Saturday, October 19, 2013

The Living Planet - The Open Ocean

This programme concentrates on the marine environment. Attenborough goes underwater himself to observe the ocean's life forms and comment on them at first hand.
He states that those that live on the sea bed are even more varied than land inhabitants.
Much sea life is microscopic, and such creatures make up part of the marine plankton.
Some animals are filter feeders and examples include the manta ray, the basking shark and the largest, the whale shark.
Bony fish with their swim bladders and manoeuvrable fins dominate the seas, and the tuna is hailed as the fastest hunter, but the superiority of these types of fish did not go unchallenged: mammals are also an important component of ocean life.
Killer Whales, dolphins, narwhals and Humpback Whales are shown, as well as a school of beluga whales, which congregate annually in a bay in the Canadian Arctic — for reasons unknown. Marine habitats can be just as diverse as those on dry land.
Attenborough surmises that the coral reef, with its richness of life, is the water equivalent of the jungle.
Where the breezes of the Gulf Stream meet those of the Arctic, the resulting currents churn up nutrients, which lead to vegetation, the fish that eat it, and others that eat them.
Attenborough remarks that it is man who has been most responsible for changing ocean environments by fishing relentlessly, but in doing so has also created new ones for himself — and this leads to the final episode.

Friday, October 18, 2013

Robert Ballard, discoverer of the Titanic is mapping underwater America

USA (4.69 M sq mi), France (3.93 M sq mi), Australia (3.5 M sq mi),
Russia (2.97 sq mi), UK (2.62 M sq mi) and New Zealand (2.59 M sq mi) : 
these six countries maintain sovereign rights over more marine area than other nations,
due to their lengthy coastlines or empire-building pasts—or both, in the case of the United States.

From National Geographic

America has had two great ages of exploration.
The one that every schoolchild learns about began in 1804, when Thomas Jefferson sent Meriwether Lewis and William Clark on their epic journey across North America.
The other one is just beginning.
During this new age of exploration we will go farther than Lewis and Clark and learn the secrets of territories beyond even Jefferson’s wildest imagination.
Yet it seems safe to say that most Americans don’t know anything about it.

Few realize that the single largest addition to the American domain came on March 10, 1983, when President Ronald Reagan, with the stroke of a pen, expanded the country’s sovereign rights 200 nautical miles from its shores “for the purpose of exploring, exploiting, conserving, and managing natural resources.”
By establishing an exclusive economic zone (EEZ), Reagan roughly doubled the area within United States boundaries, as Jefferson had with the Louisiana Purchase.

Expanded Boundaries and Hidden Treasures
The United Nations Convention on the Law of the Sea grants all coastal countries sovereign rights to the areas extending 200 nautical miles beyond their coasts, known as the exclusive economic zone (EEZ).
These watery properties contain abundant natural resources: large oil and gas reserves, valuable minerals, and teeming fisheries.
So does the seabed beyond, where countries can make additional claims if they can prove that the continental shelf stretches past the underwater border of their EEZs and meets other criteria set by the convention.
 Robert Ballard’s Exploration Vessel Nautilus and the National Oceanic and Atmospheric Administration’s Okeanos Explorer are in the midst of a long-term program to discover what riches lie within America’s EEZ—and perhaps beyond.

Other countries have increased their jurisdiction over natural resources through EEZs and are eager to add more.
Under the 1982 UN Convention on the Law of the Sea, which the United States has not joined, countries can claim sovereign rights over a larger region if they can prove that the continental shelf—the submerged portion of a continent—extends beyond their EEZ and meets certain other conditions.
The United States potentially has one of the largest continental shelves in the world.

 Bob Ballard looks out to sea from the research ship Knorr.
"I have the luxury of having my own trust and having my own ship. I'm a 13th-generation American. I've got exploration in my genes. It just seemed like something that ought to be done. If the government wasn't going to do it, then the heck with it, I was going to go do it."
Photograph by David McLain, National Geographic

A lot is at stake.
Just like the land that Lewis and Clark explored, the ocean floor contains natural resources, many of them untapped.
Vast oil and gas deposits lie under the waves.
So do hydrothermal vents, where copper, lead, silver, zinc, and gold have been accumulating for hundreds of millions of years.
By some estimates there are more than 100,000 seamounts containing minerals critical for national defense.
That’s not all that lies beneath.
These watery zones encompass fisheries that nations rely on for sustenance, shipwrecks that may reveal lost chapters of history, and habitats that need to be preserved as marine sanctuaries.

Ocean explorer Robert Ballard takes us on a mindbending trip to hidden worlds underwater, where he and other researchers are finding unexpected life, resources, even new mountains.
He makes a case for serious exploration and mapping
(TED conference 2008)

Most of the U.S. EEZ hasn’t been explored.
In 1803, with the territory from the Louisiana Purchase newly in hand, Jefferson instructed expedition leader Lewis to “take observations on ... the soil & face of the country, its growth & vegetable productions ... the mineral productions of every kind ... volcanic appearances [and] climate as characterized by the thermometer.”

Reagan did not follow Jefferson’s example.
To this day we have better maps of Venus, Mars, and the far side of the moon than we do of much of underwater America.

But now it’s time for a new epic journey.
Last June the United States’ only dedicated ships of exploration launched a joint, concentrated effort to find out what lies within the country’s EEZ.

 3-D depiction of Bear Seamount, with Physalia Seamount in the background.

The National Oceanic and Atmospheric Administration’s Okeanos Explorer mapped some of the New England Seamount chain near Rhode Island, among other places, while my vessel—the Ocean Exploration Trust’s Nautilus—mapped portions of the Gulf of Mexico and the Caribbean.
Both ships use multibeam sonars mounted on their hulls, which enable the creation of maps in three dimensions.

Follow Dr. Robert Ballard and his team as they explore the ocean on the E/V Nautilus.
Watch live video 24 hours a day on

Lewis and Clark traveled for more than two years and had to wait until their return home to share their discoveries with an expectant nation.
Although the ocean depths plumbed by these modern expeditions are more remote than the land Lewis and Clark charted, we are in constant communication with oceanographers and other experts on shore.
The moment a discovery is made, scientists can step aboard either of the two ships virtually, take over operations, and share findings in real time with a plugged-in world.
This is a voyage of discovery everyone can make.

Links :

Thursday, October 17, 2013

The curious cartographical case of the island of California

First edition of the first regional map to focus closely on California as an Island.
Prior to this map, all maps with California shown as an Island were either World maps, Western Hemisphere, North America, Pacific Ocean or some substantially larger geographical region.
The region illustrated was still largely unknown.
First map to show the so-called Second Sanson Model of insular California (two bays shown in Northernmost portion of the island). Nomenclature is a combination of Blaeu and Sanson.
New Indian tribes named along the Rio Grande.
The peninsula above California is a curious and unexplained addition.
A  seminal map, which influenced California Cartography for the next 50 years.

From MostlyMaps blog (by Gary Gale)

We’ve become firmly accustomed to instant gratification of Internet Time, which can be roughly summarised as “I want it now, dammit“.
Nowhere is this more evident than in maps.
If something is wrong on a map, we expect it to be fixed.
Ten or so years ago, it would be common to wait somewhere between 12 and 18 months for a map’s updates to be collected, validated and published.
These days, thanks to our modern digital maps, we get our updates in more or less Internet Time and that means fast.
It hasn’t always been that way.

Although waiting over a year for a map update seems almost unthinkable now, consider for a moment having to wait almost half a century for a map to be updated.
Yet this is what happened in the curious cartographical case of the Island of California.
I should state up front that I’ve been to California, quite a few times.
The weather is fine (apart from San Francisco’s fog), it’s home to the technical hub of Silicon Valley and the local food and wine are rather good.
It is most definitely not an island and what’s more, there’s a distinct lack of tribes of beautiful Amazonian warriors wielding gold tools and weaponry.

Yet in 1510, Spanish author Garci Rodríguez de Montalvo published a novel entitled Las Sergas de Esplandián, or The Adventures Of Esplandián, which mentions the Island of California, populated by the aforementioned female warriors.
The name and concept of an island stuck and early Spanish explorers of what we now call Baja California were convinced the new territory they had found was part of the Island of California.
 In retrospect, early maps of the New World actually got the geography of California right.
Both Mercator, he of web map projection controversy, in 1538 and Ortelius, in 1570, made maps that correctly showed California as a peninsula.

 Americae Sive Novi Orbis Nova Descriptio (1571)

But that all changed in 1602.
A merchant, Sebastián Vizcaíno, was appointed by the Viceroy of New Spain to examine the coastal regions and make new maps.
One board one of Vizcaíno’s expeditions was one Antonia de la Ascensión who wrote …
that the whole Kingdom of California discovered on this voyage, is the largest island known…and that it is separated from the provinces of New Mexico by the Mediterranean Sea of California.
This geographic blunder was further reinforced by Antonia Vázquez de Espinosa, who wrote in 1615 that …
California is an island, and not continental, as it is represented on the maps made by the cosmographers.
The notion of California as an island was thus firmly cemented in the minds of the day’s cartographers, featuring in the first general atlas of the world that was published in England between 1626 and 1627.
Even European cartographers finally gave up in their portrayal of California as a peninsula and by 1650 all maps of note showed the Island.

The North Part Of America by Henry Briggs 1625

And so it remained until 1705 when a Jesuit missionary, Father Eusebio Kino, made a report of his journeys, with an accompanying map, that showed that California really was attached to the rest of the North American continent.
Even then, it took until 1746 when another Jesuit, Fernando Consag, tried and failed to sail around the non-existant island, to put an end to the Island of California.
Despite this, it took a further 50 or so years before maps showed California as we now know it to be, part of North America and not, as de Montalvo wrote, being close to the Asian mainland and also “very close to the side of the Terrestrial Paradise“.

Next time you get annoyed and frustrated by a modern map not being entirely up to date, you can rest assured that it’ll probably take a month or two at the most to be updated and not a half century.
In the meantime, the Island of California remains an enduring oddity in the history books of exploration and cartography and one which is showcased on Stanford University’s web site as part of the Glen McLaughlin collection.

 Links :

Wednesday, October 16, 2013

How red crabs on Christmas Island speak for the tropics

Christmas Island red crabs are native to the small Australian territories of Christmas Island and the Cocos (Keeling) Islands, which are in the Indian Ocean.
>>> geolocalization with the Marine GeoGarage <<<

From Princeton University

Each year, the land-dwelling Christmas Island red crab takes an arduous and shockingly precise journey from its earthen burrow to the shores of the Indian Ocean where weeks of mating and egg laying await.

Each year, millions of Christmas Island red crabs make a two-week journey to the coast to mate.
The migration begins in November at the start of the rainy season, and female crabs must release their eggs into the ocean before the morning of the high tide that precedes the December new moon.
The researchers found that a late or light rainy season can delay or entirely cancel this meticulous process.

Native to the Australian territories of Christmas Island and the Cocos (Keeling) Islands, millions of the crabs start rolling across the island roads and landscape in crimson waves when the November rains begin.
After a two-week scuttle to the sea, the male crab sets up and defends a mating burrow for himself and a female of his kind, the place where she will incubate their clutch for another two weeks.
Before the morning of the high tide that precedes the December new moon, the females must emerge to release their millions of eggs into the ocean.
A month later, the next generation of crabs comes ashore.
But a lack of rain can delay or entirely cancel this meticulous process, according to research conducted through Princeton University that could help scientists understand the consequences of climate change for the millions of migratory animals in Earth's tropical zones.

The researchers report in the journal Global Change Biology that the crabs' reproductive cycle tracked closely with the amount and timing of precipitation.
Writ large, these findings suggest that erratic rainfall could be detrimental to animals that migrate with the dry-wet seasonal cycle that breaks up the tropical year, the researchers report.
If fluctuations in rainfall become more extreme and frequent with climate change, then scores of animals could be in trouble — not just the migrators themselves, but also the creatures reliant on them for food.

 Great Migrations: Millions of Crab Babies

Lead author Allison Shaw, who conducted the work as a Princeton doctoral student in ecology and evolutionary biology, explained that what scientists understand about the possible impact of a warming planet on animal movement is dominated by studies of how creatures that migrate with the summer-to-winter seasonal shifts of Europe and North America will be affected by changes such as the severity and duration of summers and winters.
For tropical creatures such as the Christmas Island red crabs, or the wildebeests and gazelles of Africa, however, the regular quest for safety, food and reproduction is driven by wet and dry seasons.
Yet how the erratic rainfall expected to accompany an altered climate will affect these animals is not well understood, Shaw said.
"Potentially there's been a perspective bias in how migratory species are studied, and this particular species represents two perspectives that have not been well documented — species that are migrating because they have to breed in a certain area, and species that are migrating in response to rainfall," said Shaw, a postdoctoral researcher at the Australia National University who will start as a University of Minnesota assistant professor of ecology in 2014.
"Targeting those two types of migration patterns that have so far been understudied is really what we're hoping to accomplish with this paper, and to encourage more studies in those areas," Shaw said.

 Migratory animals have a role in the ecosystems spanning the territory they traverse.
For instance, whale sharks migrate to Christmas Island to feast on the red crabs' larvae.
As the parental crabs journey to the coast and back, they feed on plants and saplings that keep the island from being overgrown.

Shaw and her co-author Kathryn Kelly, an oceanography professor at the University of Washington, obtained migration data for 36 years that fell between 1919 and 1939, and 1976 to 2011
They predicted the egg-release date for each year, and compared the later figures to actual rainfall measurements from 1973 to 2011.
Except in three years, the crabs did not launch their procreative journey if there had not been at least 22 millimeters (0.87 inches) of rainfall.
A light or late rainy season could push their journey forward or back months — in 1989, for instance, a November dry spell followed by heavy rain in late December kept the crabs in their burrows until early January.
During the especially dry 1997 season, the crabs never migrated or mated.
The culprit was a strong El Niño, the warm-water climate pattern that creates dry conditions in the Indian Ocean.
The occurrence of the El Niño is projected to become more common as the planet gets hotter.
"We know that 1997 was a very big El Niño event and we can predict changes in migration patterns by using climate models that suggest that El Niño frequencies will potentially increase in the future," Shaw said.
"So, years like this could potentially become more common. If the crabs' response is to not migrate in El Niño years, that's going to be a very big problem."
Climate change could be a special challenge to species such as Christmas Island red crabs or sea turtles that migrate to specific locations to reproduce, Shaw said.
These animals do not live and breed in the same ecosystem, so any obstacle between one location and the other threatens their survival as a species.
"If they don't migrate, they can't reproduce," Shaw said.
"That's true for a subset of migratory species that have to breed in a specialized area, but spend most of their adult lives in a different area. They rely on migration to bring them between the two areas that they need. On the other hand, species like many temperate birds migrate to avoid harsh winters, but if winters become less harsh they can still survive even if they don't migrate."

 The researchers found that the crabs largely only migrate if there has been at least 22 millimeters (0.87 inches) of rainfall.
The crabs never migrated or mated during the especially dry 1997 season because of a strong El Niño, the warm-water climate pattern that creates dry conditions in the Indian Ocean.
The occurrence of the El Niño is projected to become more common as the planet gets hotter.

The movement of little red crabs does not only benefit the species itself, Shaw said.
Migratory animals have a role in the ecosystems spanning the territory they traverse.
For instance, whale sharks migrate to Christmas Island to feast on the red crabs' larvae.
As the parental crabs journey to the coast and back, they feed on plants and saplings that keep the island from being overgrown, Shaw said.
"Migratory species by definition are traveling either long distances or spanning across different ecosystems," Shaw said.
"The crabs migrate from terrestrial areas to drop their eggs in marine environments.
"Because they're spanning these ecosystems, they have the potential to impact not only marine environments and species such as the whale sharks, but also terrestrial species and forest dynamics," she said.
"If you took away migratory species you could potentially be affecting multiple ecosystems."

David Sims, who heads the behavioral ecology group at the Marine Biological Association in England, said that most climate-change studies relate to temperate species because the outcome of climate change has often been more clearly observed outside of the tropics.
"I suspect most studies have been on temperate species because the long-term datasets needed to support robust analysis are more available for species in these regions," said Sims, who is familiar with the research but had no role in it.
"In addition, some of the largest changes in sea temperatures seen globally have been recorded in temperate regions such as the North Sea, so biological signals have been clearer."
The work by Shaw and Kelly might help provide a basis for applying research on temperate species to their counterparts along the equator, Sims said.
"The paper exemplifies well that the migration timing of tropical species is perhaps more similar to the responses of temperate species than previously realized," Sims said.
"Generally it seems that ectothermic [cold-blooded] species' migrations [such as that of the red crabs] correlate with environmental temperature changes, however the picture for individual species can be complex."

Shaw, who received her Ph.D. from Princeton in 2012, began the study at the University while planning a research trip to Christmas Island.
Her research focuses on modeling migratory patterns and determining why animals migrate in the first place.
Her interest in the red crabs began in 2008 when, as a Princeton doctoral student funded by the National Geographic Society/Waitt Grants Program, Shaw studied how size, sex and other factors influence if a red crab migrates.
She used global climate data to time a second visit in 2009 with the crabs' migration, but was at first disappointed when climate alone did not seem to precisely predict crab movement.
After reading more about climate change and migration, Shaw realized that her finding that climate generally influenced migration via rainfall was valuable.
"In the process of trying to ask this question about timing we were able to link migration patterns to rainfall, and rainfall to El Niño and global climate patterns," Shaw said.
"I realized that, seen in a different light, the analysis we had done on the crabs was quite valuable — it demonstrated a connection between climate and migration through rainfall, which hadn't been done for many species."
The paper, "Linking El Niño, local rainfall and migration timing in a tropical migratory species," was published in the November 2013 edition of Global Change Biology.
This work was supported by grants from the National Science Foundation Graduate Research Fellowships program (grant number DGE-0646086), the National Geographic/Waitt Institute for Discovery, NASA (grant number 61-7449) and the University of Washington.

Tuesday, October 15, 2013

France SHOM update in the Marine GeoGarage

4 charts have been withdrawn since the last update

  • 1461    Ile Capraja   
  • 1988    Entrées du Golfe du Mexique Banc de Campêche  
  • 6237    Ile Mayotte   
  • 6318    Abords Nord de Tamatave    

and 2 charts have been added :

  • 7677    Île de Mayotte
  • 7682    Abords Nord de Toamasina (Tamatave) 

so 598 charts from SHOM are displayed in the Marine GeoGarage

See the SHOM updated charts

Arctic's Hudson Bay warming rapidly, at Tipping Point

In exploring the lakes of the Hudson Bay Lowlands, five researchers have found one of the world's last refuges from global warming has been heating up dramatically since the mid-1990s
>>> geolocalization with the Marine GeoGarage <<<

From National Geographic

The Arctic has experienced some of Earth's first and greatest effects of climate change, but the icy lowlands around Hudson Bay have remained remarkably resistant to warming—until recently.
A new study reports that, since the mid-1990s, aquatic ecosystems in one of the Arctic's last refugia have undergone dramatic climate-driven changes and appear to have reached an ecological tipping point.

While local temperatures had remained relatively steady before the last two decades, they've risen since then at rates that are extremely high even for the Arctic.
The increase has changed the mix of freshwater organisms that anchor local food chains in a way never before seen over centuries of historical record.
(Related: "Summer Arctic Sea Ice Recovers From 2012, But Trend 'Decidedly' Down.")

"The Arctic is often described as Earth's 'canary in the coal mine' because it's the first area to show change. Shifts also happen very quickly there," said John Smol, a paleolimnologist at Queen's University in Kingston, Ontario, whose new research on the area was released today.
Smol added that, although data show Arctic warming dating back to the 1800s, there were always a few refugia that seemed relatively resistant to change—including this area around Hudson Bay.
"There were good reasons for that," he said.
"Hudson Bay is the second largest inland sea in the world, and it is choked with ice that helped keep the area cool," he said.
"So it had to pass a kind of tipping point. Only since the mid-1990s has it warmed up enough that it started losing its ice."
Hudson Bay has warmed about three degrees Celsius since the 1990s, and change has accelerated, said Smol.
"We see some striking ecosystem shifts in these lakes."
Smol pointed to increased stratification in the lake by temperature layers and shifts in algae.

 An aerial view shows the landscape typical of the Hudson Bay Lowlands in Ontario.
A new study of lake sediment core samples by Queen's University researchers shows the area has warmed rapidly in the last 15 years. (Kathleen Ruehland/Queen's University)
Paleoclimate History Written in Mud

While the area's native peoples maintain traditional knowledge of past conditions and stress significant recent changes, there isn't any long-term historical record of climatological data in the region.
But the evidence for these changes and their unique historical context is locked in mud on the bottom of local lakes in what Smol calls "natural archives."

"Lake sediments slowly accumulate, 24 hours a day and 365 days a year, layering and preserving an incredible amount of information in the mud," Smol said.
"So they are like a paleoclimatological history book if we learn to pull the information out of them."
Many organisms left microscopic fossils behind, especially algae.
Since different species survive under different conditions—like altered water chemistry or icy flows, compared with more open water—scientists can work out past conditions by studying such tiny fossils.
Sediment cores and the ancient algae they contain go back a thousand years in some cases and show that the Hudson Bay region's lakes experienced very little biological change over the centuries—until the past few decades.
After the mid-1990s, the aquatic biota in the sediment record show striking shifts in ecosystems that are very similar to those seen elsewhere across the Arctic in regions where air temperatures warmed and time periods of ice-free water increased.
"Essentially, this region warmed a couple of decades later than most of the rest of the Arctic, and the lake flora has experienced rapid shifts similar to previous changes in other lakes," said Konrad Hughen, a researcher at the Woods Hole Oceanographic Institution who was not affiliated with the study.
"One important observation they make is that the timing of these late changes coincides with local warming, not regionally increased nitrogen [nutrient] deposition. So, this supports the previous conclusions about changes in other lakes around the Arctic that they were caused by widespread warming and not nutrient changes."

Strange New World

On the other side of the globe, Antarctic sea ice has expanded so much it set a record—for the second year in a row.
Back-to-back iciest years since record keeping began in 1978 have left scientists searching for explanations—especially because the Southern Ocean waters below have continued to warm. (Related: "Antarctic Sea Ice Hits Record ... High?")
Physical changes on tap around Hudson Bay could mirror those seen earlier in the high Arctic, Smol said, including less lake ice, shallower or dried-up lakes and ponds, and the loss of productive wet peat lands.
Recent studies have suggested negative impacts on brook charr and other fish important to local peoples who must deal with the shifting landscape.
"There are real changes happening, and now we have paleoclimatological records," Smol said.
"This was one of the last holdouts in the Arctic, but now I feel we've lost it and we're entering uncharted territory." (Related: "Why Predicting Sea Ice Cover Is So Difficult.")

The research was published in Proceedings of the Royal Society B.

Links :

Monday, October 14, 2013

NZ Linz update in the Marine GeoGarage

9 charts have been updated in the Marine GeoGarage
(Linz September update published October 10, 2013

  • NZ63 Kaikoura Peninsula to Banks Peninsula
  • NZ64 Banks Peninsula to Otago Peninsula
  • NZ82 T 82 Tonga
  • NZ827 T 827 Approaches to Tongatapu including ‘Eua
  • NZ5111 Whangaruru Harbour
  • NZ5219 Approaches to Marsden Point
  • NZ5314 Mercury Islands
  • NZ8275 T 8275 Approaches to Nuku’alofa Harbour
  • NZ8277 T 8277 Nuku’alofa Harbour
Today NZ Linz charts (178 charts / 340 including sub-charts) are displayed in the Marine GeoGarage.

Note :  LINZ produces official nautical charts to aid safe navigation in New Zealand waters and certain areas of Antarctica and the South-West Pacific.

Using charts safely involves keeping them up-to-date using Notices to Mariners
Reporting a Hazard to Navigation - H Note :
Mariners are requested to advise the New Zealand Hydrographic Authority at LINZ of the discovery of new or suspected dangers to navigation, or shortcomings in charts or publications.

Global warming will increase intensity of El Nino, scientists say

How the impact of El Nino is felt on sea height across the world

From BBC (by Matt McGrath)

Scientists say they are more certain than ever about the impact of global warming on a critical weather pattern.
The El Nino-Southern Oscillation (ENSO) occurs in the Pacific Ocean but plays an important part in the world's climate system.
Researchers have until now been unsure as to how rising temperatures would affect ENSO in the future.
But this new study suggests that droughts and floods driven by ENSO will be more intense.

The ENSO phenomenon plays a complicated role in the global weather system.
The El Nino part of the equation sees a warming of the eastern and tropical Pacific, while its cooler sister, La Nina, makes things chillier in these same regions.

Normal Condition
Normally, sea surface temperature is about 14°F higher in the Western Pacific than the waters off South America.
This is due to the trade winds blowing from east to west along the equator allowing the upwelling of cold, nutrient rich water from deeper levels off the northwest coast of South America.
Also, these same trade winds push water west which piles higher in the Western Pacific.
The average sea-level height is about 1½ feet higher at Indonesia than at Peru.
The trade winds, in piling up water in the Western Pacific, make a deep 450 feet (150 meter) warm layer in the west that pushes the thermocline down there, while it rises in the east.
The shallow 90 feet (30 meter) eastern thermocline allows the winds to pull up water from below, water that is generally much richer in nutrients than the surface layer.

 El Niño conditions
However, when the air pressure patterns in the South Pacific reverse direction (the air pressure at Darwin, Australia is higher than at Tahiti), the trade winds decrease in strength (and can reverse direction).
The result is the normal flow of water away from South America decreases and ocean water piles up off South America. This pushes the thermocline deeper and a decrease in the upwelling.
With a deeper thermocline and decreased westward transport of water, the sea surface temperature increases to greater than normal in the Eastern Pacific.
This is the warm phase of ENSO, called El Niño.
The net result is a shift of the prevailing rain pattern from the normal Western Pacific to the Central Pacific.
The effect is the rainfall is more common in the Central Pacific while the Western Pacific becomes relatively dry.

 La Niña conditions
There are occasions when the trade winds that blow west across the tropical Pacific are stronger than normal leading to increased upwelling off South America and hence the lower than normal sea surface temperatures.
The prevailing rain pattern also shifts farther west than normal.
These winds pile up warm surface water in the West Pacific.
This is the cool phase of ENSO called La Niña.
What is surprising is these changes in sea surface temperatures are not large, plus or minus 6°F (3°C) and generally much less.

Impacts across the world
Like water in a bathtub, the warmer or cooler waters slosh back and forth across the Pacific Ocean. They are responsible for rainfall patterns across Australia and the equatorial region, but their effects are also felt much further away.
During the Northern Hemisphere winter, for example, you can get more intense rainfall over the southern part of the US in a warmer El Nino phase.
For years, scientists have been concerned about how this sensitive weather system might be changed by rising temperatures from global warming.

Now, in this new paper, published in the journal Nature, researchers give their most "robust" projections yet.
Using the latest generation of climate models, they found a consistent projection for the future of ENSO.
According to the lead author, Dr Scott Power from the Australian Bureau of Meteorology, global warming interferes with the way El Nino temperature patterns affect rainfall.
"This interference causes an intensification of El Nino-driven drying in the western Pacific and rainfall increases in the central and eastern equatorial Pacific," he said.

Models in agreement
According to Dr Wenju Cai, a scientist at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), who was not involved with the study, the paper is "significant".
"Up until now, there has been a lack of agreement among computer models as to how ENSO will change in the future," he explained.
"This paper is significant in that there is stronger agreement among different climate models in predicting the future impact.
"This study finds that both wet and dry anomalies will be greater in future El Nino years. This means that ENSO-induced droughts and floods will be more intense in the future."

Links :
  • Washington Post : El Niño, La Niña, La Nada and forecast implications for the upcoming winter

Sunday, October 13, 2013

US NOAA update in the Marine GeoGarage

21 charts have been updated in the Marine GeoGarage
(NOAA update September 2013)

  • 11370 ed30 Mississippi River-New Orleans to Baton Rouge
  • 11502 ed24 Doboy Sound to Fernadina
  • 11520 ed12 Cape Hatteras to Charleston
  • 11534 ed29 Intracoastal Waterway Myrtle Grove Sound and Cape Fear River to Casino Creek
  • 12270 ed38 Chesapeake Bay Eastern Bay and South River; Selby Bay
  • 12288 ed16 Potomac River Lower Cedar Point to Mattawoman Creek
  • 13226 ed39 Mount Hope Bay
  • 13267 ed43 Massachusetts Bay; North River
  • 14906 ed42 South Haven to Stony Lake;South Haven;Port Sheldon;Saugatuck Harbor
  • 14933 ed16 Grand Haven. including Spring Lake and Lower Grand River
  • 14937 ed34 Ludington Harbor
  • 17400 ed44 Dixon Entrance to Charham Strait
  • 17423 ed22 Harbor Charts-Clarence Strait and Behm Canal Dewey Anchorage. Etolin Island;Ratz Harbor. Prince of Wales Island;Naha Bay. Revillagigedo Island;Tolstoi and Thorne Bays. Prince of Wales ls.;Union Bay. Cleveland Peninsula
  • 18432 ed7 Boundary Pass
  • 18700 ed38 Point Conception to Point Sur
  • 25641 ed40 Virgin Islands-Virgin Gorda to St. Thomas and St. Croix;Krause Lagoon Channel
  • 25673 ed46 Bahia de Mayaguez and Approaches
  • 25687 ed36 Bahia de Jobos and Bahia de Rincon
  • 25689 ed18 Puerto Arroyo
  • 411 ed52 Gulf of Mexico
  • 11006 ed24 Gulf Coast - Key West to Mississippi River
Today 1024 NOAA raster charts (2166 including sub-charts) are included in the Marine GeoGarage viewer.

How do you know if you need a new nautical chart?
See the changes in new chart editions.
NOAA chart dates of recent Print on Demand editions

Note : NOAA updates their nautical charts with corrections published in:
  • U.S. Coast Guard Local Notices to Mariners (LNMs),
  • National Geospatial-Intelligence Agency Notices to Mariners (NMs), and
  • Canadian Coast Guard Notices to Mariners (CNMs)
While information provided by this Web site is intended to provide updated nautical charts, it must not be used as a substitute for the United States Coast Guard, National Geospatial-Intelligence Agency, or Canadian Coast Guard Notice to Mariner publications

Please visit the
NOAA's chart update service for more info.

Journey to the South Pacific

Narrated by Cate Blanchett, Journey to the South Pacific will take moviegoers on a breathtaking IMAX® 3D adventure to the lush tropical islands of remote West Papua, where life flourishes above and below the sea.

Join Jawi, a young island boy, as he takes us on a journey of discovery to this magical place where we encounter whale sharks, sea turtles, manta rays, and other iconic creatures of the sea.
Home to more than 2,000 species of sea life, this exotic locale features the most diverse marine ecosystem on earth.
An uplifting story of hope and celebration, Journey to the South Pacific highlights the importance of living in balance with the ocean planet we all call home.