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.

Computer model shows moon's core surrounded by liquid - Earth Gravitational pull

A team of researchers with team members from China, the U.S. and Japan has created a computer model that shows that the moon is not solid all the way through, instead, it shows a liquid layer surrounding the core. 

In their paper published in the journal Nature Geoscience, the team suggests the liquid layer, if it's really there, is caused by friction due to Earth's gravity.

Scientists have noted anomalies in measurements of the moon's orbit and associated gravitational readings for some time.

Such anomalies have defied explanation, however, as models built to replicate them have generally produced results that weren't very clear.

The Earth and the Moon, an image taken from Mars by the MRO.

Credit: Nasa

At root however, has been the idea that the moon's core may be covered by a thin layer of liquid.

The team noted that gravitational readings of the moon indicate that there is rotation at the core that is not the same as other rotation measurements near the core. This suggests a liquid outer layer.

To getter a better idea of what might be going on at the moon's center, the researchers built a computer model that takes into account the gravity exerted by the moon, the earth and the sun.

Early Science Fiction Image of Moon

When set into motion, the model showed that a liquid layer over the core gave the same gravity readings as scientists have found when measuring the real moon.

This suggests, the team reports, that a liquid layer does truly exist, and likely has been there for a very long time.

As for why such a layer would exist, the team suggests that the tug of Earth's gravity, tidal heating, is likely playing a role, causing friction between the core and material above it, resulting in the creation and maintenance of a liquid layer.

A lot more research will have to be done, of course, before scientists accept the results of the computer model but if such research should prove that there is a liquid layer, scientists might have to do some rethinking of theories that describe the origin of the moon.

If the moon was created due to a large body striking Earth, why did it not cool down over the four and half billion years since then, to the extent that it would be too cold for a liquid layer to exist today?

More information: Nature Geoscience (2014) DOI: 10.1038/ngeo2211

New computer model may explain moon Europa's chaotic terrain

This rendering shows the temperature field in a simulation of Europa’s global ocean dynamics, where hot plumes (red) rise from the seafloor and cool fluid (blue) sinks downward from the ice-ocean interface. 

More heat is delivered to the ice shell near the equator where convection is more vigorous, consistent with the distribution of chaos terrains on Europa. 

Credit: Model image created by K. M. Soderlund with the image of Europa taken from NASA/JPL/University of Arizona

A team of researchers at the University of Texas with assistance from a computer modeler at the Max Planck Institute in Germany has put together a computer model that might just explain the peculiar surface of Jupiter's moon Europa.

In their paper published in the journal Nature Geoscience, the team suggests the odd surface terrain patterns likely come about due to convection. Jason Goodman of Wheaton College offers a perspective on the researchers' findings in a News & Views piece printed in the same journal.

The NASA space probe Voyager flew past Jupiter and its moons in 1979, and in so doing, set off a debate about the nature of the surface of one such moon, Europa, that has continued to this day—why is the surface so smooth, and why are there odd rough patches covering nearly 40 percent of its surface?

Scientists agree that the general smoothness is likely due to the existence of water beneath the icy surface—the lack of craters indicates a surface that is able to heal itself after impacts.

Less of a consensus has been found regarding the rough patches, however, which scientists call "chaotic terrain."

Galileo

In this new study, the researchers used data from hydro-systems here on Earth as well as data from both Voyager and the Galileo spacecraft (which detected a magnetic field) to create what they believe is a reasonable model of a convection process working beneath the icy shell of Europa's surface.

Some have suggested Europa's surface gets its unique features due to the pull of gravity from Jupiter—others have suggested the sun plays a role.

Such theories have not held much weight however, as there is little evidence to suggest that either could account for the chaotic terrain.

Instead, the modelers suggest, it's due to convection driven by heat from the interior of the moon itself.

Their model shows, they write that currents beneath the ice tend to deliver heat primarily to the equatorial regions of the surface which in turn causes constant heating, melting and refreezing—resulting they say, in the chaotic terrain that we are able to observe.

More information: Ocean-driven heating of Europa's icy shell at low latitudes, Nature Geoscience (2013) DOI: 10.1038/ngeo2021