Saturday, July 18, 2015

The secret to the sea sapphire’s colors and invisibility

Sapphirina, or sea sapphire, has been called “the most beautiful animal you’ve never seen,” and it could be one of the most magical.
Some of the tiny, little-known copepods appear to flash in and out of brilliantly colored blue, violet or red existence.
Now scientists are figuring out the trick to their hues and their invisibility.
The findings appear in the Journal of the American Chemical Society and could inspire the next generation of optical technologies.

Copepods are tiny aquatic crustaceans that live in both fresh and salt water.
Some males of the ocean-dwelling Sapphirina genus display striking, iridescent colors that scientists think play a role in communication and mate recognition.
The shimmering animals’ colors result when light bounces off of the thin, hexagonal crystal plates that cover their backs.
These plates also help them vanish, if only fleetingly.
Scientists didn’t know specifically what factors contributed to creating different shades.
Scientists at the Weizmann Institute and the Interuniversity Institute for Marine Sciences in Eilat wanted to investigate the matter.

The researchers measured the light reflectance — which determines color — of live Sapphirina males and the spacing between crystal layers.
They found that changes of reflectance depended on the thickness of the spacing.
And for at least one particular species, when light hits an animal at a 45-degree angle, reflectance shifts out of the visible light range and into the ultraviolet, and it practically disappears.
Their results could help inform the design of artificial photonic crystal structures, which have many potential uses in reflective coatings, optical mirrors and optical displays.

The authors acknowledge funding from the Israel Science Foundation, the Crown Center of Photonics and the ICORE: the Israel Excellence Center “Circle of Light” and the Interuniversity Institute for Marine Sciences in Eilat (Israel).

Friday, July 17, 2015

Scientists predict huge sea level rise even if we limit climate change

Sea level rises of eight inches have already worsened flooding effects from storms
such as Hurricane Sandy.
Photograph: John G Wilbanks/Alamy

From The Guardian

Study of past sea level changes shows coastal communities may face rises of at least six metres even if we limit global warming to 2C, reports Climate Central

Even if world manages to limit global warming to 2C — the target number for current climate negotiations — sea levels may still rise at least 6 meters (20 ft) above their current heights, radically reshaping the world’s coastline and affecting millions in the process.
That finding comes from a new paper published on Thursday in Science that shows how high sea levels rose the last time carbon dioxide levels were this high.
That was about 3m years ago, when the globe was about 3-5F warmer on average, the Arctic 14.4F warmer, megasharks swam the oceans, and sea levels stood at least 20 ft above their current heights.

The megasharks aren’t coming back but those sea levels could be, no matter what happens in December’s climate summit in Paris.
“Even if we meet that 2C target, in the past with those types of temperatures, we may be committing ourselves to this level of sea level rise in the long term,”Andrea Dutton, a geochemist at the University of Florida and one of the study’s co-authors, said.
“The decisions we make now about where we want to be in 2100 commit us on a pathway where we can’t go back. Once these ice sheets start to melt, the changes become irreversible.”

The study examined past changes and laid out a framework for using them to refine our understanding of what the future holds for coastal communities.
According to separate research by Climate Central, a 20-ft sea level rise would reshape the US coast, causing Louisiana to lose its boot and transforming the Bay Area into the Bays Areas by forming a second inland bay. It would also threaten the world’s coastal nations and megacities.

Sea levels have already risen about eight inches (200mm) compared to pre-industrial times.
That rise has helped boost the surge and flooding damage from storms such as Sandy and Typhoon Haiyan, and dramatically increased the occurrence of everyday flooding during high tide in cities from Baltimore to Honolulu.

The most recent projections from the Intergovernmental Panel on Climate Change (IPCC) indicate that if emissions continue on their current trend, sea levels could continue to rise another 39 in by the end of this century.

By 2050, 26 major US cities will face an “emerging flooding crisis.” Globally, storm damage could cost cities from Hong Kong to Dhaka to New York trillions annually unless adaptation measures are taken.
According to Climate Central estimates, 150 million or more people are currently living on land that will either be submerged or exposed to chronic flooding by 2100.

But sea level rise isn’t going to just turn off after 2100 and according to climate scientists, current greenhouse gases are baking much more than three feet of sea level rise into the system.
The world’s oceans, ice sheets and climate are constantly performing an intricate dance.
The current rate of warming could have them dancing a different routine forcing ice sheets to accommodate by melting, and sea levels in turn to rise.
“Ice sheets as we see them today appear to be out of equilibrium with the present climate,” Dutton said.

Recent research showed the West Antarctic Ice Sheet, which contains enough ice to lift sea levels 10-13 ft, appears to have entered collapse, mostly driven by warm water and, to a lesser degree, air melting its ice shelves from above and below.
Those ice shelves essentially act as doorstops, keeping the rest of Antarctica’s massive stores of ice on land.
Losing them would send ice tumbling to the sea and, after it melted, lapping up against the shorelines around the world.
Other parts of the Antarctic ice sheet are also less stable than previously believed and could further drive sea level rise from the southern hemisphere’s store of ice.

Greenland melting

The planet’s other major cache of land ice is Greenland.
Its melt and contribution to sea level rise have increased over the past decade and scientists project that it will play an increasingly larger role in raising the oceans.

In addition to looking at the deep past, Dutton’s analysis also considered the more (geologically) recent past by looking at periods around 400,000 and 125,000 years ago when global temperatures were 3.6F and 1.8F above pre-industrial times, respectively.
Because they’re more recent, Dutton’s analysis was able to get better estimates of the upper bounds of sea level rise.
And those results don’t bode well for the world’s coastlines as they showed that sea levels were up to 42 ft higher than the present.
“These numbers are consistent with our study on sea level commitment,” Anders Levermann, a sea level rise expert at the Potsdam Institute for Climate Impact Research who authored a 2013 study, said.
Levermann said the Dutton’s approach of breaking down sea level rise by the different ice sheets could help with regional sea level estimates. For example, Greenland’s melt could drive up sea levels on the Eastern Seaboard in addition to having a potential impact on ocean circulation.

“We’re going to reach temperatures we had in the past periods in the next couple of decades. Understanding which are the most vulnerable sectors of polar ice sheets is critical to projecting future pattern of sea level rise regionally,” Dutton said.

The big outstanding question — and the one that’s most relevant to people living along the coasts — is just how long it could take sea levels to rise to such great heights. The process isn’t linear. It’s currently accelerating and that trend is expected to continue. Dutton said her group is working on new techniques to better define the rates of rise, but other efforts have shown tipping points could cause sudden, rapid rises faster than previous estimates.

“There are some recent modeling efforts that now show you could get a section of the Antarctic ice sheet, several meters worth of sea level rise, to go in a decade. We used to think it was centuries,” she said.

Links :
  • The Boston Globe : The big Chill 
  • The Guardian : Warming of oceans due to climate change is unstoppable, say US scientists 
  • NOAA : International report confirms: 2014 was Earth’s warmest year on record
  • Climate Central : Coastal Nations, Megacities Face 20 Feet of Sea Rise

Thursday, July 16, 2015

Human impact on the oceans is growing — and climate change is the biggest culprit

(a) Absolute difference between current (as of 2013) and earlier (as of 2008) per-pixel cumulative impact scores based on 12 anthropogenic stressors that could be compared across time (max cumulative impact score for both periods=11.1). Positive scores represent an increase in cumulative impact. (b) Extreme combinations of cumulative impact and impact trend include areas with combinations of the highest (top quartile) and lowest (bottom quartile) impact and increasing (top quartile) and decreasing (bottom quartile) impact. In both panels, areas of permanent sea ice are shaded white and the area within maximum sea ice extent is shaded to indicate where scores are less certain because change in sea ice extent could not be included
From WashingtonPost by Chelsea Harvey

Human impact on the oceans is growing - and climate change is the biggest culprit. 

The world’s oceans have suffered a lot at the hands of humans — ask any marine conservationist. Unsustainable fishing, pollution and the effects of climate change are just a few of the issues that worry scientists and environmentalists.

While we have a good idea of which activities are causing harm to the ocean, scientists have been less clear on which ones are the most damaging and which regions of the ocean are getting the worst of it.
Now, new research has allowed scientists to map the impacts of 19 different types of human activity that have harmed the ocean over a span of five years.
The study was published Tuesday in the journal Nature Communications.

The researchers used global-scale data to map the cumulative impacts of human activities between 2008 and 2013, pinpointing which areas are under increasing stress, which areas are experiencing a decrease and which human activities are having the biggest impacts in which areas.
They found that nearly two-thirds of the ocean in experiencing an increase in these man-made impacts — and climate change is the worst of all, driving the majority of the changes the researchers observed.

 (a) Sea surface temperature anomalies, (b) nutrient input, (c) demersal destructive fishing and (d) pelagic high bycatch fishing. Positive scores represent an increase in stressor intensity. Note that colour scales differ among panels and are nonlinear.

The effects of this climate change include temperature anomalies in the water, ocean acidification and an increase in ultraviolet radiation.
These factors can create conditions unfavorable to some marine organisms, changing the composition of ecosystems, driving animals to different parts of the ocean and even causing some species to begin dying off. Ocean acidification, for instance, is notorious for interfering with the ability of certain organisms, such as coral, to build the shells they use to protect their bodies.

And while the study reveals that some types of activities, such as overfishing, tend to cluster in specific regions, the effects of climate change appear to be “truly global,” says lead author Benjamin Halpern, a professor of environmental science and management at the University of California, Berkeley.
“Any global or regional scale efforts to improve ocean condition really need to address climate change,” he says.

Within the two-thirds of the ocean experiencing an increase in stress, the researchers found that five percent of the world’s oceans are heavily harmed by human activity and likely require immediate attention.
Five percent may not sound like much, but Halpern says these areas are among the parts of the oceans most important to humans.
“Many of them are in coastal areas where a lot of people live, and so they’re places that we care about a lot and places that we don’t want to see disappear because they’re providing us so many goods and benefits from the oceans,” he says.
Some of the most highly impacted coastal regions the study identified included the Faroe Islands, the eastern Caribbean, Cape Verde and the Azore Islands.

 The relationship between current cumulative impact (as of 2013) and 5-year change in impact from 5 years before for each country’s EEZ (200 nm) is shown based on the 12 common stressors. Bubbles are scaled to the area (ln) of each country’s EEZ and colour-coded by the change in the log of coastal population (25 miles inland) per year from 2008 to 2013; a subset of countries is labelled. Grey bubbles are nearly uninhabited. Horizontal dashed red line is the global median cumulative impact score in 2013; vertical line is no change over time.

Mapping out the parts of the oceans experiencing heavy or increasing stress can help policymakers better allocate resources for conservation, targeting the areas that are in the most need.
And these maps can also help world leaders figure out the scale of the effort required to combat a problem.
For example, local efforts may be enough to target specific regions that are heavily affected by overfishing.
But combating the effects of climate change, which are widespread throughout the Earth’s oceans now, will likely require an international effort, Halpern says.

The study also identifies regions experiencing a decrease in stress from human activity.
Admittedly, these regions comprise a much smaller percentage of the world’s oceans — just 13 percent.
But pinpointing these areas can provide equally valuable information, according to Halpern.
“In some cases they do likely indicate success stories where management action has helped improve the condition of the ocean,” he says, meaning policymakers can look to these areas for information on management techniques that have proved effective.

In fact, figuring out the kinds of conservation efforts that are most effective is the most important next step for research in the field, Halpern says.
Tuesday’s study may be able to pinpoint areas that are doing well and areas that are not, but it’s not able to provide any information about the management techniques that are affecting these areas.

The study does present a fairly dire view of the health of the world’s oceans — but Halpern stresses that there are some positive takeaways, too.
“Although things are generally getting worse across the planet, there are places that are getting better,” he says.
“And hopefully we can learn from those, see what we’re doing well, and apply those lessons to other parts of the planet.”

Links :

Wednesday, July 15, 2015

The strongest El Niño on record may be brewing in the Pacific

Sea surface temperature anomalies showing the telltale sign of an El Nino in the tropical Pacific.

From Mashable by Andrew Freedman

El Niño conditions are intensifying in the tropical Pacific Ocean, potentially leading to a record event that would help control rainfall in East Africa and possibly bring desperately needed drought relief to California, while temporarily cutting off rainfall to parts of the Indonesian rainforest.

A record strong event would also virtually guarantee that 2015 will beat 2014 as the warmest year this planet has seen since records began in the late 19th century.
In recent weeks, the water temperatures have grown warmer, propelled by a reversal of seasonal trade winds and the sloshing of mild ocean waters from west to east across the Pacific.

The atmosphere has shown telltale signs of positive feedback that are reinforcing the El Niño, including the formation of several tropical cyclones spinning in the central and northwestern Pacific Basins.
Taking these observations into account, a new forecast released Thursday by the Climate Prediction Center (CPC) in Maryland calls for a strong El Niño event to occur between now and the coming northern hemisphere winter, which is when El Niño conditions tend to peak, as well as when they have their greatest influence on global weather patterns.

 Sea surface temperature anomalies, showing the milder ocean waters near the equator with time.

According to a more detailed forecast from the CPC and the International Research Institute for Climate and Society (IRI) at Columbia University, there is a 96% chance of continued El Niño conditions from September through November, with a 94% chance of such conditions lasting through January.
The CPC outlook can be viewed as conservative when it comes to the predicted intensity of the El Niño event, considering that many individual El Niño experts, armchair meteorologists on Twitter, and individual computer model runs are predicting a potentially record strong event, exceeding the previous record-holder of 1997-98. El Niño data extends back to 1870.
The CPC takes such models into account when making its forecasts.
However, Michelle L'Heureux, a climate forecaster at CPC, told Mashable that the hype surrounding the potentially unprecedented intensity of the El Niño may be just that, hype.
"Even one or two westerly wind bursts does not necessarily always "make" an El Niño," she wrote in an email.
"Last year is a perfect example of that... a few westerly wind bursts in early 2014 and then they died out. It is the series of westerly wind bursts (or cumulative average over many months) that we forecasters pay attention to," she added.

Huge atmospheric response to pumped up El Niño

In a blog post, L'Heureux wrote that focusing on weekly average sea surface temperatures can be distracting, and is largely meaningless.
Right now, the weekly sea surface temperature departures from average are comparable to the record 1997-98 El Niño, she wrote.
"While a short-term (daily or weekly) number might be striking, it shouldn’t be used as an indicator of El Niño strength unless it is carefully placed into a larger context," she continued.
L'Heureux noted that none of the major forecasting centers responsible for monitoring El Niño are predicting a record event at this time, including CPC.

Conscious coupling between the air and ocean 

In order for El Niño events to occur and strengthen, an intricate dance must take place between the ocean and atmosphere, and some aspects of these interactions are not well understood.
So far this spring and summer, however, the atmosphere has been reinforcing the ocean conditions, and vice versa, with a temporary reversal of the east-to-west trade winds observed near the equator, because of a phenomenon known as a westerly wind burst.
Such wind bursts are crucial to creating and reinforcing strong El Niño events, since they drive pulses of mild sea surface temperatures eastward toward South America, according to recent research.
The strength of an ongoing wind burst, may be a sign of a particularly strong event to come.

"Right now we slightly favor a strong El Niño because we are seeing more bursts and we are further along in the year," L'Heureux wrote in her blog post.
"This causes us to be more confident in the staying power of this El Niño."

The bottom line: To get a significant El Niño event going (and keep it going), the atmosphere and ocean need to communicate like a healthy couple does — one in which one listens and responds to the other while bringing something new to the table.
There is a reason why meteorologists refer to the process of creating and maintaining an El Niño as reliant on "coupling" between the ocean and the atmosphere.

 Comparing the strong years of 1982,97 w/this year in Jun. 2015

Why you need to pay attention to El Niño

There are two main reasons why El Niño is a big deal — including its intensity.

First and foremost, the climate cycle is the most consequential natural climate phenomenon on the time scale of individual seasons to a couple of years, since it has ripple effects in areas far removed from the tropical Pacific.
El Niño events typically occur once every three to seven years, and predicting them in advance can protect lives as well as save businesses and governments money.

Second, El Niño events usually boost global average surface temperatures, elevating the probability that a particular year will set a record for the warmest year. So far, 2015 has been running hotter than 2014 did, and last year was the warmest year recorded since reliable instrumental records began in the late 19th century.
An intense El Niño would virtually assure that 2015 will break last year's record, since it acts as an added factor on top of long-term, manmade global warming.

 Typical El Nino winter weather pattern.

From Australia to California, El Niño brings alters weather extremes

Typically, El Niño events tend to shift rainfall away from northeastern Australia, with unusually dry conditions spreading south to encompass much of the Queensland coastline.
In the past, strong El Niño events, including one in 1982-83 and another in 1997-98, were accompanied by major droughts in parts of Australia, Indonesia and Papua New Guinea, although drought can also occur there in the absence of El Niño.

A major drought has been ongoing in Java, for example, even though conditions during the past year were only defined as resembling El Niño, without satisfying the formal scientific criteria.
Drier than average conditions are also likely to occur in Indonesia, according to IRI forecasts. Rainfall patterns that are crucial to agricultural production can also shift in eastern Africa as a result of El Niño and Indian Ocean temperatures.
In the U.S., El Niño usually exerts most of its influence during the fall and winter, with increased precipitation along the West Coast in particular.
This would be good news for drought-plagued California and other Western states, but a wetter than average winter is far from certain at this point.

 The tropical W Pacific has been very active recently, and this video shows the development of Typhoons Nangka, Chan-hom, and Linfa over the past few days through the Himawari-8 infrared, water vapor, and visible satellite imagery.
Linfa is the westernmost system, and is shown making landfall in China. Chan-hom is the next system to the east, and is currently approaching the coast of China.
Nangka is the easternmost system to the W of Guam.

One likely connection to El Niño that is already manifesting itself is a below average Atlantic hurricane season, since El Niño events tend to increase upper level winds across the tropical North Atlantic, tearing nascent storms apart before they can intensify.
At the same time, El Niño conditions can favor more tropical cyclones in the eastern and central Pacific Ocean.
Currently, there are three tropical cyclones spinning their way toward China and Japan, one storm moving toward Hawaii, and two new storms predicted to develop in coming days off the west coast of Mexico.
L'Heureux says that El Niño alters the air circulation over the globe, and increases the likelihood of certain weather conditions.
"This can be a huge advantage to those who want to hedge bets or plan for certain outcomes. The fact that our probabilities are [greater than] 90% means that folks can start making those bets and preparing for potential impacts."

Tuesday, July 14, 2015

50 million year old volcano cluster near Sydney

Australia’s new ocean-going research vessel Investigator has discovered extinct volcanoes likely to be 50 million years old, about 250 km off the coast of Sydney in 4,900 m of water.
While scientists were searching for the nursery grounds for larval lobsters, the ship was also routinely mapping the seafloor when the volcanoes were discovered.
They haven’t been found before now, because the sonar on the previous Marine National Facility (MNF) research vessel, Southern Surveyor, could only map the sea floor to 3,000 m, which left half of Australia’s ocean territory out of reach.

From The Guardian

Scientists searching for lobster larvae on Investigator research vessel instead find cluster of four volcanoes thought to be about 50m years old

Four enormous underwater volcanoes, thought to be about 50m years old, have been discovered off the coast of Sydney by a team of scientists who were looking for lobster larvae.

The volcano cluster was spotted through sonar mapping of the sea floor by Investigator, Australia’s new ocean-going research vessel, about 250km off the coast.

 Position with the GeoGarage platform
The centre of the volcanic cluster is 33 31 S, 153 52 E, which is 248 km from Sydney Heads.
The cluster is 20 km long and six km wide and the seafloor 4890 metres deep, with the highest point in the cluster rising up to 3998 metres.

The four volcanoes are calderas, large bowl-shaped craters caused when a volcano erupts and the land around it collapses.
The largest is 1.5km across the rim and rises 700m from the sea floor.
The 20km-long volcano cluster is nearly 5km underwater.

Professor Iain Suthers, a marine biologist at the University of NSW, said the volcano discovery was made when the team was searching for nursery grounds for larval lobsters.
“My jaw just dropped,” Suthers told Guardian Australia.
“I immediately said, ‘What are they doing there and why didn’t we know about them before?’ It really backs up the statement that we know more about the surface of the moon than our sea floor.
“I’m elated. We went there to look at eddies in the east Australia current and it was completely serendipitous to find this volcano cluster. We can only just imagine what will be around the corner if we continue to scan this area.”

Scientists believe the volcanoes were created by a series of shifts in geological plates that caused Australia to split from New Zealand. Suthers said the area was thought to be “billiard-table flat” but the enhanced mapping capability of the Investigator unveiled the calderas.

The 94-metre Investigator was commissioned by the CSIRO in 2009 via $120m from the federal government.
The vessel, which undertook its first sea tests in March, can map the seafloor at any depth, whereas its ageing predecessor, the Southern Surveyor, was limited to 3,000 metres.

 Mapping the sea floor on RV Investigator
Australia has the third largest ocean territory in the world, but we've only mapped 12 per cent of it. The RV Investigator is using state of the art equipment and design to map the sea floor, to any depth.  

Professor Richard Arculus, an igneous petrologist and volcano expert at the Australian National University, said the Investigator’s mapping ability has unveiled an “enormously exciting” discovery.
“They tell us part of the story of how New Zealand and Australia separated around 40m to 80m years ago, and they’ll now help scientists target future exploration of the sea floor to unlock the secrets of the Earth’s crust,” he said.

The team of 28 scientists, led by Suthers, included researchers from NSW, Latrobe, British Columbia, Sydney, Auckland, Technology Sydney and Southern Cross universities.
The voyage left Brisbane on 3 June and arrived in Sydney on 18 June.

Suthers said it was “inevitable” that other undiscovered volcanoes were in the region, but the Investigator has funding to operate at sea for only 180 days a year.
For the rest of the year it is tied up at a wharf in Hobart.
“We should thank Canberra for the funding we do have but it’s frustrating to build a state-of-the-art vessel only to have it sitting in a wharf for six months of the year,” Suthers said.
“This is a vessel that Australia has been crying out for for decades. It’s an incredibly stable vessel for those of us who are seasick. Usually when you’re hit by four-metre waves you lose a couple of days of research because you’re vomiting.”

A spokeswoman for Ian Macfarlane, the industry and science minister, said the shortfall was because Labor “left absolutely no money in the budget” to operate the Investigator.

Monday, July 13, 2015

GeoGarage Time Zone API : for maritime areas

Time Zone World map (source CIA 2013) / 2014 / 2015

Heat is being stored beneath the ocean surface

see picture


For much of the past decade, a puzzle has been confounding the climate science community.
Nearly all of the measurable indicators of global climate change—such as sea level, ice cover on land and sea, atmospheric carbon dioxide concentrations—show a world changing on short, medium, and long time scales.
But for the better part of a decade, global surface temperatures appeared to level off.
The overall, long-term trend was upward, but the climb was less steep from 2003–2012.
Some scientists, the media, and climate contrarians began referring to it as “the hiatus.

If greenhouse gases are still increasing and all other indicators show warming-related change, why wouldn’t surface temperatures keep climbing steadily, year after year?
One of the leading explanations offered by scientists was that extra heat was being stored in the ocean.

Now a new analysis by three ocean scientists at NASA’s Jet Propulsion Laboratory not only confirms that the extra heat has been going into the ocean, but it shows where.
According to research by Veronica Nieves, Josh Willis, and Bill Patzert, the waters of the Western Pacific and the Indian Ocean warmed significantly from 2003 to 2012.
But the warming did not occur at the surface; it showed up below 10 meters (32 feet) in depth, and mostly between 100 to 300 meters (300 to 1,000 feet) below the sea surface.
They published their results on July 9, 2015, in the journal Science.

 Schematic of the trends in temperature and ocean–atmosphere circulation in the Pacific over the past two decades.
Colour shading shows observed temperature trends (°C per decade) during 1992–2011 at the sea surface (Northern Hemisphere only), zonally averaged in the latitude-depth sense and along the equatorial Pacific… 
source : Nature

“Overall, the ocean is still absorbing extra heat,” said Willis, an oceanographer at JPL.
“But the top couple of layers of the ocean exchange heat easily and can keep it away from the surface for ten years or so because of natural cycles.
In the long run, the planet is still warming.”
To understand the slowdown in global surface warming, Nieves and colleagues dove into two decades of ocean temperature records; specifically, they examined data sets compiled from underwater floats and other instruments by the Argo team at the Scripps Institution of Oceanography, by the World Ocean Atlas (WOA), and by Japanese scientist Masao Ishii and colleagues.
The JPL team found that for most of the decade from 2003–2012, waters near the surface (0–10 meters) of the Pacific Ocean cooled across much of the basin.
However, the water in lower layers—10–100 meters, 100–200 meters, and 200–300 meters—warmed.

The animated map at the top of this page shows the trends in water temperatures in various depth layers of the ocean as measured between 2003 and 2012.
Areas in red depict warming trends in degrees Celsius per year, while blues depict cooling trends.
Warming is most acute between 100–200 meters in the western Pacific and the eastern Indian Ocean. Some areas of the Pacific appear to cool—particularly near the surface and in the eastern half, which correlates well with the cool phase of the Pacific Decadal Oscillation (PDO), which has been underway for much of the past 15 to 20 years.

Note that the Atlantic Ocean does not show significant trends at any depth, with warming temperatures in one place counter-balanced by cooling in others.
The Atlantic basin is also relatively small compared to the Pacific and does not have as much impact on global temperatures.
The JPL team also noted that the temperature signal was neutral or inconclusive at depths below 300 meters, where measurements are relatively sparse.

The figure below depicts the trends in a different way.
It represents a cross-section of the top 300 meters of the global ocean and how temperatures changed from 1993 to 2012.
Note how there are cooler waters near the surface in several years in the 2000s, but that waters at depth grow much warmer.
Note, too, how the overall trend in 20 years goes from a cooling ocean to a significantly warmer ocean.

Nieves, Willis, and Patzert were provoked to launch the study because they wanted a more detailed, nuanced picture of ocean temperatures than is possible with most models.
On a broad scale, models can replicate broad and long-term trends in the sea; but on smaller scales of space and time, a lot of the models cannot match real-world conditions.
The new findings should help improve models of ocean heat storage and climate impacts on regional scales.

The Pacific Ocean covers nearly one-third of Earth’s surface, so it has an outsized impact on the global thermostat.
“As the top 100 meters of the Pacific goes, so goes the surface temperatures of the planet,” said Patzert, a climatologist at JPL.
With the surface layer of the ocean being cooler for much of the study period, those waters had a moderating effect on air masses and weather systems on the continents.
However, ocean and air temperatures have started to rise swiftly in the past two to three years, which suggests that the cool phase of the PDO and the warming hiatus is over.

“Natural, decadal variability has been with us for centuries, and it continues to have big regional impacts on society,” said Nieves, a JPL scientist with a joint appointment at the University of California, Los Angeles.
“We can expect to have more hiatuses in the future, but unless future hiatuses are stronger than usual, they will be less visible due to fast rising greenhouse gases. Right now, the combined effect of the human-caused warming and the Pacific changing to a warm phase can play together and produce warming acceleration.”

Sunday, July 12, 2015

Trailer : The finest hours

Disney has released the trailer for a new movie based on the true story of heroic US Coast Guard rescue of 32 mariners aboard the SS Pendleton.

In the winter of 1952, a four-man crew from the USCG braved 60-foot waves and 70-knot winds to save men trapped in stern section of the oil tanker after one of the worst Nor’Easter gales on record tore the vessel in two.
Using only a 36-foot wooden motorized boat the men carried out one of the most daring rescue missions in Coast Guard history.

"Coast Guard photo of bow section of tanker PENDLETON grounded near Pollock Rib Liteship, six miles off Chatham, Mass on the morning of Feb. 19, 1952."
Official USCG Photo;  by Richard C. Kelsey, Chatham, Mass.

The incident occurred on February 18 while the tanker was underway off of Cape Cod.
In the early morning hours fierce snow fall and hues waves snapped the vessel in two.
The captain and seven crewmen sank in the bow section of the ship.
Reports after the accident said the tanker had been constructed with “dirty steel”, which was not able to withstand gales force winds.

The Finest Hours recounts this amazing story from the perspectives of the US Coast Guard men that carrying out the operation as well as the desperate mariners stranded aboard the mangled tanker.