© NOAAA layer of Antarctic Bottom Water colder than 0ยบC (colors, with darkest blue areas having the thickest layer, and white none) covers the ocean floor around Antarctica (center, shaded grey). Rates at which this layer is thinning during the study period (red numbers in meters per decade) are shown for for each deep basin (outlined by thin grey lines). These rates are estimated using data from repeated oceanographic expeditions (ship tracks shown by thick black lines). Note that seawater at the ocean surface stays liquid even at temperatures approaching -2ยบC because of its high salt content.
The coldest deep ocean water that flows around Antarctica in the Southern Ocean has been mysteriously disappearing at a high rate over the last few decades, scientists have found.
This mass of water is called
Antarctic Bottom Water, which is formed in a few distinct locations around Antarctica, where seawater is cooled by the overlying air and made saltier by ice formation (which leaves the salt behind in the unfrozen water). The cold,
salty water is denser than the water around it, causing it to sink to the sea floor where it spreads northward, filling most of the deep ocean around the world as it slowly mixes with warmer waters above it.
The world's deep ocean currents play a critical role in transporting heat and carbon around the planet, which helps
regulate the Earth's climate. Previous studies had indicated that this deep water has become warmer and less salty over the past few decades, but a new study has found that significantly less of this water has also been formed during this time.
Oceanographers examined temperature data collected from 1980 to 2011 at about 10-year intervals by an international program of repeated ship-based oceanographic surveys in the Southern Ocean.
They found that Antarctic Bottom Water has been disappearing at an average rate of about 8 million metric tons per second over the past few decades, equivalent to about 50 times the average flow of the Mississippi River, according to statement from the National Oceanic and Atmospheric Administration (NOAA), which helped fund the data collection.
"In every oceanographic survey repeated around the Southern Ocean since about the 1980s, Antarctic Bottom Water has been shrinking at a similar mean rate, giving us confidence that this surprisingly large contraction is robust," said lead author of the study Sarah Purkey, a graduate student at the University of Washington in Seattle.
What's causing the reduction and what it means are things the researchers must still investigate.
"We are not sure if the rate of bottom-water reduction we have found is part of a long-term trend or a cycle," said co-author Gregory C. Johnson, an oceanographer at NOAA's Pacific Marine Environmental Laboratory in Seattle.
Changes in the temperature, salt content, dissolved oxygen and dissolved carbon dioxide of this prominent water mass have important ramifications for Earth's climate, including
contributions to sea level rise and the rate of Earth's heat uptake.
"We need to continue to measure the full depth of the oceans, including these deep ocean waters, to assess the role and significance that these reported changes and others like them play in the Earth's climate," Johnson said.
Our heliosphere is being compressed, its gas being lighter than the surrounding Fluff which itself is being energized and expanding (hence the compression of Sol's heliosphere) by neutrinos shed by G1.9 on its periodic brief incursion. This anti matter neutron bitsy is almost immediately repelled by Sol's matter once it penetrates the ORT shell. It may then 'orbit' back to the Centauri system where it is repelled and repeats its 'orbit.'
The neutrinos are heating all bodies in Sol's heliosphere, including Sol itself. Venus' dramatic flares is an indication that the compression front, which may be described as DL plasma layers, has passed Venus and is now approaching Earth. It is unknown how the 25,000 y alignment with the galactic core will add to this effect. As the Earth was not outside the compressed heliosphere 10,000 y ago or we would have had significant catastrophe areas, it is assumed that Earth will again be inside the compressed heliosphere. Science is using this compression to disclose many significant aspects that heretofore had been undiscovered in functioning. This may imply that our original solar system composition was a dim sun and one or two close in planets.
The neutron bitsy departs and immediately the heliosphere rebounds to 'normal.' The planets 'protected' by compression are immediately released and the heated cores would 'blast out' as the Hot Spots on Earth note globally. Note that Venus has recently been identified as releasing a super flare from the surface. The pyramids may be the way mankind has found to moderate the incoming neutrinos and also moderate the heat released from the core. In this way we have been protected for the last 10,000 y from a core 'blast out.'
The cold bottom water is not so cold due to heating from the bottom, the Earth's core heat rising upward.