Stories tagged The Water Cycle, Weather and Climate

Apr
03
2007

The 2007 Atlantic hurricane season officially begins June 1 and runs through November 30.

Two hurricanes: This satellite image, captured 8/30/05, shows Hurricane Iris in the central Atlantic Ocean, with Tropical Storm Karen to the southeast. (The original image, from which this is cropped, also showed Hurricane Humberto moving northeast across the Atlantic.)
Two hurricanes: This satellite image, captured 8/30/05, shows Hurricane Iris in the central Atlantic Ocean, with Tropical Storm Karen to the southeast. (The original image, from which this is cropped, also showed Hurricane Humberto moving northeast across the Atlantic.)

Check back often for the latest predictions, forecasts, and discussion.

Mar
28
2007

Rip Current Sign.: Photo courtesy Dawn Endico, via Flickr.
Rip Current Sign.: Photo courtesy Dawn Endico, via Flickr.
Rip currents are something that I have very little experience with – I find them mysterious, fascinating, and frightening. Growing up in Minnesota they are just not a part of my day to day life. I’ve encountered them on vacations. I’ve seen the signs posted on beautiful beaches with the ocean just calling you to swim in it. “Warning: Dangerous Rip Currents Do Not Swim”. Why? What are they?

Rip currents are strong flows of water returning seaward from the shore. Wind and waves push water to the shore, and the resulting backwash is pushed sideways by more oncoming waves. This sideways moving backwash flows along the shoreline until it finds a place where the waves are not as strong to return seaward. This location is “found” by a large amount of backwash resulting in a large flow of water using the same place to return to the ocean. Rip currents are usually narrow and located in trenches between sandbars, under piers, or along jetties. The current is usually strongest near the surface.

Portuguese Man-O-War: Photo courtesy U.S. National Oceanic and Atmospheric Administration.
Portuguese Man-O-War: Photo courtesy U.S. National Oceanic and Atmospheric Administration.
Rip currents cause approximately 100 deaths a year in the U.S., and are in the news now as we approach spring break. Apparently weather conditions down in Florida are ideal right now for the formation of rip currents. On March 24 lifeguards in Brevard County, Florida made 20 rescues as a result of rip currents. With the influx of spring break visitors – probably lots of folks like me who have little experience or understanding of rip currents – the situation is quite serious.

Adding to the woes of lifeguards and inexperienced ocean swimmers is the Portuguese man-‘o-wars which are being blown into shallow waters by the same winds that are causing the rip tides. Man-‘o-wars have a poisonous sting which can be fatal, but more often causes excruciating pain near the sting site.

Stay safe, spring breakers.

Mar
23
2007

The real cause of climate change?: A new film argues that the Sun, not people, is driving global warming.  Photo by NASA.
The real cause of climate change?: A new film argues that the Sun, not people, is driving global warming. Photo by NASA.

An earlier thread discussed the movie An Inconvenient Truth. Now, a British television network has produced a documentary of its own, entitled The Great Global Warming Swindle. (Streaming video; one hour and 13 minutes.) The film interviews many top scientists who disagree with the theory that human-produced CO2 causes global warming. It offers compelling evidence that climate change is driven by the Sun. And it ends with a rather disturbing look at how science and politics have influenced each other, with potentially dire consequences.

Regardless of how you feel about climate change and global warming, it's worth watching to film, to hear another side of the debate.

Mar
22
2007

Prehistoric pollen contains a record of climate change: Photo USGS
Prehistoric pollen contains a record of climate change: Photo USGS

Scientists want to study the mud at the bottom of Lake Van in Turkey to see how often, and how fast, the climate has changed in the past.

Every year, plants release millions of pollen grains. Some of those grains fall onto bodies of water and settle in the bottom. The layers of mud pile up like rings in a tree, preserving a record of the past. Scientists can dig through the muck to see what kinds of plants lived in the area. Were these plants that needed a lot of water, or very little? Could they survive in cold temperatures, or did they like it hot? The mud gives the scientists a record of the environment going back hundreds of thousands of years.

A similar study is going on in Minnesota. Researchers at the Science Museum’s St. Croix Watershed Research Station study diatoms – shells of tiny animals – preserved in the river bottom. This tells us what water quality was like at various times dating back to 1840.

Mar
22
2007

Super size me: With more concentrated efforts on researching the topic, scientists now believe that super snowflakes do exist. They can measure between three and six inches in width and be the size of table plates.
Super size me: With more concentrated efforts on researching the topic, scientists now believe that super snowflakes do exist. They can measure between three and six inches in width and be the size of table plates.
Spring is finally here and what better topic to bring up than snow, right?

A story in the New York Times this week is providing more evidence about “super snowflakes.”

For ages artists and writers have waxed poetically about huge flakes of snow. Hollywood movie producers and Hallmark card creators have used those images to depict winter. But they’re just figments of our imagination, right?

Hard scientific data is now being collected about the size of snowflakes, the researchers doing that work have been pleasantly surprised. They’ve found that snowflakes measuring from 2 to 6 inches wide regularly fall around the world. Some reports about the “super flakes” say that they’re so large – the size of saucers or plates – that their edges turn up and centers sag due to their weight.

A snowflake expert from the California Institute of Technology points out that there’s scientific basis that limits the size of snowflakes. But, he points out, large snowflakes may often break apart due to the pressures from high winds hitting them as they fall to the Earth.

For ages, scientists had never really measured the size of snowflakes. But on some recent research trips, researchers have seen snow falling that measured two or three inches in size. That’s spurred on more interest – and research – into the size of snowflakes.

In the future, some of that research may be done from space. NASA will be launching a global satellite in 2013 that will monitor global precipitation patterns. That technology will be able to gauge the moisture in each rain or snow fall, along with the size of the flakes falling.

Mar
18
2007

What a beach: In the aftermath of Hurricane Wilma in 2005, Cancun has had a hard time keeping sand on its beaches in its resort areas. Rebuilding efforts from the hurricane are quickly eroding away again, with up to 30 percent losses.
What a beach: In the aftermath of Hurricane Wilma in 2005, Cancun has had a hard time keeping sand on its beaches in its resort areas. Rebuilding efforts from the hurricane are quickly eroding away again, with up to 30 percent losses.
After a devastating hit by Hurricane Wilma in 2005, Mexico spent $19 million to rebuild beaches in the popular tourist destination of Cancun. Now, those efforts appear to be quickly eroding away.

Following the devastating impacts of the hurricane, ocean depths were dredged and eight miles of popular beach front were rebuilt, and actually expanded, to try to prevent the huge loss of beach to happen again.

But less than two years later, up to 30 percent of that sand is now missing. On some portions of the beach, swimmers and tanners have to jump down a three-foot drop in the beach to get to the current sand level.

What’s going on?

Environmentalists in the area insist any efforts will be wasted efforts unless more vegetation is worked into the areas between hotels and beaches. The roots of those plants and trees would help stabilize the impacts of erosion along the coast, they contend.

But the people in the tourist industry feel that building an artificial reef along the beach would help to lessen the impacts of waves and tides on the beaches. They’re drawing up plans to create a public/private partnership to develop and maintain such a reef.

The tourist industry concerns also say that there is a cyclical action to the growth and decrease of Cancun’s beaches. It contends that erosion happens in the winter months when coastal winds and currents are stronger. Then the sands return to the beach in calmer months.

But the environmentalists contend that situation has been getting progressively worse since the 1970s when large hotels began being developed along the beaches and native vegetation was pulled out.

What do you think? Share your thoughts here with other Science Buzz readers.

Mar
10
2007

Calm waters: This picture shows the Amazon River very calmly, but last week a 30-foot wave wiped out a village, carring alligators, fish and boats along with it.
Calm waters: This picture shows the Amazon River very calmly, but last week a 30-foot wave wiped out a village, carring alligators, fish and boats along with it.
A wild wave rocked life along the Amazon River earlier this week.

Media reports are saying that a huge wave, maybe up to 30 feet high, crashed into a village and wiping out two houses. One man was reported missing following the wave.

The wave is officially under investigation, but is believe to have started by a mudslide. The wave carried alligators, boats and fish into the village of Costa da Aguia, which is 1,700 miles northwest of Rio de Janeiro.

All 21 people who live in Costa da Aguia had to be relocated as all their homes were destroyed. The houses were built on wooden stilts along the river’s bank.

"It looked like a building, growing with an immense velocity,'' Marisson Garcia, who lives just across the river from the damaged village, told the Folha de S. Paulo newspaper.

Feb
17
2007

January 2007 global warming smashes previous record.

Hottest Jan ever.: NOAA
Hottest Jan ever.: NOAA
Climate monitoring branch chief, Jay Lawrimore, has grown accustomed to having records broken but says that January was a bigger jump than the world has seen in about ten years. The global land average temperature didn't just nudge past the old record set in 2002, but broke that mark by 0.81 degrees Fahrenheit (0.56C), which meteorologists said is a lot, since such records often are broken by hundredths of a degree at a time.

The temperature of the world's land and water combined -- the most effective measurement -- was 1.53 degrees Fahrenheit (0.96C) warmer than normal, breaking the old record by more than one-quarter of a degree. The world's temperature record was driven by northern latitudes. Siberia was on average 9 degrees Fahrenheit (5.1C) warmer than normal. Eastern Europe had temperatures averaging 8 degrees Fahrenheit (4.55C) above normal. Canada on average was more than 5 degrees Fahrenheit (2.88C) warmer than normal. NOAA

United States had warmest year ever in 2006

The United States yearly average temperature record was broken in 2006(NOAA News). Here in Minneapolis-St Paul, the temperature was 17 degrees F above average for the last three weeks of 2006. Also in 2006, the United States set an all-time record for forest fires with more than 9.8 million acres burned in more than 96,000 wildfires.

What other records are being set?

We seem to be living in turbulent times. Can you give examples of other records being set?

Jan
22
2007

A Wisconsin snowflake: Photo NASA
A Wisconsin snowflake: Photo NASA

We've all heard that no two snowflakes are alike. But a scientist in Japan argues it ain't necessarily so.

As each water molecule freezes onto the forming ice crystal, a snowflake can take billions and billions of different shapes. But, each year, billions and billions of snowflakes fall to Earth. Over time, the number of flakes that have fallen exceeds the number of possible shapes, meaning that -- at least for the smaller, simpler flakes -- there must be some duplicates.

Of course, Cecil Adams addressed this topic with his usual wit and flair some time ago.

Jan
18
2007

Coming soon to a neighborhood near you: Starting on Oct. 1, the National Weather Service will not be issuing severe weather warnings on a county basis. Rather, it will mark the area at risk for tornadoes, thunderstorms and other severe weather by geographical landmarks.
Coming soon to a neighborhood near you: Starting on Oct. 1, the National Weather Service will not be issuing severe weather warnings on a county basis. Rather, it will mark the area at risk for tornadoes, thunderstorms and other severe weather by geographical landmarks.
It used to drive me nuts.

Before I moved to St. Paul a couple years ago, I lived in a large county north of the Twin Cities. When severe stormy weather arose in one part of the county, the sirens would sound, even if the part of the county I lived in was calm and sunny.

That’s all going to change this fall.

The National Weather Service has announced that starting on Oct. 1, it will no longer be issuing severe weather warnings on a county-wide basis. Instead, it will be delineating storm warning areas by geographic landmarks, such as highways and rivers. Storms situations covered by the new warning system include tornadoes, thunderstorms, flash floods and marine hazards.

Watches will still cover entire counties, but those aren’t the conditions when the weather service sounds emergency alarms to take cover.

Even worse than my former personal situation north of the Twin Cities, under the old county-based storm warning system in some parts of the U.S., people could be alerted to a storm and still be more than 100 miles away from the action.

Weather Service Director David Johnson hopes that the new system won’t make people get complacent.
"I do not want to teach America to ignore warnings," Johnson said, so under the new program, "if you get the warning, there is a direct correlation to you being at risk."

Do you think you’ll be able to adjust to the new system? Remember, it doesn’t start until the fall, so any storms we have yet this summer will be reported under the old county-alerting system.