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Geography & Environment / Another Hole in the Ozone Layer? Climate Change May Be to Blame

« on: May 28, 2020, 09:26:38 PM »

You may have heard about the hole in the ozone layer, which hovers over Antarctica. It has shrunk over time thanks to policies that curbed the use of ozone-depleting chemicals. In the nearly 40 years that NASA has kept track, it has never been smaller. That's the good news.

The bad news is that a separate hole in the ozone layer briefly opened up in the Arctic in March before closing in April, and climate change may be partly to blame.

This isn't the first such rift to develop in the Arctic, but it is the largest. Scientists say that in March, a stratospheric polar vortex — a band of strong, frigid winds circling the pole — corralled chlorine and bromine that chewed away at the ozone layer. Scientists said that climate change may have set the stage for a colder, and thus more powerful, polar vortex.

"In those years when a vortex can spin and set itself up and be undisturbed, it's getting colder and colder," said Ross Salawitch, a climate scientist at the University of Maryland. Cold air strengthens polar vortexes, allowing them to deal more damage to the ozone layer, he said.

This year's Arctic polar vortex was unusually strong and long-lived, helping to deplete the ozone layer. At the same time, currents that would normally deliver ozone from surrounding areas were stagnant. The bruising was far less severe than what is typically seen over the South Pole, though. At the South Pole, stratospheric polar vortexes are reliably strong thanks to the extreme cold, so the ozone layer regularly thins.

In a stratospheric polar vortex, high-altitude clouds form from trace gasses in the atmosphere. Pollutants containing chlorine and bromine are essentially benign until they run into one of these clouds. Then they transform into chemicals capable of terrorizing the ozone layer.

They still need sunlight to do their dirty work, however. That comes at the start of spring —around September in the Southern Hemisphere and around March in the Northern Hemisphere. As the days get longer, these chemicals react with sunlight to deplete stratospheric ozone.

Because Antarctica is so isolated from the rest of the world, a strong polar vortex can form undisturbed. That's not the case in the Arctic, where the mix of land and water surrounding the North Pole produces more dynamic weather that can weaken or disrupt a polar vortex.

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Geography & Environment / Arctic Sea Ice

« on: May 28, 2020, 09:19:03 PM »

Please click the link below:
http://nsidc.org/arcticseaicenews/

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Environmental Science and Disaster Management / Daffodil International University (DIU) signs MoU with Bangladesh Atomic Energy

« on: April 26, 2018, 12:34:02 AM »

Please click the following link:

http://news.daffodilvarsity.edu.bd/1338-daffodil-international-university-diu-signs-mou-with-bangladesh-atomic-energy-commission-to-strengthen-education-and-research.html

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Environmental Science and Disaster Management / Wind, sea ice patterns point to climate change in western Arctic

« on: March 22, 2018, 04:59:15 PM »

A major shift in western Arctic wind patterns occurred throughout the winter of 2017 and the resulting changes in sea ice movement are possible indicators of a changing climate, says Kent Moore, a professor of physics at the University of Toronto Mississauga.

Thanks to data collected by buoys dropped from aircraft onto the Arctic Ocean's sea ice, Moore and colleagues at the University of Washington, where he spent the year as the Fulbright Visiting Chair in Arctic Studies, were able to observe this marked, anomalous shift in Arctic wind patterns and sea ice movement during the winter of 2017.

Their study is published in Geophysical Research Letters.

Usually, the western Arctic has relatively stable weather during the winter; it is home to a quasi-stationary region of high pressure known as the Beaufort High, which promotes "anti-cyclonic" winds that travel in a clockwise direction and move sea ice along with it. By contrast, the eastern Arctic has a more dynamic climate where cyclones are a common winter phenomenon with storms moving from Greenland towards Norway and the Barents Sea.

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Environmental Science and Disaster Management / In pictures: amazing Airbnb homes for families

« on: July 30, 2017, 07:43:14 PM »

https://www.theguardian.com/airbnb-families/gallery/2017/may/15/in-pictures-amazing-airbnb-homes-for-families

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Environmental Science and Disaster Management / Polluted air 'poisoning thousands' across north of England, warns report

« on: July 30, 2017, 07:41:12 PM »

Dangerous levels of air pollution in towns and cities across the north of England are threatening the health of hundreds of thousands of people and stifling economic growth, according to a new report.

The analysis by the Institute for Public Policy Research (IPPR) North describes air pollution as “the tobacco of the 21st century” and says that while there has been a growing concern about the problem in London, many residents in regional towns and cities are unaware of the threat to their health.

Darren Baxter, researcher at IPPR North, said it was time the government took radical action.


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“Too often the attention focuses on unclean air in the capital, but the reality is that it’s poisoning thousands in our regional cities too,” said Baxter. “Michael Gove [the new environment secretary] must show that the government is not prepared to sit on its hands while up to 40,000 people are killed every year from dirty air. We need to see radical plans to ditch diesel, introduce incentives for electric cars and bring in clean air zones in our major cities.”

The government has suffered two legal defeats over its plans to improve air quality in the UK after judges ruled they were so poor as to be unlawful. The courts have given ministers until 31 July to publish a new plan.

Campaigners want Gove to introduce a range of measures including charging clean air zones in the worst hit areas and a diesel scrappage scheme to compensate drivers who bought diesel cars after being told they were better for the environment.

The government’s own figures show that although London has by far the highest level of nitrogen dioxide (NO2) pollution, many urban areas – including large swaths of the Midlands, the north-west, West Yorkshire and the northeast – suffer dangerous levels of pollution.

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Environmental Science and Disaster Management / UK-built pollution monitoring satellite ready for launch

« on: July 30, 2017, 07:39:21 PM »

Last year, the European Space Agency launched the Trace Gas Orbiter to Mars. It is designed to look for methane – a key tracer of life – to determine if Martian microbes are present on the red planet.

Now, ESA is preparing to launch another spacecraft to look at methane on another planet: our own.

The UK-built Sentinel-5P, a pollution monitoring satellite, is ready to begin its journey from Airbus Defence and Space, Stevenage, to the Plesetsk Cosmodrome, Russia, where it will lift off in late September/early October.

Sentinel-5P is part of the Copernicus global monitoring programme, a joint venture between the European Commission and the European Space Agency. This particular spacecraft is the first Copernicus satellite dedicated to monitoring atmospheric chemistry.

Missions like this are essential for making the connection between space and everyday life on Earth, according to Colin Paynter, Managing Director of Airbus Defence and Space, UK. He says, “Space is not just for geeks, it is part of our national and international infrastructure.”

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Environmental Science and Disaster Management / The Environmental Protection Agency is not the nation's janitor

« on: July 30, 2017, 07:38:29 PM »

The Environmental Protection Agency’s new administrator, Scott Pruitt, has called for a “back-to-basics” or “originalist” approach to the agency. It is unclear what he means, but in a 22 May memo he said he would prioritize the EPA’s program that handles heavily contaminated waste areas, known as “Superfund sites”.

In the memo, Pruitt heralds that under his administration, “Superfund and the EPA’s land and water cleanup efforts will be restored to their rightful place at the center of the agency’s core mission”.


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For Pruitt, the primary role of the EPA is janitorial: using taxpayer money to clean up after polluting industries. But that is neither how the EPA was originally envisaged, nor how the Superfund program was conceived.

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Environmental Science and Disaster Management / Linear parks and the drive to ease congestion

« on: July 30, 2017, 07:37:48 PM »

You would think that ending a traffic restriction would improve journey times, but the sudden termination of Jakarta’s high-occupancy vehicle (HOV) lanes had the opposite effect. To use these lanes drivers required two passengers, but a trade in hiring people bought the lanes to an abrupt end last year. The traffic could spread across all lanes, but journey times and congestion increased. In fact, traffic worsened over the whole network almost immediately. Even on roads with no HOV lanes, at times when the lanes had not operated, delays increased by up to two minutes per km. The US embassy measures air quality from its roof in Jakarta. It is too early to see the changes, but we can be sure that it did not get better.

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Environmental Science and Disaster Management / Earth is becoming 'Planet Plastic'

« on: July 30, 2017, 07:35:03 PM »

US scientists have calculated the total amount of plastic ever made and put the number at 8.3 billion tonnes.
It is an astonishing mass of material that has essentially been created only in the last 65 years or so.
The 8.3 billion tonnes is as heavy as 25,000 Empire State Buildings in New York, or a billion elephants.
The great issue is that plastic items, like packaging, tend to be used for very short periods before being discarded.
More than 70% of the total production is now in waste streams, sent largely to landfill - although too much of it just litters the wider environment, including the oceans.
"We are rapidly heading towards 'Planet Plastic', and if we don't want to live on that kind of world then we may have to rethink how we use some materials, in particular plastic," Dr Roland Geyer told BBC News.

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Environmental Science and Disaster Management / Clean water finally flows to transform lives of tea pickers in Bangladesh

« on: July 30, 2017, 07:34:17 PM »

In tea country around Sylhet, conditions for workers such as Bina – descendants of labourers imported by the British during the 19th century from what is now India – have long been as wretched as the landscape is enchanting.

The estates are the only world they know, run by managers overseeing business from hilltop, British-era bungalows in semi-feudal operations that have changed little since colonial days.


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Isolated by geography, as well as by their Hindu culture in the predominantly Muslim country, Bangladesh’s tea pickers are among the most excluded and marginalised communities, earning 85 taka (barely $1) for a day of back-breaking work.
Look at the following link for further information.
https://www.theguardian.com/global-development/2017/mar/14/clean-water-finally-flows-to-transform-lives-tea-pickers-bangladesh-surma-valley

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Environmental Science and Disaster Management / Child labourers exposed to toxic chemicals dying before 50, WHO says

« on: July 30, 2017, 07:32:54 PM »

Children as young as eight, working in the tanneries of Bangladesh producing leather that is in demand across Europe and the USA, are exposed to toxic chemical cocktails that are likely to shorten their lives, according to a new report.

Approximately 90% of those who live and work in the overcrowded urban slums of Hazaribagh and Kamrangirchar, where hazardous chemicals are discharged into the air, streets and river, die before they reach 50, according to the World Health Organisation.


The river runs black: pollution from Bangladesh's tanneries – in pictures
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Their plight spurred the volunteer doctors of Médecins Sans Frontières (MSF) to set up clinics in the area to diagnose and treat those who are the victims of their workplace. It is, says a paper published in BMJ Case Reports, “the first time they have intervened in an area for reasons other than natural disasters or war”.

MSF’s intervention was triggered by “the widespread industrial negligence and apathy of owners of tanneries and other hazardous material factories” towards the more than 600,000 largely migrant population who have no access to government-funded healthcare.

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Environmental Science and Disaster Management / Galaxy Zoo: Citizen science trailblazer marks tenth birthday

« on: July 30, 2017, 07:32:18 PM »

Galaxy Zoo began with a call for volunteers to help classify distant galaxies in space telescope images. The collaborative project made spectacular discoveries, spawning a family of similar projects - collectively known as the Zooniverse. We look back on 10 years of a citizen science phenomenon.
It started with a strange blue smudge on a computer screen.
Now that mysterious blob, spotted by a Dutch primary school teacher during a few idle hours one evening, has become one of the most remarkable recent discoveries in astronomy.
Hanny's Voorwerp, named after its discoverer Hanny van Arkel, is providing scientists with a striking new window on the universe.
They have found these distant clouds of glowing gas provide a kind of time capsule that can reveal what their neighbouring galaxies have been doing in the previous few thousand years.
For Miss van Arkel, it is fitting for the object that now bears her name to be providing such insights - it marks 10 years since she first encountered it during her summer break from teaching.
She had been taking part in a citizen science project called Galaxy Zoo, which asked members of the public to classify different types of galaxies from images taken by robotic telescopes.

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Environmental Science and Disaster Management / Fossil site shows impact of early Jurassic's low oxygen oceans

« on: July 16, 2017, 03:26:43 PM »

Using a combination of fossils and chemical markers, scientists have tracked how a period of globally low ocean-oxygen turned an Early Jurassic marine ecosystem into a stressed community inhabited by only a few species.

The research was led by Rowan Martindale, an assistant professor at The University of Texas at Austin Jackson School of Geosciences, and published in print in Palaeogeography, Palaeoclimatology, Palaeoeconology on July 15. The study was co-authored by Martin Aberhan, a curator at the Institute for Evolution and Biodiversity Science at the Natural History Museum in Berlin, Germany.

The study zeroes in on a recently discovered fossil site in Canada located at Ya Ha Tinda Ranch near Banff National Park in southwest Alberta. The site records fossils of organisms that lived about 183 million years ago during the Early Jurassic in a shallow sea that once covered the region.
The fossil site broadens the scientific record of the Toarcian Oceanic Anoxic Event, a period of low oxygen in shallow ocean waters which is hypothesized to be triggered by massive volcanic eruptions. The Oceanic Anoxic Event was identified at this site by the geochemical record preserved in the rocks. These geochemical data were collected in a previous research project led by Benjamin Gill and Theodore Them of Virginia Tech. The oxygen level of the surrounding environment during the Early Jurassic influences the type and amount of carbon preserved in rocks, making the geochemical record an important method for tracking an anoxic event.

"We have this beautiful geochemical record that gives us a backbone for the timing of the Oceanic Anoxic Event," said Martindale, a researcher in the Jackson School's Department of Geological Sciences. "So with that framework we can look at the benthic community, the organisms that are living on the bottom of the ocean, and ask 'how did this community respond to the anoxic event?"

The fossils show that before the anoxic event, the Ya Ha Tinda marine community was diverse, and included fish, ichthyosaurs (extinct marine reptiles that looked like dolphins), sea lilies, lobsters, clams and oysters, ammonites, and coleoids (squid-like octopods). During the anoxic event the community collapsed, restructured, and the organisms living in it shrunk. The clams that were most abundant in the community before the anoxic event were completely wiped out and replaced by different species.

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Environmental Science and Disaster Management / Earth's magnetic field 'simpler than we thought'

« on: July 16, 2017, 03:25:49 PM »

Scientists have identified patterns in Earth's magnetic field that evolve on the order of 1,000 years, providing new insight into how the field works and adding a measure of predictability to changes in the field not previously known.

The discovery also will allow researchers to study the planet's past with finer resolution by using this geomagnetic "fingerprint" to compare sediment cores taken from the Atlantic and Pacific oceans.

Results of the research, which was supported by the National Science Foundation, were recently published in Earth and Planetary Science Letters.

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the "solar wind") would blow away the atmosphere, scientists say. The field also aids in human navigation and animal migrations in ways scientists are only beginning to understand. Centuries of human observation, as well as the geologic record, show our field changes dramatically in its strength and structure over time.
Yet in spite of its importance, many questions remain unanswered about why and how these changes occur. The simplest form of magnetic field comes from a dipole: a pair of equally and oppositely charged poles, like a bar magnet.

"We've known for some time that Earth is not a perfect dipole, and we can see these imperfections in the historical record," said Maureen "Mo" Walczak, a post-doctoral researcher at Oregon State University and lead author on the study. "We are finding that non-dipolar structures are not evanescent, unpredictable things. They are very long-lived, recurring over 10,000 years -- persistent in their location throughout the Holocene.

"This is something of a Holy Grail discovery," she added, "though it is not perfect. It is an important first step in better understanding the magnetic field, and synchronizing sediment core data at a finer scale."

Some 800,000 years ago, a magnetic compass' needle would have pointed south because Earth's magnetic field was reversed. These reversals typically happen every several hundred thousand years.

While scientists are well aware of the pattern of reversals in Earth's magnetic field, a secondary pattern of geomagnetic "wobble" within periods of stable polarity, known as paleomagnetic secular variation, or PSV, may be a key to understanding why some geomagnetic changes occur.
Earth's magnetic field does not align perfectly with the axis of rotation, which is why "true north" differs from "magnetic north," the researchers say. In the Northern Hemisphere this disparity in the modern field is apparently driven by regions of high geomagnetic intensity that are centered beneath North America and Asia.

"What we have not known is whether this snapshot has any longer-term meaning -- and what we have found out is that it does," said Joseph Stoner, an Oregon State University paleomagnetic specialist and co-author on the study.

When the magnetic field is stronger beneath North America, or in the "North American Mode," it drives steep inclinations and high intensities in the North Pacific, and low intensities in Europe with westward declinations in the North Atlantic. This is more consistent with the historical record.

The alternate "European mode" is in some ways the opposite, with shallow inclination and low intensity in North Pacific, and eastward declinations in the North Atlantic and high intensities in Europe.

"As it turns out, the magnetic field is somewhat less complicated than we thought," Stoner said. "It is a fairly simple oscillation that appears to result from geomagnetic intensity variations at just a few recurrent locations with large spatial impacts. We're not yet sure what drives this variation, though it is likely a combination of factors including convection of the outer core that may be biased in configuration by the lowermost mantle."