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Satellite Eye on Earth: May 2017 in pictures

Vesuvius in Italy and volcanoes in northern Tanzania, lights going out in Syria, and flooding in Sri Lanka are among images captured by Nasa and the ESA this month.

A vertical view of Vesuvius in southern Italy, taken by the European Space Agency (ESA) astronaut Thomas Pesquet from the International Space Station. The Proxima mission is named after the closest star to the sun, continuing a tradition of naming missions with French astronauts after stars and constellations. The mission is part of the ESAs plan to use Earth-orbiting spacecraft as a place to live and work while preparing for future voyages of exploration further into the solar system.

Garabogazkl

Photograph: OLI/Landsat 8/Nasa

The next time you are out at sea, keep an eye out for long filaments of foam and debris floating on the surface. This common phenomenon usually the product of natural decomposition processes and wind is seen on Garabogazkl, a shallow, salty lagoon near the Caspian Sea in Turkmenistan. In most cases, foam is the product of decaying aquatic plants, algae, phytoplankton, or other microorganisms. The decomposition process releases oils and other substances called surfactants that rise up and reduce the surface tension of the water, making it easier for bubbles to form in windy conditions. (In addition to these natural sources, detergents and other manmade pollutants can act as surfactants.) In the case of Garabogazkl, the white lines are likely the intersections of warmer and cooler waters. When two surface currents bump into each other, they dive.

Monterrey,

Photograph: ISS/Nasa/ESA

Mount Silla also referred to as Cerro de la Silla or Saddle Hill is an iconic landscape feature of the Monterrey, the capital of the Mexican state of Nuevo Len. When viewed from the west, the ridges and peaks resemble a saddle. Mount Silla has been declared a natural monument under the guidelines of the World Commission on Protected Areas. The Monterrey metropolitan area sits 1,300 meters (4,200 feet) below the steep, forested flanks of the mountain. Monterrey straddles several large rivers flowing out of the mountains. The Santa Catarina river cuts through the older parts of the city (such as Monterrey Antiguo). Major highways follow the river to the nearby cities of Guadalupe, San Pedro Garza, and Santa Catarina. Rio La Silla (Saddle river) flows from the northern Sierra Madre Oriental mountain range and joins the Santa Catarina just outside the top left corner of the image. The semi-arid climate keeps these rivers dry for much of the year. Nuevo Len state is home to the third largest economy in Mexico thanks to Monterreys extensive manufacturing facilities and infrastructure.

Flooding along the Mississippi, Missouri, and Illinois rivers. At the time, the Mississippi was transitioning from moderate to minor flood stage. For comparison, the first image shows the three rivers a year earlier.

Lake

Photograph: OLI/Landsat 8/Nasa

Not many people venture near the shores of Lake Natron in northern Tanzania. The lake is mostly inhospitable, except for a few species adapted to its warm, salty, and alkaline water. The lake is seen here very early in the rainy season that runs from March to May. The climate here is arid. In a non-El Nio year, the lake receives less than 500mm (20in) of rain. Evaporation usually exceeds that amount, so the lake relies on other sources such as the Ewaso Ngiro river at the north end to maintain a supply of water through the dry season.

But it is the regions volcanism that leads to the lakes unusual chemistry. Volcanoes, such as Ol Doinyo Lengai (about 20km to the south), produce molten mixtures of sodium carbonate and calcium carbonate salts. The mixture moves through the ground via a system of faults and wells up in more than 20 hot springs that ultimately empty into the lake. While the environment is too harsh for most common types of life, there are some species that take advantage of it. Small, salty pools of water can fill with blooms of haloarchaea salt-loving microorganisms that impart the pink and red colours to the shallow water. And when the waters recede during the dry season, flamingos favour the area as a nesting site as it is mostly protected from predators by the perennial moat-like channels and pools of water.

Lake

Photograph: ISS/Nasa/ESA

Drainage patterns are visible on the south-western end of the Gobi desert in Chinas Gansu province. The desert landscape part of the Hexi corridor along the historical Silk Road is low in elevation, generally flat, and surrounded by mountains and rolling hills. The foothills of the Tien Shan mountains lie to the north. As temperatures warm in the spring, snow melt from the higher elevations flows down into streams, forming narrow alluvial fans. The water carries sand, silt, and clay that accumulate at the mouths of the streams. These sediments are then available for further transport by larger valley rivers such as the Shule. The grid pattern superimposed on the basin is part of the Gansu wind farm project. Narrow roads mark the paths between dozens of wind turbines. Currently China is the largest emitter of greenhouse gases, and the wind farms are part of an effort to reduce carbon emissions and to harness cleaner energy. Several small towns skirt the Shule river, diverting water for cultivation of wool, tobacco, and a variety of grain and fruit crops.

Phytoplankton

Photograph: VIIRS/Suomi NPP/Nasa

Phytoplankton blooms in the waters around Britain and France. Increasing sunlight in the spring provides the energy for the floating, microscopic plant-like organisms to bloom in vast numbers.

These images show differences in night-time lighting between 2012 and 2016 in Syria and Iraq, among several Middle Eastern countries. Such images can indicate economic development or the lack of it. Some changes reflect increases or decreases in electric power generation or in the steadiness of the supply.

Night light images also have value for international relief and humanitarian organisations, which can use this data to pinpoint areas in need. Nasa makes its Earth observations openly available to those seeking solutions to important global issues.

In the above images, the changes are most dramatic around Aleppo, but also extend through western Syria to Damascus. Over the four years, lighting increased in areas north of the Syrian border in Turkey and to the west in Lebanon. According to a 2015 report from the Voice of America, as much as 80 percent of the lights have gone out in Syria over the past few years.

In Iraq, some northern sections near Mosul saw a decrease in light, while areas around Baghdad, Irbil, and Kirkuk saw increases. Note, too, the change in electric light patterns along the Tigris and Euphrates river basins.

South

Photograph: Modis/Terra/Nasa

By late autumn the temperatures in southern South America begin to turn chilly and grasses develop the first traces of the brown colouration of senescence as they start to wilt and dry. It is also the time when precipitation increases as the season heads into winter. A broad bank of open-celled marine cumulus clouds covers the South Pacific. Thick clouds also hang over the Andes, obscuring all of Chile (along the west coast) and much of western Argentina. Smaller clumps of cloud are scattered across the semi-desert of Argentina some reaching over the Argentine Sea.

Mokpo

Photograph: Proba-V/Vito/ESA

Mokpo is a city of 250,000 inhabitants in the south-west of South Korea. It is a main gate to the countrys largest granary at the Honam plain and was a naval base during the Joseon dynasty (13921910). The port city is surrounded outside the coast by more than 1,400 islands, which provide fishing grounds and also protect the area from large typhoon and tsunami impacts. Mokpo lies in the bottom right of the image, a blue-grey area located at the Yeonsang river estuary. Scattered smaller and larger islands lie off the coast, while an extensive area with large sediment concentrations extends further into the Yellow Sea in a bow shape.

The Arctic is largely hemmed in by the northern edges of Eurasia and North America. As a result, pieces of drifting pack ice have few outlets for escape when sea ice is thinning and breaking up in the spring and summer.

The primary passageway out of the Arctic is the Fram Strait between Greenland and Svalbard. However, a narrower waterway to the west the Nares Strait, which separates Greenland and Ellesmere Island is also important. The amount of ice flowing through the Nares Strait in 2017 will likely be higher than usual. A key arch of pack ice that blocks other pieces of ice from entering the strait has broken apart earlier than usual. Typically, ice arches form between Ellesmere Island and Greenland in January and break down in early July. In 2017, sensors on Nasa satellites observed a key arch breaking down in mid-May. By May 12, large pieces of sea ice had begun to break into slivers and move into the strait. By May 17, even more pack ice north of the arch had broken up.

That is not good news because an unusually warm winter means that the overall extent of Arctic sea ice between January and May 2017 had already shrunk well below the 1981-2010 median.

Early breaks of ice arches have happened in this area before. In 2007, unusually warm winter weather prevented this ice arch from forming at all. That doubled the amount of ice that flowed through the strait that year compared to the average, according to an analysis of satellite data led by Ronald Kwok of the Jet Propulsion Laboratory. While that doubling was significant, the total flow of ice through the Nares Strait that year was still just 10% of what regularly passes through the larger Fram Strait.

Corinth

Photograph: ISS/Nasa/ESA

The straight line in the centre of the image is the Corinth canal as it crosses a narrow isthmus between mainland Greece (right) and the Peloponnese peninsula. The towns of Corinth and Isthmia stand near the west and east ends. A highway crosses the canal and connects Athens to the Peloponnese. Twenty-six hundred years ago, the ruler of Corinth Periander proposed digging a canal to connect the Mediterranean (via the Gulf of Corinth) to the Aegean (via the Saronic Gulf). The goal was to save ships from the dangerous 700km voyage around the ragged coastline of the peninsula. But the canal was still too ambitious a digging project and construction was not started.

Not Julius Caesar, nor the Roman emperors Caligula or Nero, were able to complete their plans for this ambitious project. The Venetians laid plans to dig the canal in the late 1600s but they never started it. In lieu of a water passage, boats have been hauled overland for centuries on a portage created by Periander. It runs roughly along the line of the modern canal. Construction of the modern Corinth canal which is 6.4km long (4 miles) was started in 1882 and completed by 1893. The canal is narrow (only 21.3 metres), making many ships too wide for it. Landslides from the steep walls have occasionally blocked the canal, while channeled winds and tides can also make navigation difficult.

Canada

Photograph: Modis/Aqua/Nasa

With the onset of spring and warmer temperatures in the Northern Hemisphere, sea ice is thinning and breaking up along Canadas Labrador coast. On 13 May 2017, a combination of winds and currents steered the ice into the interlocking swirls.

Torrential rains caused severe flooding in Sri Lanka in late May 2017. After more than 48 hours of non-stop rain, water levels rose rapidly in the countrys south, spurring emergency evacuations in multiple districts. An earlier image taken in January 2017, shows the same area before the waters rose.

Matara was among the hardest hit towns. Low-lying areas around the Nilwala Ganga river (in blue) have also been submerged. In many areas, flooding has contaminated wells and tainted water supplies. Sri Lankas disaster management centre reported that more than half a million people have been affected by the flooding.

Rann

Photograph: Copernicus Sentinel-2A/ESA

A seasonal salt marsh known as the Rann of Kutch in western India is one of the largest salt deserts in the world.

Read more: https://www.theguardian.com/environment/2017/jun/14/satellite-eye-on-earth-may-2017-in-pictures

Sci-fi forest tracks carbon impact – BBC News

An industrial-scale experiment in a Staffordshire forest will help fill gaps in knowledge about climate change.

The project has created an outdoor laboratory by encircling trees with 25m masts gushing high levels of carbon dioxide.

The site is surrounded by a 3m anti-climb fence, and silvery tubes snake along the forest floor in what looks like a sci-fi alien invasion.

The scientists behind the experiment want to find how forests will respond to the levels of carbon dioxide expected in the atmosphere by the middle of the 21st Century.

That means full lab conditions: no food and drink in the woods, and no relieving yourself behind a tree.

Carbon locked up

The role of plants in taking up CO2 is one of the known unknowns in climatology. CO2 is a plant fertiliser and researchers think that as levels increase the trees will fix more of it into their trunks, roots and organic matter in the earth.

But they believe the fertilizing effect will be limited over time by other factors such as lack of nutrients, lack of water and rising temperatures.

Humans and forests currently participate in a mutually beneficial exchange in which trees are fed by increasing CO2, and the trees in turn lock up carbon that would otherwise remain in the atmosphere, heating the planet.

Trees are estimated to be storing between a quarter and a third of the carbon produced by burning fossil fuels, and the earth is becoming greener as a result.

One of the great imponderables in climate science is how long forests will continue to buffer climate change as CO2 levels continue to spiral.

The lead scientist in the woodland, Professor Rob Mackenzie, from Birmingham University, agreed that scientists had previously under-estimated the amount of carbon trees would fix.

But he told BBC News: “We are confident that trees will continue to take in more CO2, though we are quite sure that there will be other things that will start to limit that. Rising temperatures will (also) change the ability of plants (to absorb CO2) – they are adapted to current temperatures.”

Some scientists argue that the tree fertilization effect offers a reason to be less pessimistic about the effects of increasing CO2.

But Professor Mackenzie disagreed: “Not at all, not at all. The land is providing us with a fantastic free service by taking up carbon, and there are uncertainties about how much carbon is going into the land but there is no chance that will offset hazardous climate change.”

Hunting ground

The experiment he is leading will be one of four in different countries measuring the effect of CO2 on trees in the forest environment.

It is the first of its kind in Europe.

The woodland, named Mill Haft, is part of the former hunting ground of the Earl of Lichfield.

It covers 25 hectares and is thought to have been under continuous tree cover for more than than 300 years. The dominant species is the English oak, Quercus Robur, of around 160-180 years.

Experiments in the woods will also examine the effects of CO2 at 550ppm levels on the whole ecosystem including leaves, soil, insects and diseases.

Professor Mackenzie said: “The impact of changing CO2 should show up in the leaf chemistry of exposed trees within days, and in the soil within weeks.

“Within three years stem growth, canopy structure, and a host of other structural forest elements should be different in the patches exposed to elevated CO2.

“Continuing out to 2026, the ‘push’ provided by the elevated CO2 will pass through all the checks and balances of a mature forest ecosystem, allowing, as each year passes, increasingly better estimates to be made of the extent and capacity of the land carbon sink in 2050 and beyond.”

Stuff of dreams

He said his experiment might reveal other intriguing effects. So trees in a mature forest, in which intake and release of CO2 are in balance, might adapt to high CO2 levels by reducing their pores, which in turn would make them more tolerant to drought.

Professor Mackenzie describes the extraordinary site as “a scientist’s dream all my Christmases come at once.”

Scientists say it is vital to obtain more certainty about how much CO2 rises will be buffered by the sea and land.

Optimists hope that the ability of the natural world to soak up carbon can buy time for humans to wean themselves off fossil fuels.

A recent study estimated that the growing season had been extended on 25%-50% of vegetated land, largely as a result of more available CO2.

Carbon gesture

One of the co-authors, Professor Ranga Myneni from Boston University told BBC News: “Experiments do indicate a fertilization effect (from CO2) and higher water use efficiency. The same experiments also indicate diminishing effects over time.

“We do not know how much of what we observe in experiments translates into the real world. Much of this has to do with how nutrient limitations would play out when CO2 becomes abundant.

“Personally, I would not buy the fertilization benefit for the price of global warming and all the impacts that this warming implies, including global warming, loss of sea-ice, rise in sea level, severe storms and loss of biodiversity.”

The experiment site in Staffordshire has been funded by a Birmingham alumnus and philanthropist, Professor Joe Bradwell, who made money selling diagnostic medical kits developed at the university – mainly in the US.

Professor Mackenzie said Professor Bradwell calculated that to offset his carbon footprint he needed to plant 300,000 trees – and the research project was part of his commitment.

Follow Roger on Twitter @rharrabin

Read more: http://www.bbc.co.uk/news/science-environment-39472425

Can you judge a book by its odour?

Cocoa, wood, rusks every book has a distinctive smell. And each smell says something about how and when it was made, and where it has been.

What does it mean to experience a book? To a bibliophile such as Alberto Manguel, smell plays an important part. In a talk at the British Library this week, the one-time protege of Jorge Luis Borges and director of the National Library of Argentina said he was particularly partial to old Penguin paperbacks, which he loved for their odour of fresh rusk biscuits.

Audience members responded with their own sense impressions. Peter, a pensioner, said he experienced books as smelling of salt and pepper that dryness when you open the cupboard with a touch of the sea, while 46-year-old Donna confessed that she had recently bought a book for her young son partly because it smelled of the rain.

To conservators and historians, smell has always played an important role in assessing the origin and condition of historic books, and in working out how to look after them. I have no vocabulary to define this, but there is a curious warm leathery smell to English parchment, unlike the sharper, cooler scent of Italian skins, wrote the Cambridge University don and librarian Christopher de Hamel in his bestselling Meetings with Remarkable Manuscripts.

But that lack of vocabulary could be about to change, thanks to a groundbreaking project by researchers at UCL Institute for Sustainable Heritage, who have devised a way of relating such apparently subjective descriptions directly to the chemical composition of books. In a paper published this week in the journal Heritage Science, Cecilia Bembibre and Matija Strli describe how they analysed samples from an old book, picked up in a second-hand shop, and developed a historic book odour wheel, which connects identifiable chemicals with peoples reactions to them.

Using fibres from the novel, they produced an extract of historic book, which was presented to 79 visitors to Birmingham Museum and Art Gallery. Chocolate, cocoa or chocolatey were the most frequent words used to describe the smell of a copy of French writer Bernard Gassets 1928 novel Les Chardons du Baragan, followed by coffee, old, wood and burnt.

From the analytical perspective, and given that coffee and chocolate come from fermented/roasted natural lignin and cellulose-containing product, they share many VOCs (volatile organic compounds) with decaying paper, wrote the researchers, who combined the results with those of earlier research projects, such as studies of a 1940s visitors book at the National Trusts Knole House in Kent. Their study also took them beyond books themselves, to the places in which many of them are read: libraries. In another experiment, they asked visitors to the Wren Library in St Pauls cathedral to describe what the library smelled like to them. Everyone described its smell as woody, while 86% also experienced it as smoky, 71% as earthy and just under half (41%) reported the scent of vanilla all smells associated with particular chemicals in old books.

researcher
The smell of heritage researcher Matija Strli with his nose in a book Photograph: Supplied

The project originated in Strlis observation of the importance of smell to conservators and librarians. Librarians have told us that its the smell that hits readers first. Its the way libraries communicate, before people even get to the books; but what the books communicate through smell is also interesting. The idea is to propose a large theoretical framework of which smells hold cultural value for us as a society, he says.

Strli, a professor of heritage science at UCL, is a chemist by training. We know very well how to analyse the chemicals, but what they mean, and the emotions they trigger, is a completely different matter. For that, you need a multi-disciplinary study, he says. It wasnt until the arrival of Bembibre a PhD student with a background in communications that the project began to acquire an anthropological and cultural breadth.

Libraries such as St Paul’s, dedicated to historic books, smell different to those housing more recent literature,” says Strli. “We know that books produced before approximately 1850 have a different smell to those produced between 1850 and 1990, and that’s because late 19th- and most 20th-century printing was dominated by acid sizing the process to which pulp was subjected to reduce the water-absorbancy of paper, so that it could then be written on.”

The life of individual books also affects their smell: how far they have travelled; whether they have been kept in damp or dry environments. As De Hamel points out, some manuscripts have hardly stirred from their original shelves since the day they were completed; others have zig-zagged across the known world in wooden chests or saddle bags, swaying on the backs of horses or over the oceans in little sailing ships, or as aircraft freight.

The medieval manuscripts De Hamel was dealing with were created by hand on long-lasting parchment made from animal skins which also have their own distinctive smell. Industrialised publishing from the mid 19th-century created less-hardy books, prone to a fate that every secondhand book collector fears: foxing, the brown blotches that appear on so many old volumes. Foxing happens when small impurities left by the metal beaters used to process the paper pulp combine with fungal growth on the ageing paper.

Many people assume the blotches themselves give old books their familiar musty pong. “In fact,” says Strli, “the smell is due to the release of chemicals such as furfural and hexanol as the paper itself decays.” Hexanol is often described as smelling farmlike or of old clothing or old room, which the odour wheel consigns to a category labelled earthy/musty/mouldy.

Bembibre
Bembibre investigating the science of book smells in the lab. Photograph: National Trust/James Dobson

But foxing itself is likely to be less prevalent as manufacturing changes. In the 1980’s, the technology changed because of environmental concerns about the chlorinated chemicals emitted through the manufacture process. The happy consequence of that was that the paper became more stable again, says Strli.

The researchers believe the historic book odour wheel could become a useful diagnostic tool for conservators across a wide range of areas, helping them to assess the condition of objects through their olfactory profile. If a book smells chocolatey, its likely that it is releasing vanillin, benzaldehyde and furfural three chemicals associated with the degradation of the cellulose and lignin in paper. But the study also has wider implications, as the heritage industry grapples with a new interest in the historical importance of smell. By documenting the words used to describe a heritage smell, our study opens a discussion about developing a vocabulary to identify aromas that have cultural meaning and significance, says Bembibre.

So what can the odour wheel tell us about Manguels description of Penguin books as smelling like fresh rusk biscuits? Biscuits is a word that often comes up when describing books. Two compounds in particular: furfural (smelling of sweetness or bread) and vanillin (smelling of vanilla) could be responsible, says Bembibre. His words might indicate that the books themselves are deteriorating, but they also reveal his pleasure in them. The gift industry has long wised up to this. The British Library shop, a few metres from the theatre where Manguel was speaking, sells a candle that purports to smell of library.

“This is not just about the composition of smell itself, but about human sensibility,” Bembibre says. “By reconstructing the smell and assessing the human reaction to it, we will be able to work out what it is that we want to preserve.”

Read more: https://www.theguardian.com/books/2017/apr/07/the-smell-of-old-books-science-libraries

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