“To observe how winds move high in Earth’s atmosphere, scientists sometimes release clouds of barium as tracers to track how the material corkscrews and sweeps around – but scientists have no similar technique to study the turbulent atmosphere of the Sun. So researchers were excited in December 2011, when Comet Lovejoy swept right through the sun’s corona with its long tail streaming behind it.
I captured images of the comet, showing how its long tail was buffeted by systems around the Sun, offering scientists a unique way of observing movement as if they’d orchestrated the experiment themselves. Since comet tails have ionized gases, they are also affected by the Sun’s magnetic field, and can act as tracers of the complex magnetic system higher up in the atmosphere. Comets can also aid in the study of coronal mass ejections and the solar wind.”
This new global view of Earth’s city lights is a composite assembled from data acquired by the Suomi National Polar-orbiting Partnership (NPP) satellite.
Credit: NASA’s Earth Observatory/NOAA/DOD
The data was acquired over nine days in April 2012 and 13 days in October 2012. It took 312 orbits to get a clear shot of every parcel of Earth’s land surface and islands. This new data was then mapped over existing Blue Marble imagery of Earth to provide a realistic view of the planet.
The image was made possible by the satellite’s “day-night band” of the Visible Infrared Imaging Radiometer Suite, which detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as city lights, gas flares, auroras, wildfires and reflected moonlight.
The day-night band observed Hurricane Sandy, illuminated by moonlight, making landfall over New Jersey on the evening of Oct. 29. Night images showed the widespread power outages that left millions in darkness in the wake of the storm.
(via scinerds)
(Source: biscodeja-vu)
Arctic Sea-Ice: Feeling Low. Really Low.
It’s official. Nearly a month before we see the usual “seasonal low” of Arctic sea ice as it melts throughout the summer, we have hit the record low for sea ice extent.
This means that there is now less Arctic sea ice than at any time since records began in 1978. And we still have nearly a month of additional melting to go before the autumn ice sets in.
This is due to climate change. More dark ocean water means more heat absorbed by the ocean and a chance for reinforcing these lower ice levels in seasons to come. What will this mean for ecosystems? What will this mean for those who want to exploit the uncovered mineral and shipping resources of the Arctic? What will this mean for our oceans?
This image from RealClimate shows the new low level:
(via RealClimate)
(via thescienceofreality)
Thousands of fish are dying in the Midwest as the hot, dry summer dries up rivers and causes water temperatures to climb in some spots to nearly 100 degrees. About 40,000 shovelnose sturgeon were killed in Iowa last week as water temperatures reached 97 degrees.
![sagansense:
Summer Solstice Brings Changing Seasons Wednesday
On Wednesday (June 20), the sun will arrive at its northernmost point in the sky and herald a season change on Earth, with summer officially beginning in the Northern Hemisphere, while the winter season kicks off in the Southern Hemisphere.
The northern summer solstice will occur at 7:09 p.m. EDT (2309 GMT). Just as the word “armistice” is defined as a staying of the action of arms, “solstice” is a staying of the sun’s apparent motion over the latitudes of the Earth. At the summer solstice, the sun stops its northward motion and begins heading south. At the winter solstice, it turns north.
I’ll bet if you ask most people in which month of the year they believe Earth is closest to the sun most probably would say we’re closest during June, July or August. But our warm weather doesn’t relate to our distance from the sun. It’s actually because of the 23.5-degree tilt of the Earth’s axis that the sun is above the horizon for different lengths of time at different seasons.
The Earth’s tilt determines whether the sun’s rays strike us at a low angle or more directly. At the latitude of New York or Madrid, the more nearly direct rays at the summer solstice of June 20 bring about three times as much heat as the more slanting rays at the winter solstice on Dec. 21. [Video: See Seasons Change from Space]
Heat received by any region is dependent on the length of daylight and the angle of the sun above the horizon. Hence the noticeable differences in temperatures that are registered over different parts of the world.
Summer heat to come
If the sun’s insolation, which is the total energy received from the sun, alone governed the temperature, then right now we should be experiencing the year’s hottest weather. But the atmosphere in temperate regions continues to receive more heat than it gives up to space, a situation that lasts about a month or more, depending on the latitude.
A reverse process occurs after the winter solstice in December. So therefore that our hottest weather usually comes in late July and our coldest in late January. The solar heating depends directly on the sun’s altitude in the sky, which also controls its daily path and the number of hours the sun is above the horizon.
As a result, on April 12 the insolation is the same as on Aug. 31, but because of that seasonal temperature lag we can freeze at the former date, or have a 90-degree heat wave at the latter.
Incidentally, on July 4 at 10 p.m. EDT (0200 July 5 GMT), Earth will reach that point in its orbit where it’s farthest from the sun in space. Called aphelion, the sun at that moment will be 94,505,849 miles away, or 3,103,882 miles farther as compared to when our Earth was closest to it (called perihelion) last Jan. 4.
High sun, long days
From the latitude of New York, you can never see the sun directly overhead, but on Wednesday at 12:57 p.m. EDT (1657 GMT), the sun will attain its highest point in the sky for this entire year, standing 73 degrees above the southern horizon. Since the sun will appear to describe such a high arc across the sky, the duration of daylight is now at its most extreme, lasting 15 hours and 4 minutes.
Contrary to popular belief, the earliest sunrise and latest sunset do not coincide with the summer solstice. For temperate latitudes, he earliest sunrise actually occurred back on June 14, while the latest sunset is not due until June 27.
Lastly, take note that technically, beginning at 7:10 p.m. EDT (2310 GMT) on Wednesday, the sun will have turned around and start moving back toward the south. It will cross the equator at the autumnal equinox, passing into the Southern Hemisphere on Sept. 20, at 10:44 a.m. EDT (1444 GMT).
You can actually watch the June solstice usher in summer in the Northern Hemisphere live online via the Slooh Space Camera, which will webcast a special live show on Wednesday (June 20) at 7 p.m. EDT (2300 GMT). Slooh officials say the event will look at recent solar weather events and mark the summer solstice.
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.](http://24.media.tumblr.com/tumblr_m5wcbvlnNN1r01w8mo1_500.jpg)
Summer Solstice Brings Changing Seasons Wednesday
On Wednesday (June 20), the sun will arrive at its northernmost point in the sky and herald a season change on Earth, with summer officially beginning in the Northern Hemisphere, while the winter season kicks off in the Southern Hemisphere.
The northern summer solstice will occur at 7:09 p.m. EDT (2309 GMT). Just as the word “armistice” is defined as a staying of the action of arms, “solstice” is a staying of the sun’s apparent motion over the latitudes of the Earth. At the summer solstice, the sun stops its northward motion and begins heading south. At the winter solstice, it turns north.
I’ll bet if you ask most people in which month of the year they believe Earth is closest to the sun most probably would say we’re closest during June, July or August. But our warm weather doesn’t relate to our distance from the sun. It’s actually because of the 23.5-degree tilt of the Earth’s axis that the sun is above the horizon for different lengths of time at different seasons.
The Earth’s tilt determines whether the sun’s rays strike us at a low angle or more directly. At the latitude of New York or Madrid, the more nearly direct rays at the summer solstice of June 20 bring about three times as much heat as the more slanting rays at the winter solstice on Dec. 21. [Video: See Seasons Change from Space]
Heat received by any region is dependent on the length of daylight and the angle of the sun above the horizon. Hence the noticeable differences in temperatures that are registered over different parts of the world.
Summer heat to come
If the sun’s insolation, which is the total energy received from the sun, alone governed the temperature, then right now we should be experiencing the year’s hottest weather. But the atmosphere in temperate regions continues to receive more heat than it gives up to space, a situation that lasts about a month or more, depending on the latitude.
A reverse process occurs after the winter solstice in December. So therefore that our hottest weather usually comes in late July and our coldest in late January. The solar heating depends directly on the sun’s altitude in the sky, which also controls its daily path and the number of hours the sun is above the horizon.
As a result, on April 12 the insolation is the same as on Aug. 31, but because of that seasonal temperature lag we can freeze at the former date, or have a 90-degree heat wave at the latter.
Incidentally, on July 4 at 10 p.m. EDT (0200 July 5 GMT), Earth will reach that point in its orbit where it’s farthest from the sun in space. Called aphelion, the sun at that moment will be 94,505,849 miles away, or 3,103,882 miles farther as compared to when our Earth was closest to it (called perihelion) last Jan. 4.
High sun, long days
From the latitude of New York, you can never see the sun directly overhead, but on Wednesday at 12:57 p.m. EDT (1657 GMT), the sun will attain its highest point in the sky for this entire year, standing 73 degrees above the southern horizon. Since the sun will appear to describe such a high arc across the sky, the duration of daylight is now at its most extreme, lasting 15 hours and 4 minutes.
Contrary to popular belief, the earliest sunrise and latest sunset do not coincide with the summer solstice. For temperate latitudes, he earliest sunrise actually occurred back on June 14, while the latest sunset is not due until June 27.
Lastly, take note that technically, beginning at 7:10 p.m. EDT (2310 GMT) on Wednesday, the sun will have turned around and start moving back toward the south. It will cross the equator at the autumnal equinox, passing into the Southern Hemisphere on Sept. 20, at 10:44 a.m. EDT (1444 GMT).
You can actually watch the June solstice usher in summer in the Northern Hemisphere live online via the Slooh Space Camera, which will webcast a special live show on Wednesday (June 20) at 7 p.m. EDT (2300 GMT). Slooh officials say the event will look at recent solar weather events and mark the summer solstice.
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.
(via thescienceofreality)
Stay healthy my friends…
(via thescienceofreality)
Massive underground reserves of water found in Africa
Huge reserves of underground water in some of the driest parts of Africa could provide a buffer against the effects of climate change for years to come, scientists said.
Researchers from the British Geological Survey and University College London have for the first time mapped the aquifers, or groundwater, across the continent and the amount they hold.
‘The largest groundwater volumes are found in the large sedimentary aquifers in the North African countries Libya, Algeria, Egypt and Sudan,’ the scientists said in their paper.
They estimate that reserves of groundwater across the continent are 100 times the amount found on its surface, or 0.66 million cubic kilometres.
» via Daily Mail
(via thescienceofreality)
Earth’s Haunting Craters
Meteor Crater, Arizona
- Meteor Crater, shown above, became the world’s first confirmed extraterrestrial impact crater when the famous planetary scientist Eugene Shoemaker found the rare minerals stishovite and coesite, which only form during cosmic collisions or nuclear blasts, at the crater site in 1960. It was formed when an iron-rich asteroid about 160 feet in diameter smacked into the Arizona desert 40,000 years ago.
Gosses Bluff, Northern Territory, Australia
- Gaz’s riveting, stark images make you wonder if you’re actually looking at Earth. In the image above, he turned the sky into a black, alien thing by using a red filter (in front of black and white film) when he shot the 14 mile-wide Gosses Bluff, which formed 142.5 million years ago.
Upheaval Dome, Utah
- Such is the case at Upheaval Dome, shown above. Scientists have gone back and forth over whether the pummeled, uplifted rocks were abused by a salt dome that rose from below, or cosmic artillery from above. In 2008, researchers discovered the presence of shocked quartz (stishovite, or its close cousin coesite) in the dome, confirming its extraterrestrial origins.
New Quebec (aka Pingualuit) Crater, Quebec, Canada
- Located in the treeless tundra of the Canadian Arctic, Pingualuit, shown above, certainly fits the “treasure” bill. Its almost perfectly round, 2.1 mile-wide rim encloses an isolated, crystal clear lake that plummets almost 900 feet to the crater floor. Local Inuits know the 1.4 million year-old dimple as the “Crystal Eye of Nunavik;” pretty impressive for a region strewn with pristine lakes and waterways.
Henbury, Northern Territory, Australia
- Nothing could be more appropriate for Henbury, shown above. In a turn of tragic cosmic irony, the great crater hunter and legendary scientist Shoemaker — the one who put Meteor Crater on the map — died in a head-on collision with another car while driving outside Alice Springs, Australia in 1997, not far from Henbury.
Article by Michael Reilly. Images courtesy of Princeton Architectural Press
(via thescienceofreality)
