Heavy yellow dust hits S. Korea, warnings issued

The heaviest yellow dust in five years hit South Korea on Monday, driving the country's meteorological authorities to issue yellow dust warnings and advisories.

As of 10 a.m. local time, yellow dust warnings were in place in capital Seoul, Incheon, Gyeonggi Province and part of Gangwon Province, according to the Korea Meteorological Administration. Dust advisories were issued for most other parts of the country.

The yellow dust warnings are issued when a per-hour fine dust concentration of more than 800 micrograms per cubic meter is expected to last for more than two hours. More than 400 micrograms per cubic meter leads to dust advisories in place.

The concentration of atmospheric "particulate matter (PM)-10," which measures fine dust concentration, in Seoul surged to 1,044 micrograms per cubic meter as of 4 a.m., the highest since Dec. 25, 2009 when it recorded 963 micrograms per cubic meter. PM-10 refers to airborne particles less than 10 micrometers in diameter.

As of 1 p.m., the Seoul metropolitan government revised down the dust warning to dust advisory, but the sandy wind is expected to stay until Tuesday.

People are advised to stay indoors and to wear protective spectacles and masks when going outside.
  Source: Xinhua - globaltimes.cn
23/2/15

China's unmanned lunar orbiter returns home, first in nearly four decades

BEIJING, Nov. 1 (Xinhua) -- China succeeded Saturday in the world's first mission to the Moon and back in some 40 years, becoming the third nation to do so after the former Soviet Union and the United States.

The test lunar orbiter, nicknamed "Xiaofei" on Chinese social networks, landed in Siziwang Banner of China's Inner Mongolia Autonomous Region early Saturday morning.

Search teams have already recovered the orbiter at the designated landing area, about 500 kilometers away from Beijing.

The last documented mission of this kind was by the Soviet Union in the 1970s.

Launched Friday last week, the orbiter traversed 840,000 kilometers on its eight-day mission that saw it round the far side of the Moon and take some incredible pictures of Earth and Moon together.

The re-entry process began at around 6:13 a.m. Saturday morning, with the orbiter approaching Earth at a velocity of about 11.2 kilometers per second.

The high speed led to hefty friction between the orbiter and air and high temperatures on the craft's exterior, generating an ion sheath that cut off contact between ground command and the orbiter.

To help it slow down, the craft is designed to "bounce" off the edge of the atmosphere, before re-entering again. The process has been compared to a stone skipping across water, and can shorten the "braking distance" for the orbiter, according to Zhou Jianliang, chief engineer with the Beijing Aerospace Command and Control Center.

"Really, this is like braking a car," said Zhou, "The faster you drive, the longer the distance you need to bring the car to a complete stop."

• The "bounce" was one of the biggest challenges of the mission, because the craft must enter the atmosphere at a very precise angle. An error of 0.2 degrees would have rendered the mission a failure.

Wu Yanhua, vice director of China's State Administration of Science, Technology and Industry for National Defense, said the successful test mission has gathered a lot of experimental data and laid a solid foundation for future missions.`.......................http://news.xinhuanet.com/english/china/2014-11/01/c_133757831.htm
1/11/14

NASA spacecraft seeks answers to lost water in Mars. (Mars Atmosphere and Volatile Evolution/MAVEN)

A NASA spacecraft designed to investigate how Mars lost its water is expected to put itself into orbit around the Red Planet today after a 10-month journey....

After traveling 711 million km from Earth, the Mars Atmosphere and Volatile Evolution, or MAVEN, probe faces a do-or-die burn of its six braking rockets beginning.
If successful, the thruster burns will trim enough speed for MAVEN to be captured by Mars' gravity and fall into a looping orbit.

Over the next six weeks, as engineers check MAVEN's nine science instruments, the spacecraft will maneuver itself into an operational orbit that comes as close as 150 km and as far away as 6,200 km from Mars' surface.

• Unlike previous Mars orbiters, landers and rovers, MAVEN will focus on the planet's atmosphere, which scientists suspect was once far thicker than the puny envelope of mostly carbon dioxide gas that surrounds it today.

Denser air would be needed for water to pool on the surface. While no water appears there today, Mars is covered with ancient river channels, lakebeds and chemical evidence of a warmer, wetter past.

• "Where did the water go? Where did the CO2 (carbon dioxide) go from that early environment?" MAVEN lead science Bruce Jakosky, of the University of Colorado, asked reporters this week. "It can go two places: down in the crust or up to the top of the atmosphere where it can be lost to space," he said.

• MAVEN's focus is the latter. The spacecraft, built by Lockheed Martin, will spend a year monitoring what happens when the solar wind and other charged particles hit the upper layers of Mars' atmosphere, stripping it away.

By studying the atmosphere today, scientists expect to learn about the processes involved and then use computer models to extrapolate back in time. Ultimately, scientists want to learn if Mars had the right conditions for life to evolve.
MAVEN, said Jakosky, will tell them "the boundary conditions that surround the potential for life."
MAVEN will join a fleet of two US orbiters, two US rovers and a European orbiter currently working at Mars. India's first Mars probe is due to arrive on Wednesday.
buenosairesherald.com
21/9/14
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• NASA rover discovers lake on Mars(10/12/14)

• NASA to Look at Climate Change - On Mars (18/11/13)

 

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UN Says Ozone Layer Might Recover by 2050

The Earth's protective ozone layer may fully recover in the next few decades thanks to harmonized international action against ozone depleting substances, a new assessment by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) reads.
"There are positive indications that the ozone layer is on track to recovery towards the middle of the century. The Montreal Protocol - one of the world's most successful environmental treaties - has protected the stratospheric ozone layer and avoided enhanced UV radiation reaching the earth's surface," said UN Under-Secretary-General and UNEP Executive Director Achim Steiner in a press-statement Wednesday.

Scientific Assessment of Ozone Depletion 2014 carried out by 300 scientists has found out that actions taken under the Montreal Protocol are enabling the return of the ozone layer to benchmark 1980 levels, as they led to a significant decrease in substances causing greenhouse effect. Moreover, according to UNEP, the Protocol will have prevented 2 million cases of skin cancer annually by 2030, averted damage to human eyes and immune systems, and protected wildlife and agriculture.
However, the report also warns that the rapid increase in certain substitutes for these substances, which are themselves also potent greenhouse gases, has the potential to undermine the gains.
The stratospheric ozone layer is a fragile shield of gas that protects the Earth from harmful ultraviolet rays of the sun. The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for its depletion.
The treaty entered into force in 1989 and is ratified by 196 countries, including Russia. Without the Montreal Protocol and associated agreements, atmospheric levels of ozone depleting substances could have increased tenfold by 2050, according to UNEP.
[en.ria.ru]
11/9/14
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Related:

• Mysterious source of ozone-depleting chemical baffles NASA / La Nasa a détecté une substance détruisant la couche d'ozone en quantité inexpliquée

• La couche d’ozone stratosphérique est toujours convalescente, mais les scientifiques espèrent sa guérison avant 2050 dans la plupart des régions et une résorption complète du célèbre « trou dans la couche d’ozone » au-dessus de l’Antarctique vers la fin du siècle.

L’Organisation météorologique mondiale (OMM) et le Programme des Nations unies pour l’environnement (PNUE) ont rendu publiques, mercredi 10 septembre, les conclusions de leur dernier rapport sur la couche d’ozone.

Encourageantes, celles-ci entérinent le succès du protocole de Montréal, adopté en 1987 par la communauté internationale pour protéger l’ozone stratosphérique.

Considéré comme un polluant lorsqu’il s’accumule au niveau du sol, l’ozone revêt au contraire une importance cruciale au sommet de l’atmosphère, où il joue le rôle de filtre à ultraviolets (UV).

UNE STABILISATION DEPUIS LE DÉBUT DES ANNÉES 2000

Les mesures prises dans le cadre du protocole de Montréal ont permis de bannir la plupart des composés chlorés et bromés responsables du célèbre « trou d’ozone » en Antarctique.

Mis à jour tous les quatre ans, le rapport indique que leur concentration atmosphérique a baissé de 10 % à 15 % par rapport au pic de la fin des années 1990.

Seul un composé, le tétrachlorure de carbone (CCl4), atteint des concentrations trop élevées par rapport aux émissions déclarées par les Etats.

Globalement, l’effet positif est cependant déjà tangible puisque les scientifiques notent une stabilisation du fragile bouclier anti-UV depuis le début des années 2000.

« On voit même l’ozone augmenter un peu dans la haute stratosphère, au niveau des latitudes moyennes de l’hémisphère Nord, explique Sophie Godin-Beekmann, chercheuse au CNRS et coauteure du rapport rendu par le PNUE et l’OMM. Au-dessus de l’Antarctique, on n’observe pas encore de franche remontée.»..........................................http://www.lemonde.fr/pollution/article/2014/09/10/la-couche-d-ozone-en-bonne-voie-de-guerison_4485413_1652666.html
11/9/14

UN: Greenhouse Gases Hit Record Levels Last Year. (Large percentage of carbon dioxide emissions are absorbed by the oceans)

The United Nations says surging carbon dioxide emissions sent greenhouse gases in the atmosphere to record levels last year.

In its annual report on greenhouse gas concentrations released Tuesday, the World Meteorological Organization (WMO) said carbon dioxide levels between 2012 and 2013 marked the largest yearly increase since reliable global records began 30 years ago.

A large percentage of carbon dioxide emissions are absorbed by the oceans.


In a statement accompanying the report, WMO chief Michel Jarraud warned that "past, present and future carbon dioxide emissions will have a cumulative impact on global warming and ocean acidification." He said the "laws of physics are non-negotiable."

Many scientists believe that increased greenhouse gases are responsible for global warming, or the warming of the atmosphere. Jarraud has said there is no doubt that global temperatures are rising.
http://www.voanews.com/content/un-greenhouse-gases-hit-record-levels/2443400.html
9/9/14
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Related:

• Ρεκόρ επιπέδου συγκέντρωσης αερίων του «θερμοκηπίου»/Greenhouse gas in atmosphere hits new record. -World Meteorological Organization (WMO)

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• Μείωση των εκπομπών από τις μονάδες λιθάνθρακα υπόσχεται το σχέδιο Ομπάμα

• Οι Μεγάλες Πετρελαϊκές Ευθύνονται για Τεράστιο Μέρος των Εκπομπών Αερίων του Θερμοκηπίου.

• Τελευταία Ελπίδα για το CCS από την Κομισιόν

Mysterious source of ozone-depleting chemical baffles NASA / La Nasa a détecté une substance détruisant la couche d'ozone en quantité inexpliquée

WASHINGTON: A chemical used in dry cleaning and fire extinguishers may have been phased out in recent years but NASA said Wednesday (Aug 20) that carbon tetrachloride (CCl4) is still being spewed into the atmosphere from an unknown source. The world agreed to stop using CC14 as part of the Vienna Convention on Protection of the Ozone Layer and its Montreal Protocol, which attained universal ratification in 2009.
"Parties to the Montreal Protocol reported zero new CCl4 emissions between 2007-2012," the US space agency said in a statement. "However, the new research shows worldwide emissions of CCl4 average 39 kilotons per year, approximately 30 per cent of peak emissions prior to the international treaty going into effect."

CC14 levels are not enough to reverse the decreasing trend of ozone-depletion, but experts are still mystified as to where it is coming from. With no new reported emissions, atmospheric concentrations of the compound should have declined at an expected rate of four per cent per year since 2007.

However, observations from the ground showed atmospheric concentrations were only declining one per cent per year.

"We are not supposed to be seeing this at all," said Qing Liang, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "It is now apparent there are either unidentified industrial leakages, large emissions from contaminated sites, or unknown CCl4 sources."

Researchers used NASA's 3-D GEOS Chemistry Climate Model and data from global networks of ground-based observations to establish the first estimate of average global CC14 emissions from 2000 to 2012. In going through the data, researchers also learned that the chemical stays in the atmosphere were 40 per cent longer than previously thought.
"People believe the emissions of ozone-depleting substances have stopped because of the Montreal Protocol," said Paul Newman, chief scientist for atmospheres at NASA. "Unfortunately, there is still a major source of CCl4 out in the world."
The study was published in the journal Geophysical Research Letters.

- AFP/ac

http://www.channelnewsasia.com/news/lifestyle/mysterious-source-of/1322804.html

21/8/14

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• La Nasa a détecté une substance détruisant la couche d'ozone en quantité inexpliquée...

La Nasa a détecté en quantité inexpliquée dans l'atmosphère du tétrachlorure de carbone(CC14), une substance chimique qui détruit la couche d'ozone et qui est proscrite dans le monde depuis près de 30 ans, a indiqué mercredi l'agence spatiale.
Le CCl4, qui était utilisé dans les extincteurs ou par les pressings pour le nettoyage à sec, a été interdit en 1987 en même temps que les chlorofluorocarbones dans le cadre du Protocole de Montréal. Les pays membres de ce protocole n'ont annoncé aucune nouvelle émission de CC14 entre 2007 et 2012. Mais l'étude de la Nasa montre que les émissions mondiales de ce polluant sont en moyenne de 39.000 tonnes par an, soit environ 30% du volume maximum jamais enregistré avant l'entrée en vigueur du Protocole international. "Nous ne devrions pas avoir tout ce CC14", a lancé Qing Liang, un scientifique de la Nasa au Centre Goddard des vols spatiaux dans le Maryland (est) et principal auteur de cette recherche. "Il est clair que nous sommes en présence soit de fuites industrielles non identifiées, soit d'émissions importantes de sites contaminés ou de sources inconnues de CCl4", a-t-il ajouté. Les scientifiques et autorités règlementaires veulent savoir d'où vient ce CC14, qui comptait en 2008 pour environ 11% du chlore contribuant à la diminution de la couche d'ozone. Depuis près de dix ans, les scientifiques s'interrogent sur les raisons pour lesquelles les niveaux observés de CCl4 dans l'atmosphère diminuent plus lentement qu'anticipé en fonction des processus naturels connus de sa destruction, comme le rayonnement solaire. "Existe-t-il un mécanisme de perte de CCl4 que nous ne comprenons pas ou y aurait-il des sources d'émission non signalées ou non identifiées", s'est interrogé Qing Liang. Sans aucune émission de CCl4 signalée entre 2007 et 2012, les concentrations atmosphériques de cet agent chimique auraient dû diminuer de 1 à 4% par an, ont relevé les scientifiques, soulignant que des observations depuis le sol montrent une diminution de seulement 1% chaque année. (Belga)  
http://www.rtl.be/info/monde/international/1118038/la-nasa-a-detecte-une-substance-detruisant-la-couche-d-ozone-en-quantite-inexpliquee
21/8/14
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France limits vehicle use in Paris amid pollution

PARIS, March 15 (Xinhua) -- The French government on Saturday decided to limit vehicle use in Paris and suburbs on next Monday after air pollution reached high levels in several regions in France.
In a statement posted on Matignon website, Prime Minister Jean-Marc Ayrault decided to set a system of "alternating traffic" in Paris and suburbs in March 17 from 5:30 a.m. (0430 GMT) as pollution was expected to continue unabated through the weekend.
"We forecast an improvement in the situation tomorrow. However, the forecasts show a rise in pollution from Sunday night and on Monday and Tuesday," Ayrault's office said.

The prime minister said limiting vehicles' use was "necessary" to deal with the new peak of air pollution despite the "difficulties that this measure may cause to the everyday lives of Parisians."
Following recurring spikes in French air pollution, the government offered free public transport over the weekend while Parisians were called to use Velib and Autolib, public sharing services of bicycle and electric cars.
Adding to that, officials recommended to reduce driving speeds, avoid intense physical activity and outdoor walks with children under six years old, and a prohibition against lighting fires outside.
According to Ecology Minister Philippe Martin, France would implement a plan of atmosphere protection in the next few months.
"By the summer, the most affected areas will be the subject of atmosphere protection plan that will provide appropriate measures: reducing emissions from construction sites, transfer of companies and administrations and reducing traffic speeds on certain sections of high-traffic," the minister told the daily Liberation.
On Saturday, the Airparif Association, an environmental body responsible for monitoring air quality of Ile-de-France, expected the pollution index to be high for the fifth consecutive day at 90 due to increased pollutant of PM10.
The increase in pollution level was caused by searing temperatures heating up traffic and industrial pollutants and the hot air re-circulating slowly across densely populated north France and the capital. 
 http://english.cntv.cn/20140316/100878.shtml
16/3/14

NASA to Look at Climate Change - On Mars

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The U.S. space agency, NASA, expects to launch its next mission to Mars on Monday, sending an orbiter to look at the red planet's upper atmosphere.

Scientists hope that MAVEN, which stands for Mars Atmosphere and Volatile Evolution, can help them better understand what happened to cause Earth's neighbor to lose its surface water and its atmosphere to thin. The causes of the dramatic climate changes on Mars over billions of years - from warm with liquid water on its surface to today's cold and barren desert world - have not previously been studied.

The spacecraft is set to launch from Cape Canaveral at 13:28 EST. Weather forecasters say there is a 60 percent chance that conditions will be good for the launch.

MAVEN will not arrive at its Mars orbit until September 22, 2014. At that point, the 2.5-meter cube will extend its gull-wing-shaped solar panels and begin its data collection.
 voanews.com
18/11/13

Photo, Video: voanews.com