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 Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>