Ikigai Daily
Menu
WonderAutonomous ocean observing fact

Argo is a fleet of nearly 4,000 robotic floats that drift through the world's oceans, sinking to about 2,000 metres and rising again to measure the water's temperature and saltiness. At the surface each float sends its data by satellite, free for anyone to use.

Argo (oceanography)

OceanClimateTechnology

The story behind the card

A typical float drifts for most of its cycle at about 1,000 metres, then sinks to about 2,000 metres and measures the water as it rises to the surface, completing each cycle in roughly ten days. The programme began around 2000, and in November 2007 it reached its goal of 3,000 floats spread across the open ocean. Its name comes from the Argo, the ship of Jason in Greek myth, because the floats work alongside the Jason satellites that measure sea level. Newer Biogeochemical-Argo floats also carry sensors for oxygen, acidity, nutrients and chlorophyll, the green pigment of microscopic ocean plants. Before Argo, most deep-ocean measurements came from ships on a few busy routes; now scientists can follow how the whole ocean is warming.

Türkçe oku
Argo, dünya okyanuslarında sürüklenen 4.000'e yakın robot şamandıradan oluşan bir filodur. Şamandıralar 2.000 metre kadar derine inip yeniden yükselir, bu sırada suyun sıcaklığını ve tuzluluğunu ölçer. Her biri verilerini yüzeyde uyduyla gönderir; herkes bu verileri ücretsiz kullanabilir.

Tipik bir şamandıra döngüsünün büyük bölümünü yaklaşık 1.000 metre derinlikte sürüklenerek geçirir, sonra 2.000 metreye iner ve yüzeye çıkarken suyu ölçer; her döngü yaklaşık on gün sürer. Program 2000'lerin başında başladı ve Kasım 2007'de açık okyanuslara yayılmış 3.000 şamandıra hedefine ulaştı. Adını Yunan mitolojisindeki İason'un gemisi Argo'dan alır; çünkü şamandıralar deniz seviyesini ölçen Jason uydularıyla birlikte çalışır. Daha yeni Biyojeokimyasal Argo şamandıraları oksijeni, asitliği, besin maddelerini ve okyanustaki mikroskobik bitkilerin yeşil pigmenti klorofili ölçen algılayıcılar da taşır. Argo'dan önce derin okyanus ölçümlerinin çoğu birkaç işlek rotadaki gemilerden gelirdi; bugün bilim insanları bütün okyanusun nasıl ısındığını izleyebiliyor.

Sources and further reading

Background reading: Argo (oceanography)
Get the mobile appAbout our cards

Related cards

These cards share a subject or reading mode with the card above.

WonderArchitecture

A windcatcher, badgir in Persian, is a tall tower on a roof that catches passing breezes and channels them down into the rooms below. It has cooled houses in hot, dry places such as Iran for centuries, without any machinery.

The top of the tower has openings that face the wind. Air pushed in is forced down a shaft into the house, while warm air leaves through openings on the sheltered side; on still days the sun-warmed tower works like a chimney and draws air through the rooms. Yazd, a desert city in central Iran listed by UNESCO in 2017, is famous for its many windcatchers, and the one in its Dowlatabad Garden, about 33 metres high, is often described as the tallest in the world. Paired with covered water reservoirs called ab-anbars, windcatchers helped keep drinking water cool. Similar towers are found from Egypt to the Persian Gulf, and architects now study them for low-energy cooling.

Traditional Persian architectureRead card
WonderClimate

When Syria's civil war cut the agricultural research centre ICARDA off from its genebank near Aleppo, it turned to the backup seeds it had stored in the Svalbard Global Seed Vault in Arctic Norway. Those seeds were used to rebuild its collections in Lebanon and Morocco.

ICARDA, the International Center for Agricultural Research in the Dry Areas, kept one of the world's major collections of wheat, barley, lentil and other crop varieties at Tel Hadya, near Aleppo. A genebank stores seeds alive for plant breeders and researchers, and between 2008 and 2014 ICARDA sent duplicates of 116,484 samples to Svalbard. The vault, opened in 2008, is dug into a mountain on an Arctic island and keeps seeds frozen at about minus 18°C. ICARDA withdrew seeds in 2015, the first withdrawal in the vault's history, and again in 2017 and 2019, until every sample had come back. Once the seeds had been grown again in Lebanon and Morocco, fresh duplicates were returned to Svalbard.

Crop Trust / NordGenRead card
WonderOcean

Coral reefs cover less than 1 per cent of the ocean floor, yet they support about a quarter of all known marine species. They also shield coasts from storm waves.

A reef is built by coral polyps, tiny animals related to jellyfish that lay down skeletons of limestone. Most reef corals carry single-celled algae inside their tissue; the algae photosynthesise and pass food to the coral in return for shelter, and they also give it its colour. When the water stays too warm for too long, corals expel the algae and turn white, which is called bleaching; if the heat lasts, they starve and die. A global bleaching event from 2014 to 2017 hit about two-thirds of the world's reefs, and a fourth, from 2023 to 2025, the most severe on record, reached about 84 per cent of reef area.

Coral reefsRead card
StillnessOcean

Marine snow is a continuous fall of organic particles, including plankton remains, mucus, faecal pellets and other debris, from upper waters into the deep sea.

Much of this material is eaten or broken down by bacteria on the way, and only a small fraction settles on the seabed, yet it is the main food supply for many deep-sea animals, far below where sunlight lets algae grow. Flakes grow as particles clump together and can sink tens to hundreds of metres a day. The name is often traced to the naturalist William Beebe, who saw particles drifting in his lights during bathysphere dives off Bermuda in the 1930s. Scientists measure the fall with sediment traps and underwater cameras, because it is a key part of the ocean's biological carbon pump: carbon taken up by plankton at the surface sinks, and what reaches the seabed can stay there for centuries or longer.

Marine snowRead card
WonderOcean

Coccolithophores are tiny single-celled algae that cover themselves in intricate plates of chalk (calcium carbonate). Drifting in sunlit seawater in vast numbers, they link microscopic life to ocean chemistry and the global carbon cycle.

Each plate, called a coccolith, is a few thousandths of a millimetre across; it is built inside the cell and then pushed out to its surface. When coccolithophores die, their plates sink, and over millions of years thick layers of them have hardened into chalk: the White Cliffs of Dover are made largely of coccoliths laid down in the Cretaceous period, roughly 100 to 66 million years ago. The commonest species today, Emiliania huxleyi, forms blooms that turn the sea milky turquoise and can be seen from space. Coccolithophores take up carbon through photosynthesis, and their sinking plates carry carbon to the seabed, where scientists read their fossil remains to reconstruct past climates.

CoccolithophoreRead card
Next card in the archiveIn 1823 the American fur trapper Hugh Glass survived a grizzly bear attack in what is now South Dakota and was left behind by two companions who believed he would die. He then made his way to Fort Kiowa, about 200 miles (320 km) away, a journey said to have taken some six weeks.Read next →