Strange Skies
S


Bizarro Earth

A Day of Night-Shining Clouds


NASA Earth Observatory
Thu, 27 Jan 2011 17:41 UTC
Mesospheric Clouds
© Robert SimmonPolar mesospheric clouds acquired June 20, 2007.

Scientists have a good reason to track noctilucent or polar mesospheric clouds: they are a pretty good gauge of even the tiniest changes in the atmosphere. These "night-shining clouds," as they are sometimes called, are thin, wavy ice clouds that form at very high altitudes and reflect sunlight long after the Sun has dropped below the horizon.

To look for changes in the atmosphere, scientist Matthew DeLand (of Science Systems and Applications Inc. and NASA's Goddard Space Flight Center) has been monitoring polar mesospheric clouds with instruments that were actually designed to study ozone, including the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. OMI provides more detailed and frequent observations than previous instruments, giving DeLand a way to refine his previous measurements of a long-term trend towards more and brighter noctilucent clouds linked to rising greenhouse gases.

These images show OMI measurements of polar mesospheric clouds on July 10, 2007. The clouds, detectable because they are the only things that reflect light in this part of the atmosphere, are shown in white and pink. The Aura satellite travels in a polar orbit, circling from south to north as the Earth turns beneath it. As a result, the satellite gets several opportunities to image the poles every day. This series of images shows the clouds over six consecutive orbits between 7:16 and 15:52 Universal Time. Throughout the day, a wide area of polar mesospheric clouds developed over northern Greenland and Canada, peaking around 10:30 UTC (the third orbit).
Read More...
Question

Night-Shining Clouds are Getting Brighter


NASA
Wed, 26 Jan 2011 20:47 UTC
Mesopheric Clouds
© Jan Erik PaulsenIncrease of Polar Mesospheric Clouds, 1979–2010.
Mesopheric Clouds_1
© Robert SimmonAdapted from Latitude-dependent long-term variations in polar mesospheric clouds from SBUV version 3 PMC data. - January 1, 1979 - December 31, 2010
After the Sun sets on a summer evening and the sky fades to black, you may be lucky enough to see thin, wavy clouds illuminating the night, such as these seen over Billund, Denmark, on July 15, 2010. Noctilucent or polar mesospheric clouds, form at very high altitudes - between 80 and 85 kilometers (50 - 53 miles) - which positions them to reflect light long after the Sun has dropped below the horizon. These "night-shining" clouds are rare - rare enough that Matthew DeLand, who has been studying them for 11 years, has only seen them once in person. But the chances of seeing these elusive clouds are increasing.

DeLand, an atmospheric scientist with Science Systems and Applications Inc. and NASA's Goddard Space Flight Center, has found that polar mesospheric clouds are forming more frequently and becoming brighter. He has been observing the clouds in data from Solar Backscatter Ultraviolet instruments that have been flown on satellites since 1978. The graph shows how the brightness of the clouds has changed in the Northern Hemisphere. For reasons no one fully understands, the brightness wiggles up and down in step with solar activity, with fewer clouds forming when the Sun is most active. The biggest variability is in the far north. Underlying the changes caused by the Sun, however, is a trend toward brighter clouds. The upward trend in brightness, says DeLand, reveals subtle changes in the atmosphere that may be linked to greenhouse gases.

Polar mesospheric clouds are extremely sensitive to changes in atmospheric water vapor and temperature. The clouds form only when temperatures drop below -130 degrees Celsius (-200 Fahrenheit), when the scant water freezes into ice clouds. This happens most often in far northern and southern latitudes (above 50 degrees) in the summer when, counter-intuitively, the mesosphere is coldest.
Read More...
Meteor

Noctilucent clouds filmed from Space Station - why are these 'nightshiners' visible at ever lower altitudes?

wired
YouTube
Sun, 09 Jan 2011 12:39 UTC
Noctilucent clouds were captured on the following video by the International Space Station's Science Officer, Ed Lu, in 2003. Now, the rare high-altitude clouds are showing up at lower and lower latitudes and scientists aren't sure why.


Comment: You may want to read these, then wake up and smell the ozone:

A Puzzling Collapse of Earth's Cooling Upper Atmosphere

Shields down! Earth's magnetic field may drop in a flash

Earth's Magnetic Field Is Fading

Read More...
Sun

Spectacular sundogs and ice halo seen from Stockholm


Spaceweather.com
Sun, 12 Dec 2010 11:28 UTC
Last Wednesday in Stockholm, Sweden, the sun was only up for a little while, but it made good use of its time. Sunbeams lanced through ice crystals in the air, producing a busy halo of surpassing beauty:

Image
© Peter Rosén
"This was the most spectacular sun halo I have seen in recent years from Stockholm," says photographer Peter Rosén. "It was visible for the whole (short) day." In addition to the sundogs, upper tangent arc, and 22° halo captured in the snapshot above, Rosén also witnessed "a 46° outer halo and a circumzenithal arc as ice crystals blew in gusts across the sun. What a show!"

Now is the time of year when low-hanging suns shine through high-floating ice to produce such vistas. People of the northern hemisphere should be alert for halos.
Read More...
Sun

Swaziland: Panic Over Sun's Strange Appearance

Cassandra Shaw
Times of Swaziland
Tue, 02 Nov 2010 13:45 UTC
Halo Around Sun
© Times of SwazilandHalo around sun.
Mbabane - It was an unusual day for many, and some thought the world was coming to an end yesterday.

This was due to a circle of light (a halo) that was seen in the morning hours surrounding the sun. A halo, in simple terms, refers to a circle of light or radiance. This caused a lot of panic for many people as most were of the view that the world was coming to an end.

The Times of Swaziland office was inundated with calls from the public who wanted to find out about the halo around the sun.

This is similar to a rainbow line, though this time it was just around the sun. According to a statement from the Swaziland Meteorological Department, this phenomenon is known as a 22 Degree Halo.

The rainbow-like circle around the sun is caused by the bending of the sun's light due to tiny hexagonal ice crystals in the upper atmosphere.
Read More...
Info

Orbital Sunrise


NASA
Thu, 02 Sep 2010 17:47 UTC
Noctilucent Cloud
© NASA
The Expedition 24 crew on the International Space Station photographed this image of polar mesospheric clouds illuminated by an orbital sunrise. Polar mesospheric, or noctilucent ("night shining"), clouds usually are seen at twilight, following the setting of the sun below the horizon and darkening of Earth's surface. Occasionally the station's orbital track becomes nearly parallel to Earth's day/night terminator for a time, allowing the clouds to be visible to the crew at times other than the usual twilight because of the station's altitude.

This photograph shows polar mesospheric clouds illuminated by the rising, rather than setting, sun at center right. Low clouds on the horizon appear yellow and orange, while higher clouds and aerosols are illuminated a brilliant white. Polar mesospheric clouds appear as light blue ribbons extending across the top of the image. The station was located over the Greek island of Kos in the Aegean Sea (near the southwestern coastline of Turkey) when the image was taken at approximately midnight local time. The orbital complex was tracking northeastward, nearly parallel to the terminator, making it possible to observe an apparent "sunrise" located almost due north. A similar unusual alignment of the ISS orbit track, terminator position and seasonal position of Earth's orbit around the sun allowed for this striking imagery of over the Southern Hemisphere.
Read More...
Meteor

Hampton University gets $6.3M from NASA to continue noctilucent cloud study

Samieh Shalash
Daily Press
Wed, 11 Aug 2010 09:51 UTC
Noctilucent Clouds Finland 7-28-2001
© Tom Eklund/Daily PressNoctilucent (NLC) or "night-shining" clouds that HU and NASA are studying.
Hampton University has received a $6.3 million contract extension from NASA to continue researching mysterious noctilucent, or "night-shining" clouds in Earth's polar regions and their relationship to climate change.

NASA originally gave HU $140 million in 2002 to spearhead its proposed Aeronomy of Ice in the Mesosphere satellite mission The university launched the satellite in April 2007. It's now in polar orbit to collect images and data about the noctilucent clouds, which are formed by ice and only seen from the ground about an hour after sunset or an hour before sunrise.

This is the university's second multi-million dollar contract extension since the launch. In December, it received $10.2 million to extend the project through September 2012. So far the project has totaled $156.5 million.

The latest $6.3 million extension will allow HU to further track the clouds through the 11-year solar cycle, said James Russell, co-director of the school's Center for Atmospheric Sciences and principal investigator of the mission.
Read More...
Camera

Northern lights and noctilucent clouds over Alberta, Canada


Spaceweather.com
Fri, 30 Jul 2010 10:28 UTC
A high speed solar wind stream is buffeting Earth's magnetic field, and this is causing geomagnetic activity around the poles. Zoltan Kenwell of Edmonton, Alberta, witnessed this display on July 27th:

Image
© Zoltan Kenwell/InFocus Imagery Inc.
"It was a beautiful night on the Alberta prairies," says Kenwell. "Aurora activity was subtle, but definitely present. The full Thunder Moon was lighting up the canola fields and the arrival of a few noctilucent clouds just put the icing on the cake!"

Image
© Zoltan Kenwell/InFocus Imagery
Read More...
Meteor

Ice Crystals on the Rise: Stunning 'Sun Dog' Spotted from Bournemouth Beach, England


Daily Mail
Wed, 21 Jul 2010 07:24 UTC
sun dog halo ice crystals
© BN&PSBournemouth photographer Chris Skone-Roberts captured this amazing 'sun dog' hovering over the seaside town yesterday.
It looks like a giant eye gazing down from the heavens.

But the spectacular sight of the sun surrounded by a mysterious halo is known as a 'sun dog'.

The phenomenon, which had beachgoers in Bournemouth gazing at the sky yesterday, occurs when sunlight is refracted by hexagonal-shaped ice crystals in high and cirrus clouds - and is quite common.


Comment: It is interesting to note that a competing version of this story actually classifies this as a "rare phenomenon"


This picture was taken from Bournemouth beach in Dorset by photographer Chris Skone-Roberts.

The phenonemen is officially called a pathelia but is also known as a 'halo' or 'mock sun'.
Read More...
Meteor

Noctilucent Clouds Photographed over Denmark


SpaceWeather.com
Thu, 03 Jun 2010 09:25 UTC
Recent data from NASA's AIM spacecraft show that noctilucent clouds (NLCs) are like a great "geophysical light bulb." They turn on every year in late spring, reaching almost full intensity over a period of no more than 5 to 10 days. News flash: The bulb is beginning to glow. Jesper Grønne photographed a bank of NLCs rippling over Silkeborg, Denmark, on June 1st:
Image
© Jesper Grønne
Read More...