Monday, November 11, 2013

Our Perpetual Ocean

This is an animation of ocean surface currents from June 2005 to December 2007 from NASA satellites. Watch how bigger currents like the Gulf Stream in the Atlantic Ocean and the Kuroshio in the Pacific carry warm waters across thousands of miles at speeds greater than four miles per hour (six kilometers per hour); how coastal currents like the Agulhas in the Southern Hemisphere move equatorial waters toward Earth's poles; and how thousands of other ocean currents are confined to particular regions and form slow-moving, circular pools called eddies. Credit: NASA/SVS
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The swirling flows of tens of thousands of ocean currents were captured in this scientific visualization created by NASA's Goddard Space Flight Center in Greenbelt, Md.

"There is also a 20-minute long tour, which shows these global surface currents in more detail," says Horace Mitchell, the lead of the visualization studio. "We also released a three-minute version on our NASA Visualization Explorer iPad app."

Both the 20-minute and 3-minute versions are available in high definition here:

The visualization covers the period June 2005 to December 2007 and is based on a synthesis of a numerical model with observational data, created by a NASA project called Estimating the Circulation and Climate of the Ocean, or ECCO for short. ECCO is a joint project between the Massachusetts Institute of Technology and NASA's Jet Propulsion Laboratory in Pasadena, Calif. ECCO uses advanced mathematical tools to combine observations with the MIT numerical ocean model to obtain realistic descriptions of how ocean circulation evolves over time.

These model-data syntheses are among the largest computations of their kind ever undertaken. They are made possible by high-end computing resources provided by NASA's Ames Research Center in Moffett Field, Calif.

ECCO model-data syntheses are being used to quantify the ocean's role in the global carbon cycle, to understand the recent evolution of the polar oceans, to monitor time-evolving heat, water, and chemical exchanges within and between different components of the Earth system, and for many other science applications.

In the particular model-data synthesis used for this visualization, only the larger, ocean basin-wide scales have been adjusted to fit observations. Smaller-scale ocean currents are free to evolve on their own according to the computer model's equations. Due to the limited resolution of this particular model, only the larger eddies are represented, and tend to look more 'perfect' than they are in real life. Despite these model limitations, the visualization offers a realistic study in both the order and the chaos of the circulating waters that populate Earth's ocean.

Data used by the ECCO project include: sea surface height from NASA's Topex/Poseidon, Jason-1, and Ocean Surface Topography Mission/Jason-2 satellite altimeters; gravity from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment mission; surface wind stress from NASA's QuikScat mission; sea surface temperature from the NASA/Japan Aerospace Exploration Agency Advanced Microwave Scanning Radiometer-EOS; sea ice concentration and velocity data from passive microwave radiometers; and temperature and salinity profiles from shipborne casts, moorings and the international Argo ocean observation system. More


Saturday, November 2, 2013

A Man Leaves His Island

Recently a news story about a man seeking asylum in New Zealand as a climate change refugee made headlines all over the world.

His original appeal to the Immigration and Protection Tribunal of New Zealand was dismissed in June 2013 because, according to the tribunal, he is not a considered a refugee under the terms laid out in the international Convention and Protocol Relating to the Status of Refugees. He is now asking the New Zealand High Court to let him appeal this case.

Mangroves planted on Kiribati to prevent erosion.

“There’s no future for us when we go back to Kiribati,” Ioane Teitiota told the appeal tribunal, adding that a return to his tiny Pacific atoll would pose a risk to his children’s health, according to Reuters.

The relationship between climate change and migration is complicated. And pointing to climate change as the main factor affecting the living conditions on small island states is difficult.

People such as inhabitants on small island states, in many cases find themselves caught between wrongs of the past and the future consequences of these wrongs, explains Ilan Kelman, Reader in Risk, Resilience and Global Health at University College London.

Kelman points out that many island states are still struggling with the effects of colonialism, post-colonialism, modernism, forced relocation efforts and misguided aid, as well as the consequences of greenhouse gas emissions, mainly from the rich countries of the world.

His story

No matter how the New Zealand High Court concludes on Mr. Teitiotas’ appeal, his story is also a story about the nation of Kiribati, as an icon for other islands regarding the challenges they face concerning overpopulation, resource management, poverty, sea level rise and climate change.

The following text is adapted from the official decision from the Immigration and Protection Tribunal of New Zealand.

Ioane Teitiota was born in the 1970s on an islet situated three days journey by boat, or two hours by plane, north of Tarawa, the main island and capital of Kiribati.

As is common in the Kiribati island group, his home island is a low-lying atoll with houses built on coral debris which has accreted over time. When in his early teens, he was sent to school on a nearby island.

Republic of Kiribati

In 2002, Teitiota married his wife and moved in with her family in another village situated on Tarawa. He lived there with his wife’s family in a traditionally constructed dwelling which had been built on coral, which had accreted on a sea wall built some years previously. The dwelling was situated on ground level and had electricity. Water was obtained from a well and from supplies provided by the Government. There were no sewerage facilities.

Over time, the villages on Tarawa in which Teitiota resided became overcrowded. People travelled to Tarawa from outlying islands because this was where most government services such as the main hospital were located. Land was purchased from existing landholders or acquired through kinship ties to Tarawa.

As the villages became overcrowded, tensions were generated and there were often physical fights in which people were injured, and on occasion, killed. When this happened, the police intervened, taking the injured to the hospital and arresting those responsible.

Life generally became progressively more insecure on Tarawa as a result of sea level rise. From the late 1990s onwards, Tarawa suffered significant amounts of coastal erosion during high tides. Also the land surface was regularly flooded and land could be submerged up to knee-deep during king tides. Transportation was affected as the main causeway separating north and south Tarawa was often flooded.

This caused significant hardship for Teitiota, his wife and family as well as other inhabitants on Tarawa. The wells upon which they depended for water became salty. Salt water was deposited onto the ground destroying crops. Crops were difficult to grow and the land was stripped of vegetation in many places.

The Government’s supplies of water are coming under pressure through overpopulation and because people can increasingly no longer rely on well water for an alternative source. The sea wall in front of the Teitiota’s parents-in-law’s house was often damaged and required constant repair. The family existed largely by subsistence fishing and agriculture. One of the appellant’s brothers-in-law works at a local government port agency and provides cash income for the whole family as best as he is able. However, life is generally becoming more difficult. More