Label: Weather

February 4, 2011

Kids all across America have had plenty of snow days this winter, with a series record-setting snowstorms that started back in December. Today, even kids from Texas to the Carolinas are having a snow day.

It sounds like a good time to settle in, make yourself a cup of cocoa, and browse Seymour’s online Science Dictionary. You can start with the entry for SNOWFLAKE!

October 25, 2010

Tornadoes were reported yesterday in Tennessee and Alabama, and a particularly destructive tornado struck Rice, Texas at 5:30 p.m. on Sunday, destroying homes, turning over vehicles and knocking a railroad car right off the tracks, according to Navarro County Chief Deputy Mike Cox. Fortunately the only injuries were relatively minor, but also caused extensive damage to Rice Elementary School, which means it struck very close to home for local kids.

 Children who live in "Tornado Alley" (from Texas north to Nebraska) can learn what to do to protect themselves and their families. I’m going to reiterate some of what I’ve written previously on this subject, as well as answer some questions that kids are likely to ask. Giving elementary-age (and older) children information is the best way to offer reassurance and reduce anxiety.

 Why is this happening when it’s not "tornado season" (usually defined as April through July, with May and June being the peak months)? Like thunderstorms, tornadoes can form any time of the year.

 What is a tornado and why does it cause such destruction? A tornado’s funnel looks like a huge elephant’s trunk hanging down from a cloud. The funnel acts like a giant vacuum cleaner…whenever the "hose" touches the ground, it sucks things up into the air.

Usually, tornadoes are local storms. A typical tornado is only 400 to 500 feet wide, has winds of less than 112 miles per hour, and last only a few minutes. But sometimes, monster tornadoes a mile wide with winds up to 500 miles per hour are born in very large thunderstorms - also called supercells - and they can cause tremendous destruction. Tornadoes have moved houses down a whole block, bounced 20-ton tractor-trailers up and down on the highway, even picked up a pond full of frogs and rained them down on a nearby town!

If you live near an area that is prone to tornadoes at this time of year, the most important things to remember are:

*     Pay attention to early warning sirens and alerts on radio and television, so that you can take shelter before a tornado strikes.

*      Cars and mobile homes are NOT safe during a tornado. Go to the basement of a solidly built house.

 *     If you are in an apartment or home without a basement, getting into a bathtub and covering yourself with a couch cushion or a mattress protects you on all sides.

*     If you are out walking or biking, life flat in a ditch if there is no rain. If there is rain, there may be a danger of flash flooding, so stay out of the ditch, get away from trees and power lines, crouch down and make yourself as small as possible - be a "human basketball"!

You don’t have to worry too much in advance about tornadoes, but finding out when they are coming and knowing what to do is certain to help you if one strikes.     

October 14, 2010

I am wearing my favorite shirt today - a drawing of planet Earth with a "Saving" status bar below, registering about 30%. Saving Earth is something I find myself thinking about nearly every day…..especially when I read the news and see how many of the predictions of the consequences of global warming are coming to pass.

2010 has been a year of weather extremes - huge snowfalls in places that normally don’t get much snow at all, a deadly heat wave this summer in Russia leading to fires that killed 700 people per day, and unprecedented flooding in Pakistan that has affected 21 million people (1-out-of-8 Pakistanis), leaving at least 6 million people homeless and an area the size of Italy underwater.

Scientists say that the devastating floods in Pakistan and Russia’s heatwave were both the kind of extremes caused by global warming. We don’t know enough to blame manmade pollution and the greenhouse effect for directly causing any single, specific weather disaster, but we are certainly seeing an escalating pattern of climate extremes that are most likely part of a change in Earth’s climate, caused by global warming.

How is it that we get both extreme drought and extreme precipitation, even huge amounts of snow, when temperatures are increasing? The reasons that droughts are getting worse is pretty obvious for areas that generally have little rainfall - when the temperature gets hotter, drought conditions get even worse. But extreme rain and snow? Well, there is a physical law (it’s called the Clausius-Clapeyron relation, for those of you who want to look it up!) which established that the water-holding capacity of the atmosphere increases by about 7% for every 1°C rise in temperature. Because precipitation comes mainly from weather systems that feed on the water vapor stored in the atmosphere, this has generally increased precipitation intensity and the risk of heavy rain and snow events. 

2010 has also been a very bad year for our planet’s coral reefs. Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration’s Coral Reef Watch, said high ocean temperatures in 2010 are causing corals to whiten, or bleach. "Major bleaching started in the Central Pacific in the early part of this year, then there was bleaching in the Indian Ocean and especially Southeast Asia throughout May and June. And now the big concern is that we may be seeing the worst bleaching ever in the Caribbean, later this year." According to NOAA, this thermal stress to corals is the highest it has been since 1998, when 15% of the world’s coral reefs died.

I am about to begin work on a book about coral reefs, which are some of the most biologically diverse and economically valuable ecosystems on earth. Coral reefs are a source of food for millions of people, protect coastlines from storms and erosion; provide habitat for thousands of fish species, and provide many human jobs in both the fishing and tourism industries. In a nutshell, no reefs, no fish. Not...

August 4, 2010

Take a look at this great satellite photo of the beginning of a hurricane. Tropical Storm Colin became the third named storm of the 2010 Atlantic hurricane season yesterday morning as it strengthened from a tropical depression to a tropical storm. You can see that although the cloud formation hints at the spiral shape characteristic of hurricanes, it doesn’t (yet) have a distinct eye. The photo comes from the U.S. National Hurricane Center (NHC) at NASA’s Earth Observatory. Photography buffs may be interested in knowing that the natural color image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.

July 25, 2010

Depending on where you live in North America, you’ve been experiencing some variation of unstable summer weather - extreme heat, heavy rains and flooding, violent summer thunderstorms or tornadoes, tropical storms and potential hurricanes. Children are fascinated by weather, and full of questions about why these things happen.

Just in time to help you explain all these various phenomena we’ve published three new Teacher Guides for Seymour’s WEATHER, LIGHTNING, and HURRICANES books. These are free downloads from SeymourSimon.com. Try them out today with a kid that you love!

July 15, 2010

The Atlantic Ocean from the coast of West Africa to the Caribbean Sea is hotter than usual this summer and that means more hurricanes are coming. This area of the Atlantic is where tropical storm systems gain speed and size as they move toward the eastern coast of the US and the Gulf of Mexico. Weather scientists say that the surface temperatures are one to two degrees above average and that means that this year’s Atlantic Hurricane season might well have from 14 to 23 storms large enough to be given names. Hurricanes are bad enough in normal times but this year there are two areas already battered by catastrophic events: The Gulf Coast trying to clean up spilled oil from BP’s well and Haiti after January’s earthquake. 

You can read more about this year’s hurricane season on the NY Times’ GREEN blog, which covers stories about energy and the environment.

May 11, 2010

Tornado season can be a scary time for kids who live in affected areas. The last 24 hours have been deadly in Oklahoma, and thousands of people in Kansa and Oklahoma are still without power.

I wrote an extensive post recently about tornadoes, which you can still access online. And,  since giving kids a sense of what they can do to stay safe helps them to feel less frightened, I’d like to reiterate the key things for kids to know if they live in the southern plains, or in a place where tornadoes might strike.

** Pay attention to early warning sirens and alerts on radio and television, so that you can take shelter before a tornado strikes.

** Cars and mobile homes are NOT safe during a tornado. Go to the basement of a solidly built house.

** If you are in an apartment or home without a basement, getting into a bathtub and covering yourself with a couch cushion protects you on all sides.

** If you are out walking or biking, life flat in a ditch if there is no rain. If there is rain, there may be a danger of flash flooding, so stay out of the ditch, get away from trees and power lines, crouch down and make yourself as small as possible - be a "human basketball"!

Reassure children that they don’t have to worry too much in advance about tornadoes, but finding out when they are coming and knowing what to do is certain to help them if one strikes.   

 (Editor’s Note): For kids who want more information about storms, Seymour has also written a Level 2 SeeMore Reader called SUPER STORMS, which is also available in Spanish, titled TORMENTOS INCREíBLES.

May 10, 2010

Sunday, Mother’s Day, was very windy with gusts reaching 40 miles per hour. It was sunny and there were many cumulus clouds in the blue skies. But there weren’t the usual puffy cumulus clouds that look like cotton balls.

Instead they were cumulus fractus (or fractocumulus) clouds, sometimes also called "scud"  by pilots. Fractus clouds are clouds that are torn by high winds and look very much like cotton balls that have been torn apart by fingers.   They change constantly and often move rapidly across the sky.

April 23, 2010

Did you see the images on television last night of snowplows removing hail (not snow – HAIL!) from the highways in Colorado? And if you click here you’ll see video of a tornado that touched down in Texas last night.

There are strong thunderstorms predicted throughout this weekend in the Eastern two-thirds of the US, and Tornado Watches are in effect for communities that regularly experience these violent storms.

Why is all this happening at once? Well, it’s April, and that generally marks the beginning of the tornado season in the U.S.

A tornado’s funnel looks like a huge elephant’s trunk hanging down from a cloud. The funnel acts like a giant vacuum cleaner…whenever the “hose” touches the ground, it sucks things up into the air.

 Usually, tornadoes are local storms. A typical tornado is only 400 to 500 feet wide, has winds of less than 112 miles per hour, and last only a few minutes. But sometimes, monster tornadoes a mile wide with winds up to 500 miles per hour are born in very large thunderstorms – also called supercells – and they can cause tremendous destruction. Tornadoes have moved houses down a whole block, bounced 20-ton tractor-trailers up and down on the highway, even picked up a pond full of frogs and rained them down on a nearby town!

If you live near an area that is prone to tornadoes at this time of year, the most important things to remember are:

·      Pay attention to early warning sirens and alerts on radio and television, so that you can take shelter before a tornado strikes.

·      Cars and mobile homes are NOT safe during a tornado. Go to the basement of a solidly built house.

·      If you are in an apartment or home without a basement, getting into a bathtub and covering yourself with a couch cushion protects you on all sides.

·      If you are out walking or biking, life flat in a ditch if there is no rain. If there is rain, there may be a danger of flash flooding, so stay out of the ditch, get away from trees and power lines, crouch down and make yourself as small as possible - be a "human basketball"!

You don’t have to worry too much in advance about tornadoes, but finding out when they are coming and knowing what to do is certain to help you if one strikes.     

April 19, 2010

Our Planet Earth is putting on quite a show in celebration of the 40th Anniversary of Earth Day! For those interested in seeing photographs, the Boston Globe.com ran a feature this weekend with twenty striking images of the volcano, including shots of people on cross country skis taking photographs at the edge of the hot lava. Talk about a study in contrasts!

 The volcano continues to erupt in Iceland,  and air travel is still disrupted in northern Europe and Great Britain. If you look at this satellite image, you can see why:

The land mass at the top/left of the photo is Iceland. The two land masses at the bottom/center of the photo are Ireland and Britain. You can see why no planes are flying out of England - the country is enveloped in volcanic ash.

This volcano has not been studied extensively, so scientists do not know how long the eruptions might continue. From what has been observed so far, there will not be a significant impact on Europe’s weather. It takes a very big volcanic event to impact weather across a continent, or across the globe. When Mount Pinatubo erupted in the Phillippines on June 15,  1991, scientists   estimated that 20-million tons of sulfur dioxide and ash particles   blasted more than 12 miles high into the atmosphere. The eruption caused widespread destruction and loss of human life. And, the gases and solids injected into the stratosphere enveloped our globe for three weeks.That volcano caused an average 10% drop in temperatures,  affecting the world’s weather that year.

The eruption of   the Tambora volcano in 1815 (in what is now Indonesia) was one of the biggest weather influencers ever, triggering the famous Year   without a Summer in 1816. 

Scientists do not agree on whether even a huge volcanic eruption (much bigger than the one we’re experiencing this week) could ever have a long-term impact on climate.

Remember, weather is different from climate. When you talk about weather, you are talking about       what is happening in the atmosphere that day in a particular location. Weather tells...

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