific islands of Vanuatu.

In early March, the strongest wave of tropical convection ever measured (known as the Madden Julian Oscillation) by modern meteorology moved into the western Pacific from Indonesian waters bringing an outbreak of 3 tropical cyclones, including deadly category 5 Pam which ravaged the south Pacific islands of Vanuatu. This extreme outburst of tropical storms and organized thunderstorms pulled strong westerly winds across the equator, unleashing a huge surge of warm water below the ocean surface. Normally, trade winds blow warm water across the Pacific from the Americas to Australia and Indonesia, pushing up sea level in the west Pacific. When the trade winds suddenly reversed to strong westerlies, it was as if a dam burst, but on the scale of the earth's largest ocean, the Pacific. The front edge of that massive equatorial wave, called a Kelvin wave, is now coming ashore on the Americas.

Detailed research in California has found that nutrient upwelling was at a minimum in the El Nino year of 1992 and the super El Nino year of 1998. A huge surge of warm water from an enormous deep equatorial wave called a Kelvin wave is now hitting the west coast of the Americas. A wave of similar size struck last year brought a massive marine die off to the west coast, but this year's die offs will likely be global because climate models are predicting a super El Nino. Credit NOAA.

Last year the largest Kelvin wave ever seen in the Pacific ocean developed in February. After it came ashore and the surge of warm water moved up the Pacific coast, the upwelling of nutrient rich cold water dramatically slowed, and marine life began starving up and down the coast of north America. As the warm water moved north from the equator it merged with an enormous mass of warm stagnant water dubbed "the blob" which had built up in the central north Pacific ocean under the mound of high barometric pressure known as the Pacific high. Because the Pacific high had expanded north of its normal position, possibly because of climate change, warm, stagnant low nutrient water covered a large percentage of the surface of the north Pacific ocean. That stagnant water came ashore on the coast of the Pacific northwest and Alaska as the surge of warm water from the Kelvin wave moved up the California coast. The warm stagnant water lacked nutrients to support the growth of krill and copepods which are at the bottom of the food chain. Species that fed on krill and copepods had little to eat. Juvenile birds were the first to be affected by the lack of food. The west coast marine die off is already a crisis but it's likely to get much worse this summer and fall as  the surge of warm water moves up the coast from the huge Kelvin wave now coming ashore.

"The Pacific Coast saw record numbers of dead Cassin’s Auklets this winter. " Audubon.

10,000 baby sea lions dead on one California island — Experts: “It’s getting crazy… This is a crisis… Never seen anything like it… Very difficult to see so much death” — TV: “Numbers skyrocketing at alarming rates”

An unprecedented number of auklets, a tiny sea bird that dives for plankton, were found dead in Fall 2014, apparently of starvation, along the west coast from California to Canada. Nutrient poor warm waters are the probable cause of the lack of food.

Last year, beginning about Halloween, thousands of juvenile auklets started washing ashore dead from California's Farallon Islands to Haida Gwaii (also known as the Queen Charlotte Islands) off central British Columbia. Since then the deaths haven't stopped. Researchers are wondering if the die-off might spread to other birds or even fish.

"This is just massive, massive, unprecedented," said Julia Parrish, a University of Washington seabird ecologist who oversees the Coastal Observation and Seabird Survey Team (COASST), a program that has tracked West Coast seabird deaths for almost 20 years. "We may be talking about 50,000 to 100,000 deaths. So far."

The warming that last year's huge Kelvin wave brought started a global coral bleaching event is likely to get much worse after this year's huge wave of warm water spreads up and down the coasts of north and south America.

“It started in 2014 – we had severe bleaching from July to October in the northern Marianas, bad bleaching in Guam, really severe bleaching in the north western Hawaiian Islands, and the first ever mass bleaching in the main Hawaiian Islands,” said said Mark Eakin, Noaa’s Coral Reef Watch coordinator.

“It then moved south, with severe bleaching in the Marshall Islands and it has moved south into many of the areas in the western south Pacific. Bleaching just now is starting in American Samoa. In Fiji we’re starting to see some, the Solomon Islands have seen some. We’ve already seen a big event."

Bleaching takes place when corals are stressed due to changes in light, nutrients or temperature – though only the latter can cause events of this magnitude. This causes them to release algae, lose their colour and in some cases die off. It is a relatively rare occurrence. Large-scale bleaching was recorded in 1983, followed by the first global scale event in 1998. A second global wave came in 2010.

NOAA's CFSv2 model is forecasting a strong El Nino event will develop this summer and continue through 2015. Warm water along the west coast, combined with weaker than normal winds caused by El Nino will prevent nutrient rich cold water from welling up along the coast. Species that depend on nutrient upwelling will face starvation. Australia's Bureau of Meteorology has an excellent El Nino forecasting model which is also predicting a strong El Nino. Because the jet stream has already gone into an El Nino pattern by moving south over the eastern Pacific ocean and Mexico and further north than normal over the eastern Atlantic ocean, the likelihood of El Nino failing to strengthen is small. Last year's Kelvin wave failed to bring on a strong El Nino because trade winds in the south Pacific didn't weaken but this year they have and waters along the west coast of south America have already warmed. The south Pacific has moved out of the cool mode it was in a year ago.

NOAA forecast of the departure from normal of Pacific ocean sea surface temperatures. NOAA's CFSv2 model predicts a strong El Nino with much above normal sea surface temperatures along the west coasts of south and north America up to January, 2016.

The forecast of a strong El Nino brings good news to California. NOAA's CFSv2 model is forecasting above well above normal precipitation for October through December, 2015. Because models are forecasting El Nino conditions to continue through January 2016 there is a good chance that heavy winter rains will break the California drought. The downside will be massive landslides and flooding in areas that have been affected by recent wild fires.

California is likely to get relief from the drought in November and December 2015.

http://www.dailykos.com/story/2015/04/30/1380954/-Super-El-Nino-Likely-as-Huge-Warm-Water-Wave-Hits-West-Coast-Extreme-Marine-Die-Off-Developing#

World headed for an El Nino and it could be a big one, scientists say

by Peter Hannam, Environment Editor, The Sydney Morning Herald, May 7, 2015

El Nino conditions are setting in over the Pacific.

• A big El Nino may quell 'hiatus' debate

The world is headed into a major drought-bringing El Nino event, which will lift global temperatures and lead to bushfires and water shortages in eastern Australia, climate scientists have confirmed.

Fairfax Media understands that Australia's Bureau of Meteorology will announce next Tuesday that the El Nino event is all but certain.

The most recent El Nino in 2009-2010, with its characteristically warm sea-surface temperature anomalies in the central and eastern Pacific. Photo: NASA

Sea-surface temperatures in the central and eastern Pacific are recording anomalies of more than 1 degree, a combination that has not previously been seen in weekly data going back to 1991, according to a bureau climate forecaster. 

Australia's measure of El Nino thresholds is sustained warmth of sea-surface temperatures of 0.8 degrees above average in the key regions surveyed, a higher bar to clear than set by the US and some other agencies.

"You can see a warming in the eastern Pacific, which looks to be a classic [El Nino] event," said Agus Santoso, an El Nino modeller at the University of NSW's Climate Change Research centre. 

 

Scientists, though, are surprised that the build-up of unusual warmth in the eastern Pacific compared with the west is happening so early in the year. "It's quite rare – this is an interesting one," Dr Santoso said.

In typical El Nino years, the usual easterly trade winds stall or even reverse in winter or later, dragging rainfall eastwards away from Australia and also south-east Asia. Droughts tend to deepen and spread and bushfire seasons are more active than normal. 

A study by the bureau of 12 strong El Nino years since 1905 found rainfall declines were most evident in winter and spring – key agricultural seasons. The hardest hit areas cover most of NSW and parts of southern Queensland, while almost all of the eastern states have significantly reduced rain (see below).

An El Nino event this year would be bad news for areas also suffering serious or severe rainfall deficiency. A bureau drought report out this week identified such areas over the past 30 months to include much of inland Queensland, western Victoria and north-central NSW – some of which are already receiving federal and state aid.

The bureau declined to say that its up-coming El Nino report will confirm the event.

"The tropical Pacific has continued to warm in the past week and all indices now exceed 1 degree," Andrew Watkins, head of the bureau's climate prediction services, said. "This warming has been fairly consistent since the start of the year, as noted in our fortnightly ENSO updates. Likewise, the models we survey suggest this warming will continue."

As the bureau notes, its survey of all most all model runs place the central NINO3.4 region clearly in El Nino territory:

Big El Nino possible

It's the early start to the process, though, that has climate scientists concerned the planet may be on course for a particularly strong El Nino event.

"If it peaks in winter then dies off it's interesting," Dr Santoso said. "But if it keeps going up and peaks in summer, that could potentially be a big El Nino."

Wenju Cai, a leading climate modeller at the CSIRO, said experts were predicting a strong El Nino a year ago but sustained westerly winds failed to eventuate. As a result, the atmosphere did not "couple" with, or reinforce, the warming trends in the oceans.

 "Last year at this time, we didn't see the [westerly] winds," Dr Cai said. "This time, we see the strong westerly winds all along the equator."

If anything, forecasters have been overly cautious, he added. Some models generated by the US National Oceanic and Atmospheric Administration and not widely seen are pointing to "humungous anomalies" of as much as 5 degrees by October–November for parts of the eastern Pacific.

Even the ensemble of models is pointing to a 3-degree temperature anomaly by then, placing the departure from the norm in a similar league to previously powerful events such as the "super El Nino" of 1997 or 1982, Dr Cai said, cautioning that conditions could yet ease back.

Water issues

Water storage levels in eastern Australia typically drop in El Nino years as little run-off makes it into reservoirs.

Sydney is currently well-placed to cope with a lengthy dry spell after last month's storms helped lift overall storage levels to 92.4% as of Wednesday.

Melbourne's storages, though, continue to see a reduction, with recent below-average rain pulling dam levels below 70%, slightly lower than a year ago.

The bigger impact is likely to be felt in towns in the Murray-Darling Basin, with Broken Hill's storage levels down to about 4%.

Graeme Anderson, a climate specialist at the Victorian Department of Economic Development, said El Nino tended to double the chances of a dry spring in Victoria, though did not guarantee it. 

He said it would be important strong rains occurred this winter before any El Nino event kicked in, particular for farmers in large parts of Western Victoria who suffered a dry end to last year and start of 2015.

EFFECTS OF EL NINO

Rainfall 

Eastern Australian rainfall is typically below average, particularly in winter and spring, the key agricultural seasons. During 12 strong El Nino events analysed by the Bureau of Meteorology, the biggest departures from long-term average rains were in most of inland NSW and parts of southern Queensland. 

Drought, frost, snow 

Relatively clear skies mean areas already dry – such as western Victoria and inland parts of NSW and Queensland – may not get much near-term relief, while others may be declared drought-hit. With diminished cloud cover, frosts can also be bad. 

Heatwave and bushfires 

With dry soils, evaporation is reduced, leading to potentially hot summers. Warm, dry springs make for worse bushfire seasons than usual.

Shifting weather 

El Nino years are also disruptive to our neighbors, with increased chance of forest fires and drought in South-East Asia and a reduced monsoon in south Asia. Across the Pacific, the reverse is true, with above-average rainfall.

Global temperatures 

El Nino conditions mean the Pacific absorbs less heat from the atmosphere and can even give some back. Global temperatures typically get a 0.1–0.2 degree kick in such years, meaning 2015 and 2016 are shaping up to exceed the warmest year on record, set only last year.

With Tom Arup 

http://www.smh.com.au/environment/weather/world-headed-for-an-el-nino-and-it-could-be-a-big-one-scientists-say-20150507-ggw8bo.html

Why This New Study On Arctic Permafrost Is So Scary

Greenland’s permafrost could be melting faster than expected due to active microbes, according to new research. CREDIT: SHUTTERSTOCK

by Emily Atkin, ClimateProgress, April 8, 2015

Scientists might have to change their projected timelines for when Greenland’s permafrost will completely melt due to man-made climate change, now that new research from Denmark has shown it could be thawing faster than expected.

Published Monday in the journal Nature Climate Change, the research shows that tiny microbes trapped in Greenland’s permafrost are becoming active as the climate warms and the permafrost begins to thaw. As those microbes become active, they are feeding on previously frozen organic matter, producing heat, and threatening to thaw the permafrost even further.

In other words, according to the research, permafrost thaw could be accelerating permafrost thaw to a “potentially critical” level.

“The accompanying heat production from microbial metabolism of organic material has been recognized as a potential positive-feedback mechanism that would enhance permafrost thawing and the release of carbon,” the study, conducted by researchers at the University of Copenhagen’s Center for Permafrost, said. “This internal heat production is poorly understood, however, and the strength of this effect remains unclear.”

The big worry climate scientists have about thawing permafrost is that the frozen soil ischock-full of carbon. That carbon is supposed to be strongly trapped inside the soil, precisely because it’s supposed to be permanently frozen — hence, “permafrost.”

However, as temperatures in the Arctic have risen due to human-caused climate change, permafrost is thawing, and therefore releasing some of that trapped carbon into the atmosphere. It’s yet another feedback loop manifesting itself in Arctic permafrost regions — as climate change causes it to thaw, the thawing causes more climate change, which causes more thawing, et cetera, et cetera.

What makes this new research so important is that it adds to the urgency of stemming permafrost thaw. Because even without this new discovery of heat-producing microbes, estimates for carbon releases from thawing permafrost have been alarmingly large. According to the National Snow & Ice Data Center, there are about 1,700 gigatons of carbon currently frozen in permafrost — more than the total amount in the atmosphere now (Earth’s atmosphere contains about 850 gigatons of carbon, according to the Center).

Without considering microbes, the average estimate is that 120 gigatons of carbon will be released from thawing permafrost by 2100, which would raise the average global temperature 0.29 degrees. After 2100, if climate change worsens, total permafrost emissions roughly double. That’s confirmed by National Snow and Ice Data Center research scientist Kevin Schaefer’s research, which took the average of 15 peer-reviewed estimates of future carbon releases from thawing permafrost.

Schaefer, who was also one of the reviewers of the microbe study, told ThinkProgress that this is particularly alarming because emissions from permafrost are “completely irreversible.”

“These are permanent emissions,” he said. “Once you thaw out that material, there’s no way to put that organic matter back into the permafrost … you can’t re-freeze the permafrost.”

It’s also unclear whether the carbon that gets released once permafrost thaws will manifest itself as carbon dioxide or methane, which has a much greater impact on climate change — specifically, for each pound emitted compared with carbon dioxide, methane has a 20 times greater impact on atmospheric warming over a 100-year period, according to the Environmental Protection Agency. The New Scientist reports that if the Arctic gets warmer and drier, the microbes trapped within the permafrost can be expected to produce carbon dioxide. But if the environment gets warmer and wetter, the microbes that thrive will tend to produce methane.

The discovery of heat-producing microbes only threatens to add more uncertainty to permafrost emissions projections. Because even though we do know they can accelerate thaw, we don’t know how much.

“One of the biggest uncertainties is how much heat do the microbes generate as they eat the organic material,” Schaefer said. “It will accelerate thaw, but the question is how much. I don’t think that has been answered yet.”

So, that’s a lot of bad news when it comes to global climate change. But the good news, Schaefer said, is that accelerated thawing of Arctic permafrost can be prevented if warming is limited to a global average of 2 degrees Celsius. That 2 degree limit is, incidentally, the objective of international climate negotiations scheduled to take place at the end of this year.

“If we limit the warming to 2 degrees, it will also limit the emissions from thawing permafrost,” Schaefer said. “But the more we dump into the atmosphere, the greater the emissions from permafrost will be.”

http://thinkprogress.org/climate/2015/04/08/3643953/greenland-permafrost-thaw-microbes/

Joe Romm: Florida’s Climate Denial Could Cause Catastrophic Recession

Miami streets see heavy flooding from rain in September 2014. Some neighborhoods flood regularly during deluges or extreme high tides. CREDIT: AP PHOTO/LYNNE SLADKY

by Joe Romm, Climate Progress, March 30, 2015

Governor Rick Scott (R-FL) has made Florida the punchline for countless jokes since we learned in early March he barred state officials from using the term “climate change.” As Jon Stewart joked last week holding a copy of “Roget’s Denial Thesaurus,” Florida is headed toward “statewide jacuzzification,” and “It appears by 2020, Miami will be involved in a surprise pool party.”

But the joke is on all of us: Florida has led the way in all but ignoring the growing twin threats created by human-caused climate change — sea level rise and superstorm surge — thereby creating a trillion-dollar real-estate bubble in coastal property. When the next superstorm like Katrina or Sandy makes its target Florida and bursts that bubble, the state can declare bankruptcy. So too could some insurance companies. But taxpayers — you and I — will get the several hundred billion dollar bailout bill.

And a bailout will be the best-case scenario for all of us. When the coastal property real estate bubble bursts, what measures do we have in place to stop another catastrophic recession like the most recent one, which was also driven by a real estate bubble bursting?

Let’s do the math. There is now at least $1.4 trillion in property within 660 feet of the U.S. coast, a detailed analysis of the data by Reuters found. Worse, “incomplete data for some areas means the actual total is probably much higher.”

While Florida is denying the very existence of climate change, astrophysicist Neil deGrasse Tyson is here to remind us that, “The good thing about science is that it’s true whether or not you believe in it.” And what science told us in the last 12 months about likely sea level rise has been shocking. It’s the kind of news that should have stopped coastal development cold.

Last May, we learned that the West Antarctic Ice Sheet (WAIS) appears close to, if not past, the point of irreversible collapse. Relatedly, “Greenland’s icy reaches are far more vulnerable to warm ocean waters from climate change than had been thought.”

We also learned in August that Greenland and the WAIS more than doubled their rate of ice loss in the last five years.

Already this year, we learned two more stunners. First, a large glacier in the East Antarctic Ice Sheet turns out to be as unstable and as vulnerable to melting from underneath as WAIS is. This alone could “could lead to an extreme thaw increases sea levels by about 11.5 feet (3.5 meters) worldwide if the glacier vanishes.”

Second, two new studies find that global warming is weakening a crucial ocean circulation pathway in the North Atlantic, the Gulf Stream system, to a level “apparently unique in the last thousand years.” And if that circulation continues to weaken, it would also add another few feet of sea level rise to the East Coast. Indeed, this weakening is maybe one reason why large parts of the East Coast are already experiencing much faster sea level rise than the rest of the world.

A January study found that global sea level rise since 1990 has been speeding up even faster than we knew. “The sea-level acceleration over the past century has been greater than had been estimated by others,” explained lead writer Eric Morrow. “It’s a larger problem than we initially thought.”

The recent findings have led top climatologists to conclude we are headed toward what used to be the high end of projected global sea level rise this century: four to six feet or more. A 2013 NOAA study found that, under such sea level rise, the areas that received the very worst storm surges from Superstorm Sandy — such as devastated places like Sandy Hook and The Battery — will be inundated by such storm surges every year or two. In fact, in that scenario, the New Jersey shore from Atlantic City south would see Sandy level storm surges almost every year by mid-century

Worse, as discussed above, the East Coast of the United States is very likely headed toward considerably higher sea level rise over the next century than the planet as a whole. If we don’t take very aggressive action to slash carbon pollution, we could be facing a rise upwards of 10 feet. And considerably more than that after 2100 — sea level rise exceeding a foot per decade.

And so we are in a major coastal real estate bubble.

How big is the bubble, and who will pay when it bursts? The excellent Reuters series, “The crisis of rising sea levels: Water’s Edge,” has a sobering chart:

It’s a trillion-dollar bubble. And it looks like American taxpayers are on the hook for much of it.

Florida is ground-zero for this bubble for several reasons. First, as the chart shows, Florida’s $484 billion leads the country in “the value of property covered by the National Flood Insurance Program, often at below market rates.” Indeed, its covered property is three times as much as the next state, Texas.

Second, Florida’s topology makes some of its urban coastal areas especially vulnerable to warming-driven sea level rise and storm surge. Tampa Bay has unique geography that puts it atop Climate Central’s list of U.S. cities most vulnerable to a direct hit from a major hurricane. And Miami is second on the list!

The Miami area is so flat that even with a mere three feet of sea-level rise, “more than a third of southern Florida will vanish; at six feet, more than half will be gone.”

Third, Miami-Dade County by itself has some $94 billion worth of property along coastal waters — and the city can’t protect itself the way many coastal cities can. “Conventional sea walls and barriers are not effective here,” explained Robert Daoust, who works at a Dutch firm specializing in designing responses to rising sea levels. Why? As Jeff Goodell noted in Rolling Stone:

South Florida sits above a vast and porous limestone plateau. “Imagine Swiss cheese, and you’ll have a pretty good idea what the rock under southern Florida looks like,” says Glenn Landers, a senior engineer at the U.S. Army Corps of Engineers. This means water moves around easily – it seeps into yards at high tide, bubbles up on golf courses, flows through underground caverns, corrodes building foundations from below.

For all these reasons, Harold Wanless, chair of University of Miami’s Geological Sciences Department, told National Geographic in 2013, “I cannot envision southeastern Florida having many people at the end of this century.” In 2014, he said, “Miami, as we know it today, is doomed. It’s not a question of if. It’s a question of when.”

Under these dire circumstances, a rational statewide response might be to stop all new coastal development, have insurance priced according to risk, and start doing some intense planning. Instead we have Rick Scott’s complete denial, and sharp cuts in the budget for the South Florida Water Management District. Chuck Watson, a disaster ­impact analyst with a great deal of Florida experience, has warned, “There is no serious thinking, no serious planning, about any of this going on at the state level.

“The view is, ‘Well, if it gets real bad, the federal government will bail us out,’ ” he said. “It is beyond denial; it is flat-out delusional.”

The state level denial, while easy to milk for laughs, is thus epicly tragic — and not just for Floridians, but for all of us.

Significantly, the planning going on at the local level, while better informed, is still relatively blind to what’s coming and what the response needs to be. That is clear from a very recent article by WLRN, South Florida Public Radio, “An Idea To Mitigate Rising Seas In Miami Beach: Lift The Entire City.”

KLRN interviewed public works director for the City of Miami Beach, Eric Carpenter, who asserted “The only tried and true solution to combating rising sea levels is to raise with it.” Seriously.

KLRN asked Carpenter about the sea-level rise projections Miami uses:

“All we can really count on are the projections that are made by the people that do this for a living. The Army Corps of Engineers are a great source of information. They’re projecting anywhere between seven and 24 inches of sea-level rise over the next 50 to 75 years. … We’re kind of picking numbers that are in the mid to upper portion of that range to be on the conservative side.”

Two feet by 2090 is not conservative. As KLRN points out, South Florida task forces “projected seas to rise anywhere from two to six feet by the end of the century” — last decade. The new findings discussed above make clear that the worst-case scenarios for sea level rise from the last decade have now become simply the “business-as-usual” scenario. Generally people prepare for the plausible worst-case — buying catastrophic health insurance, for instance — since the consequences of underestimating what’s to come can be so ruinous.

Miami should be planning for sea level rise of 6 to 10 feet by century’s end and a foot per decade rise after that. And it’s hard to see how “raising the city” is the optimal response. Is the plan to turn Miami into Venice? Will the valuable parts of Miami simply keep elevating themselves until the place becomes an island disconnected from the rest of South Florida, which will be underwater?

And what about storm surge? What happens when the new island fortress of “Miami Beachless” gets devastated by a major hurricane post-2050, with a storm surge of 10 to 20 feet?

There is a trillion-dollar bill on its way, with no one stepping up to pay it.

http://thinkprogress.org/climate/2015/03/30/3600645/rick-scott-climate-denial/

Sea levels along the Northeast rose 4-5 inches in just 2 years

by James Gerken, Huffington Post, February 27, 2015

Sea levels across the Northeast coast of the United States rose nearly 3.9 inches between 2009 and 2010, according to a new study from researchers at the University of Arizona and the National Oceanic and Atmospheric Administration. The waters near Portland, Maine, saw an even greater rise -- 5 inches -- over the two-year period.

While scientists have been observing higher sea levels across the globe in recent decades, the study found a much more extreme rise than previous averages. Such an event is "unprecedented" in the history of the tide gauge record, according to the researchers, and represents a 1-in-850 year event.

"Unlike storm surge, this event caused persistent and widespread coastal flooding even without apparent weather processes," the study's authors wrote. "In terms of beach erosion, the impact of the 2009-2010 [sea level rise] event is almost as significant as some hurricane events."

The analysis relied on data from dozens of tide gauges along the eastern seaboard. The nearly 4-inch rise for the Northeast represents the average of 14 tide gauges located between New York and Canada. Tide gauges farther south in the Mid-Atlantic and Southeast indicated a sea level rise far less extreme in 2009 and closer to average in some areas. The jump occurred most quickly between April 2009 and March 2010.

The study found that the increase in the Northeast was caused by a 30% slowdown in a major ocean current system known as the Atlantic meridional overturning circulation (AMOC) and a fluctuation in atmospheric pressure at sea level. The Gulf Steam is one component of the AMOC, which moves warm water northward in the upper levels of the Atlantic.

A 2014 study of the AMOC over that period found the slowdown also contributed to severe winter conditions in northwestern Europe and the intensity of the 2010 Atlantic hurricane season, which was the third-most active on record.

The U.N.'s Intergovernmental Panel on Climate wrote in its latest report that AMOC currents are "very likely" to weaken in the 21st century. Models project that unusual rises in sea level, like that observed in the study, will be bigger and more frequent along the Northeastern seaboard this century, study coauthor Jianjun Yin told The Huffington Post.

And events like the one observed in the study, combined with ongoing global sea level rise, "will pose an even higher coastal flooding risk," Yin told Mashable.

A 2012 study determined that sea levels between North Carolina and Boston are rising at a rate three to four times faster than the global average. Yet this only represents a rise of 2-3.7 mm/yr year since 1980, far less than the 100 millimeters observed in the Northeast between 2009 and 2010.

This week's study, published in Nature Communications, follows a new report from the New York City Panel on Climate Change that warns of significant sea level rise and coastal flooding threats for the city in coming decades. Sea levels in New York City have already risen more than a foot since 1900, and the trend is very likely to accelerate: If greenhouse gas emissions from human activities are not curtailed, the panel projects seas to rise by an additional 11-21 inches by the middle of the century, by 18-39 inches by the 2080s, and by as much as 6 feet by the end of the century.

Warm Atlantic waters are bringing heat deep into the Arctic Ocean, mixing with colder waters above

Sea ice photographed by Bangor student, Joshua Griffiths.

from phys.org, February 17, 2015

Researchers have identified how warm Atlantic water that is flowing deep into the Arctic Ocean is mixing with colder waters above to contribute to sea-ice loss in the Arctic. The results, published this week in the journal Nature Geoscience, show that tidal flows in the Arctic are causing deep, warm water (originating from the Gulf Stream) to mix with cold, fresh water lying above, in turn contributing to melting the floating sea ice.

Past research on how warm layers of ocean water mix with cold layers lying above has focused on turbulence driven by winds and waves, rather than on tidal mixing, since tidal flows around the Arctic Ocean are generally weak. However, direct measurements of turbulence from across the seasonally ice-free Arctic Ocean show that tidal motions interacting with steep sea bed slopes are in fact a major cause of vertical mixing.

Lead author, Tom Rippeth from Bangor University explains, "Our oceans are not made up of one body of water, but contain waters of different temperatures and salinity, lying in different 'layers,' so the Arctic Ocean is a bit like a jam sandwich, where the 'bread' is the cold water layers above and below the 'jam,' which is the warm, salty water that enters the Arctic from the Atlantic. Sea-ice floating on the surface of the ocean is insulated from the heat of the Atlantic layer by the 'top slice' of cold polar water.

"We studied the warm body of water from the Atlantic that represents the largest oceanic input of heat into the Arctic – it is four degrees Celsius warmer than the surrounding water, and it is the warmest it has been in nearly two thousand years. The top of the warm layer sits at depths between 40 and 200 m, and its heat slowly diffuses upwards into the cold, fresher water above, but sometimes this movement of heat can be greatly accelerated by turbulence which drives mixing. We have found that tides are producing significant amounts of turbulence over steep sea bed topography, and so are greatly enhancing the upward movement of heat in these regions. In areas where tidal currents interact with steep sea bed slopes, this process causes mixing of the warmer waters with the over-lying colder waters, and this in turn can generate 'hot spots' for sea-ice melt or thinning."

Sheldon Bacon, from the National Oceanography Centre, says, "Arctic sea ice is likely to retreat further in coming decades, and if it does, interactions between the wind and ocean currents may strengthen. These mixing hot spots may then grow into other areas of the Arctic Ocean with steep sea bed slopes, resulting in further sea-ice retreat. We know that the Arctic is already warming faster than the rest of the planet, and other research conducted in the past few years is pointing to the impact of Arctic warming on mid-latitude weather, so the Arctic may have had a role in recent weather extremes in the US, UK and Europe. Therefore the importance of the discovery of this new mechanism for moving heat up towards the Arctic ocean surface lies in its potential to further enhance Arctic warming."

Bangor University, the Norwegian Polar Institute (NPI) and the National Oceanography Centre (NOC) collaborated on four extensive Arctic research cruises covering the Arctic Ocean north of Svalbard, north of eastern and western Siberia, and in the Canada Basin. This was done by directly measuring turbulence around the Arctic Ocean and showing its direct correlation with tidal energy dissipation estimates made using satellite data.

 Explore further: Large sea ice changes North of Svalbard.

More information: "Tide-mediated warming of Arctic halocline by Atlantic heat fluxes over rough topography." Nature Geoscience (2015) DOI: 10.1038/ngeo2350

http://phys.org/news/2015-02-tides-deep-atlantic-arctic-ocean.html

Submarine data used to investigate turbulence beneath Arctic ice

from phys.org, February 27, 2015

Using recently released Royal Navy submarine data, researchers at the National Oceanography Centre (NOC) have investigated the nature of turbulence in the ocean beneath the Arctic sea ice.

Recent decreases in Arctic sea ice may have a big impact on the circulation, chemistry and biology of the Arctic Ocean, due to ice-free waters becoming more turbulent. By revealing more about how these turbulent motions distribute energy within the ocean, the findings from this study provide information important for accurate predictions of the future of the Arctic Ocean.

NOC scientist and lead author of this research, Charlotte Marcinko, said "By investigating the nature of turbulence under sea ice, we can begin to understand how the circulation of the Arctic Ocean is likely to change as it becomes more ice-free during the summer."

The melting of Arctic sea ice is expected to be accelerated as the cold, fresh layer of water just beneath the ice mixes with a relatively warm, salty layer below it. This mixing is caused by turbulent motions, such as internal waves and eddy currents, which are likely to increase as the sea-ice thins and breaks up, causing a positive feedback effect.

Turbulence also plays a key role in the ocean circulation, linking currents spanning ocean basins to others spanning just millimetres. The wind is a major factor in driving these ocean currents, but in the Arctic sea ice can shield the ocean from it. However, this lid of sea ice also makes it difficult for scientists to investigate what is happening in the ocean currents beneath. As a result currently little is known about turbulence in oceans covered in sea ice, and how these processes might change in future.

Submarines are equipped with sensors that collect various ocean measurements, including temperature and salt content.  Due to the sensitive nature of submarine environmental data collection, MoD approval for access to a relevant dataset has only recently been given to the scientists at the NOC.

The study, published in the Journal of Geophysical Research: Oceans, shows that there are differences in the way energy is distributed by turbulent motions in the Arctic when compared to open, ice-free seas. Findings showed that the nature of turbulence was very similar in Arctic regions with high and low amounts of sea ice. This suggests that the nature of turbulence in the Arctic is altered by the way sea ice affects the structure and stability of the water column, rather than just by the ice acting as a lid protecting the ocean from the wind.

This research was conducted by a team of scientists at the National Oceanography Centre and the University of Portsmouth. It forms part of the Arctic Research Programme, a £15m programme to enhance the UK's research effort in the Arctic, funded by the Natural Environment Research Council (NERC).

 Explore further: Tides stir up deep Atlantic heat in the Arctic Ocean

More information: Arctic Ocean halocline (2015). Journal of Geophysical Research: Oceans, Vol. 120 Issue 1.

http://phys.org/news/2015-02-submarine-turbulence-beneath-arctic-ice.html