Image of the week
Interesting Images from Around the Universe
Stunning images captured on earth or from space
Known as the green “Christmas comet”, even the northern lights over Norway could not prevent it from being seen on Monday night, December 17th, 2018.
A GOES-East satellite image reveals the deep snow pack that still remains across much of western North Carolina and southern Virginia. Clouds can be seen off the east coast and over the Great Lakes, but clear skies over the snow pack allow for great viewing today, Wednesday, December 12th.
Since 13 September, European Space Agency’s Mars Express has been observing the evolution of an elongated cloud formation hovering in the vicinity of the 20 km-high Arsia Mons volcano, close to the planet’s equator.
In spite of its location, this atmospheric feature is not linked to volcanic activity but is rather a water ice cloud driven by the influence of the volcano’s leeward slope on the air flow – something that scientists call an orographic or lee cloud – and a regular phenomenon in this region.
The cloud can be seen in this view taken on 10 October by the Visual Monitoring Camera (VMC) on Mars Express – which has imaged it hundreds of times over the past few weeks – as the white, elongated feature extending 1500 km westward of Arsia Mons. As a comparison, the cone-shaped volcano has a diameter of about 250 km.
Mars just experienced its northern hemisphere winter solstice on 16 October. In the months leading up to the solstice, most cloud activity disappears over big volcanoes like Arsia Mons; its summit is covered with clouds throughout the rest of the martian year.
Hurricane Willa has strengthened into a cat 5 storm as of Monday, October 22, 2018 and it will actually play a role in a potential nor’easter this weekend by feeding energy and moisture into the Gulf of Mexico region. Hurricane Willa is likely to weaken into a category 2 or 3 storm before making landfall in Mexico over the next couple of days.
These spectacular lenticular clouds were seen in California on Sunday, September 30th, 2018. Lenticular clouds are stationary clouds that form in the troposphere, usually in perpendicular alignment to the wind direction. As air travels along the surface of the Earth, obstructions are often encountered. These include both natural features of the Earth such as mountains or hills, and man-made structures, such as buildings and other structures. These disrupt the flow of air into "eddies", or areas of turbulence influenced by these obstructions. When moist, stable air flows over a larger eddy, like those caused by mountains, a series of large-scale standing waves form on the leeward side of the mountain. If the temperature at the crest of the wave drops below the local dew point, moisture in the air may condense to form lenticular clouds. (info from Wikipedia; credit for image to “Weather Nation” - twitter)
The view of the California wildfires from the International Space Station (August 6, 2018).
GOES NOAA-20 VIIRS day/night band captures this “hot spot” associated with the CarrFire in northern California on July 28, 2018. The full moon provided ample illumination to see the smoke billowing from the wildfires.
The sky has turned orange around the Parthenon in Athens, Greece as a result of wildfires in the region. The winter was dry and high winds in recent days are fanning the flames of two separate fires: one to the west of the city in pine forest regions and to the northeast of the city in coastal towns. [Image from Monday, July 23, 2018; courtesy AFP/Getty Images]
This optical phenomena is caused by tiny ice crystals diffracting light; hence, the rainbow effect. (Algoma, MS on July 3rd, 2018)
This product from the University of Wisconsin/CIMSS shows the extent of Saharan dust (dry) air over the Atlantic Ocean that is inhibiting tropical storm formation in the Atlantic Basin. This dry air moves in a general east-to-west fashion with the trade winds and can play a critical role in the development or intensification of tropical systems in the Atlantic Basin. In addition to this widespread extent of dry air from the western regions of Africa, sea surface temperatures have been running at below-normal levels in the eastern Atlantic and inhibiting tropical storm formation.
NOAA-20 “visible image at night” on April 27, 2018 was generated by leveraging the moonlight. Clouds seen are associated with a strong low pressure system moving northeast towards the the Mid-Atlantic region. In addition, big city lights are seen throughout the image as well as a lightning streak near Miami, Florida. Image courtesy NOAA/University of Wisconsin/CIMSS
A little bit of snow this winter/spring in the Julian Alps of northwest Slovenia. This photograph taken on Sunday, April 8th, 2018 in a location just a few miles from the northeast border with Italy.
There was orange-tinted snow on Friday, March 23, 2018 in parts of eastern Europe and it also occurred over the weekend. The rare phenomenon is caused by sand from Sahara Desert storms that gets mixed into the precipitation associated with these systems. It happens roughly once every five years or so, but concentrations of sand are higher than usual this time. This MODIS image is of the northeast coast of Libya.
GOES-East got a nice close-up of convective clouds that were part of the second major nor'easter in 5 days for the Northeast US (March 7, 2018). This convection actually resulted in "thunder snow" for many parts of New Jersey and New York City during the height of the coastal storm. (Image courtesy NOAA)
Lenticular clouds (Altocumulus lenticularis in Latin) are stationary clouds that form in the lwoer atmosphere, typically in perpendicular alignment to the wind direction. They are often comparable in appearance to a lens or "saucer" and have been often mistaken for UFOs. This particular lenticular cloud formed on February 8th, 2018 over Mount Hood in Oregon which stands 11, 250 feet tall.on February 8, 2018
Image credit: Washington Post/Capital Weather Gang
This 216-hour forecast map by NOAA's GFS computer model of stratospheric temperature anomalies features a dramatic rise in 10-millibar temperatures on the North America side of the North Pole (map is "top-down" view of the Northern Hemisphere with the North Pole in the center). Sudden Stratospheric Warming (SSW) events are among the most impressive dynamical events in the physical climate system. If history is any guide, this unfolding stratospheric warming event can result in Arctic air outbreaks for the central and eastern US in coming days.
During the winter months in the polar stratosphere, temperatures are typically lower than minus 70°C. The cold temperatures are combined with strong westerly winds that form the southern boundary of the stratospheric polar vortex which plays a major role in determining how much Arctic air spills southward toward the mid-latitudes. This dominant structure is sometimes disrupted in some winters or even reversed. Under these circumstances, the temperatures in the lower stratosphere can rise by more than 50°C in just a few days. This sets off a reversal in the west-to-east winds and the collapse of the polar vortex.
In response to the stratospheric warming (and associated layer expansion) at the high latitudes, the troposphere in turn cools down dramatically (with layer contraction) at the high latitudes. This tropospheric cold air can then be transported from the high latitudes to the middle latitudes given the right overall weather pattern (e.g., "high-latitude blocking"). The tropospheric response to the SSWs closely resembles the negative phase of the North Atlantic Oscillation (NAO), involving an equatorward shift of the North Atlantic storm track; extreme cold air outbreaks in parts of North America, northern Eurasia and Siberia; and strong warming of Greenland, eastern Canada, and southern Eurasia (Thompson et al., 2002). The entire process from the initial warming of the stratospheric at high latitudes to the cooling in the troposphere at middle latitudes can take weeks to unfold.