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Archive for November, 2009

Photosynthetic Activity of Italy and Coastal Tunisia and Algeria

40.2N 13.3E

November 29th, 2009 Category: Snapshots

Italy - November 17th, 2009

Italy - November 17th, 2009

This FAPAR image shows the vegetation index of Italy, including the islands of Sardinia and Sicily, as well as Corsica and parts of coastal Tunisia and Algeria. The vegetation index corresponds to the Fraction of Absorbed Photosynthetically Active Radiation, which provides data on the planet’s climate system.

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. Dark red regions correspond to agricultural zones for which there is high photosynthetic activity and therefore vegetation productivity, while yellow to white areas, with the exception of white patches of clouds,  indicate a low degree of photosynthetic activity.

Here, some red areas can be seen on the islands of Sardinia and Sicily, while most of Italy and Corsica appears green with some yellow zones. Algeria and Tunisia show photosynthetic activity near the coast, while the area further south is yellow and white, reflecting the low photosynthetic activity of more arid regions.

Nida (26W) Becomes Category 5 Super Typhoon – November 29th, 2009

20.4N 137.8E

November 29th, 2009 Category: Image of the day, Tropical Cyclones

Typhoon Nida (26W) - November 28th, 2009

Typhoon Nida (26W) - November 28th, 2009

Track of STY 26W - November 28th, 2009 © Univ. of Wisconsin

Track of STY 26W

Enhanced image

Enhanced image

Super Typhoon Nida (STY 26w), located approximately 350 nautical miles south-southwest of Iwo To, has tracked north-northeastward at 2 knots over the past six hours. Maximum significant wave height is 34 feet.

Maximum sustained winds are at 140 knots, with stronger gusts of up to 170 knots. Winds of 64 knots extend outward for a radius of 50 to 55 nautical miles from the eye of the storm, while the radius of winds of up to 50 knots is 75 to 80 nautical miles.

Sediments Clouding Lake Erie, Canada and USA – November 28th, 2009

42.0N 81.3W

November 28th, 2009 Category: Image of the day, Lakes, Rivers

USA - November 8th, 2009

USA - November 8th, 2009

The waters of Lake Erie (below) are clouded by tan sediments, particularly along the upper shoreline to the left, while those of Lake Ontario (above) are much clearer with the exception of a small stretch along the southern shore.

Lake Erie is the fourth largest lake (by surface area) of the five Great Lakes in North America. It is the southernmost, shallowest, and smallest by volume of the Great Lakes, and therefore also has the shortest average water residence time. Lake Erie drains via the Niagara River and Niagara Falls into Lake Ontario.

It is bounded on the north by the Canadian province of Ontario, on the south by the U.S. states of Ohio, Pennsylvania, and New York, and on the west by the state of Michigan.

Santander and Mountains of the Cantabria Region, Spain

43.4N 3.8W

November 28th, 2009 Category: Snapshots

Spain - November 12th, 2009

Spain - November 12th, 2009

Cantabria is a Spanish historical region and autonomous community, bordered on the north by the Cantabrian Sea. Its capital city is Santander, visible at the top center of this orthorectified image along the shores of Santander Bay, the most prominent indentation in the coastline.

Cantabria is a mountainous and coastal region, with important natural resources. The coastal area is a strip of low, wide and gently rolling valleys some 10 kilometers in width, whose altitude does not rise above 500 meters, and which meets the ocean in a line of abrupt cliffs broken by river estuaries, creating rias and beaches.

To the south, the coastal strip rises to meet the Cantabrian mountains. This is a long barrier made up of abruptly rising mountains parallel to the sea. The ranges are mostly made of limestone with karst topography, and occupy most of Cantabria’s area. They form deep valleys oriented north-south. The torrential rivers are short, fast flowing and of great eroding power, so the slopes are steep.

The valleys define different natural regions, delimited physically by the intervening mountain ranges: Liébana, Saja-Nansa, Besaya, Pas-Pisueña, Miera, Asón-Gándara and Campoo. The Escudo Range, a mountain range of 600 to 1,000 metres high that covers 15 or 20 km in a parallel line to the coast in the west part of Cantabria.

Towards the south are higher mountains, whose crests mark the watershed between the drainage basins of the Rivers Ebro, Duero and those that flow into the Bay of Biscay. These peaks generally exceed 1,500 m from the Pass of San Glorio in the west to the Pass of Los Tornos in the eastern part: Peña Labra, Castro Valnera and the mountain passes of Sejos, El Escudo and La Sía. The great limestone masses of Picos de Europa also stand out in the southwest of the region: most of their summits exceed 2,500 m, and their topography is shaped by the former presence of glaciers.

Dust Blowing Across Thar Desert in Pakistan

24.7N 68.0E

November 28th, 2009 Category: Dust Storms, Rivers

Pakistan - November 15th, 2009

Pakistan - November 15th, 2009

Dust blows over eastern Pakistan, blowing from the northeast towards the Arabian Sea. The dust is blowing across the Thar Desert, also known as the Great Indian Desert, a large, arid region in the northwestern part of the Indian subcontinent.

Visible west of the dust and Thar Desert is the Indus River and Valley. Continuing west of this fertile green area, the brown and tan grooves of the Balochistan Plateau can also be seen.

To the south, near the coast, the Rann of Kutch appears as a bright white area. It is a seasonally marshy saline clay desert located in the Thar Desert biogeographic province  by the Surendranagar District of northwestern India and the Sind province of Pakistan.  Below this area, tan sediments spill into the Gulf of Kutch and the Arabian Sea.