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Archive for November 18th, 2009

Vegetation Index of Coastal Texas as Seen by FAPAR

29.7N 95.3W

November 18th, 2009 Category: Climate Change

USA - November 10th, 2009

USA - November 10th, 2009

This FAPAR image of the coast of Texas along the Gulf of Mexico shows the area’s vegetation index, which corresponds to the Fraction of Absorbed Photosynthetically Active Radiation (from which its name is derived). Measuring the radiation over land surfaces in this way provides data on the planet’s climate system. To compare this FAPAR image to the original satellite view of this area, please click here.

In FAPAR images, the color spectrum over land runs from red (1.0), to green, to yellow and white (0.0), while bodies of water appear blue. Red regions correspond to agricultural zones for which there is high photosynthetic activity and therefore vegetation productivity, while yellow to white areas indicate a low degree of photosynthetic activity.

Here, some red areas can be seen upon opening the full image, but most of the area appears yellow-green to medium green, or between 0.2 and 0.5 on the numerical scale. Yellow and white areas are also present, indicating low photosynthetic activity, particularly to the south. The city of Houston also stands out as a white area near the coast.

The Sutter Buttes in California’s Sacramento Valley, USA – November 18th, 2009

39.1N 121.6W

November 18th, 2009 Category: Image of the day, Volcanoes

California, USA - October 22nd, 2009

California, USA - October 22nd, 2009

Rising up above the agricultural areas and flat plains of the Sacramento Valley, which stretches between the Coastal Mountains (left) and the Cascade Mountains (right) in this orthorectified image, are the Sutter Buttes.

The Sutter Buttes are a small circular complex of eroded volcanic lava domes. The highest peak, South Butte, reaches about 2,130 feet (650 m) above sea level. The Buttes are located just outside of Yuba City, California in the Sacramento Valley, the northern part of the Central Valley.

The mountains are about 10 miles (16 km) from north to south and east to west, and are the smallest mountain range in the world. They were formed over 1.5 million years ago by a now-extinct volcano.

The Okavango Inland Delta in Botswana

19S 23.0E

November 18th, 2009 Category: Rivers

Botswana - October 7th, 2009

Botswana - October 7th, 2009

The sands of the Kalahari Desert in Botswana appear green where the Okavango River pours onto them, creating the Okavango Delta. The other green area at the top is swampland in Africa’s “Four Corners” region.

The delta is fed from Angola’s October to April rainy season, although the waters generally don’t reach Botswana until December and don’t travel to the bottom end of the delta until July. As this image was taken in early October, at the start of Angola’s rainy season, the delta has not yet expanded to its maximum area.

Smoke from Agricultural Fires in Pakistan Spreads into India

30.7N 76.7E

November 18th, 2009 Category: Fires

India and China - November 16th, 2009

India and China - November 16th, 2009

Smoke from agricultural fires in Pakistan blows eastward into the states of Punjab, Haryana and Uttar Pradesh (from west to east) in India. The Himalayas to the north prevent the smoke from spreading farther, into China.

Here, the side of the Himalayas facing Tibet in China is covered in snow, while the side facing India remains untouched. The mountain areas visible here are part of several national parks and reserves, including Govind Pashu National Park, Gangotri National Park and Nanda Devi Biosphere Reserve (visible from west to east).