Climate

Thunder Snow!
February 8, 2011 04:10 PM - Andy Soos, ENN

Thundersnow, also known as a winter thunderstorm or a thunder snowstorm, is a relatively rare kind of thunderstorm with snow falling as the primary precipitation instead of rain. It typically falls in regions of strong upward motion within the cold sector of an extratropical cyclone, where the precipitation consists of ice pellets rather than snow. Snowstorms that trigger lightning are rare. Of the roughly 10,000,000 cloud-to-ground lightning flashes observed over the continental United States each year, about 0.1 percent to 0.01 percent are associated with snow, says Walter Petersen, atmospheric physicist with NASA's Marshall Space Flight Center in Huntsville, Alabama. This thundersnow happened this winter in northern Alabama and was observed first hand by sophisticated lightning mapping station in Huntsville

The Dunes of Mars
February 7, 2011 12:41 PM - Andy Soos, ENN

A dune is a hill of sand built by the wind. Dunes occur in different forms and sizes. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter slip face in the lee of the wind. Dunes can be found in any environment where there is a substantial atmosphere, winds, and dust to be blown. Dunes are common on Mars, and they have also been observed in the equatorial regions of Titan. Sand dunes in a vast area of northern Mars long thought to be frozen in time are changing with both sudden and gradual motions, according to research using images from a NASA orbiter. These dune fields cover an area the size of Texas in a band around the planet at the edge of Mars' north polar cap. The new findings suggest they are among the most active landscapes on Mars. However, few changes in these dark-toned dunes had been previously detected before a campaign of repeated imaging by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

Torrential rain in Sri Lanka kills 11
February 7, 2011 06:10 AM - Ranga Sirilal, Reuters, COLOMBO

Heavy rain triggered flooding in Sri Lanka that killed at least 11 people and is threatening up to 90 percent of the staple rice crop, heightening concern about supply shocks and inflation, officials said on Sunday. Heavy monsoon rain caused flooding across the Eastern, Northern and North Central provinces for the second time in less than a month. More than 250,000 people have been forced into temporary shelters by this latest inundation. "A large amount is destroyed. More than 90 percent of the crop will be destroyed this time, " Agriculture Minister Mahinda Yapa Abeywardene told Reuters, referring to the rice crop.

Russia poised to breach mysterious Antarctic lake
February 5, 2011 09:57 AM - Alissa de Carbonnel, Reuters, MOSCOW

For 15 million years, an icebound lake has remained sealed deep beneath Antarctica's frozen crust, possibly hiding prehistoric or unknown life. Now Russian scientists are on the brink of piercing through to its secrets. "There's only a bit left to go," Alexei Turkeyev, chief of the Russian polar Vostok Station, told Reuters by satellite phone. His team has drilled for weeks in a race to reach the lake, 3,750 meters (12,000 ft) beneath the polar ice cap, before the end of the brief Antarctic summer. It was here that the coldest temperature ever found on Earth -- minus 89.2 Celsius (minus 128.6 Fahrenheit) -- was recorded. With the rapid onset of winter, scientists will be forced to leave on the last flight out for this season, on Feb 6.

The Alarming Amazon Droughts of 2005 and 2010
February 4, 2011 08:58 AM - David A Gabel, ENN

When thinking of the wettest place on land, most people think about rainforests such as the Amazon, which can get up to 78 inches of rain per year. All this precipitation supports the Amazon's rich plant life which helps moderate carbon dioxide levels in the atmosphere. It is then quite alarming to learn that the Amazon has suffered two devastating droughts in the last five years. Researchers fear a continuation of this disturbing trend.

Ice Cores Yield Rich History of Climate Change
February 4, 2011 08:23 AM - Editor, Science Daily

On Friday, Jan. 28 in Antarctica, a research team investigating the last 100,000 years of Earth's climate history reached an important milestone completing the main ice core to a depth of 3,331 meters (10,928 feet) at West Antarctic Ice Sheet Divide (WAIS). The project will be completed over the next two years with some additional coring and borehole logging to obtain additional information and samples of the ice for the study of the climate record contained in the core.

Eurasian Arctic Rivers
February 2, 2011 08:55 AM - Andy Soos, ENN

Changes in the amount and timing of the discharge of major Eurasian Arctic rivers have been well documented, but whether or not these changes can be attributed to climatic factors or to the construction of man made reservoirs remains unclear. A new research report helps to identify the key processes (snow cover and air temperature) that have regulated seasonal stream flow fluctuations in the Eurasian Arctic over the last half-century (1958–1999) and to understand the regional coherence of timing trends, using a set of Eurasian Arctic rivers selected specifically because they are free of known effects of dams. A shift toward the earlier onset of spring runoff as measured by a modest change in the spring pulse onset (26 of 45 stations) and a strong change in the timing (39 of 45 stations). Winter stream flows increased over the period of record in most rivers, suggesting that trends observed by others in larger regulated Eurasian Arctic rivers may not be entirely attributable to reservoir construction.

Australian Cyclone Yasi
February 1, 2011 04:27 PM - Andy Soos, ENN

Down under they are called cyclones. In the Atlantic they are called hurricanes. Queensland in northeast Australia has recently been hit with devastating floods. Now Yasi, a very large cyclone, is bearing down. Yasi has reached maximum sustained winds near 90 knots (103 mph), equivalent to a Category Two hurricane on the Saffir-Simpson Scale early on January 31). Since then the winds have increased to a category 3 storm. It was centered about 875 miles east of Cairns, Australia, moving west at about 19 knots per hour (22 mph). Cyclone-force winds extend out to 30 miles from the center. Yasi is forecast to move west, then southwestward, into an area of low vertical wind shear (strong wind shear can weaken a storm). Forecasters at the Joint Typhoon Warning Center expect Yasi to continue to strengthen over the next 36 hours. The Center forecasts a landfall just south of Cairns as a large 100-plus knot-per-hour (115 mph) system by around midnight local time on February 2.

Brazil beats US in climate change awareness
February 1, 2011 09:07 AM - Luisa Massarani, SciDevNet

[RIO DE JANEIRO] Almost 80 per cent of Brazilians think global warming is caused by human activities, a survey has found, compared with less than half of Americans and around 70 per cent of Britons according to similar recent surveys.

The Complex Business of Measuring Climate Change
January 31, 2011 09:03 AM - Nick Engelfried, Justmeans, Clean Techies

Have you ever wondered exactly how scientists track climate change and the warming of the world at a global level? Estimating the overall surface temperature of the Earth isn't easy when you have to account for seasonal variations across six continents and four oceans. It requires compiling data from satellites positioned high up in the atmosphere and from hundreds of meteorological stations scattered across the globe. However being able to compare average global temperatures from year to year is incredibly important, and allows scientists to track the progress of climate change.

First | Previous | 375 | 376 | 377 | 378 | 379 | Next | Last