Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Appearance of Night-Shining Clouds Has Increased

11.04.2014

First spotted in 1885, silvery blue clouds sometimes hover in the night sky near the poles, appearing to give off their own glowing light. Known as noctilucent clouds, this phenomenon began to be sighted at lower and lower latitudes -- between the 40th and 50th parallel -- during the 20th century, causing scientists to wonder if the region these clouds inhabit had indeed changed -- information that would tie in with understanding the weather and climate of all Earth.

A NASA mission called Aeronomy of Ice in the Mesosphere, or AIM, was launched in 2007 to observe noctilucent clouds, but it currently only has a view of the clouds near the poles.


Night-shining, or noctilucent clouds on July 3, 2011, in Lock Leven, Fife, Scotland.

Image Credit: Courtesy of Adrian Maricic


NASA's Aeronomy of Ice in the Mesosphere, or AIM, mission captured this image of noctilucent clouds over the poles in 2010. By compiling data from several missions at once, researchers have now created a record of the clouds at lower latitudes as well.

Image Credit: NASA/AIM

Now scientists have gathered information from several other missions, past and present, and combined it with computer simulations to systematically show that the presence of these bright shining clouds have indeed increased in areas between 40 and 50 degrees north latitude, a region which covers the northern third of the United Sates and the lowest parts of Canada.

The research was published online in the Journal of Geophysical Research: Atmospheres on March 18, 2014.

"Noctilucent clouds occur at altitudes of 50 miles above the surface -- so high that they can reflect light from the sun back down to Earth," said James Russell, an atmospheric and planetary scientist at Hampton University in Hampton, Va., and first author on the paper.

"AIM and other research has shown that in order for the clouds to form, three things are needed:  very cold temperatures, water vapor and meteoric dust. The meteoric dust provides sites that the water vapor can cling to until the cold temperatures cause water ice to form." 

To study long-term changes in noctilucent clouds, Russell and his colleagues used historical temperature and water vapor records and a validated model to translate this data into information on the presence of the clouds.

They used temperature data from 2002 to 2011 from NASA's Thermosphere Ionosphere Mesosphere Energetics and Dynamics, or TIMED, mission and water vapor data from NASA's Aura mission from 2005 to 2011. They used a model previously developed by Mark Hervig, a co-author on the paper at GATS, Inc., in Driggs, Idaho.

The team tested the model by comparing its output to observations from the Osiris instrument on the Swedish Odin satellite, which launched in 2001, and the SHIMMER instrument on the U.S. Department of Defense STPSat-1 mission, both of which observed low level noctilucent clouds over various time periods during their flights. The output correlated extremely well to the actual observations, giving the team confidence in their model.

The model showed that the occurrence of noctilucent clouds had indeed increased from 2002 to 2011. These changes correlate to a decrease in temperature at the peak height where noctilucent clouds exist in the atmosphere. Temperatures at this height do not match temperatures at lower levels – indeed, the coldest place in the atmosphere is at this height during summertime over the poles – but a change there certainly does raise questions about change in the overall climate system.

Russell and his team will research further to determine if the noctilucent cloud frequency increase and accompanying temperature decrease over the 10 years could be due to a reduction in the sun’s energy and heat, which naturally occurred as the solar output went from solar maximum in 2002 to solar minimum in 2009.

"As the sun goes to solar minimum, the solar heating of the atmosphere decreases, and a cooling trend would be expected," said Russell.

NASA's Goddard Space Flight Center in Greenbelt, Md. manages the TIMED mission for the agency's Science Mission Directorate at NASA Headquarters in Washington. The spacecraft was built by the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.

Related Links:

› TIMED mission
› Noctilucent clouds and AIM mission
  

Karen C. Fox
NASA's Goddard Space Flight Center, Greenbelt, Md.

Rob Gutro | Eurek Alert!

Further reports about: AIM Flight Greenbelt Mesosphere NASA STPSat-1 Space atmosphere clouds decrease observations satellite spacecraft temperature

More articles from Earth Sciences:

nachricht NASA sees wind shear affecting Hurricane Ignacio
02.09.2015 | NASA/Goddard Space Flight Center

nachricht Oxygen oasis in Antarctic lake reflects Earth in the distant past
02.09.2015 | University of California - Davis

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How wind sculpted Earth's largest dust deposit

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...

Im Focus: An engineered surface unsticks sticky water droplets

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.

Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Tracking Down the Causes of Alzheimer’s

03.09.2015 | Studies and Analyses

Tiny Drops of Early Universe 'Perfect' Fluid

02.09.2015 | Physics and Astronomy

Learning from Nature: Genomic database standard alleviates search for novel antibiotics

02.09.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>