Our first meeting with the South of the world begins in Rome, where the ENEA and the CNR run the National Antarctic Research Program (PNRA), which each year selects journalists to be invited to follow the Italian expedition. In 2016 we were the lucky ones.
So let’s start by plane to New Zealand to embark on Italy, the historic oceanographic vessel “Italica”, which this year will definitely be retired. From 31 December 2016 to 6 April 2017, it does its last round trip to South Pole. In the future, Italian shipping will have to use other means of transport.
After seven uninterrupted navigation days crossing the Antarctic Polar Circle, we reach the Ross Sea and Newfoundland Bay, where the Italian base on the frozen continent is nestled.
From here we continue a little along the coast and a bit wide, in the stony sea climber that widens between Cape Washington and Cape Hallet, zigzagging through the banchis fragments. Mission: to follow a route that will allow you to touch the most desirable points for doing the various research activities to find out how Antarctica and climate change are affecting each other.
The area covered by Italica is a precious natural laboratory, unique in the world, where you can study the climatic secrets that lie in the deep, freezing waters of the South Sea, more commonly known as the Antarctic Sea. Not surprisingly, at the end of 2016, the Ross Sea biosphere was transformed into the world’s largest marine protection reserve.
That global warming has a direct impact on Antarctica is now asserted, mocking the skeptics who do not believe in changes in the Earth’s climate. The latest satellite-based studies of the European Space Agency show that Antarctica loses nearly 160 million tonnes of ice each year, especially in its western area where glacier elevation has already fallen by 12 meters.
The question posed by scientists is: how is Antarctica reacting in turn? It is to find an answer that we came with them to the world.
“Antarctica, and especially the Ross Sea, where we conduct our oceanographic campaign, is a key engine of the Earth’s climate,” explains Giorgio Budiller, Professor of Oceanography and Meteorology at the Naples Parthenope University and scientific coordinator of the expedition, “Here is a physiological cycle that allows the continuous exchange between the polar cold and the heat of our territories, thus maintaining the average temperature of Earth.”
How does this extraordinary planetary thermal balancing mechanism work? This is explained in detail by researchers on board in Italy, engaged in gathering clues that may indicate whether this mechanism works correctly or not. Hints that are hidden in the physico-chemical properties of water.
The formation of marine ice, the researchers explain, frees up salt that accumulates in the cold waters underneath. These become so much heavier and sinking by cooling the oceanic abyss, invoking towards the polar regions hot surface water that absorbed excess heat in the temperate zones of the planet. These waters cool in turn, increase their salinity and sink back to where they came from, namely in the Red Sea, Antarctica – Everything works like a slow conveyor belt that takes about 1000 years to complete its cycle.
“If you overlook this mechanism that moves the heat from where there is too much to where there is little, we would get hotter while in Antarctica it would get colder,” continues Budillon, “We are in the Sea of Ross To do a series of tests that will allow us to see if the system works properly or if there are anomalies. ”
The surveys made during the last shipments show that something is changing: the melting of the polar fleece in Western Antarctica, particularly in the Bellinghouse area, due to global warming has brought fresh water to the Ross Sea. This helps to reduce the salt concentration in the Red Sea, thus relieving water masses that may have difficulty plunging to the bottom and triggering the thermal compensation process.
To call warning are instruments called ‘mooring’, rope serpentins anchored to the bottom and vertically supported underwater thanks to buoys, to which various temperature, salinity, current and sediment detectors are engaged.
During navigation, we recover those that were left two years ago and then put them back to sea to capture new data, through acrobatic ropes that oppose the force of the sea to the members of the crew tied to the strap of safety belts so as not to be dragged into frozen water Where a man would not survive for more than two minutes. Moments in which to win is the team solidarity that man can always prove in the face of the hostility of nature and the desire for knowledge.
“The mooring allows us to record variations over a long period of time to find trends, but still can not come to definitive conclusions,” says Budillon.
“It is known that the amount of heat stored in the middle layers of the Atlantic Ocean has recently increased because of global warming that transmits heat from the surface down,” adds Pierpaolo Falco, also oceanographer and professor at the Parthenope University, “Understanding how this excess of heat can possibly be combined with a smaller influx of cold water from Antarctica, due to declining salinity, is a very ambitious goal we intend to pursue.”
To find out, the researchers dropped in the race of the big float-shaped smart thermometers, which went deep and then went on to transmit the information collected to the passing satellites. “We carry out operations in the area of the Circumpolar Antarctic Current that whirls around the Earth around the South 60’s,” Falco explains. The Circumpolar Current is a gigantic planetary cooling circuit that distributes the glacial waters of Antarctic waters in all the other oceans, balancing the excess heat present in the tropical band.
Apart from relieving heat, the Antarctic Sea stores 40% of the CO2 we emit with our activities. “CO2 dissolves more easily in cold and dense waters, just like those of Antarctica,” says Leonardo Langone, the CNR ISMAR marine geologist, who daily slips into his blue metal box with a grip of ” Air to measure the amount of CO2 in the atmosphere.
“We have found increasing percentages here also in Antarctica, although it is the area most distant from our sources of emissions,” Langone continues, “this, together with heating and reducing water salinity, could reduce the CO2 absorption capacity Of the Antarctic Sea “.
However, as is often the case, nature finds the way to balance itself, by remedying human harm. The algae, CO2 aries – Will they be able to save us from ourselves?
In order to ensure this, the team of scientists and the crew flees in a 30-hour offshore marathon, during which the ship departs and stops repeating at key points of the Ross Sea to bottling water with a tool called ‘Rosetta ‘. The goal is to measure the concentrations of chlorophyll and other chemical parameters that influence the growth of algae.
“Measurement of these parameters and chlorophyll allows us to understand the extent to which algae, through photosynthesis, consume CO2,” explains Paola Rivaro, chemical oceanographer and professor at the University of Genoa, “the algae are abundant in the more superficial layers And hottest where sunlight penetrates and, by reducing CO2 in water, will further the passage from the atmosphere to the sea. ”
In short, CO2 that the sea may no longer absorb due to the fact that it becomes warmer and less dense may still be absorbed by the growth of the algae favored, paradoxical, by the same temperature rise. However, this process, the researchers say, has a positive effect only if part of the CO2 recycled from the algae accumulates in the sediments and is buried in the backdrops leaving the global carbon cycle.
There is also to be said that this self-regulating system has a price: the acidification of sea water, due to the greater CO2 input. A process that endangers marine ecosystems, especially molluscs, hindering the creation of their protective skeleton. A threat that may affect the entire food chain to our table.
In other words, there is a limit to the amount of CO2 we can produce beyond which the storage at sea risks altering delicate global equilibria.
Autore: Stefano Valentino
Stefano Valentino è un reporter-editore freelance, appassionato di intrecci tra sostenibilità, conflitti e digitale. È fondatore di MobileReporter, piattaforma di giornalismo collaborativo vincitrice del News Innovation Contest di Google. Ha ralizzato reportages da tutto il mondo per testate italiane ed estere.