Posted on May 6, 2012 by Rashid Faridi
Posted in Uncategorized | Leave a comment

Reassuring News:Greenland’s Ice Melting Not As Fast As Expected

Posted on May 5, 2012 by Rashid Faridi
Retreating calving front of the Jacobshavn Isb...

Retreating calving front of the Jacobshavn Isbrae glacier in Greenland from 1851 – 2006. (Photo credit: Wikipedia)

A new study has some reassuring news.

Greenland’s glaciers hold  water to raise sea level by 20 feet, and they are melting as the planet warms, so there’s a lot to worry.

A few years ago, the Jakobshavn glacier in Greenland was in news all over.   The slow-moving stream of ice suddenly doubled its speed. It started dumping a whole lot more ice into the Atlantic. Other glaciers also sped up.The big concern was that If the world’s big glaciers were on their way to a 10-fold speedup, that could lead to a staggering 6 feet of sea level rise by the end of this century.

 

So Joughin and team have been trying to see if that acceleration is under way.

 

They studied radar images of 200 Greenland glaciers gathered over the past decade. Graduate student Twila Moon says some of Greenland’s glaciers picked up the pace and started surging forward more than 5 miles in a year.

 

It turned out that glacial pace isn’t very slow. she says.

 

It also turned out that glacial pace isn’t consistent. The glaciers like Jakobshavn that started surging haven’t kept on picking up speed. In fact, some have slowed down. And glacier speeds vary dramatical

 

read more  here

 

Related articles

 

Posted in Glaciers | Tagged , | 1 Comment

Posted on May 5, 2012 by Rashid Faridi

Stephen Vilaseca's avatarurbanculturalstudies

A new, exciting museum is being planned to keep alive the rich history of reclaimed urban space in New York City. The Museum of Reclaimed Urban Space, MoRUS, will be located in the storefront of the historic East Village building C-Squat and will house artifacts like videos, photographs, fliers, posters and communiqués by grassroots community members who have squatted abandoned buildings, championed community gardens, and protested the restrictions placed on public space. MoRUS has the potential to strengthen transversal relays between activists and academics, and establish the environment and setting for new social creativity. However, it is not yet open to the public because it still needs additional funding. If you are interested, you can donate here: http://www.crowdrise.com/helpusstartanewhisto.

View original post

Posted in Uncategorized | Leave a comment

Does cloud weigh? How Much?

Posted on May 4, 2012 by Rashid Faridi

Have clouds  any weight at all ? How can they, if they are floating in the air like a balloon filled with helium? If one tie a helium balloon to a kitchen scale it won’t register any weight, so why should a cloud?

Since air has weight it must also have density, which is the weight for a chosen volume, such as a cubic inch or cubic meter. If clouds are made up of particles, then they must have weight and density. The key to why clouds float is that the density of the same volume of cloud material is less than the density of the same amount of dry air. Just as oil floats on water because it is less dense, clouds float on air because the moist air in clouds is less dense than dry air.

A good sized cumulonimbus cloud, or thunderhead, might be ten kilometers tall, with a base ten kilometers in diameter with a volume of about 1 cubic kilometer (km) located about 2 km above the ground. In other words, it is a cube about 1 km on each side. The National Oceanic and Atmospheric Administration (NOAA) provides some estimates of air and cloud density and weight. NOAA found that dry air has a density of about 1.007 kilograms/cubic meter (kg/m3) and the density of the actual cloud droplets is about 1.003 kg/m3. In the final calculations, the 1 km3 cumulus cloud weighs a whopping 2.211 billion pounds (1.003 billion kilograms)! However, remember that air also has mass, so the cloud floats because the weight of the same volume of dry air is even more, about 2.220 billion pounds (1.007 billion kilograms). So, it is the lesser density of the cloud that allows it to float on the dryer and more-dense air.

To put it another way, a modest-size cloud, one kilometer in diameter and 100 meters thick, has a mass equivalent to one 747. And they let these things just float around up there! Why, if one fell on us, it would . . . it would . . . well, it would get real foggy, that’s what. Because of course weight isn’t the same as mass–a cloud put on a scale wouldn’t weigh anything. This fine but crucial distinction gets you off the hook in the argument you’re having with your coworker.

Links and Sources:

USGS , StraightDope

Related articles
Posted in rain, water, Weather, Winds | Tagged , , , | 2 Comments