Thursday, January 14, 2010
Past 2 days showers over Karnataka & Maharastra is now over Orissa and fast vanishing .. http://yfrog.com/35p2jj
Wednesday, January 13, 2010
Heavy Snow in Eastern China
Some 2 million schoolchildren in the Beijing region enjoyed an extra day off at New Year’s in January 2010 while authorities put some 300,000 people to work clearing streets. Up to 30 centimeters (12 inches) of snow fell on the capital city of Beijing and nearby port city of Tianjin, closing schools, clogging roads, and canceling flights. Although not as bad as the 2008 freeze that ruined travel plans for millions of Chinese trying to visit family for the lunar new year, this snowstorm was described as the heaviest snow to fall on Beijing in almost 60 years.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this true-color image on January 4, 2010. Snow cover encircles Bo Hai and extends to the north and west of that water body. Snow also covers Beijing, Tianjin, and a constellation of smaller settlements. The large cities leave big gray splotches on the blanket of snow, and the smaller cities make small gray dots. Snow caps the mountains north and west of Beijing, but the snow cover gradually fades southwest of Beijing and Tianjin. Cloud streets—clouds arranged in neat rows—similar to those observed over Hudson Bay and the Great Lakes float over Bo Hai.
Unlike the deep freeze of 2008, this storm was not expected to cause weeks-long fuel shortages for northern China, although disruptions to transportation and damage to greenhouses were expected to raise food prices. Temperatures in Beijing were expected to fall to -18 degrees Celsius (-0.4 degrees Fahrenheit) on the night of January 5, 2010, and some of the northernmost parts of China might experience temperatures as low as -32 degrees Celsius (-25.6 degrees Fahrenheit) by the following morning
Winter Temperatures and the Arctic Oscillation
If you live nearly anywhere in North America, Europe, or Asia, it’s no news that December 2009 and early January 2010 were cold. This image illustrates how cold December was compared to the average of temperatures recorded in December between 2000 and 2008. Blue points to colder than average land surface temperatures, while red indicates warmer temperatures. Much of the Northern Hemisphere experienced cold land surface temperatures, but the Arctic was exceptionally warm. This weather pattern is a tale-tell sign of the Arctic Oscillation.
The Arctic Oscillation is a climate pattern that influences winter weather in the Northern Hemisphere. It is defined by the pressure difference between air at mid-latitudes (around 45 degrees North, about the latitude of Montreal, Canada or Bordeaux, France) and air over the Arctic. A low-pressure air mass usually dominates the Arctic, and while higher pressure air sits over the mid-latitudes. This pressure difference generates winds that confine extremely cold air to the Arctic. Sometimes, the pressure systems weaken, decreasing the pressure difference between the Arctic and midlatitudes and allowing chilly Arctic air to slide south while warmer air creeps north. A weaker-than-normal Arctic Oscillation is said to be negative. When the pressure systems are strong, the Arctic Oscillation is positive.
Throughout December 2009, the North Atlantic Oscillation was strongly negative, said the National Weather Service. This image shows the impact of the negative Arctic Oscillation on land surface temperatures throughout the Northern Hemisphere as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Cold Arctic air chilled the land surface at midlatitudes, while Arctic land, such as Greenland and Alaska, was much warmer than usual.
Subscribe to:
Posts (Atom)