Environment Archives

February 20, 2009December 24, 2015 by Tammy Plotner

Earth Hour 2009 – Where Will You Be When The Lights Go Out?

With less than six weeks to go, more than 500 cities around the world have officially agreed to go dark in support of global action on climate change. On March 28, 2009 at 8:30 p.m., local time, World Wildlife Fund is asking individuals, businesses, governments and organizations around the world to turn off their lights for one hour — Earth Hour — to make a global statement of concern about climate change and to demonstrate their commitment to finding solutions. Step inside and find out how you can become a part of this historic event…

Wherever you happen to be in the world on March 28th at 8:30 p.m., you’re likely to find a city or community somewhere nearby that is making plans to turn out the lights for Earth Hour – a global goal of 1,000 cities! WWF’s initiative aims to increase awareness about climate change and demonstrate that people from all over the world care about the issue. “Climate change and what we do about it is going to transform the world much more rapidly than people realize.” say Richard Moss, Vice President and Managing Director for Climate Change. “It’s my goal to get us moving to a world we will want, not one we’ll regret leaving for our children and grandchildren.”

Before you start knocking “Earth Hour” as something that just won’t make a difference, take just a moment of your time and watch this, please…

And now, here are some highlights of what’s going on around Earth Hour 2009 as we count down the days…

NASHVILLE: Earth Hour launched in Music City with a musical press conference that included live performances by Nashville superstars pledging to turn out against climate change.

THE STARS AND STRIPES ARE ALIGNING: Houston, TX; Santa Rosa, CA; St Louis, MO; Sarasota, FL; Minneapolis, MN; and Valdosta, GA signed up to be part of Earth Hour 2009. They join Atlanta, Chicago, Dallas, Las Vegas, Los Angeles, Miami, Nashville, New York City and San Francisco.

NOBEL PEACE PRIZE WINNER ARCHBISHOP DESMOND TUTU ANNOUNCES HIS SUPPORT: “Climate change is the greatest human induced crisis facing the world today. It is totally indiscriminate of race, culture and religion. It affects every human being on the planet. Earth Hour is an opportunity for every man, woman and child from all corners of the globe to come together with a united voice and make a loud and powerful statement on the issue of climate change.”

BACK TO MY OLD SCHOOL: The University of Miami became the first American campus to officially sign up to turn off, but was quickly joined by Michigan State, University of Nevada, Las Vegas, University of Virginia, Belmont, Columbia, Ohio University, Howard University, Georgia Tech, Northwestern, Spellman, University of Missouri, St. Louis and Vanderbilt.

I GOT THE POWER: 10,000 college students from across the nation will converge on Washington DC on February 27–March 2 for Power Shift ’09, asking for “bold, comprehensive and immediate federal climate action.” Earth Hour Project Director Meg Pearce and Campus Organizer Sophie Latham will be there holding a special session on how to be part of Earth Hour 2009, the largest global climate event in history.

CITY OF LIGHTS TO TURN LIGHTS OFF IN SUPPORT OF WWF’S EARTH HOUR 2009: Paris—known as the City of Lights—will lead a list of 28 cities and towns across France that have committed to join the world in making a visual vote for decisive action on climate change by turning off their lights for one hour during Earth Hour 2009 on March 28th.

LAS VEGAS FLICKS THE SWITCH FOR EARTH HOUR 2009: Officials from World Wildlife Fund joined Clark County, Nevada Commissioner Lawrence Weekly, City of Las Vegas Mayor Oscar B. Goodman and City of Henderson Mayor James B. Gibson at the iconic “Welcome to Fabulous Las Vegas” sign to officially kick off the Las Vegas Valley’s participation in Earth Hour–a global event calling for action on climate change.

For now? Be sure to visit the Earth Hour website, where you can sign up to show your support and find all kinds of wonderful tools and ideas on how to motivate your community, school, family and friends to pledge just one hour of their time to darkness and become part of this global event.

Don’t forget to mark your calendar…Earth Hour is March 28, 2009, at 8:30 pm. Be there with us when the lights go out…

February 18, 2009December 24, 2015 by Anne Minard

NASA Study Predicted Outbreak of Deadly Virus

Scientists have long suspected that climatic variables like sea surface temperature and precipitation could foreshadow outbreaks of disease. Now, they have confirmation.

Responding to a deadly 1997 outbreak of the mosquito-borne disease Rift Valley fever, researchers had developed a “risk map,” pictured above, using NASA and National Oceanic and Atmospheric Administration measurements of sea surface temperatures, precipitation, and vegetation cover. As reported in a recent NASA-led study, the map gave public health officials in East Africa up to six weeks of warning for the 2006-2007 outbreak of the deadly Rift Valley fever in northeast Africa — enough time to lessen human impact.

On the map above, pink areas depict increased disease risk, while pale green areas reflect normal risk. Yellow dots represent reported Rift Valley fever cases in high-risk areas, while blue dots represent occurrences in non-risk areas. The researchers have detailed the map’s effectiveness in the Proceedings of the National Academy of Sciences.

313585main_riftvalley_scientists_hi — Scientists study a typical dambo habitat at Sukari Farm, a long-term Rift Valley Fever study site just outside Nairobi, Kenya. Dambos are natural breeding grounds for disease-carrying mosquitoes and can be observed from space with the aid of satellites. Credit: Assaf Anyamba

During an intense El Niño event in 1997, the largest known outbreak of Rift Valley fever spread across the Horn of Africa. About 90,000 people were infected with the virus, which is carried by mosquitoes and transmitted to humans by mosquito bites or through contact with infected livestock. That outbreak prompted the formation of a working group — funded by the U.S. Department of Defense Global Emerging Infections Surveillance and Response System — to try to predict future outbreaks.

The working group didn’t start from scratch. The link between the mosquito life cycle and vegetation growth was first described in a 1987 Science paper by co-authors Kenneth Linthicum of the U.S. Department of Agriculture and Compton Tucker of NASA’s Goddard Space Flight Center. Later, a 1999 Science paper described a link between Rift Valley fever and the El Niño-Southern Oscillation, a cyclical, global phenomenon of sea surface temperature changes that can contribute to extreme climate events around the world.

Building on that research, Assaf Anyamba of NASA Goddard and the University of Maryland, and his colleagues, set out to predict when conditions were ripe for excessive rainfall — and thus an outbreak. They started by examining satellite measurements of sea surface temperatures. One of the first indicators that El Niño will boost rainfall is a rise in the surface temperature of the eastern equatorial Pacific Ocean and the western equatorial Indian Ocean. Perhaps the most telling clue is a measure of the mosquito habitat itself. The researchers used a satellite-derived vegetation data set that measures the landscape’s “greenness.” Greener regions have more than the average amount of vegetation, which means more water and more potential habitat for infected mosquitoes. The resulting risk map for Rift Valley fever, showing areas of anomalous rainfall and vegetation growth over a three-month period, is updated and issued monthly as a means to guide ground-based mosquito and virus surveillance.

As early as September 2006, the monthly advisory from Anyamba and colleagues indicated an elevated risk of Rift Valley fever activity in East Africa. By November, Kenya’s government had begun collaborating with non-governmental organizations to implement disease mitigation measures—restricting animal movement, distributing mosquito bed nets, informing the public, and enacting programs to control mosquitoes and vaccinate animals. Between two and six weeks later—depending on the location—the disease was detected in humans.

After the 2006-2007 outbreak, Anyamba and colleagues assessed the effectiveness of the warning maps. They compared locations that had been identified as “at risk” with the locations where Rift Valley fever was reported. Of the 1,088 cases reported in Kenya, Somalia, and Tanzania, 64 percent fell within areas delineated on the risk map. The other 36 percent of cases did not occur within “at risk” areas, but none were more than 30 miles away, leading the researchers believe that they had identified most of the initial infection sites.

The potential for mapping the risk of disease outbreaks is not limited to Africa. Previous research has shown that risk maps are possible whenever the abundance of a virus can be linked to extremes in climate conditions. Chikungunya in east Africa and Hantavirus and West Nile virus in the United States, for example, have been linked to conditions of rainfall extremes.

“We are coming up on almost 30 years of vegetation data from satellites, which provides us with a good basis for predicting,” said Linthicum, co-author on the 1987 paper, upon his return from a Rift Valley fever workshop in Cairo, Egypt last month. “At this meeting, it was clear that using this tool as a basis for predictions has become accepted as the norm.”

Sources: NASA and the Proceedings of the National Academy of Sciences

February 13, 2009December 24, 2015 by Anne Minard

Climate Change Satellite gets Green Light for Launch

The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) satellite has been cleared for takeoff, following nearly a year in limbo while the mission team awaited the go-ahead from a private launch company.

Originally expected to launch in 2008, SMOS has been in storage at Thales Alenia Space’s facilities in Cannes, France since last May, awaiting a launch appointment at the Russian Plesetsk Cosmodrome, north of Moscow. If all goes according to plan, the craft will now launch between July and October, the second ESA mission in a series of six designed to observe Earth from space and bolster an understanding of climate change. The first of the satellites in its new Living Planet Program, The Gravity field and steady-state Ocean Circulation Explorer (GOCE), is scheduled to go up March 16.

Over its lifetime of about 20 months, GOCE will map global variations in the gravity field – crucial for deriving accurate measurements of ocean circulation and sea-level change, both of which are affected by climate change.

SMOS, circulating at a low orbit of around 750 km (466 miles) above the Earth, will be the first mission dedicated to mapping soil moisture and ocean salinity. Salinity in the oceans has a significant impact on ocean circulation, which in turn helps drive the global climate. Among other applications, understanding the salinity and temperature of the seas will lead to easier predictions of the zones where hurricanes intensify. A specialized radiometer has been developed for the mission that is capable of observing both soil moisture and ocean salinity by capturing images of emitted microwave radiation around the frequency of 1.4 GHz (L-band). SMOS will carry the first-ever, polar-orbiting, space-borne, 2-D interferometric radiometer. The mission is designed to last three years.

Here’s a rundown of the final four planned crafts in the series:

ADM-Aeolus (Atmospheric Dynamics Mission), with a 2010 launch date, will collect data about the global wind profile to improve weather forecasting.
CryoSat-2, set to launch in late 2009, will determine variations in the thickness of the Earth’s continental ice sheets and marine ice cover to further our understanding of the relationship between ice and global warming. CryoSat-2 replaces CryoSat, which was lost at launch in 2005.
Swarm, due for launch in 2010, is a constellation of three satellites to study the dynamics of the magnetic field to gain new insights into the Earth system by studying Earth’s interior and its environment.
EarthCARE (Earth Clouds Aerosols and Radiation Explorer), lanching in 2013, is a joint European-Japanese mission that aims to improve the representation and understanding of the Earth’s radiative balance in climate and numerical weather forecast models.

Source: ESA

February 8, 2009December 24, 2015 by Nancy Atkinson

Satellite Images of 2009 Australian Bushfires

Satellite image of bushfires in southeast Australia taken Feb. 7, 2009. NASA image courtesy the MODIS Rapid Response Team, NASA Goddard Space Flight

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UPDATE: Satellite Images from February 9 have now been added below.

As of this writing, ~~94 people~~ (update 2/9/09) 135 have been killed by out-of-control bushfires in southeast Australia. This image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite shows multiple large fires (outlined in red) burning in Victoria on February 7. Huge plumes of smoke spread southeast, driven by fierce winds. Click here to see a larger version of the image, which shows a larger area, and a dust storm blowing over interior deserts to the northwest. News sources report these fires sprang up and exploded in size in just a few short hours. According to ABC News, authorities suspect arsonists are responsible for some of the fires. NASA says images captured by another satellite, the Terra MODIS sensor, just a few hours prior to this image showed no sign of these fires. Twice-daily images of southeastern Australia are available from the MODIS Rapid Response Team, and Universe Today will try to update the images when they are available. See more below.

Satellite image aquired Feb. 9 of southeastern Australia bushfires. NASA image courtesy the MODIS Rapid Response Team, GSFC.

The bushfire pictures above and below shows the Barry Mountains of central Victoria on February 9, 2009. The image at top is a natural-color (photo-like) view captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Places where the sensor detected active fire are outlined in red. The image below is the same scene shown in false color, using visible, near-infrared, and shortwave infrared light. Burned areas are brick red, and places of intense heat—often a sign of open flame in this kind of image—are glowing pink. Smoke turns a transparent blue, which makes it easier to see the ground.

False color image acquired Feb. 9. NASA image courtesy the MODIS Rapid Response Team, GSFC

Southeast Australia has a history of severe fire problems, with some historic deadly fires such as Ash Wednesday of 1983, and lesser fires almost every year. The state of Victoria averages about 19 large fires (over 1,000 hectares) per year, but the fires this year are considered to be the worst ever. These fires are often fast like grassfire but more intense. 700 homes have been destroyed, and it is feared the death toll will rise to over 100. Twenty-six fires continue to burn across Victoria; 12 of those are out of control.

Satellite image of Australian bushfires from January 30, 2009. NASA image created by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center.

This image was taken on January 30, during the beginning of when some of the fires began to break out. A crippling heat wave and strong winds contributed to an outbreak of forest and grassland fires in Victoria.

Sources: NASA Earth Observatory, ABC News

September 22, 2008December 24, 2015 by Ian O'Neill

NASA Uses 90 Rubber Ducks to Study Global Warming

Little yellow ducks, the new face of fighing climate change (Wikimedia Commons)

[/caption]NASA scientists have dropped 90 yellow rubber ducks into holes in Greenland’s Jakobshavn glacier in an attempt to understand why glaciers speed up during summer months as they slip into the sea. The ducks, attached to a football-sized probe, have an email address and message prompting anyone who discovers the ducks to contact NASA to reveal where and when the duck was found. There is an undisclosed award for anyone who finds one of these rubber global warming crusaders. The NASA scientists, based at the Jet Propulsion Laboratory (JPL) in California, hope this campaign will shed new light on the melting mechanisms behind Greenland’s fastest moving glacier…

This story brings back memories of when 30,000 rubber ducks were washed off a cargo ship bound for the US from China back in 1992. Since then, these intrepid explorers have travelled on the world’s ocean currents, ending up as far afield as the middle of the Pacific to the coast of England. Although they have lost their yellow colouring after years of high seas and Sun damage, the duck-shaped pieces of plastic have provided scientists with a valuable insight into ocean circulation and are still found on beaches today. They have also become a commodity (changing hands for over Â£500 or $1000), been the focus of children’s story books and provided data for a computer model called the Ocean Surface Currents Simulation (used to help fisheries and find people lost at sea). So, in the footsteps of their forefathers, these new NASA rubber recruits hope to provide climatologists with information about the current global warming trend and impacts on polar ice.

Alberto Behar, one of the JPL scientists working with the army of rubber ducks explains, “Right now it’s not understood what causes the glaciers themselves to surge in the summer.” The rubber ducks will help to tackle this problem by carrying a probe with them so their progress can be tracked via GPS. The football sized probe will also relay information about the glacier’s innards as the rubber ducks flow with the ice into the sea.

So far, nobody has reported finding a duck or a probe, but Behar is hopeful that a fisherman or hunter might do in the near future. “We haven’t heard back but it may take some time until somebody actually finds it and decides to send us an e-mail that they have found it,” he said. “These are places that are quite remote so there aren’t people walking around.” Let’s hope the promise of a reward will be enough incentive for the finder to make contact with NASA (otherwise we might see them being advertised on eBay for Â£500 or $1000…).

The Jakobshavn Glacier is famous in its own right. The iceberg that sank the Titanic in 1912 is thought to originate from it and the glacier has a phenomenal ice discharge rate today, responsible for nearly 7% of the ice flowing from Greenland.

Sources: The Sydney Morning Herald, Times Online (from June 28th, 2007)

August 12, 2008December 24, 2015 by Ian O'Neill

The Chinese “Weather Manipulation Missile” Olympics

Chinese weather control rocket blasts off (Source: ImpactLab.com)

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One thing is for certain, the Chinese cannot be accused of being subtle when it comes to insuring good weather for the biggest party on Earth. Sounding like a military operation, the Chinese government authorized the use of 1,104 cloud seeding missile launches from 4:00-11:39pm on Friday night to remove the threat of rain ahead of the 29th Olympic opening ceremony in Beijing. This was the first time the weather manipulation technique was used during any Olympic event in the history of the games. This summer period can be a very wet season for Beijing and officials have been concerned their moment of huge national pride would be a wash-out. But it would appear the 21 rain dispersal launch sites kept nature at bay and made sure the celebration fireworks didn’t get soggy…

Although cloud seeding remains a hugely controversial practice, both China and Russia are large-scale advocates of various delivery systems. In June, it was reported that during a Russian Air Force cloud seeding operation, a chunk of cement fell from the sky, making a hole in someone’s roof. Although this incident was quite entertaining (not, however, to the owner who vowed to sue the Kremlin), there are some very big local climate concerns associated with cloud seeding. Scientists have pointed out that weather manipulation can amplify drought conditions in one area or increase the risk of floods in another. It is an unpredictable practice at best, and often considered to be highly unreliable. However, the Chinese and Russian governments continue to seed clouds, in an attempt to disperse rain ahead of public holidays and events.

Chinese meteorologists claim that the weather manipulation rockets were highly effective ahead of the opening ceremony on Friday, keeping the skies clear and audience dry inside the main Olympic National Stadium (a.k.a. “The Birds Nest”).

“We fired a total of 1,104 rain dispersal rockets from 21 sites in the city between 4 p.m. and 11:39 p.m. on Friday, which successfully intercepted a stretch of rain belt from moving towards the stadium” – Guo Hu, Beijing Municipal Meteorological Bureau (BMB).

According to Xinhua news, Chinese meteorologists decided cloud seeding was the only option as the humidity was rising toward 90% and rain clouds had been tracked since 7:20am approaching the Chinese capital city. Under these conditions, scientists felt for certain rain would pour over the opening ceremony. “Under such a weather condition, a small bubble in the rain cloud would have triggered rainfall, let alone a lightening,” said Guo, presumably indicating that any slight instability in the atmosphere may have caused a storm.

Sounding more like a terror threat than a rain warning, the Beijing Municipal Meteorological Bureau issued a “Yellow Alert” (the third highest) for a thunderstorm at 9:35pm, with heavy rain hitting downtown Beijing soon after. According to officials, at 10:42pm, the clouds had been dispersed and the opening ceremony remained storm-free. They also stated that other areas surrounding Beijing recorded heavy rain, possibly indicating that the focused cloud seeding campaign worked.

Source: Xinhua

June 19, 2008December 24, 2015 by Ian O'Neill

When Cloud Seeding Goes Wrong: Cement Chunk Falls From the Sky

The Russian Air Force, during a mission to clear the skies of potentially rain-filled clouds, dropped a mixture of silver iodide, liquid nitrogen and cement powder in an attempt to seed the clouds. This form of climate modification is common practice in Russia, when attempting to engineer dry days on public holidays and special events in Moscow. However, during the cloud seeding operation last week, cement dropped from one of the aircraft failed to fragment when falling through the air, falling as a solid mass, crashing through the roof of a Moscow suburban home…

Cloud seeding is a highly controversial method used to modify local climates. Russia and China are two large nations that believe various methods of cloud seeding are effective in deflecting storms and preventing rain clouds from precipitating on events requiring dry weather. Silver iodide, dry ice and various salts are used as artificial particles acting as water droplet nuclei. Dropping these particles can trigger precipitation, but any form of climate modification can be unpredictable, and in some cases, dangerous.

One such unpredictable outcome from last week’s “routine” cloud seeding effort by the Russian Air Force above the skies of Moscow resulted in something bigger than rain hitting the ground. A pack of cement (with rain-making properties I’m guessing) was dropped from one of the 12 seeding planes with a cocktail of silver iodide and liquid nitrogen. The point? To clear the skies above Moscow in preparation for a dry national holiday on June 12th known as Russia Day. The result? The cement mix failed to break apart, creating the desired cloud of dust after it was released. Instead it maintained its shape (and presumably its cement-like hardness) and dropped to the ground like a ~~stone~~ rock.

“A pack of cement used in creating good weather in the capital region failed to pulverize completely at high altitude and fell on the roof of a house, making a hole about 80-100 cm (2.5-3 ft).” – Naro-Fominsk Police when talking with agency RIA-Novosti.

Fortunately no one was hurt, but the Russian homeowner is less than impressed. He has shunned the Air Force’s offer of $2,100 to fix the roof and is suing for “moral suffering” damages instead. The Air Force claims this was a freak accident and unheard of in the 20 years of cloud seeding operations.

Sources: Reuters, Environmental Graffiti

June 1, 2008December 24, 2015 by Ian O'Neill

Harvesting Solar Power from Space

Artist's concept of a space-based solar array. Credit NASA/SAIC

In a new report, the viability of sending solar panels into space to collect a vast quantity of uninterrupted energy has been re-investigated. Although the idea has been around since the 1970’s, space solar power has always been viewed as prohibitively expensive. In the current energy climate down here on Earth with spiralling oil prices and a massive push toward green energy sources, sending massive solar arrays into geosynchronous orbit doesn’t seem like such a strange (or expensive) idea. There are many obstacles in the way of this plan, but the international community is becoming more interested, and whoever is first to set up an orbital array will have a flexible and unlimited energy resource…

It sounds like the perfect plan: build a vast array of solar panels in space. This avoids many of the practical problems we have when building them on Earth such as land availability, poor light conditions and night time, but sending a sunlight farm into space will be expensive to set up. In the 1970’s a plan was drawn up by NASA for the possibility of orbital sunlight “harvesting”, but it was deemed too expensive with a hefty price tag of at least $1 trillion. There was no country in the world that could commit to such a plan. But as we slowly approach an era of cheaper space travel, this cost has been slashed, and the orbital solar energy case file has been re-opened. Surprisingly, it isn’t the most developed nations in the world that are pushing for this ultimate renewable energy source. India and China, with their ballooning populations are reaching a critical point for energy consumption and they are beginning to realise their energy crisis may be answered by pushing into space.

“A single kilometer-wide band of geosynchronous Earth orbit experiences enough solar flux in one year to nearly equal the amount of energy contained within all known recoverable conventional oil reserves on Earth today.” – Pentagon’s National Security Space Office 2007 report.

So how could this plan work? Construction will clearly be the biggest expense, but the nation who leads the way in solar power satellites will bolster their economy for decades through energy trading. The energy collected by highly efficient solar panels could be beamed down to Earth (although it is not clear from the source what technology will go into “beaming” energy to Earth) where it is fed into the national grid of the country maintaining the system. Ground based receivers would distribute gigawatts of energy from the uninterrupted orbital supply. This will have obvious implications for the future high demand for electricity in the huge nations in Asia and will wean the international community off carbon-rich non-renewable resources such as oil and coal. There is also the benefit of the flexible nature of this system being able to supply emergency energy to disaster (and war-) zones.

“It will take a great deal of effort, a great deal of thought and unfortunately a great deal of money, but it is certainly possible.” – Jeff Keuter, president of the George C. Marshall Institute, a Washington-based research organization.

The most optimistic time frame for a fully operational space-based sunlight collection satellite would be 2020, but that is if we started work now. Indeed some research is being done (Japan is investing millions of dollars into a potential prototype to be put into space in the near future), but this is a far cry from planning to get full-scale operations underway in a little over a decade…

Source: CNN International

May 27, 2008December 24, 2015 by Ian O'Neill

The A-Train: Using Five Satellites as One to Analyze Polluted Clouds

The A-Train - 5 satellites collaborate to scan polluted clouds (NASA)

This is one of the finest examples of satellite collaboration. Five Earth-observing orbiters, four from NASA and one from France, are working together to provide the deepest analysis of cloud cover ever carried out. The satellites orbit in a close formation, only eight minutes apart, and create what is known as the “Afternoon Constellation” (or “A-Train” for short). They are so close in fact, that they can be considered to act as one satellite, capable of carrying out a vast suite of measurements on the pollution content of clouds. This work is shedding new light on the link between clouds, pollution and rainfall, a study that could never be achieved with one satellite alone…

Pollution in clouds is a critical problem for the international community. These rogue particles can seriously change the natural behaviour of clouds and entire weather systems, but until now, scientists have been uncertain about the difference in rainfall from polluted and unpolluted cloud cover. This is primarily because no single environmental satellite has been able to probe deep into clouds with the limited number of instruments it can carry. But using the collective power of five independent satellites, scientists are beginning to unlock the secrets polluted clouds have been hiding.

Researchers at NASA’s Jet Propulsion Labs (JPL) in Pasadena have recently discovered that clouds peppered with pollutant particles do not produce as much rain as their unpolluted counterparts. This finding was only possible after analysing data from the near-simultaneous measurements made by the five A-Train satellites. The constellation includes NASA’s Aqua, Aura, CloudSat and CALIPSO and the French Space Agency’s PARASOL.

“Typically, it is very hard to get a sense of how important the effect of pollution on clouds is. With the A-Train, we can see the clouds every day and we’re getting confirmation on a global scale that we have an issue here.” – Anne Douglass, project scientist at Goddard for NASA’s Aura satellite.

The A-Train is turning up some interesting, if alarming, results. When focusing on the skies above South America during the June-October dry season, the JPL team found that the increased level of agricultural burning during this period injected more aerosols into the clouds. This had the effect of shrinking the size of ice crystals in the clouds, preventing the crystals from getting large enough to fall as rain. This direct effect of burning and ice crystal formation has never been connected before the use of the A-Train. However, during wet seasons, the aerosol content in clouds appeared not to be a critical factor on the amount of rainfall.

How is it possible to distinguish between polluted and unpolluted clouds? Firstly, the A-Train’s Aura satellite measures the concentration of carbon monoxide in the clouds. This is a strong indicator for the presence of smoke and other aerosols originating from a power plant or agricultural activities. When the polluted clouds are identified, the A-Train’s Aqua satellite can be called into use. Using its Moderate Resolution Imaging Spectroradiometer instrument, the size of ice crystals in polluted and unpolluted clouds can be measured. Next up is NASA’s Tropical Rainfall Measuring Mission satellite that can measure the amount of precipitation (rain) from polluted and unpolluted clouds.

Through this combination of satellites, scientists are able to link pollution with clouds with precipitation. This is only one example of the flexibility behind collaborations such as A-Train, so cloud science can only go from strength to strength.

Source: Physorg.com

May 1, 2008December 24, 2015 by Ian O'Neill

Ocean Currents May Cool the Climate for a Decade

False-color image of the temperature of the Gulf Stream off the East Coast of the US (NASA)

It would appear that rising atmospheric temperatures may be slowed or even stopped over the next ten years due to periodic changes in ocean circulation. As the Gulf Stream slows the flow of warm tropical waters from the equator to the North Atlantic, North America and Northern Europe will experience a slight reduction in atmospheric temperatures. This appears to be a natural process that has occurred in historic records. But don’t go getting too excited, this will only pause the global warming trend at best. The UN’s Intergovernmental Panel on Climate Change (IPCC) forecasts a global temperature rise of 0.2°C (0.36°F) per decade, and this trend will continue after the currents have settled…

The oceans are the planets huge heaters and refrigerators. Within the oceans are complex and highly dynamic flows of warm and cool streams. One stream in particular, the Gulf Stream, reaches from the tropical waters of the Gulf of Mexico to the cold waters of Northern Europe. As the tropical stream of water travels north and cools, it sinks and flows back in the opposite direction, carrying the cold North Atlantic water south. This ocean “conveyor belt” maintains the surprisingly warm weather systems that Europe experiences. Without this supply of ocean heat, countries at these high latitudes (like the UK where weather systems are dominated by ocean conditions) would experience the harsh winters more associated with Moscow.

So, in research published in Nature on Thursday, it would seem the North Atlantic is about to get a little cooler. Mojib Latif, professor at the Leibniz Institute of Marine Sciences in Kiel, northern Germany and his team predict a cooling in North American and European regions, whilst the temperatures of tropical regions will be stabilized. Scientists have known about the weakening of the Gulf Stream for a long time, but this is one of the first studies to demonstrate how this process may influence global temperatures and how global warming isn’t necessarily a gradual increase. But there’s a catch. This trend can only be sustained for ten years, after which atmospheric global warming will continue to increase at the IPCC rate. The German scientists are clear that they are not disputing the IPCC figures:

“Just to make things clear, we are not stating that anthropogenic [man-made] climate change won’t be as bad as previously thought. What we are saying is that on top of the warming trend, there is a long-periodic oscillation that will probably lead to a lower temperature increase than we would expect from the current trend during the next years.” – Mojib Latif

This work predicts that the Gulf Stream will slow over the next few years, but other studies argue change is happening now. The saltiness of the Atlantic waters is also a concern. Due to the huge input of fresh melt water from Greenland’s glaciers and Siberian permafrost over the past few years, the stream has been strongly affected. It would appear there are many factors when considering how these vast currents can be influenced.

There is a warning in this new study. The weakening of the Gulf Stream is part of a natural oscillation. We may be facing a weakened stream over the next ten years, cooling the climate, but there will also be a strengthening of ocean currents in the future. What happens when the stronger currents begin heating North Atlantic waters?

Source: Physorg.com