Stories tagged weather

NASA scientists spent a month flying a sensor-packed airplane into storms brewing off the western coast of Africa. Data collected from these missions might someday allow better storm prediction and forecasting, and will definitely contribute to our knowledge of how hurricanes form and sustain themselves.

Sep
16
2006

There's been a rash of cool weather sites written up in the Twin Cities newspapers and other media lately.

Here are just a few:

Skeetobiteweather is one of the most popular hurricane sites run by amateurs. Jonathon Grant, of Lakeland, Florida, runs it. He says the site gets 1.8 million page views a week, and you can plug in your zip code and get a prediction of wind forces for your block, hour-by-hour, before a hurricane hits. (Not even the National Weather Service does that.) And pretty soon, you'll be able to enter your exact address.

Mark Sudduth, of Wilmington, North Carolina, runs HurricaneTrack and HurricaneLiveNet. He deploys several battery-powered, waterproof cameras at the exact points where hurricanes are expected to hit. He also collects weather data to accompany the live, streaming video.

Jesse Bass, of Hampton Roads, Virginia, is a weather chaser who posts photos and commentary on his website, VAStormPhoto.

HurricaneCity, despite its name, is one of the more comprehensive severe weather sites. Jim Williams, of Delray Beach, Florida, focuses on the city being hit, and you can see all live, streaming radio stations or TV from the site. He also has a towercam on his roof, which captured images from Hurricane Wilma last year, and he hosts "The Hurricane Warning Show" from his living room.

Mike Watkins, of Coconut Creek, Florida, covers Atlantic hurricane action on TropicalUpdate. And if there's no news on the hurricane front, he hosts an Internet radio show where he interviews the "celebrities" of the weather world--guys like Max Mayfield, of the National Hurricane Center, or William Gray, the Colorado State University professor who's known for his hurricane season forecasts.

A new study found a link between human use of fossil fuels and an increase in the severity of hurricanes. The burning of fossil fuels has increased the level of greenhouse gases in the atmosphere, which has led to the warming of oceans in regions where hurricanes develop. The warmer the ocean water, the more severe the hurricane.

UK doctors have warned mobile phone users of the risks associated with mobile phone usage during thunderstorms. Metal found in mobile phones is able to send lightening currents directly into your body-possibly creating lots of damage!

The National Museum of American History is in the planning stages of building an exhibition displaying numerous Hurricane Katrina artifacts. The exhibit will be on display after the museum reopens in 2008.

May
18
2006


Rainbow: (Photo credit: Mark Ryan)

Living in Minneapolis, I often ride my bike for exercise around the city lakes. The other day, while trying to get a ride in between rain showers, I was presented with a stunning rainbow. Actually, only a small portion of the arc was visible when I first saw it at Lake Harriet, but by the time I reached the west side of Lake Calhoun it had grown into a full blown double arced rainbow.

I stopped to admire it and regretted not having my camera with me because it was truly one of the best rainbows I had witnessed in a long time. A kid next to me, snapping a picture of it with his cell phone, wondered out loud, “How far away do you think that rainbow is?”

It was a good question and made me want to learn more about the atmospheric phenomenon.


Raindrop refraction and reflection: Sunlight is refracted as it enters a raindrop, reflected inside, then refracted again as it exits. An observer sees only one color reflected from a particular raindrop.Graphic by Mark Ryan

Basically, rainbows are the result of sunlight being once reflected and twice refracted by raindrops. Certain conditions are required. First and foremost, the viewer needs to be located between the sun and rain clouds. A ray of sunlight enters an individual drop of water and is refracted (bent) as it enters, then reflected from the back of the drop, and refracted again as it exits the drop. The refractions cause the white sunlight to divide into separate colors. Each color refracts in slightly different amounts, red the least, and violet the most. A particular raindrop will reflect red light because it is positioned at just the right angle from your eye (42°). This is known as the “rainbow ray”. Another droplet located at a slightly different position will reflect blue light to your eye. Now multiply this by the innumerable suspended water droplets that make up a rain cloud, and you have a rainbow.

The main colors in a primary rainbow will have red at the top followed by orange, yellow, green, blue, indigo, and violet. An easy way to remember the order is to note that the first letter of each color spells out the name ROY G. BIV.

The rainbow I witnessed had a second, fainter rainbow just above the first. This is the result of some light being reflected twice, and at a higher angle. The colors in a secondary arc are reversed with red on the bottom and violet on top.

The inside of a rainbow is always brighter than the sky outside the arc. This is because other rays of light are reflected from individual raindrops at angles smaller than the rainbow ray. Since this scattered light is made up of all the other incidental colors the light inside the bow is white.

So, how far away is a rainbow? I’ll let you figure that out for yourselves. The answer may surprise you.

Well spring is pretty much wrapped up but I still enjoyed browsing through this BBC website Springwatch. Our updated summer phenology exhibits are coming soon.
May
04
2006

After all the rain we've had recently, parents of toddlers in the Twin Cities area surely have two questions on their minds:

  • Will this rain EVER stop? Or, more accurately, will this rain PLEASE let up before I'd rather lie down and get eaten by bears then spend one more second cooped up in the house with my two-year-old?
  • And why are there worms all over the sidewalk whenever it rains?

I can't help with the first question.
But the second, that's a topic for Science Buzz!

I always thought that the worms came out of the ground when it rained to avoid being drowned in their burrows. Turns out I was wrong, wrong, wrong.

A series of Straight Dope articles, by Cecil Adams, have enlightened me.


Worm: (Photo by Jiva)

Turns out that the worms are in no danger of drowning. They can actually survive underwater for quite a long time. They are out on the sidewalk after it rains to engage in, um, "amorous activity." For the slimy details, read the Adams' column!

Of course, that's not ALL the worms are doing. They're also trying to move safely to new areas; vulnerable to drying out as they are, they can only do this aboveground at night or after a rain.

My toddler will be blown away by all this. Her explanation is that worms come out because of some altruistic notion that robins are hungry...

For more information about earthworms, check out this JourneyNorth Q&A page.

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
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.)