新幹線と富士山 (via かがみ~)
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What drives auroras on Saturn? To help find out, scientists have sorted through hundreds of infrared images of Saturn taken by the Cassini spacecraft for other purposes, trying to find enough aurora images to correlate changes and make movies. Once made, some movies clearly show that Saturnian auroras can change not only with the angle of the Sun, but also as the planet rotates. Furthermore, some auroral changes appear related to waves in Saturn's magnetosphere likely caused by Saturn's moons. Pictured here, a false-colored image taken in 2007 shows Saturn in three bands of infrared light. The rings reflect relatively blue sunlight, while the planet itself glows in comparatively low energy red. A band of southern aurora in visible in green. In has recently been found that auroras heat Saturn's upper atmosphere. Understanding Saturn's auroras is a path toward a better understanding of Earth's auroras.
Image Credit: NASA, Cassini, VIMS Team, U. Arizona, U. Leicester, JPL, ASI
photography by Adam Kyle Jackson powerful nature
Umbriel as seen by Voyager 2 in 1986. At the top is the large crater Wunda, whose walls enclose a ring of bright material.
Credit: NASA
Gökyüzüne sevgim hiç bitmeyecek belli ki ... 😌
Satellite imagery of the disruption of the polar vortex in the northern hemisphere winter 2012-2013. The data show a major stratospheric sudden warming (SSW) event, linked to the distortion and reversal of the normal westerly (moving west to east) flow of air.
The large vortex (bright) over the North Atlantic Ocean at the start of the clip breaks up into several smaller vortices. This is due to air from lower latitudes (dark) becoming entrained in the polar flow, forming an anti-cyclonic region (dark, rotating clockwise) over Japan and eastern Russia, which disrupts the flow across the region.
Although dramatic, such events are not rare, occurring every two years on average. They can cause winds to reverse near the surface too, leading to very cold spells, especially in North America and Europe.
The brightness indicates the potential vorticity of the air, a measure of its rotation within its flow, at an altitude of 35 kilometers. Brighter regions have more vorticity.
A major SSW occurs when the temperatures in the stratosphere around the pole increases by at least 25 Kelvin within a week, causing the wind to change direction.
The data were gathered by the GEOS-5 satellite every hour between 15th December 2012 and 28th January 2013.
© GMAO / GSFC / NASA / Science Source
Lightning inside a volcanic ash cloud in Patagonia.
tomorrow's schedule
7:30 am-8 am: wake up
8-8:30 am: drink a bowl of water with a spoon like soup
8:30 am - 4:00 pm: bring bronze age petroglyphs to life with my powers
4:00 pm-: haven't figured out this part yet
So much of fluid dynamics comes down to finding the right way to observe a flow. (Image credit: Expedition 59 Crew; via NASA Earth Observatory)