NSF : Scientists use holography to peer into clouds .- Los científicos usan la holografía para mirar en las nubes

Hola amigos: A VUELO DE UN QUINDE EL BLOG., hemos recibido información de la Fundación Nacional de Ciencias de Los Estados Unidos, quienes están utilizando la halografía para sus investigaciones en la observación sobre el movimiento de las nubes, que puedan ayudar a predecir el clima en una determinada región.

More information................
http://www.nsf.gov/news/news_summ.jsp?cntn_id=136418&WT.mc_id=USNSF_51&WT.mc_ev=click

New way of seeing clouds enhances weather, climate predictions

The HOLODEC instrument, or Holographic Detector for Clouds, on a C-130 aircraft. Credit and Larger Version

October 1, 2015

Watching clouds go by, swirls of white puff up and melt away. The changes mirror mixing within the clouds as drier air mingles with water-saturated air.

New research led by scientists at Michigan Technological University, along with the National Center for Atmospheric Research (NCAR) and Mainz University, analyzes this mixing with holographic imaging and an airborne laboratory.

Results of a study using the new way of seeing clouds--and their unusual mixing behavior--are reported in the journal Science this week.

"Clouds are the most conspicuous and dynamic feature of the Earth's atmosphere," says Chungu Lu, a program director in the National Science Foundation's (NSF) Division of Atmospheric and Geospace Sciences, which funded the research.

"They play decisive roles in forecasting weather and assessing climate change," says Lu. "The initiation, development and dissipation of clouds depend on interactions between cloud droplets and their air environment. This study offers an important understanding of how these interactions occur at the finest scales."

 

Boundaries in the clouds

 

Sharp boundaries form as dry air completely evaporates some water drops and leaves others unscathed. The findings will influence models that help predict weather and climate change.

Raymond Shaw, a Michigan Tech physicist, looks at the smallest part of clouds: droplets. To understand groups of droplets, Shaw and NCAR researchers flew airplanes through fluffy cumulus clouds in Wyoming and Colorado.

Aboard the plane, the team took detailed 3-D images with an instrument called the Holographic Detector for Clouds (HOLODEC--after the "Star Trek" holodeck). These particular clouds were made up only of liquid water. The size of the drops is a key part of cloud formation and mixing.

"You can take a certain amount of water and divide it up into many small drops or just a few big drops," Shaw says, explaining that it's like having a lot of sand or just a few boulders. "And by dividing it up in different ways, you can change the optical properties of the clouds, making them brighter or darker, more or less reflective."

The differences affect how much sunlight makes it into the lower atmosphere--and can reflect, buffer or trap in heat.

The challenge, however, is that clouds don't blanket regions--let alone the world--in a uniform layer. On smaller scales within clouds, mixing affects the spacing between drops, what size they are and how they are distributed throughout the clouds.

 

Enter HOLODEC

 

The HOLODEC instrument, which is a tube about six inches in diameter and several feet long, samples a cloud volume about the size of a marker and provides unique insight into cloud mixing.

Jeff Stith, who manages the Research Aviation Facility at NCAR, compares this mingling to a marbled cake. The wet air, filled with droplets, is like red cake; the dry air is like white cake. Stith, Shaw and the team wanted to know how fine the boundaries are between red and white cake and how much pink cake there might be.

Using HOLODEC, the scientists observed clear boundaries--distinct lines between wet and dry air.

The size of the droplets remained unaffected. The ones that dissipated went away completely and the ones left behind stayed the same size, making a marbled cake.

Together the open space and large drops encourage clouds to grow. With enough mixing, the droplets tend to spread out more evenly, blurring the distinct boundaries.

 

From fiction to fact

 

Like its "Star Trek" counterpart, the HOLODEC needs a flying vessel.

In this case, the HOLODEC was carried on a C-130 airplane, maintained by NCAR and owned and supported by NSF, along with the University of Wyoming's King Air Research Aircraft, also supported by NSF.

The combination has been more than a decade in the making. Shaw says it all started with a prototype HOLODEC, machined and cobbled together over several months.

"It worked--then we had to figure out what to do with the data," Shaw says, recalling that the early years were spent tweaking the device and figuring out how to display droplets accurately. "Now, we've built a better instrument and refined the technique, and we are finally able to handle large amounts of data."

Looking at those data was only possible with high-end graphics cards, the kind favored by hardcore gamers. Further processing the data will enable Shaw and the research team to visualize mixing in clouds and provide insights into how to improve weather and climate models.

 

Layer cake of clouds

 

The challenges of understanding mixing in clouds have persisted for several decades. What the team found with the marbled cake distribution, or inhomogenous mixing, as scientists call it, goes against what most computer models assume for cloud dilution.

"It would be more accurate to say that some droplets are eroded away and that the ones that are left over are just as big as they were at the start," Shaw says, cautioning that the parameters of the study looked only at a single dry region and focused on water-only cumulus clouds. "What if we look in the tropics or in different cloud types? The process might be different."

Reviewing other conditions is possible with the airborne lab and HOLODEC. Gathering more data--and turning the data into computer modeling code--will enhance predictions for weather and climate, the scientists say.

-NSF-

Media Contacts Cheryl Dybas, NSF, (703) 292-7734, cdybas@nsf.gov
Allison Mills, MTU, (906) 487-2343, awmills@mtu.edu
David Hosansky, NCAR, (303) 497-8611, hosansky@ucar.edu

Related WebsitesNSF Grant: Laboratory and Field Studies of Cloud-Turbulence Interactions via Digital Holography: http://www.nsf.gov/awardsearch/showAward?AWD_ID=1026123&HistoricalAwards=false

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2015, its budget is $7.3 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 48,000 competitive proposals for funding, and makes about 11,000 new funding awards. NSF also awards about $626 million in professional and service contracts yearly.

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Not quite the Starship Enterprise, the C-130 is nonetheless a sophisticated airborne laboratory.
Credit and Larger Version

HOLODEC, on the ground. Once aloft, it will allow research into droplets' interactions with light.
Credit and Larger Version

With HOLODEC, atmospheric scientists can investigate clouds at the plane's wingtip.
Credit and Larger Version

HOLODEC's tip allows researchers to measure the attributes of clouds at the droplet scale.
Credit and Larger Version

Scientist Raymond Shaw and colleagues study the smallest part of clouds: water droplets.
Credit and Larger Versión
 The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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NASA - NASA's SAMPEX Mission: A Space Weather Warrior

NASA Ceremony to Rename Twin Earth Radiation Belt Spacecraft

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An artist's rendition of the Solar, Anomalous, and Magnetospheric Particle Explorer or SAMPEX. Credit: NASA .

 NASA's very first small explorer, the Solar, Anomalous, and Magnetospheric Particle Explorer or SAMPEX, was launched July 3, 1992 to study the zoo of particles and cosmic rays surrounding Earth. Surviving much longer than its expected mission of three years and providing invaluable observations for those who study space weather, the SAMPEX mission is now almost over. In early November, the spacecraft's orbit will decay enough that it will re-enter Earth's atmosphere, burning up completely on re-entry.

When SAMPEX launched, the sun was just finishing the peak of its 11-year solar cycle and beginning to move toward solar minimum. Scientists were eager to watch what happened in near-Earth space in those first few years, as eruptions on the sun shot out energy and solar material and eventually tapered down into a period of quiet. However, those same effects were also predicted to lead to the spacecraft's demise. As the sun once again ramped up to solar maximum around 2000, the sun's output would create enough atmospheric drag that SAMPEX was expected to tumble out of its stable orbit.

Contrary to such predictions, SAMPEX is still in orbit having survived that maximum and continuing in orbit long enough to see the sun move toward another solar max, currently predicted for 2013. But time is running out. As the atmosphere near Earth heats and swells in response to the sun's activity, the expansion of the uppermost atmosphere has encased SAMPEX, slowing it down. Soon the 20-year-old spacecraft will succumb to the very space weather it has helped scientists to study. Some time at the end of 2012, the orbit of the five-by-three-foot craft will spiral far enough in that SAMPEX will re-enter Earth's atmosphere, burning up completely and disappearing forever.

"SAMPEX was launched on a shoe string budget," says Shri Kanekal, a space weather scientist at NASA's Goddard Space Weather Center in Greenbelt, Md. who has been involved with SAMPEX research since its launch. "It was proposed as a minimum one-year mission with a goal of three years, but it lasted for an unexpectedly long time. It has provided 20 years of high quality data, used by nearly everyone who studies near-Earth space."

In its two decades, SAMPEX provided one of the main sources of data on how the radiation environment around Earth changed over time, waxing and waning in response to incoming particles from the sun and galaxy. SAMPEX confirmed earlier theories that cosmic rays streaming in from outer space were being trapped in Earth's own magnetic environment, the magnetosphere, and it helped pinpoint the location where they gathered in a belt around Earth. Another area of research has been to tease out the composition of various particle populations from high-speed and high-energy particles from the sun known as solar energetic particles, to the host of electrons in Earth's middle atmosphere.

Also, SAMPEX has been one of our best eyes on the radiation belts – two giant donuts of radiation surrounding Earth that can affect satellites in orbit during their occasional bouts of swelling. Indeed, scientists are eager for SAMPEX data still, eking out the last weeks of observation time to compare with early data from the Radiation Belt Storm Probes (RBSP) mission that launched in August, 2012.

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 SAMPEX data have provided some of the most useful observations of the Van Allen Belts -- two rings of radiation around Earth. This SAMPEX data shows the belts during what's known as the Halloween Storms in October 2003, a time when the radiation belts around Earth swelled so much that they merged into a single ring. Credit: NASA/Goddard Space Flight Center

 When those who study the radiation belts realized how imminent was the demise of SAMPEX, they adjusted the schedule to turn on a SAMPEX-compatible instrument aboard RBSP, an instrument called Relativistic Electron Proton Telescope (REPT), earlier than planned. One of the space phenomena that SAMPEX has helped categorize is something called microbursts, an intense but short lived phase during which electrons drop out of the radiation belts. From its viewpoint under the radiation belts, SAMPEX can still record such microbursts. As part of RBSP, on the other hand, REPT can look at the electron population while traveling through the radiation belts proper. In combination, the data may help show what occurrences in the radiation belts correlate to the rain of electrons, the microbursts.

"Since one of the main goals of RBSP is to understand why and how electrons rain down out of the radiation belts, this will be important science," says Kanekal. "It's made all the more impressive that we can do this kind of research despite the fact that SAMPEX's science mission officially ended in 2004."

Although the spacecraft has remained in orbit, the official SAMPEX science mission ended in June 2004. New data remained available, however, thanks to The Aerospace Corporation of El Segundo, Calif., which continued to fund costs to download data, and to Bowie State University in Bowie, Md., which operated the spacecraft to maintain the download process as an educational tool for its students. Kanekal was also instrumental in getting a grant to process all the data from 2004 to 2012, so it will be usable by the science community.

NASA's first small explorer had an impressive run, far outliving its planned three-year mission. It provided data crucial to understanding how the space around Earth responds to space weather from the sun and will continue to do so up until the moment it re-enters Earth's atmosphere, disappearing forever.
Karen C. Fox

NASA Goddard Space Flight Center, Greenbelt, MD

 NASA

Guillermo Gonzalo Sánchez Achutegui

ayabaca@gmail.com

ayabaca@hotmail.com

ayabaca@yahoo.com

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