Contact the author rss astronoo


Iceland under snow in October

 Automatic translation  Automatic translation Updated June 01, 2013

Envisat, the Advanced Along Track Scanning Radiometer (AATSR), shows Iceland covered by the first snow of winter 2008.
Iceland (capital: Reykjavik) is located in the North Atlantic Ocean south of the Arctic Circle, is the most Western European countries.
We see in this picture the largest glacier in Europe, the glacier of Vatnajökull (8 000 sq km and 900 m thick).
The green border that runs along the south and west coasts of Iceland, shows the presence of phytoplankton, present only in the superficial layers of the oceans. Here it performs its photosynthesis by absorbing minerals and carbon (as CO2) and releases oxygen under the effect of light.


Image: Picture of the largest glacier in Europe, the Vatnajokull glacier, it was taken October 4, 2008 by the camera MERIS (Medium Resolution Imaging Spectrometer) Envisat high resolution (source ESA).

 envisat iceland

The Amazon Basin 


The space satellite Envisat, the Advanced Along Track Scanning Radiometer (AATSR), shows the confluence of the Rio Negro and Solimões downstream from Manaus, Brazil in the Amazon basin. The Amazon, the longest and most powerful river in the world flows slowly between the 5th parallel north and 20th parallel south.
The river originates in the Peruvian Andes in the west of Lake Titicaca and empties into the Atlantic Ocean at the equator after crossing Peru and Brazil.
The Amazon is responsible for 18% of the total volume of freshwater discharged into the oceans of the world and its drainage network has more than 1 000 rivers including the Rio Negro and Solimões.
The Rio Negro is named after the color of decomposed plant that carries throughout his career (black river in the photo). The Solimões carries him over 1600 km, sand, mud and silt that tint the water a yellowish color.
The forest of the Amazon is the largest virgin forest in the world, it absorbs a huge amount of carbon dioxide.
The conservation of the Amazon forest is one of the biggest environmental problems of the early 21st century.


The forests are gradually disappearing in the world at an alarming rate while their role is vital in the overall climate of the planet.

Image: Manaus is visible as a white spot, placed at the confluence of two rivers black and yellow, the Amazon basin.
This picture was taken September 28, 2008 by the camera MERIS (Medium Resolution Imaging Spectrometer) Envisat high resolution (source ESA).

 Rio Negro and Solimoes (envisat)

The Great Lakes African Rift


Lake Victoria (upper center) is the largest lake in Africa and second largest freshwater lake in the world.
The waters of Lake Victoria are shared by 3 states. In Northern Uganda is located in southern Tanzania and the North East, Kenya.
Bottom left is the longest freshwater lake in the world, Tanganyika (670 km long, 1470 m deep and 32 900 km2 in area).
Its waters are shared by 4 states, Burundi, northern, north-eastern Tanzania, west of the Congo and the southern Zambia.
North of Lake Victoria is located on Lake Kyoga, Lake Albert (160 km) is located in the upper left, Lake Edward, in Lake Albert and Lake Kivu in Lake Edward.


Image: African Great Lakes of the fault in the western Great Rift Valley as seen by Envisat.
This image shows details of 300 m on the ground.
Picture taken October 6, 2008 by the camera MERIS (Medium Resolution Imaging Spectrometer) Envisat high resolution (source ESA).

 envisat, African lakes

The Aral Sea


The Aral Sea is located in Central Asia, straddling two countries, Kazakhstan and Uzbekistan. This great inland sea was folded into several separate tanks, it turned into a salt lake, narrowing steadily during the second half of the 20th century.
The waters of the 2 main rivers feeding the sea, the Amu Darya in the south and the Syr Darya in the northeast, were used to irrigate the cotton plantations of the region, which has turned the Aral Sea a desert called the Desert Aralkoum. In the Aral Sea that remains in 2009 only 2 lakes, one south and one even smaller north.
The withdrawal of the Aral Sea added to years of successive droughts have left ports in the ground destroying the fishing trade. The bed of the Aral Sea covers an area of about 65 000 km2, of which more than half turned into desert. The constant winds and poor vegetation cover cause intense erosion through small sand dunes of 5 to 6 km in record time. Sand storms, more frequent on the region of the Aral Sea have serious impacts on fauna and flora. The major challenge for the 50 million people in the region, is to devote resources to a rational management of water throughout the basin.


The big brown spot south of the Aral Sea is the delta of the Amu Darya region of intensive agriculture.
Uzbekistan, a country of 27 million inhabitants is now the second largest exporter of cotton after the United States.
Cotton is the primary economic resource.
The rehabilitation of the Aral Sea began in 2001 by building a concrete structure about 13 km long lasting to contain the waters of the Small Aral.
The waters of the northern part of the Aral Sea are mounted 12 m to 42 m.
Its surface has increased by 30%. The salinity decreased to a level acceptable to the reintroduction of species of fish disappeared.
Fishing has resumed and we are seeing a revival with climate effects of dew and rain more frequent.

Image: In the bottom right of the picture, desert Kyzyl Kum. image made March 6, 2009 by the camera MERIS (Medium Resolution Imaging Spectrometer) satellite Envisat. Source: ESA

 Aral Sea dried

Typhoon Melor


Typhoon Melor seen from space, image taken by the Envisat satellite October 6, 2009 winds over the Pacific Ocean, north-western Philippines, and is about to hit Honshu, the main island of the Japanese archipelago.
The wind generated by typhoon Melor reached 198 km/h.
Typhoon and hurricane are storm type, tropical cyclone. A hurricane begins in the Atlantic or eastern Pacific, it is then called Hurricane. When it starts in the Western Pacific, it is called typhoon.
In general, the typhoon generated winds of more violent as hurricanes.
Tropical cyclones are large powerful storms and thunderstorms that form over warm tropical waters where they transfer their heat to the air.
It is essential to know their strength and their path to issue warnings.


The satellite observation of Earth are there to collect this information. The instruments that allow the satellite Envisat of ESA.
The information sought is the characteristics of tropical cyclones (cloud structure, direction and intensity of waves and winds, temperature and level of surface water).

Image: In this image taken by the Envisat satellite, the Typhoon Melor winds over the Pacific Ocean, north-western Philippines, and is about to hit Honshu, the main island of 'Japanese archipelago.
image taken October 6, 2009 by the camera MERIS (Medium Resolution Imaging Spectrometer) satellite Envisat.
Source: ESA

 Typhoon Melor seen by Envisat

1997 © − Astronomy, Astrophysics, Evolution and Ecology.
"The data available on this site may be used provided that the source is duly acknowledged."