Oceanic Temperatures and Climate Effects

Posted on June 23, 2010 by Rashid Faridi

The study of  climates from the past and oceanic temperatures can give clues as to how future climate changes will unfold. An international team of researchers, led by the members of the Institut de Ciència i Tecnologia Ambientals (ICTA) at the Universitat Autònoma de Barcelona (UAB), has  studied  the evolution of Northern Pacific and Southern Atlantic sea surface temperatures, dating from the Pliocene Era; some 3.65 million years ago. The results indicate that the regions closer to the poles of both oceans have played a fundamental role in climate evolution in the tropics.

Some High Points:

  • During the Pliocene epoch, the global average temperature was 5-7°F higher than today with global sea levels being about 80 feet higher and with a reduced northern hemisphere ice sheet. Towards he end of the era global cooling occurred.
  • A permanent El Niño state existed in the early mid Pliocene, warmer temperature in the eastern equatorial Pacific increased a water vapor greenhouse effect and reduced the area covered by highly reflective stratus clouds thus decreasing the albedo of the planet.
  • The ambient water temperature in which the organisms dwelt can be estimated from ratio of their unsaturated alkenones (C37-C39).
  • The formation of an Arctic ice cap was started as indicated by an abrupt shift in oxygen isotope ratios in the North Atlantic and North Pacific ocean beds. Mid-latitude glaciation was probably underway before the end of the epoch. The global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas.

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Polar Regions

Posted on June 22, 2010 by Rashid Faridi

The polar regions are the areas that surround Earth’s geographic North and South Poles. The area surrounding the North Pole is called the Arctic and includes almost the entire Arctic Ocean and northern areas of Europe, Asia and North America. The area surrounding the South Pole is called the Antarctic and includes the continent of Antarctica and parts of the surrounding Southern Ocean. Earth’s geographic poles are in a slightly different location than the magnetic poles.

Polar Day

Right at the Poles, the Sun shines for half the year and it is dark for the other half of the year. This makes a year like one long day. The Sun rises in spring, reaches its highest point in the sky in summer, and sets in autumn. So the Sun is visible only during the warmer months of the year. When the Sun is visible during summer at the South Pole, it is the dark winter months at the North Pole. The time when the Sun is continuously in the sky is called Polar Day.

Polar atmosphere

There are some unique phenomenon that happen in the atmosphere. Noctilucent Clouds: In the mesosphere layer of Earth’s atmosphere, noctilucent clouds form in the polar regions. The word noctilucent means to glow, and these clouds do glow blue in color when they are lit from below by the setting Sun. Less Ozone: Most of the ozone destruction has happened in the part of the stratosphere that is over Earth’s polar regions. There are now a number of ozone holes, including a very large hole over Antarctica.

Polar life

All sorts of living things call Earth’s polar regions home – from tiny lichens encrusting the rocky landscapes of the Arctic tundra to huge blue whales swimming through the frigid waters of the Southern Ocean. Some animals are only part-time residents, migrating to warmer, lower latitudes during the winter months. Others live in polar locales year-round. Most have special adaptations that allow them to survive the extreme cold of the Earth’s polar regions.

Polar culture

There are people who live in the Arctic region. Inuit – The Inuit are the native cultures that continue to live on coastal areas of Arctic tundra in Canada, Alaska, Siberia, Greenland. Inuit hunt for seals, whales, polar bears and other animals from the ocean. Norse: Norse were originally from Scandinavian countries. During the Middle Ages Norse explorers and warriors called Vikings raided regions within and near the Arctic. Today, many people living in these countries are descendants of the Nors

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Biggest Submarine Canyon

Posted on June 22, 2010 by Rashid Faridi

In many continental shelves submarine canyons have been found carving deep fissures that stretch from near shore out to the deep sea edge of the shelf. There are a number of theories as to what carved these giant cracks into the shelves, but the most prominent one states that sediment transport carved these canyons. Sediment transport in the sea occurs primarily as underwater landslides of enormous masses of rock and sediment, usually triggered by turbulent waters during a storm, or ground movement from an earthquake. The depth at which the submarine canyons have been cut depends on the make up of the underlying rock – how susceptible it is to being carved – and how much, how often and how heavy the materials are that are transported downslope during an underwater landslide. It is also believed that some canyons were carved above ground, at a time when sea level was a mile or more lower than it is today. Those canyons that are now submerged may have once held rivers and waterfalls that carved the canyon walls, carrying the sediment and debris down into shallower sea.

The largest and deepest submarine canyon ever discovered is in the middle of the Bering Sea called the Zhemchug Canyon. It is deeper than the Grand Canyon (1.83 km deep) at 2.6km deep. i, based on drainage area (11,350 km2) and volume (5800 km3). Deep, cold, oxygen-rich waters well up from the deeps into the canyon, providing sustenance to an enormous array and variety of life forms.

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India to launch five Remote Sensing Satellites

Posted on June 21, 2010 by Rashid Faridi

India plans to put five remote- sensing satellites into orbit in the first half of next month after fixing a rocket “anomaly” that forced it to delay launches in May.The Polar Satellite Launch Vehicle will carry India’s Cartosat-2B, Algeria’s ALSAT-2A and two small satellites from the University of Toronto, P.S. Veeraraghavan, director of Vikram Sarabhai Space Centre.

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Posted in Remote Sensing 101, Satellites, Space | 2 Comments