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Average Total-sky Incoming S
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| Title |
Average Total-sky Incoming Solar Flux (WMS) |
| Abstract |
The Earth's climate is determined by energy transfer from the sun to the Earth's land, oceans, and atmosphere. As the Earth rotates, the sun lights up only part of the Earth at a time, and some of that incoming solar energy is reflected and some is absorbed, depending on type of area it lights. The average amount of reflection and absorption is critical to the climate, because the absorbed energy heats up the Earth until it is radiated away as thermal radiation. This animation shows the monthly average incoming solar radiation from July, 2002 through June, 2004 as measured by the CERES instrument. This average data set is contant in longitude because of the Earth's rotation, but clearly shows the seasonal cycle as the sun heats the Northern Hemisphere more in summer than in winter. Note that the polar regions are abnormally bright in the local summer and dark in the local winter because whole day is either light or dark in those seasons. |
| Completed |
2005-02-01 |
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Average Total-sky Incoming S
…
| Title |
Average Total-sky Incoming Solar Flux (WMS) |
| Abstract |
The Earth's climate is determined by energy transfer from the sun to the Earth's land, oceans, and atmosphere. As the Earth rotates, the sun lights up only part of the Earth at a time, and some of that incoming solar energy is reflected and some is absorbed, depending on type of area it lights. The average amount of reflection and absorption is critical to the climate, because the absorbed energy heats up the Earth until it is radiated away as thermal radiation. This animation shows the monthly average incoming solar radiation from July, 2002 through June, 2004 as measured by the CERES instrument. This average data set is contant in longitude because of the Earth's rotation, but clearly shows the seasonal cycle as the sun heats the Northern Hemisphere more in summer than in winter. Note that the polar regions are abnormally bright in the local summer and dark in the local winter because whole day is either light or dark in those seasons. |
| Completed |
2005-02-01 |
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Average Total-sky Net Radian
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| Title |
Average Total-sky Net Radiant Flux (WMS) |
| Abstract |
The Earth's climate is determined by energy transfer from the sun to the Earth's land, oceans, and atmosphere. As the Earth rotates, the sun lights up only part of the Earth at a time, and some of that incoming solar energy is reflected and some is absorbed, depending on type of area it lights. The average amount of reflection and absorption is critical to the climate, because the absorbed energy heats up the Earth until it is radiated away as thermal radiation. This animation shows the monthly average net radiant flux from July, 2002 through June, 2004 as measured by the CERES instrument. This is the incoming radiation minus the outgoing reflected or thermal energy given off by areas of the Earth. Regions in red and yellow have a net incoming flux and are being heated. Regions in blue have a net outgoing flux and are being cooled. Regions in black are in rough equilibrium. Cloud-free summertime oceans are heated the most, while high latitude winter regions are cooled the most, probably because of the longer winter nights. Note that regions that reflect a lot of sunlight, such as the polar ice sheets and the Sahara desert are almost always in equilibrium or are cooling regions. |
| Completed |
2005-02-01 |
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Average Total-sky Net Radian
…
| Title |
Average Total-sky Net Radiant Flux (WMS) |
| Abstract |
The Earth's climate is determined by energy transfer from the sun to the Earth's land, oceans, and atmosphere. As the Earth rotates, the sun lights up only part of the Earth at a time, and some of that incoming solar energy is reflected and some is absorbed, depending on type of area it lights. The average amount of reflection and absorption is critical to the climate, because the absorbed energy heats up the Earth until it is radiated away as thermal radiation. This animation shows the monthly average net radiant flux from July, 2002 through June, 2004 as measured by the CERES instrument. This is the incoming radiation minus the outgoing reflected or thermal energy given off by areas of the Earth. Regions in red and yellow have a net incoming flux and are being heated. Regions in blue have a net outgoing flux and are being cooled. Regions in black are in rough equilibrium. Cloud-free summertime oceans are heated the most, while high latitude winter regions are cooled the most, probably because of the longer winter nights. Note that regions that reflect a lot of sunlight, such as the polar ice sheets and the Sahara desert are almost always in equilibrium or are cooling regions. |
| Completed |
2005-02-01 |
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Aurora over the North Pole o
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| Title |
Aurora over the North Pole on April 17, 1999 (WMS) |
| Abstract |
When the charged particles flowing outward from the Sun (the solar wind) hit the Earth's magnetic field, they are channeled down the magnetic field lines to the ionosphere at the North and South Poles. The impact of these particles on atmospheric molecules causes the molecules to emit light, which forms the visible aurora. This visualization shows the development of the aurora over the North Pole for about three hours on April 17, 1999, as seen by the ultraviolet VIS Earth Camera on the POLAR spacecraft. The two main features of these ultraviolet images are the very bright ultraviolet emission from the reflected solar radiation on the dayside of the Earth and the bright ring of the auroral oval circling the North Pole. The aurora seen in this visualization is the diffuse aurora, a very large bright band that is actually too dim to be seen well from the ground by the human eye. What we normally think of as the aurora are the even brighter curtains of light within the diffuse auroral caused by very energetic electrons. These curtains are too small to be seen in this image. The diffuse aurora appears as a ring around the pole rather than as a bright spot over the entire pole because the solar particles actually spend extended time wandering about within the Earth's magnetic field before traveling down a very select set of magnetic field lines to the Earth. Near the end of this three hour period, the spacecraft was getting so close to the Earth that the edges of the globe were outside the camera's image, which accounts for the growing circular data gaps over Asia and the Pacific Ocean. |
| Completed |
2004-07-09 |
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Aurora over the North Pole o
…
| Title |
Aurora over the North Pole on April 17, 1999 (WMS) |
| Abstract |
When the charged particles flowing outward from the Sun (the solar wind) hit the Earth's magnetic field, they are channeled down the magnetic field lines to the ionosphere at the North and South Poles. The impact of these particles on atmospheric molecules causes the molecules to emit light, which forms the visible aurora. This visualization shows the development of the aurora over the North Pole for about three hours on April 17, 1999, as seen by the ultraviolet VIS Earth Camera on the POLAR spacecraft. The two main features of these ultraviolet images are the very bright ultraviolet emission from the reflected solar radiation on the dayside of the Earth and the bright ring of the auroral oval circling the North Pole. The aurora seen in this visualization is the diffuse aurora, a very large bright band that is actually too dim to be seen well from the ground by the human eye. What we normally think of as the aurora are the even brighter curtains of light within the diffuse auroral caused by very energetic electrons. These curtains are too small to be seen in this image. The diffuse aurora appears as a ring around the pole rather than as a bright spot over the entire pole because the solar particles actually spend extended time wandering about within the Earth's magnetic field before traveling down a very select set of magnetic field lines to the Earth. Near the end of this three hour period, the spacecraft was getting so close to the Earth that the edges of the globe were outside the camera's image, which accounts for the growing circular data gaps over Asia and the Pacific Ocean. |
| Completed |
2004-07-09 |
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X-Ray Images of the North Po
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| Title |
X-Ray Images of the North Polar Region (WMS) |
| Abstract |
Here are X-rays images (shown on the same brightness scale) of the north polar region obtained by Chandra HRC-I on different days, showing large variability in soft (0.1-10.0 keV) X-ray emissions from Earth s aurora. Note that the images are not snap shots, but are approximately 20-min scans of the northern auroral region in the HRC-I field-of-view. The brightness scale in Rayleighs (R) assumes an average effective area of 40 cm2. The day-night terminator at an altitude of 0 km is displayed with lighting. The day-night terminator at an altitude of 100 km is shown by the blue line. |
| Completed |
2005-06-01 |
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