Stories tagged The Water Cycle, Weather and Climate

Apr
26
2006


Tornado: Image courtesy NOAA Photo Library, NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL)

Tornado season is here for those of us living in the Midwest. Tornadoes fascinate me – they’re so incredibly powerful and stunning and scary all at once. I used to have all sorts of elaborate emergency escape plans to the basement when I was a kid, and even had a pecking order for what prized possessions I would save and how. I also remember as a kid being told that if there was the threat of a tornado to open up a window a crack before heading to the basement so that the pressure inside the house would normalize with the pressure outside generated by the tornado thus preventing the roof from being blown off. I did this all the way up until last summer – but no more.

It turns out that a majority of damage to homes is the result of wind blowing into open (or broken) windows pushing up on the roof at the same time as winds are blowing over and under them, generating a lifting force, which increases the chances of the roof being blown off. So, all this time I’ve been making my house less safe, rather than safer. Doh.

Although it is likely wishful thinking on my part to hope that a single pane of glass is going to remain intact during a tornado, especially with all the debris that will be flying around. It makes more sense to close them to keep the rain out than to save the house from tornado damage, but it feels good to do something during those times when you have no real control. Better still to just forget the windows and get to the basement. With my most prized possessions.

For more information on tornadoes, and tornado safety, check out these sites:
Tornado Project Online
NOAA’s online Tornado FAQ
Weather.com’s Tornado page

Apr
22
2006


V. Ramanathan with AUAVs: Credit: Scripps Institution of Oceanography/UCSD V. Ramanathan, chief scientist of the Maldives Campaign, accompanied by several autonomous unmanned aerial vehicles.

Scripps Institution of Oceanography at the University of California, San Diego, has successfully sent a fleet of aerial drones through the pollution-filled skies over the Indian Ocean. Researchers hope the data produced by flights will reveal in unprecedented detail how pollution particles cause dimming and contribute to the formation of clouds which amplify the dimming caused by the pollution.

The instrument-bearing autonomous unmanned aerial vehicles (AUAVs) completed 18 successful data-gathering missions in the vicinity of the Maldives, an island chain nation south of India, said Scripps scientist V. Ramanathan. Researchers hope the data produced during the flights will reveal in unprecedented detail how pollution particles cause dimming and contribute to the formation of clouds which amplify the dimming caused by the pollution.

Cloud cover cools Earth's surface by reflecting solar radiation back into space. In recent years, researchers have realized that pollution in the atmosphere, and the dimming and cooling it causes, could be leading scientists to underestimate the true magnitude of global-warming trends observed in recent decades.

Flights took place between March 6 and March 31, 2006, taking off from an airport on the island of Hanimaadhoo in the Maldives. Each AUAV tracked a separate component of brown cloud formation. The lowest, flying beneath the cloud, quantified the input of pollution particles and measured quantities of light that penetrated the clouds.

The aircraft flying through the cloud measured the cloud's response to the introduction of particles. The aircraft flying above the cloud measured the amount of sunlight reflected by the clouds into space and the export of particles out of the clouds.

Source: National Science Foundation.

Apr
21
2006

On April 6, officials from Minnesota and Wisconsin signed an agreement designed to reduce levels of phosphorus in the St. Croix River by 20% by the year 2020.

For more information about phosphorus in the St. Croix visit the Buzz kiosk in the Mississippi River Gallery on level 5, or check out our on-line feature.

Apr
12
2006

Global warming has been in the news a lot lately. First, 60 scientists signed a petition asking the Canadian Prime Minister to open a scientific debate on the Kyoto Treaty. (The Kyoto Treaty is an international agreement to reduce global warming by reducing industrial emissions. Some people think the treaty has too many loopholes, and even if the loopholes were closed, it would still not be effective. The US has not signed the treaty. Science Buzz has had its own Kyoto debate.)

The scientists argue:

Much of the billions of dollars earmarked for implementation of the protocol in Canada will be squandered without a proper assessment of recent developments in climate science. …

It may be many years yet before we properly understand the Earth's climate system. Nevertheless, significant advances have been made since the protocol was created, many of which are taking us away from a concern about increasing greenhouse gases. …

The new Canadian government's commitment to reducing air, land and water pollution is commendable, but allocating funds to "stopping climate change" would be irrational. We need to continue intensive research into the real causes of climate change and help our most vulnerable citizens adapt to whatever nature throws at us next.

Next, a climate researcher in Australia has looked at current climate data and found that global temperatures have been holding steady since 1998:

Two simple graphs provide needed context, and exemplify the dynamic, fluctuating nature of climate change. The first is a temperature curve for the last six million years, which shows a three-million year period when it was several degrees warmer than today, followed by a three-million year cooling trend which was accompanied by an increase in the magnitude of the pervasive, higher frequency, cold and warm climate cycles. During the last three such warm (interglacial) periods, temperatures at high latitudes were as much as 5 degrees warmer than today's. The second graph shows the average global temperature over the last eight years, which has proved to be a period of stasis.

Finally, an atmospheric scientist at the Massachusetts Institute of Technology argues that there is a vicious circle between climate scientists who find evidence of global warming; environmental activists who use those findings to advance their cause; and policy makers who respond to the activists by giving more money to… the climate scientists.

(He also claims that scientists who raise doubts about global warming and human impact on climate are sometimes shut out of the debate. Science Buzz has had it’s own discussion on disagreements within the scientific community.)

So, what to make of all of this? I think the MIT professor said it well:

[L]et's start where there is agreement. The public, press and policy makers have been repeatedly told that three claims have widespread scientific support: Global temperature has risen about a degree since the late 19th century; levels of CO2 in the atmosphere have increased by about 30% over the same period; and CO2 should contribute to future warming. These claims are true. However, what the public fails to grasp is that the claims neither constitute support for alarm nor establish man's responsibility for the small amount of warming that has occurred.

This all illustrates the dynamic interaction between science and politics. Science is about facts. Politics is about opinion – what should we do in the fact of those facts? But the distinction is not always clear. Science influences political debate; and political decisions influence what science gets support. The best thing to do is to keep an open mind, remembering that most people have some sort of agenda, and that new information is coming out all the time.

(The Science Museum of Minnesota did an exhibit on global warming. You can find the website here.)

Mar
16
2006
snowflake

Have you ever wondered how to rate a snowstorm? Meteorologists classify earthquakes, tornadoes, and hurricanes…so why not snowstorms?! This past January, the American Meteorological Society released a new scale ranking snowstorm severity. Criteria include snowfall amount, size of region blanketed, and lastly the population of the affected area.

Scientists focused their research on thirteen states in the Northeast. Region selection was based on frequency of snowstorms. They classified snowstorm severity in five levels: notable, significant, major, crippling, or extreme. So the next time we get blasted with a wintry-wonderland, keep in mind the new snowstorm classification.

Resource: How to rate a snowstorm. (2006, February 18). Science News, 169, 7

Jan
18
2006

Scientists at the Max Plank Institute in Germany have discovered that living trees are a major source of methane in the Earth's atmosphere. Methane is a major "greenhouse gas," implicated in global warming.


Trees and sun: Trees and sun

Before this study, scientists thought plants only released small amounts of methane, and then only when they decomposed (as in swamps). The new research shows that plants release methane throughout their lives, and in large amounts—up to 30% or more of the planet's total methane production may come from plants.

This forces us to re-think environmental efforts. Strategies for dealing with climate change, such as the Kyoto Protocols, often call for planting more trees. And it's true that trees do take a lot of carbon dioxide out of the atmosphere—the most prevalent greenhouse gas. But now it turns out trees also release methane, so their benefit is not quite as great as once thought.

Oct
19
2005

Overnight, hurricane Wilma became a Category 5 storm with sustained 175-mile-per-hour winds and the lowest recorded barometric pressure of any Atlantic hurricane. Meteorologists expect it to weaken over the next few days, although it could dump huge amounts of rain on Bermuda, the Cayman Islands, and Cuba.


10-19-2005 Hurricane Wilma: Hurricane Wilma, 10-19-2005

The current forecast has Wilma dropping to a Category 3 storm before it makes landfall somewhere in southwestern Florida over the weekend. (Florida has been hit by six—count 'em! Six!—hurricanes since August 2004, and many people are still in the process of rebuilding from the last storm.) Wilma is the third Category 5 hurricane this year (after Katrina and Rita). The National Hurricane Center doesn't know if that's a record because they don't track the number of Category 5 storms in a season. Wilma does tie two other records, though—the most hurricanes in a season: 12; and the most named storms in a season: 21. And Wilma is the last name on the National Hurricane Center's list of names for 2005 storms. The hurricane season doesn't end until November 30; if any other tropical storms or hurricanes develop this year, they'll be named using letters from the Greek alphabet, starting with Alpha. (If that happens, it would be the first time since we started naming storms in 1953.)

Sep
22
2005

Just on the heels of the deadly Hurricane Katrina, Rita hit the gulf coast with 120mph winds. The storm grew to enormous force out at sea with winds in excess of 155mph but then slowed down some as it came inland.

UPDATE

It appears that Rita has caused flooding in New Orleans. Water is pouring over the levees in the lowest lying part of the city.

Is New Orleans in danger also?

The hurricane is came on shore near Lake Charles, TX which is very close to the Louisiana border and about a 5 hour drive to New Orleans. But the storm is was so big that the storm surge was easily able to top some of New Orleans' fragile levees. The U.S. Army Corps of Engineers said that after Hurricane Katrina, the levees could handle only 6 inches of rain and a storm surge of 10-12 feet.

Watch the waters rise

As the hurricane comes ashore, it will push massive amounts of water inland, causing a "storm surge." To watch the water rise in real-time, check out the Texas USGS stream-flow gauges. The gauge near Freeport is likely to show an effect (depending on where the storm hits). These gauges measure the water level in streams and rivers in real-time. Watch for a huge increase as the hurricane moves inland.

Get to higher ground

Right now, more than 1.3 million people are under mandatory evacuation orders. Texas Governor Rick Perry, having learned Katrina's lessons, is preparing the state for a worst-case scenario. President Bush has declared states of emergency in Texas and Louisiana, allowing FEMA to coordinate plans, and workers at the South Texas Project nuclear power plant are shutting the facility down before Rita arrives.

And watch for rising gas prices. The threatened oil rigs in the Gulf of Mexico produce more than 25% of total U.S. oil output.

Aug
30
2005
See a diagram of New Orleans' levee system
Levee break from the Sky

As the weather cleared in New Orleans officials were able to move in and begin rescue operations. However, a hole in the levee holding back the salty waters of Lake pontchartrain has been widening throughout the day. This hole is causing flood waters to steadily rise, flooding areas that had originally escaped inundation.

New Orleans's Ray Nagin said, "We're not even dealing with dead bodies...They're just pushing them on the side." This is a very gruesome situation. Although the bacteria that start the decay process when a human body dies is not dangerous to other humans, many other toxic substances pollute that waters flooding New Orleans.

Aug
29
2005

A huge category 4 hurricane (winds 131-155 mph) named Katrina struck the US gulf coast Monday morning, August 28th. Many of the major news outlets will have stories covering the hurricane.  Science Buzz will strive to bring you a perspective on the science behind this awesome force of nature and its human effect.

Waters rise quickly

For a unique perspective on storm's surge, check out the live USGS stream-flow gauges in the New Orleans, LA area.
The stream-flow gauges measure the water levels at various places around the state and are updated by computer every 15-60 minutes. As Hurricane Katrina came inland it brought with it enormous surges in the water level. At several of these gauges around the area you can see the sharp rise in the water levels starting near the middle of the day on Sunday (28th).

Unique images of the storm

NASA's MODIS satellites captured this amazing high-res image of the storm on Sunday (28th) while the storm was still many miles out from the shore.  This unique image allows you to see great detail in the clouds that swirl around the eye of the storm.

As the storm grew closer to the coast people started to feel the horrible effects of the energy wrapped up in this weather system. There are several sets of photos on the community photo sharing website, Flickr, that show what people in the area are experiencing.

Photos tagged: hurricane + katrina

Photos tagged: hurricane + louisiana

Have you ever been in a hurricane? Can you imagine what it might be like?