Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study Finds Space Shuttle Exhaust Creates Night-Shining Clouds

04.06.2003


Exhaust from the main engines of NASA’s space shuttle, which is about 97 percent water vapor, can travel to the Arctic in the Earth’s thermosphere where it forms ice to create some of the Earth’s highest clouds that literally shine at night, according to a new study led by the Naval Research Laboratory and jointly funded by NASA and the Office of Naval Research.


This image shows the launch of space shuttle STS-85 on August 7, 1997. The orange external tank contains over 700 metric tons of liquid hydrogen and liquid oxygen. The main effluent is water. The Stevens et al. results show evidence that this water was transported to the Arctic where it formed a vast region of polar mesospheric clouds covering an area about 10% of North America. Credit: NASA


Because of their high altitude, near the edge of space, noctilucent clouds shine at night when the Sun’s rays hit them from below while the lower atmosphere is bathed in darkness. They typically form in the cold, summer polar mesosphere and are made of water ice crystals. Credit: Naval Research Laboratory, Washington, D.C.



The thermosphere is the highest layer in our atmosphere, occupying the region above about 55 miles (88 kilometers) altitude. The clouds settle to 51 miles (82 km) altitude in the layer directly below called the mesosphere. The stratosphere and the troposphere lie in that order below the mesosphere.

Dr. Michael H. Stevens, the paper’s lead author and a research physicist at the Naval Research Laboratory in Washington, reports that exhaust from the shuttle and other launch vehicles may help explain how some of these mysterious clouds are formed. The paper appeared on Saturday (May 31) in Geophysical Research Letters.


Noctilucent clouds, sometimes called polar mesospheric clouds when observed from space, are too thin to be seen by the naked eye in broad daylight. However, they shine at night when the Sun’s rays hit them from below the horizon while the lower atmosphere is bathed in darkness. They typically form in the cold, summer polar mesosphere and are made of water ice particles.

The study uses data from the Naval Research Laboratory’s Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) instrument, launched on the shuttle for eight days of observation in August, 1997. MAHRSI allowed scientists to follow the plume’s rapid pole-ward transport and then to observe a discrete region of ice clouds as it appeared in the Arctic near the end of the mission. Stevens and colleagues find that the water contained in these clouds is consistent with the amount injected into the thermosphere by the shuttle on its ascent off the east coast of the United States.

“This study is important because it shows that there is a new source of water ice for the polar upper atmosphere,” said Stevens, lead scientist for MAHRSI. “Our results indicate that the water vapor released by launch vehicles can end up in the Arctic mesosphere.”

About half of the water vapor exhaust from the shuttle’s main fuel tank is injected into the thermosphere, typically at altitudes of 64 to 71 miles (103 to 114 km). Stevens and colleagues found that this water vapor can then be transported all the way to the Arctic in a little over a day, much faster than predicted by models of atmospheric winds. There is currently no explanation for why the water moves so quickly.

Stevens and colleagues also include observations from a ground-based experiment in Norway measuring water vapor moving toward the Arctic Circle. These observations reveal the passage of a large plume of water vapor overhead a little over a day after the same (STS-85) shuttle launch, confirming the plume trajectory inferred from the MAHRSI measurements.

As the water vapor moves to the Arctic it falls from the warmer thermosphere down to colder areas in the mesosphere. Over the North Pole in the summer mesospheric temperatures can plummet below minus 220 Fahrenheit (minus 140 Celsius), the lowest found in the Earth’s atmosphere. At these temperatures, water vapor condenses into ice particles and clouds form.

“The amount of water found here is tiny compared to the amount in the lower atmosphere,” Stevens said. “But the long term effects in the upper atmosphere have yet to be studied.”

The Office of Naval Research and NASA’s Office of Space Science funded the study.

Krishna Ramanujan | NASA Goddard Space Flight Center
Further information:
http://www.gsfc.nasa.gov/topstory/2003/0522shuttleshine.html

More articles from Earth Sciences:

nachricht Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation

nachricht NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

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...

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

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>