Oceanography

When you mention rich ecosystems that are vital for life on Earth, people tend to think of rainforests, but ocean plankton are actually just as crucial. The microscopic beings that drift on the upper layer of the oceans are globally referred to as "plankton"; together they produce half of our oxygen, act as carbon sinks, influence our weather, and serve as the base of the ocean food web that sustains the larger fish and marine mammals that we depend upon or draw delight from.

"Beyond the cutting-edge science that was developed thanks to our collaborative work with the Tara Expéditions Foundation, this adventure is also about showing people all over the world how important the ocean is for our own well-being," says Eric Karsenti, director of Tara Oceans, from EMBL and CNRS.

We've all been captivated by ocean waves, we accept (everyone except Galileo anyway) that the moon has an impact on tides and waves, but less well known is that the ocean contains rolling internal waves beneath the surface that displace massive amounts of water and push heat and vital nutrients up from the deep ocean.

These internal waves have long been recognized as essential components of the ocean's nutrient cycle, and key to how oceans will store and distribute additional heat brought on by global warming. Yet  thorough understanding of how internal waves start, move and dissipate has been lacking.


Two ocean hot spots have been linked to the hottest summers on record for the central United States, in 1934 and 1936. Those two summers and the "Dust Bowl" that saw farming devastated were accompanied by the worst drought in America of the last 1,000 years.

In 1934, giant dust storms and drought covered more than 75 percent of the country and affected 27 states severely. Silt from storms even covered the decks of ships 200 miles off the east coast. 


Antarctica's massive ice sheet has recently lost twice the amount of ice in the west as what it  accumulated in the east, and the southern continent's ice cap is melting ever faster, according to a new study in which researchers "weighed" Antarctica's ice sheet using gravitational satellite data and found that from 2003 to 2014, the ice sheet lost 92 billion tons of ice per year.

If stacked on the island of Manhattan, that amount of ice would be a mile high, more than five times the height of the Empire State Building.


Researchers have discovered areas in the tropical North Atlantic, several hundred kilometers off the coast of West Africa, with extremely low levels of oxygen, making them uninhabitable for most marine animals.

The levels measured in these 'dead zones' are the lowest ever recorded in Atlantic open waters.


Greenland climate during the last ice age was very unstable, the researchers say, characterized by a number of large, abrupt changes in mean annual temperature that each occurred within several decades. These so-called "Dansgaard-Oeschger events" took place every few thousand years during the last ice age. Temperature changes in Antarctica showed an opposite pattern, with Antarctica cooling when Greenland was warm, and vice versa.


The ocean sucks up heat-trapping carbon dioxide (CO2) building up in our atmosphere with help from tiny plankton.

Like plants on land, plankton convert CO2 into organic carbon via photosynthesis and then can sink into the deep ocean, carrying carbon with them. They decompose when bacteria convert their remains back into CO2.

This "biological pump," if it operated 100 percent efficiently, would mean nearly every atom of carbon drawn into the ocean would be converted to organic carbon, sink into the deep ocean, and remain sequestered from the atmosphere for millennia. But like hail stones that melt before reaching the ground, some carbon never makes it to the deep ocean, allowing CO2 to leak back into the upper ocean and ultimately exchange with the atmosphere.


We are still trying to fully understand the extent of the damage caused by the Deepwater Horizon oil spill five years ago, one of the worst environmental disasters in US history.

Though some studies have linked icebergs to abrupt climate change cycles during the last glacial period - by introducing fresh water to the surface of the ocean and changing ocean currents, which changes climate - new findings present a contradictory narrative and suggest that icebergs generally arrived too late to trigger marked cooling across the North Atlantic.

Abrupt climate change, characterized by transitions between warm and cold conditions across the North Atlantic, is a pervasive feature of the Late Pleistocene - the most recent period of repeated glacial cycles. 

The one common element in recent American weather has been its diversity. The West Coast has been drier than usual while the East Coast has had more snow. Fish are swimming into new waters and so hungry seals that don't follow them aare washing up on California beaches. 

A long-lived patch of warm water off the West Coast, about 1 to 4 degrees Celsius (2 to 7 degrees Fahrenheit) above normal, is part of what's wreaking much of this mayhem, according to two papers Geophysical Research Letters. No, that warm blob was not caused by climate change, though it has many of the same effects for West Coast weather.