Showing posts with label carbon dioxide. Show all posts
Showing posts with label carbon dioxide. Show all posts

Saturday, December 20, 2014

NASA's Curiosity Mars Rover: Organics Possibly Present

This image illustrates possible ways methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). 

NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur on modern Mars. 

Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan

NASA's Curiosity Mars rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill.

"This temporary increase in methane, sharply up and then back down, tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team.

"There are many possible sources, biological or non-biological, such as interaction of water and rock."

Researchers used Curiosity's onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere.

During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion.

Before and after that, readings averaged only one-tenth that level.

Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed 'Cumberland', the first definitive detection of organics in surface materials of Mars.

These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.

Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life.

Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harboured living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

"We will keep working on the puzzles these findings present," said John Grotzinger, Curiosity project scientist of the California Institute of Technology in Pasadena (Caltech).

"Can we learn more about the active chemistry causing such fluctuations in the amount of methane in the atmosphere? Can we choose rock targets where identifiable organics have been preserved?"

Researchers worked many months to determine whether any of the organic material detected in the Cumberland sample was truly Martian.

Curiosity's SAM lab detected in several samples some organic carbon compounds that were, in fact, transported from Earth inside the rover.

However, extensive testing and analysis yielded confidence in the detection of Martian organics.

NASA HAVOC: Manned mission to Venus Possible

HAVOC. Credit: NASA Langley Research Center

NASA's Systems Analysis and Concepts Directorate has issued a report outlining a possible way for humans to visit Venus, rather than Mars, by hovering in the atmosphere instead of landing on the surface.

The hovering vehicle, which they call a High Altitude Venus Operational Concept (HAVOC), would resemble a blimp with solar panels on top, and would allow people to do research just 50 kilometers above the surface of the planet.

Most everyone knows that NASA wants to send people to Mars, that planet also gets most of the press. Mars is attractive because it looks more like Earth and is relatively close to us.

The surface of Venus on the other hand, though slightly closer, is not so attractive, with temperatures that can melt lead and atmospheric pressure 92 times that of Earth.

There's also that thick carbon dioxide atmosphere with sulphuric acid clouds, lots of earthquakes, volcanoes going off and terrifying lightning bolts.

Perhaps humans could ride through the upper atmosphere of Venus in a solar-powered airship. Dale Arney and Chris Jones, from Nasa's Space Analysis Branch, propose that it may make sense to go to Venus before we ever send humans to Mars.

So, why would anyone rather go to Venus than Mars? Because of far lower radiation and much better solar energy.

No one wants to go the surface of Venus, at least not anytime soon, instead, researchers at NASA are looking into the possibility of sending people to hover in the sky above the planet, conducting research in a far less dangerous place than even on the surface of Mars.

At 50 kilometers up, an HAVOC would experience just one atmosphere of atmospheric pressure and temperatures averaging just 75 degrees Celsius, with radiation levels equivalent to those in Canada.

Astronauts on Mars, on the other hand would experience 40 times the amount of radiation typically faced back here on Earth, which suggests they'd have to live deep underground to survive, a problem that scientists have not yet solved.

Read the full article here

Sunday, November 23, 2014

NASA Computer Model Provides a New Portrait of Carbon Dioxide - Video



An ultra-high-resolution NASA computer model has given scientists a stunning new look at how carbon dioxide in the atmosphere travels around the globe. 

Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources.

Image courtesy NASA's Goddard Space Flight Center/K. Sharghi.

An ultra-high-resolution NASA computer model has given scientists a stunning new look at how carbon dioxide in the atmosphere travels around the globe.

Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources. The simulation also illustrates differences in carbon dioxide levels in the northern and southern hemispheres and distinct swings in global carbon dioxide concentrations as the growth cycle of plants and trees changes with the seasons.

Scientists have made ground-based measurements of carbon dioxide for decades and in July NASA launched the Orbiting Carbon Observatory-2 (OCO-2) satellite to make global, space-based carbon observations. But the simulation - the product of a new computer model that is among the highest-resolution ever created - is the first to show in such fine detail how carbon dioxide actually moves through the atmosphere.

"While the presence of carbon dioxide has dramatic global consequences, it's fascinating to see how local emission sources and weather systems produce gradients of its concentration on a very regional scale," said Bill Putman, lead scientist on the project from NASA's Goddard Space Flight Center in Greenbelt, Maryland.

"Simulations like this, combined with data from observations, will help improve our understanding of both human emissions of carbon dioxide and natural fluxes across the globe."

The carbon dioxide visualization was produced by a computer model called GEOS-5, created by scientists at NASA Goddard's Global Modeling and Assimilation Office. In particular, the visualization is part of a simulation called a "Nature Run."

The Nature Run ingests real data on atmospheric conditions and the emission of greenhouse gases and both natural and man-made particulates.

The model is then is left to run on its own and simulate the natural behaviour of the Earth's atmosphere. This Nature Run simulates May 2005 to June 2007.

While Goddard scientists have been tweaking a "beta" version of the Nature Run internally for several years, they are now releasing this updated, improved version to the scientific community for the first time.

Scientists are presenting a first look at the Nature Run and the carbon dioxide visualization at the SC14 supercomputing conference this week in New Orleans.

"We're very excited to share this revolutionary dataset with the modeling and data assimilation community," Putman said, "and we hope the comprehensiveness of this product and its ground-breaking resolution will provide a platform for research and discovery throughout the Earth science community."

In the spring of 2014, for the first time in modern history, atmospheric carbon dioxide - the key driver of global warming - exceeded 400 parts per million across most of the northern hemisphere.

Prior to the Industrial Revolution, carbon dioxide concentrations were about 270 parts per million. Concentrations of the greenhouse gas in the atmosphere continue to increase, driven primarily by the burning of fossil fuels.

Despite carbon dioxide's significance, much remains unknown about the pathways it takes from emission source to the atmosphere or carbon reservoirs such as oceans and forests.

Combined with satellite observations such as those from NASA's recently launched OCO-2, computer models will help scientists better understand the processes that drive carbon dioxide concentrations.

Saturday, November 1, 2014

Climate Change Caused by the Ocean Circulation and Atmosphere

The Thermohaline Circulation or ocean conveyor belt moves heat and water between the hemispheres, along the ocean bottom. It also moves carbon dioxide.

Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere, but in a new study published in Science, a group of Rutgers researchers have found that circulation of the ocean plays an equally important role in regulating the earth's climate.

In their study, the researchers say the major cooling of Earth and continental ice build-up in the Northern Hemisphere 2.7 million years ago coincided with a shift in the circulation of the ocean - which pulls in heat and carbon dioxide in the Atlantic and moves them through the deep ocean from north to south until it's released in the Pacific.

The ocean conveyor system, Rutgers scientists believe, changed at the same time as a major expansion in the volume of the glaciers in the northern hemisphere as well as a substantial fall in sea levels.

It was the Antarctic ice, they argue, that cut off heat exchange at the ocean's surface and forced it into deep water. They believe this caused global climate change at that time, not carbon dioxide in the atmosphere.

"We argue that it was the establishment of the modern deep ocean circulation - the ocean conveyor - about 2.7 million years ago, and not a major change in carbon dioxide concentration in the atmosphere that triggered an expansion of the ice sheets in the northern hemisphere," says Stella Woodard, lead author and a post-doctoral researcher in the Department of Marine and Coastal Sciences.

Their findings, based on ocean sediment core samples between 2.5 million to 3.3 million years old, provide scientists with a deeper understanding of the mechanisms of climate change today.

The study shows that changes in heat distribution between the ocean basins is important for understanding future climate change.

However, scientists can't predict precisely what effect the carbon dioxide currently being pulled into the ocean from the atmosphere will have on climate.

Still, they argue that since more carbon dioxide has been released in the past 200 years than any recent period in geological history, interactions between carbon dioxide, temperature changes and precipitation, and ocean circulation will result in profound changes.

Scientists believe that the different pattern of deep ocean circulation was responsible for the elevated temperatures 3 million years ago when the carbon dioxide level in the atmosphere was arguably what it is now and the temperature was 4 degree Fahrenheit higher.

They say the formation of the ocean conveyor cooled the earth and created the climate we live in now.

"Our study suggests that changes in the storage of heat in the deep ocean could be as important to climate change as other hypotheses, tectonic activity or a drop in the carbon dioxide level, and likely led to one of the major climate transitions of the past 30 million years," says Yair Rosenthal, co-author and professor of marine and coastal sciences at Rutgers

Monday, September 29, 2014

ESA Releases Bad and Good News from Earth's Atmosphere Studies

Carbon dioxide emissions increased in East Asia (right) at an average rate of 9.8% per year from 2003 to 2011, but nitrogen oxides increased by ‘only’ 5.8% per year.  

This indicates a use of cleaner technology in East Asia. 

North America and Europe, however, show slightly decreasing trends for both gases. 

The maps show the corresponding spatial pattern as obtained from the satellite data: red corresponds to regions with high values of NOx and CO2, while blue indicates background values.

Credit: ESA

While Europe and North America show a decrease in emission trends between 2003 and 2011, emissions related to economic growth in East Asia continue to rise, but with a reduction in nitrogen oxides emitted per amount of carbon dioxide.

This demonstrates the use of cleaner technology in East Asia.

Nitrogen oxides are generated during the high-temperature combustion of fossil fuels in automobiles and industrial machinery.

They contribute significantly to a reduction of air quality and can be the cause of respiratory problems.

At the same time, these sources release large amounts of carbon dioxide. Carbon dioxide is toxic only at very high concentrations, but is the most important man-made greenhouse gas, leading to global warming and its related consequences.

In a study published yesterday in Nature Geoscience, scientists from the University of Bremen in Germany used data from the Sciamachy instrument on ESA’s Envisat satellite to measure nitrogen dioxide and carbon dioxide trends from 2003 to 2011.

They also exploited  Sciamachy-based data products generated within the ‘GHG-CCI’ project under ESA’s Climate Change Initiative.

“Nitrogen dioxide has a relatively short lifetime, hours, compared to carbon dioxide, which lasts decades, and is a suitable tracer of recently emitted carbon dioxide from fossil fuel combustion,” explained Maximilian Reuter, lead author of the study.

Sciamachy measured nitrogen dioxide and carbon dioxide simultaneously. We used a spatial high-pass filtering method to isolate the anthropogenic carbon dioxide signal from overlaying signals due to uptake and release of carbon dioxide by vegetation.”

Satellite-derived CO2 concentrations proportional to local anthropogenic emissions in North America and Europe. 

The green line shows the mean value and the grey-shaded area its variability and uncertainty. 

This indicates that less CO2 is emitted during weekends compared to week days.

Using this method, the scientists were able to better see where and when carbon dioxide was emitted.

For example, it showed that less carbon dioxide from local anthropogenic sources is emitted during weekends in Europe and North America compared to week days.

“This has never been observed from space before and shows how accurate the used method is,” said Dr Reuter.

Although Envisat’s mission ended in 2012, a decade of data from its 10 instruments is still being exploited for studies on Earth’s atmosphere, land, oceans and ice caps.

“Unfortunately, none of the existing nor any of the planned near-future satellites are designed to directly observe carbon dioxide emissions of cities, power plants, volcanoes or other important emission hot spots,” said Michael Buchwitz, co-author of the study and GHG-CCI scientific leader.

“This will only be possible with the proposed mission CarbonSat.”

CarbonSat is one of the two candidates for ESA’s eighth Earth Explorer satellite.

Using the unique spectroscopic fingerprint of carbon dioxide and methane, CarbonSat aims to image these two strong greenhouse gases at very high resolution.

The mission would lead to a better understanding of the sources and sinks of atmospheric carbon dioxide and methane.

Wednesday, September 17, 2014

NASA Airborne Campaigns Focus on Climate Impacts in the Arctic

Flights are underway from Fairbanks, Alaska, with NASA’s C-130 Hercules aircraft to study the connection between retreating Arctic sea ice and climate change. 

Image Credit: NASA/Patrick Lynch

Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic.

As the region’s summer comes to a close, NASA is hard at work studying how rising temperatures are affecting the Arctic.

NASA researchers this summer and fall are carrying out three Alaska-based airborne research campaigns aimed at measuring greenhouse gas concentrations near Earth’s surface, monitoring Alaskan glaciers, and collecting data on Arctic sea ice and clouds.

Observations from these NASA campaigns will give researchers a better understanding of how the Arctic is responding to rising temperatures.

Broken sea ice captured during an ARISE flight over the Arctic Ocean by one of the C-130 Hercules’s onboard cameras. 

Credit: NASA

The Arctic Radiation, IceBridge Sea and Ice Experiment (ARISE), is a new NASA airborne campaign to collect data on thinning sea ice and measure cloud and atmospheric properties in the Arctic.

The campaign was designed to address questions about the relationship between retreating sea ice and the Arctic climate.

Arctic sea ice reflects sunlight away from Earth, moderating warming in the region. Loss of sea ice means more heat from the sun is absorbed by the ocean surface, adding to Arctic warming.

In addition, the larger amount of open water leads to more moisture in the air, which affects the formation of clouds that have their own effect on warming, either enhancing or reducing it.

Changes in more than 130 Alaskan glaciers are being surveyed by scientists at the University of Alaska-Fairbanks in a DHC-3 Otter as part of NASA’s multi-year Operation IceBridge.

Image Credit: Chris Larsen, University of Alaska-Fairbanks

ARISE will link clouds and sea ice in a way that improves our computer models of the Arctic,” said Tom Wagner, cryospheric sciences program manager at NASA Headquarters in Washington.

“Our goal is to better understand both the causes of Arctic ice loss and the connections to the overall Earth system.”

The ARISE campaign, using NASA’s C-130 Hercules aircraft from Wallops Flight Facility in Virginia, had its first science flight on Sept. 4 and has already carried out several surveys of sea ice and cloud conditions. The campaign is based in Fairbanks, Alaska.

“We are off to a great start collecting a timely and unique dataset to help better understand the potential influence of clouds on the Arctic climate as sea ice conditions change,” said William SmithARISE principal investigator at NASA’s Langley Research Center in Hampton, Virginia.

Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), is a five-year airborne research campaign that uses instruments aboard NASA aircraft to measure air and surface conditions and concentrations of gases like carbon dioxide, carbon monoxide and methane.

Using NASA’s C-23 Sherpa aircraftCARVE flies approximately two weeks per month from May to November.

Now that the mission is in its fourth year, researchers are building a detailed picture of how the land and atmosphere interact in the Arctic.

In high-latitude areas like Alaska, frozen ground known as permafrost can trap large amounts of carbon dioxide and methane produced by layers of decayed plant and animal matter.

As permafrost temperatures have been increasing faster than air temperatures in the Arctic, scientists have questioned whether these heat-trapping gases could be released into the atmosphere, increasing their global concentrations.

“The exchange of carbon between the land and the atmosphere is very important, but uncertain,” said Charles Miller, a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and principal investigator of CARVE.

Friday, August 15, 2014

NASA OCO-2 Satellite Takes First Look at Earth's Carbon Dioxide

Artist's rendition of NASA's OCO-2 satellite in orbit. 

OCO-2 was launched on July 2, 2014 and made its first science measurements a month later, on Aug. 6. 

Credit: JPL/NASA

NASA's newest satellite has arrived in its final orbit and begun tracking levels of the heat-trapping gas carbon dioxide in Earth's atmosphere.

The Orbiting Carbon Observatory 2 (OCO-2), which blasted off July 2, arrived in its final orbit 438 miles (705 kilometers) above the Earth on Aug. 3.

The satellite then collected its first test data three days later while flying over Papua New Guinea, agency officials said.

"The initial data from OCO-2 appear exactly as expected, the spectral lines are well resolved, sharp and deep," OCO-2's chief architect and calibration lead, Randy Pollock, of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement Monday (Aug. 11).

"We still have a lot of work to do to go from having a working instrument to having a well-calibrated and scientifically useful instrument, but this was an important milestone on this journey."



OCO-2 is the first operational NASA satellite dedicated to measuring atmospheric levels of carbon dioxide, which scientists say is largely responsible for Earth's recent warming trend.

Concentrations of the gas in Earth's air have risen from 280 parts per million (ppm) before the Industrial Revolution to about 400 ppm today, primarily due to the burning of fossil fuels and other human activities.

OCO-2 will use its single scientific instrument, a grading spectrometer, to gather precise CO2 data thousands of times each day, helping researchers get a much clearer picture of how the gas is cycling through the atmosphere, what sources are pumping it out, and which "sinks" are sucking it up, NASA officials said.

OCO-2 will become the leader of the Afternoon Constellation, or A-Train, as shown in this artist's concept. 

Japan’s Global Change Observation Mission - Water (GCOM-W1) satellite and NASA’s Aqua, CALIPSO, CloudSat and Aura satellites follow. 

Image Credit: NASA

By reaching its ultimate, near-polar orbit, OCO-2 joined five other Earth-observation satellites in a constellation known as the "A-Train." (The name is short for "Afternoon Train"; all of the spacecraft cross the equator going north in the early afternoon local time.)

The OCO-2 mission team will calibrate the spacecraft's spectrometer over the next few weeks.

The satellite will also beam to Earth up to 1 million scientific measurements every day, to help test out data-processing systems on the ground, NASA officials said.

The $465 million mission should start delivering calibrated science data before the end of 2014, they added.

Monday, August 11, 2014

NASA OCO-2: Carbon Counter Reaches Final Orbit, Returns Data

NASA's OCO-2 spacecraft collected "first light” data Aug. 6 over New Guinea. OCO-2’s spectrometers recorded the bar code-like spectra, or chemical signatures, of molecular oxygen or carbon dioxide in the atmosphere. 

The backdrop is a simulation of carbon dioxide created from GEOS-5 model data.

Image Credit: NASA/JPL-Caltech/NASA GSFC

Just over a month after launch, the Orbiting Carbon Observatory-2 (OCO-2), NASA’s first spacecraft dedicated to studying atmospheric carbon dioxide, has maneuvered into its final operating orbit and produced its first science data, confirming the health of its science instrument.

Atmospheric carbon dioxide is the leading human-produced greenhouse gas responsible for warming our world. It is a critical natural component of Earth’s carbon cycle.

OCO-2 will produce the most detailed picture to date of sources of carbon dioxide, as well as their natural “sinks”, places on Earth’s surface where carbon dioxide is removed from the atmosphere.

The observatory will study how these sources and sinks are distributed around the globe and how they change over time.

Artist's rendering of NASA's Orbiting Carbon Observatory (OCO)-2, one of five new NASA Earth science missions set to launch in 2014, and one of three managed by JPL.

Image Credit: NASA/JPL-Caltech

Following launch from California’s Vandenberg Air Force Base on July 2, OCO-2 underwent a series of steps to configure the observatory for in-flight operations.

Mission controllers established two-way communications with the observatory, stabilized its orientation in space and deployed its solar arrays to provide electrical power.

The OCO-2 team then performed a checkout of OCO-2’s systems to ensure they were functioning properly.

Through the month of July, a series of propulsive burns was executed to maneuver the observatory into its final 438-mile (705-kilometer), near-polar orbit at the head of the international Afternoon Constellation, or “A-Train,” of Earth-observing satellites.

It arrived there on Aug. 3. Operations are now being conducted with the observatory in an orbit that crosses the equator at 1:36 p.m. local time.

Friday, August 1, 2014

NASA Plans to test making rocket fuel ingredient on Mars

NASA plans to make oxygen, a key ingredient of rocket fuel, on Mars early next decade.

Space agency officials Thursday unveiled seven instruments they plan to put on a Martian rover that would launch in 2020, including two devices aimed at bigger Mars missions in the future.

The $1.9 billion rover will include an experiment that will turn carbon dioxide in the Martian atmosphere into oxygen.

It could then be used to make rocket fuel and for future astronauts to breathe, said NASA associate administrator for exploration Bill Gerstenmaier.

Taking fuel to Mars for return flights is heavy and expensive.

The device, named MOXIE, works like an engine but in reverse, said Michael Hecht, the scientist at the Massachusetts Institute of Technology who is running the test project.

It will make about three-quarters of an ounce of oxygen an hour.

If it works, then a larger scale device, 100 times bigger than MOXIE, would be launched two years before astronauts go, currently slated for some time in the 2030s. NASA first plans to send astronauts to an asteroid.

The bigger device would start making enough oxygen for the return trip before astronauts ever launch to Mars, Hecht said.

The other part of rocket fuel, the propellant, can be made from light hydrogen that is brought from Earth or other chemicals mined from Martian dirt or atmosphere.

John Grunsfeld, NASA's associate administrator for science, said the new rover, a clone of the chassis of the current Curiosity machine, "will lead to getting humans to Mars in the future."

Mars on average is about 140 million miles from Earth and opportunities to send spaceships to there come only every 26 months. The trip to Mars takes about 9 months, but can be as short as half a year.

The rover is scheduled to land on Mars in 2021.

NASA also plans to collect interesting rocks, put them in sealed vials for future flights to pick them up and return them to Earth for detailed study.

This would likely be another robotic mission or it could just wait for astronauts. NASA hasn't yet figured out how the rover will store the rocks.

Friday, June 13, 2014

NASA's Orbiting Carbon Observatory (OCO)-2 will measure CO2 in the atmosphere

An artists rendition of NASA's Orbiting Carbon Observatory (OCO-2), which will launch on July 1 and measure atmospheric carbon dioxide 

NASA is preparing a July 1 launch for its first satellite dedicated to measuring atmospheric levels of carbon dioxide, a greenhouse gas that plays a key role in climate change.

CO2 levels have reached their highest point in at least 800,000 years, according to the US space agency.

The Orbiting Carbon Observatory (OCO-2) satellite is very similar to its predecessor, OCO-1, which was destroyed during its launch in February 2009.

The satellite will help provide a more complete and global picture of man-made and naturally occurring CO2 emissions as well as the effects of carbon "sinks," like oceans and forests, which absorb and trap the gas.

"Carbon dioxide in the atmosphere plays a critical role in our planet's energy balance and is a key factor in understanding how our climate is changing," said Michael Freilich, director of NASA's Earth Science Division.

"With the OCO-2 mission, NASA will be contributing an important new source of global observations to the scientific challenge of better understanding our Earth and its future," he added in a statement.

The OCO-2 satellite will be launched on a United Launch Alliance Delta II rocket from Vandenberg Air Force Base in California, aiming for an orbit at 438 miles (705 kilometers) above the Earth's surface.

Tuesday, June 18, 2013

ESA Venus Express: Super-hurricane-force winds on Venus are getting stronger

False-colour image of cloud features seen on Venus by the Venus Monitoring Camera (VMC) on Venus Express

The image was captured from a distance of 30 000 km on 8 December 2011. 

The VMC was designed and built by a consortium of German institutes lead by the Max-Planck Institute for Solar System Research in Katlenburg-Lindau. 

Credit: ESA

As the closest planet to Earth, Venus is a relatively easy object to observe.

However, many mysteries remain, not least the super-rotation of Venus' atmosphere, which enables high altitude winds to circle the planet in only four days.

Now images of cloud features sent back by ESA's Venus Express orbiter have revealed that these remarkably rapid winds are becoming even faster.

Similar in size to Earth, Venus has an extremely dense, carbon-dioxide-rich atmosphere and the planet's surface is completely hidden by a blanket of bland, yellowish cloud.

Only at ultraviolet wavelengths (and to a lesser extent in the infrared) do striking cloud streaks and individual cells emerge, due to the presence of some unknown UV absorber in the cloud deck.

By tracking the movements of these distinct cloud features, observers have been able to measure the super-hurricane-force winds that sweep around the planet at the cloud tops, some 70 km above the scorching volcanic plains.

Despite decades of observation from the ground and from spacecraft, a number of mysteries remain.
  • What causes the remarkable super-rotation of Venus' atmosphere – so called because the upper winds travel 50 times faster than the planet's rate of rotation? 
  • How do the winds vary with latitude and longitude? 
  • How much do they change over time?
The answers to some of these questions are being provided by instruments on board Venus Express, such as the Venus Monitoring Camera (VMC), which have been observing the atmosphere for 10 Venus years – equivalent to 6 Earth years.

Venus Monitoring Camera (VMC)
The VMC acquires instantaneous snapshots of Venus at UV and near-infrared wavelengths.

Simultaneous imaging in these wavebands makes it possible to detect and track cloud features, and thus derive wind data, at two different levels - approximately 70 km and 60 km above the surface.

Venus Express follows a 24 hour orbit which approaches to approximately 250 km above the north pole, before moving out to a distance of 66 000 km above the south pole.

This highly elliptical path provides particularly good viewing conditions for the entire southern hemisphere, while enabling higher resolution, small scale images of the northern hemisphere.

These factors combined mean that VMC imagery provides, for the first time, an opportunity to study cloud level winds with high spatial and temporal resolution over a time scale of more than half a decade.

The latest analyses of Venus' cloud motions and wind speeds, based on VMC data, have been made by two independent teams - one led by a Russian group (Khatuntsev et al.) and the other by a Japanese group (Kouyama et al.).

By painstakingly measuring how cloud features in VMC images move between frames, the two groups have been able to reveal new patterns in the planet's circulation.

"We analysed images obtained during 127 orbits with a manual cloud tracking method, and 600 orbits with a digital correlation method," said Igor Khatuntsev from the Space Research Institute in Moscow, lead author of a paper in the journal Icarus.

"Over 45 000 features were tracked by human visual comparisons, and more than 350 000 features were tracked automatically using a computer programme."

The manual method of wind speed measurements consisted of tracking motions of high contrast cloud features in pairs of images taken at different times.

This allowed better recognition of cloud patterns and was more reliable than the digital method in middle to high latitudes, where clouds tend to be streaky, or where contrast was low.

The problem with this method is that it is very time consuming.

On the other hand, the digital tracking technique was capable of streamlining image processing and producing 10 times the number of wind vectors.

Both methods were in good agreement at low latitudes (below 40 degrees), but digital tracking was preferred for studying temporal variations of the mean (average) rate of flow.

The Japanese-Swedish team relied solely upon their own automated cloud tracking method to derive their motion from images taken about one hour apart, at latitudes between 55°S and 70°S.

A specially developed mathematical formula was used to reduce errors in the image analysis. This team's analysis is published in the Journal of Geophysical Research.

More information: I. Khatuntsev et al., Cloud level winds from the Venus Express Monitoring Camera imaging, accepted for publication in the Journal Icarus; doi:10.1016/j.icarus.2013.05.018

T. Kouyama et al., Long-term variation in the cloud-tracked zonal velocities at the cloud top of Venus deduced from Venus Express VMC images. In press at Journal of Geophysical Research - Planets; doi:10.1029/2011JE004013.

Saturday, November 24, 2012

NASA Mars HiRISE Image: Starburst Spider Terrain

Credit: NASA Mars HiRISE

Mars’ seasonal cap of carbon dioxide ice (dry ice) has eroded many beautiful terrains as it sublimates (goes directly from ice to vapor) every spring.

In this region we see troughs that form a starburst pattern.

In other areas these radial troughs have been referred to as “spiders,” simply because of their shape.

In this region the pattern looks more dendritic as channels branch out numerous times as they get further from the center.

The troughs are believed to be formed by gas flowing beneath the seasonal ice to openings where the gas escapes, carrying along dust from the surface below.

The dust falls to the surface of the ice in fan-shaped deposits.

You can find more images here

Friday, September 14, 2012

NASA MRO Monitors Poles: 'Dry Ice' Snowflakes fall

Researchers have calculated that carbon dioxide snow particles on Mars are roughly the size of a human red blood cell. 

Martian snow is depicted in this artist's rendering as a mist or fog that eventually settles to the surface. 

CREDIT: NASA, Christine Daniloff/MIT News

A spacecraft orbiting Mars has detected carbon dioxide snow falling on the Red Planet, making Mars the only body in the solar system known to host this weird weather phenomenon.

The snow on Mars fell from clouds around the planet's south pole during winter about five years ago during the Martian winter spanning 2006 and 2007, with scientists discovering it only after sifting through observations by NASA's Mars Reconnaissance Orbiter (MRO).

The Martian south pole hosts a frozen carbon dioxide, "dry ice," cap year-round, and the new discovery may help explain how it formed and persists, researchers said.

"These are the first definitive detections of carbon-dioxide snow clouds," lead author Paul Hayne, of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said in a statement.

"We firmly establish the clouds are composed of carbon dioxide — flakes of Martian air — and they are thick enough to result in snowfall accumulation at the surface."

The find means Mars hosts two different kinds of snowfall. In 2008, NASA's Phoenix lander observed water-ice snow — the stuff we're familiar with here on Earth — falling near the Red Planet's north pole.

Hayne and his team studied data gathered by MRO's Mars Climate Sounder instrument during the Red Planet's southern winter in 2006-2007.

This instrument measures brightness in nine different wavelengths of visible and infrared light, allowing scientists to learn key characteristics of the particles and gases in the Martian atmosphere, such as their sizes and concentrations.

The research team examined measurements the Mars Climate Sounder made while looking at clouds — including one behemoth 300 miles (500 kilometers) wide — from directly overhead, and from off to the side.

Observations by NASA's Mars Reconnaissance Orbiter have detected carbon-dioxide snow clouds on Mars and evidence of carbon-dioxide snow falling to the surface. 

Deposits of small particles of carbon-dioxide ice are formed by snowfall from carbon-dioxide clouds. 

This map shows the distribution of small-grain carbon-dioxide ice deposits formed by snowfall over the south polar cap of Mars. 

It is based on infrared measurements by the Mars Climate Sounder instrument on the Mars Reconnaissance Orbiter. Image released September 11, 2012. 

CREDIT: NASA/JPL-Caltech


 These combined observations clearly revealed dry-ice snow falling through the Red Planet's skies, researchers said.

"One line of evidence for snow is that the carbon-dioxide ice particles in the clouds are large enough to fall to the ground during the lifespan of the clouds," said co-author David Kass, also of JPL.

"Another comes from observations when the instrument is pointed toward the horizon, instead of down at the surface."

"The infrared spectra signature of the clouds viewed from this angle is clearly carbon-dioxide ice particles, and they extend to the surface," Kass added.

"By observing this way, the Mars Climate Sounder is able to distinguish the particles in the atmosphere from the dry ice on the surface."

Saturday, August 18, 2012

Scottish Mullite: Silicate Material That Can Cut Diesel Pollution

Platinum, a rare and expensive metal, is currently used in diesel engines to try to control the amount of pollution released into the air.

Scientists have now developed a new material that is much more effective than platinum in reducing pollution. University of Texas at Dallas scientists have found that oxide mullite could reduce pollution up to 45 percent compared to platinum crystals.

Mullite or porcelainite is a rare silicate mineral of post-clay genesis, They claim that mullite is less expensive to produce compared to platinum crystals.

Mullite was first described in 1924 for an occurrence on the Isle of Mull, Scotland. It occurs as argillaceous inclusions in volcanic rocks in the Isle of Mull and also with emerylike rocks in Sithean Sluaigh, Scotland.

"Many pollution control and renewable-energy applications require precious metals that are limited - there isn't enough platinum to supply the millions and millions of automobiles driven in the world," said Dr Kyeongjae "K J" Cho, professor at the University of Texas.

"Mullite is not only easier to produce than platinum, but also better at reducing pollution in diesel engines."

Diesel engines give higher fuel efficiency compared to gasoline but produce more nitric oxide (NO) and nitrogen dioxide (NO2), which are quite harmful to human health.

Recently, the World Health Organisation (WHO) upgraded the classification of diesel engine exhaust as carcinogenic in humans, putting it in the same category as cigarette smoke and asbestos.

Countries throughout the world have drafted guidelines to reduce diesel air pollution in the next decade.

The new material developed by scientists could be a new cheap and effective way to reduce pollution.

The discovery was made while analysing the chemical components of mullite.

The team used advanced computer modelling techniques to analyse how different forms of the mineral interacted with Oxygen (O) and Nitrous Oxide (NOx).

The study revealed that the oxide mullite reduces pollution up to 45 percent compared to platinum crystals.

"Our goal to move completely away from precious metals and replace them with oxides that can be seen commonly in the environment has been achieved," Dr Cho said.

"We've found new possibilities to create renewable, clean energy technology by designing new functional materials without being limited by the supply of precious metals."

Friday, March 2, 2012

ESA Envisat: Earth from Space: Historical view

West Africa’s coast along the Atlantic Ocean is pictured in this first image from Envisat’s MERIS instrument nearly a decade ago.

This week, Envisat celebrated ten years in orbit. The Medium Resolution Imaging Spectrometer (MERIS) on board the satellite was developed to measure sea colour in oceans and coastal areas, although it has been used for a variety of additional applications over the years.


Envisat carries ten sensors, collecting imagery and other data on Earth’s land, oceans, atmosphere, temperature and ice cover.

The first batch of data from the satellite in March 2002 was acquired via the Kiruna station in Sweden and processed at ESA’s ESRIN establishment in Italy and other centres throughout Europe.

In this first image from MERIS on 22 March 2002, a very dry desert directly borders the ocean teeming with life. To the south, a high concentration of phytoplankton was detected along the coasts of Senegal, the Gambia and Guinea-Bissau.

Small, single-celled phytoplankton play a key role in the marine food chain. They convert sunlight, carbon dioxide and nutrients into carbohydrates on which nearly all life in the ocean depends.

In most parts of Earth’s oceans, phytoplankton concentration is extremely low. However, in ‘upwelling areas’ like the one pictured here, the ocean becomes rich in minerals from the mixing of surface waters with deeper waters.

The most important fishing grounds can be found in these upwelling areas. Climate change has an effect on the intensity and geographical position of these areas, which, in turn, has important consequences for the fishing industries and those who depend on them.

Also evident in this image is the transition from the dry desert lands in the north through the savannah and to tropical vegetation in the south, which receives more rainfall. MERIS can monitor land use that leads to increased erosion and soil loss.

The Image of the Week is featured on ESA Web-TV, broadcast online every Friday at 10:00 CET.

Friday, February 24, 2012

Mars HiRise Image: Spring on Mars

Spring on Mars. This image provided by NASA/JPL and the University of Arizona shows barchan (crescent-shaped) sand dunes in the North Polar region on Mars. 

In this image, taken during the northern spring season, the dunes and ground are still covered in seasonal frost.

The speckled appearance is due to the warming of the area.

As the carbon dioxide frost and ice on the dunes warms, small areas warm and sublimate (turn from solid to gas) faster, creating small jets that expose/deposit dark sand and dust onto the surface. 

Notice that there are no spots on the ground between the dunes - that is because the ground stays more uniformly cold, unlike the darker dune sand.

Picture: NASA/JPL/University of Arizona/AFP/Getty

Tuesday, January 24, 2012

NASA Video Shows Increase in Global Warming

Global temperatures have warmed significantly since 1880, the beginning of what scientists call the "modern record." 

At this time, the coverage provided by weather stations allowed for essentially global temperature data. 

As greenhouse gas emissions from energy production, industry and vehicles have increased, temperatures have climbed, most notably since the late 1970s. 

In this animation of temperature data from 1880-2011, reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average. 

(Data source: NASA Goddard Institute for Space Studies. Visualization credit: NASA Goddard Space Flight Center Scientific Visualization Studio)

The global average surface temperature in 2011 was the ninth warmest since 1880, according to NASA scientists. The finding continues a trend in which nine of the 10 warmest years in the modern meteorological record have occurred since the year 2000.

NASA's Goddard Institute for Space Studies (GISS) in New York, which monitors global surface temperatures on an ongoing basis, released an updated analysis that shows temperatures around the globe in 2011 compared to the average global temperature from the mid-20th century.

The comparison shows how Earth continues to experience warmer temperatures than several decades ago. The average temperature around the globe in 2011 was 0.92 degrees F (0.51 C) warmer than the mid-20th century baseline.

"We know the planet is absorbing more energy than it is emitting," said GISS Director James E. Hansen. "So we are continuing to see a trend toward higher temperatures. Even with the cooling effects of a strong La Niña influence and low solar activity for the past several years, 2011 was one of the 10 warmest years on record."

The difference between 2011 and the warmest year in the GISS record (2010) is 0.22 degrees F (0.12 C). This underscores the emphasis scientists put on the long-term trend of global temperature rise. Because of the large natural variability of climate, scientists do not expect temperatures to rise consistently year after year. However, they do expect a continuing temperature rise over decades.

The first 11 years of the 21st century experienced notably higher temperatures compared to the middle and late 20th century, Hansen said. The only year from the 20th century in the top 10 warmest years on record is 1998.

Higher temperatures today are largely sustained by increased atmospheric concentrations of greenhouse gases, especially carbon dioxide. These gases absorb infrared radiation emitted by Earth and release that energy into the atmosphere rather than allowing it to escape to space. As their atmospheric concentration has increased, the amount of energy "trapped" by these gases has led to higher temperatures.

temperature graph While average global temperature will still fluctuate from year to year, scientists focus on the decadal trend. Nine of the 10 warmest years since 1880 have occurred since the year 2000, as the Earth has experienced sustained higher temperatures than in any decade during the 20th century. As greenhouse gas emissions and atmospheric carbon dioxide levels continue to rise, scientists expect the long-term temperature increase to continue as well. (Data source: NASA Goddard Institute for Space Studies. Image credit: NASA Earth Observatory, Robert Simmon)

The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, when the GISS global temperature record begins. By 1960, the average concentration had risen to about 315 parts per million. Today it exceeds 390 parts per million and continues to rise at an accelerating pace.

The temperature analysis produced at GISS is compiled from weather data from more than 1,000 meteorological stations around the world, satellite observations of sea surface temperature and Antarctic research station measurements.

A publicly available computer program is used to calculate the difference between surface temperature in a given month and the average temperature for the same place during 1951 to 1980. This three-decade period functions as a baseline for the analysis.

The resulting temperature record is very close to analyses by the Met Office Hadley Centre in the United Kingdom and the National Oceanic and Atmospheric Administration's National Climatic Data Center in Asheville, N.C.

Hansen said he expects record-breaking global average temperature in the next two to three years because solar activity is on the upswing and the next El Niño will increase tropical Pacific temperatures. The warmest years on record were 2005 and 2010, in a virtual tie.

"It's always dangerous to make predictions about El Niño, but it's safe to say we'll see one in the next three years," Hansen said. "It won't take a very strong El Niño to push temperatures above 2010."

Thursday, December 8, 2011

NASA MARS HiRise: Edge of North Polar Erg

This scene is from early spring in the northern hemisphere of Mars.

These dunes are covered with a layer of seasonal carbon dioxide ice (dry ice).

Bluish cracks in the ice are visible across the top of some of the dunes.

Dark fan-shaped deposits around the edges of the dunes are at spots where the ice has sublimated (gone directly from ice to gas) and the ice layer has ruptured, allowing the sand from the dune to escape out from under the ice. The sand is then free to be blown by the wind.

This image is one product from an observation by the High Resolution Imaging Science Experiment (HiRISE) camera taken on Sept. 30, 2011, at 73.3 degrees north latitude, 355.1 degrees east longitude. Other image products from the same observation are at http://www.uahirise.org/ESP_024265_2535 .

HiRISE is one of six instruments on NASA's Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates the orbiter's HiRISE camera, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover and Mars Reconnaissance Orbiter projects for the NASA Science Mission Directorate, Washington.

Image credit: NASA/JPL-Caltech/UA

Friday, October 14, 2011

The Hazy History of Titan's Air

What rocky moon has a nitrogen-rich atmosphere, Earth-like weather patterns and geology, liquid hydrocarbon seas and a relatively good chance to support life?

The answer is Titan, the fascinating moon of Saturn.

Titan's many similarities to Earth is why astrobiologists are so fascinated by this unusual moon.

Its atmosphere is often viewed as an analog to what the Earth's atmosphere may have been like billions of years ago.

Despite the 800 million miles between the two worlds, both may have had their atmospheres created through the gravitational layering and processing of asteroids and comets.

"Titan provides an extraordinary environment to better understand some of the chemical processes that led to the appearance of life on Earth," says Josep M. Trigo-Rodriguez, of the Institute of Space Sciences (CSIC-IEEC) in Barcelona, Spain.

"Titan's atmosphere is a natural laboratory that, in many aspects, seems to have a strong similitude with our current picture of the pre-biotic atmosphere of Earth."

This is remarkable, because it was thought that Earth and Titan were made from a vastly different recipe of materials in drastically different temperatures, he says.

The research paper, "Clues on the importance of comets in the origin and evolution of the atmospheres of Titan," by Trigo-Rodriguez and F. Javier Martin-Torres (Center for Astrobiology, Madrid, Spain), recently published in the journal Planetary and Space Science, offers insight into the atmospheric affinities of Earth and Titan.


Building an Atmosphere From Scratch
Earth presumably formed from scorched, oxygen-poor rocks (planetesimals) located in the inner solar system, while Titan formed from rocks that were rich in oxygen and other volatile chemicals (cometesimals) in the outer solar system.

Trigo-Rodriguez and Martin-Torres believe the vital organic ingredients in the early Earth's atmosphere were vaporized and swept away by solar winds.

The ingredients for the air we breathe today returned about 4 billion years ago, during a cataclysmic rock storm known as the Late Heavy Bombardment (LHB). During this period, oxygen- and volatile-rich materials from the outer solar system were hurled en masse towards the inner solar system.

Chris McKay, a planetary scientist at NASA's Ames Research Center, says comets may have made small contributions to the water, carbon dioxide, and nitrogen content of the Earth's early atmosphere, "but they were not the main source."

This is known because the Deuterium/Hydrogen ratios of our oceans do not match the ratios found in comets. He says asteroids hurled our way during the LHB could be the main source of water on Earth.

Trigo-Rodriguez says he and McKay are basically on the same page. "We think that asteroids and comets were key sources for water and organics," says Trigo-Rodriguez. Four billion years ago, some asteroids contained so much ice that they would have brought just as much water to our planet as comets did.

Trigo-Rodriguez and Martin Torres studied how hydrogen, carbon, nitrogen and oxygen isotopes reacted with their environments on Earth and Titan. They looked at data recorded by the Cassini-Huygens probe to better understand the isotopic ratios in Titan's dense, hazy atmosphere.

Different distances from the Sun, different sizes and different environmental conditions led to different chemical evolutions on the two worlds. Even so, both Earth and Titan were hit by similar water-rich bodies, which provided a volatile-rich source for both atmospheres during the late-heavy bombardment.

Outgassing and collisional processing on both worlds led to the production of molecular nitrogen-dominated atmospheres with similar isotopic ratios of hydrogen, carbon, nitrogen and oxygen.