Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellites Tell What Is Dust and What Is Clouds

08.03.2011
After spending the summer working at NASA's Langley Research Center, a graduate student at The University of Alabama in Huntsville is developing techniques that will help instruments aboard satellites more accurately measure both cloud cover and dust in the atmosphere around the globe.

"I do worry about upsetting the people I worked with, but they're always trying to improve their product," said Aaron Naeger, 25, a doctoral student in UAHuntsville's atmospheric science program.

Langley scientists use data from the CALIPSO satellite to map clouds and aerosols -- small particles of dust and other materials suspended in the atmosphere. The satellite does this by shooting laser pulses into the atmosphere, then taking sensitive measurements of the laser light that is bounced back to the satellite. The sensor also calculates the altitude of clouds and aerosols by measuring how long it takes for the signal to return.

"We noticed that many dust plumes were being designated as clouds rather than aerosols," said Naeger. "We noticed this especially in the Sahara summertime. Huge amounts of dust aerosols (more than 700 million tons every year) are being picked up and carried over the Atlantic Ocean: Over half of the dust loading in Earth's atmosphere comes from the Sahara."

The UAHuntsville team has also tested CALIPSO data from Asia's Gobi and Taklamakan deserts, Naeger said. "Not surprising, we notice that most of the aerosols being classified as clouds were near deserts."

Thick, high altitude dust plumes can confuse the CALIPSO instrument because they reflect more of the laser pulse than normal aerosols and float at altitudes usually frequented by clouds.

"If it's high enough, CALIPSO thinks it must be a cloud," Naeger said.

Working with Dr. Sundar Christopher, a professor of atmospheric science, Naeger overcomes that problem using data from the instruments aboard NASA's Aqua and Terra satellites, which fly in "close" formation with CALIPSO. If CALIPSO says something near a desert is a cloud, Naeger tests that with spectral data from the other satellites, including temperature data collected over the same spot.

Naeger spent June at Langley learning the CALIPSO team's newest techniques and showing them his preliminary work, which was used to improve the cloud-aerosol classification system.

Recently, he ran the newest Langley analysis product both with and without his algorithm.

"It is still showing areas where CALIPSO sees clouds where there is dust, although they're doing pretty well for having only two channels on the satellite," Naeger said.

Fine tuning the census of clouds and aerosols is important for global climate research because aerosols have the opposite effect on the atmosphere as greenhouse gases. Aerosols generally cool the atmosphere by blocking sunlight. Clouds can both warm and cool the atmosphere, depending on many factors.

"If we have very confident knowledge of what we see, we can do some climate research using CALIPSO," Naeger said. "It is important to know cloud and dust coverage."

Ray Garner | Newswise Science News
Further information:
http://www.uah.edu

More articles from Information Technology:

nachricht Gecko adhesion technology moves closer to industrial uses
13.12.2017 | Georgia Institute of Technology

nachricht New silicon structure opens the gate to quantum computers
12.12.2017 | Princeton University

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>