Stories tagged The Water Cycle, Weather and Climate
Great Lakes from space: Photo by NASAGlobal warming, or more accurately climate change, is being blamed for lower water levels and rising temperatures in some of the Great Lakes according to a recent article at NewScientist.com.
Lake Superior from the North Shore: Photo by Mark RyanLake Superior, which contains 10% of the world’s fresh water, is showing levels that are down about an inch-and-a-half from last year, and more than eighteen inches below its long-term mean level. Temperatures on the lake’s surface water has risen 2.5 degrees Celsius since 1979.
Both changes are attributed to the lack of ice on Superior during the winter months. Without ice cover, sunlight energy doesn’t get reflected back into the atmosphere, but is instead absorbed by the water, heating it, and causing evaporation to increase. Jay Austin, a limnologist at the University of Minnesota Duluth's Large Lakes Observatory, says most evaporation on the massive lake has been taking place during the winter.
Lakes Michigan and Huron are also experiencing increased temperatures and lower levels. However, the two smaller lakes, Ontario and Erie, are showing above average levels due to increased rainfall in the region from such non-local events as hurricanes Katrina and Dennis.
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White roofs reflect heat, leaving the structures below cooler: Photo by gadfly pro from Flickr.com
Looking for an easy way to reduce global warming, and save yourself a few bucks in the process? Paint your roof white! Most rooftops in America are black or some other dark color. These absorb heat, making the building hotter and less comfortable. People in the building run fans and air conditioners to cool off. Not only do they spend more on energy, but the power companies have to burn coal and oil to produce the electricity.
But a white roof reflects heat. The building stays cooler, and needs less electricity.
For maximum effect, you should use special heat-reflective materials. And keep the roof clean – dust and dirt darken the roof, reducing its reflective properties.
It’s been estimated that if every roof in the world were white, it would counteract all the global warming of the last 30 years! Now, the authors of this study admit that they used a very simple model – climate is much more complicated than their equations allow – but still, like changing your lightbulbs, this seems like an easy way to start having an impact now. In California, the government is giving rebates to building owners who install cool roofs.
NASA Administrator Michael Griffin: What climate is the "best" climate? (Photo from NASA.)
Several months ago, political columnist George Will argued that global warming was nothing to worry about. The Earth has warmed and cooled many times before. Even if the current warming is caused by humans (a point which Will is skeptical on), so what? What makes the current climate so special that it needs to be preserved?
Nobody paid much attention at the time. But now NASA administrator Michael Griffin has made a similar pronouncement.
"I have no doubt that a trend of global warming exists.... I am not sure that it is fair to say that it is a problem we must wrestle with. To assume that it is a problem is to assume that the state of Earth's climate today is the optimal climate, the best climate that we could have or ever have had and that we need to take steps to make sure that it doesn't change — I guess I would ask which human beings, where and when, are to be accorded the privilege of deciding that this particular climate...is the best climate for all other human beings."
This statement outraged many scientists, who feel that global warming is a crisis and needs to be dealt with. Griffin later clarified his remarks, saying that NASA’s job is to collect climate information. It does not set policy. Thus, his comments should not be seen as officially endorsing any particular course of action (or inaction).
Gray garden: A growing trend in the western U.S. is the use of gray water, water that comes from the drains of shower, bath tubs and washing machines, to go through an outdoor filtering process and then be used to water plants. Some see the idea as too big of a healthAs more and more people become environmentally conscious, to what extremes should we as a society let them go to help protect the environment?
That’s a pressing question these days in some western states where water is scarce and some people are trying to find creative ways to reduce their water consumption.
Meet gray water, that water that comes from the drains of bath tubs, showers and washing machines. It’s not full of hazardous waste products, but is not usable for drinking or cooking. How about flushing your toilets or water lawns with gray water?
A growing “gray water brigade” is finding creative home plumbing solutions to re-route gray water into other uses in their homes. Sometimes the modifications are quite simple to do, costing just a few hundred dollars.
But they rarely meet the building codes of the cities the gray water. Systems that have been put into use by contractors meeting local construction guidelines can cost as much as $7,000. In a recent story in the New York Times, a plumbing contractor admitted that he now encourages people interested in recycling grey water to find their own home remedies rather than fork out big bucks for a professional solution.
The same story gave a quick description of one such homemade system. A pipe running from the house deposits shower and sink water into an elevated bathtub in the yard that is filled with gravel and reeds. The roots of the plants begin filtering and absorbing contaminants. The water then flows into a lower tub, also containing a reed bed, before flowing into a still-lower tub of floating water hyacinths and small fish. The whole system cost about $100 and the final product is used to water flower beds at a California home. Chemical tests of the filtered done by the homeowner show a slightly high level of phosphorus, but nothing the plants can handle.
But other water experts share their concerns with gray water, including the risks of open pools of water becoming a mosquito breeding ground, the possible crossing of gray water lines with other plumbing that could contaminate clean water, or using gray water to irrigate plants that might be eaten raw.
Most states now have regulations about gray water usage. But proponents of gray water say those rules make the idea cost prohibitive.
So what should be done on the gray water front? Is it okay for people to play with gray water at their own risk? Are the health risks too great for this kind of experimentation? Share your thoughts here with other Science Buzz readers.
Ever wanted to be a storm spotter? Now's your chance! The National Weather Service (NWS) relies on local SKYWARN storm spotters to confirm, from the ground, what meteorologists are seeing on radar. NWS storm spotters are not tornado chasers like the folks in the movie "Twister." Instead, they report wind gusts, hail size, rainfall, cloud formations, and the like to NWS and local emergency management agencies.
Tornado: This tornado, seen in its early stages of formation over Union City, Oklahoma (May 24, 1973), was the first one caught by the National Severe Storms Laboratory doppler radar and chase personnel. (Photo courtesy NOAA Photo Library, NOAA Central Library; OA
New radar equipment is still not sensitive enough to determine the existence of an actual tornado. It can only predict where severe weather is likely to occur. So the NWS needs trained volunteers to verify actual severe weather.
With peak storm season just around the corner (mid-June here in the Upper Midwest), free, 2.5-hour classes are being offered to train new SkyWarn volunteers.
SkyWarn class schedule, greater Minnesota
SkyWarn class schedule, Twin Cities Metro area
Separation anxiety: Researchers are finding that thinning ice in the Arctic Ocean is leading to an increased number of walrus pups being separated from their mothers. The pups, which have no hunting skills, are in a jam to find food. (Photo by Adre Boffin)The issue of global warming took on added significance in the eyes of many skeptics when reports came out that polar bears were drowning in the Arctic because ice sheets were getting too thin. Now, new news from the Arctic may up the ante on “animal emotion” meter.
Coast Guard icebreakers going through Arctic waters have found more “orphaned” walruses on ice floes than they ever seen before, report Science Daily. And the thinking is that walrus mothers have to abandon their pups on thinner ice as they follow the thicker ice that’s retreating north.
One recent Coast Guard unit reported seeing nine abandoned walrus pups in one trip. Years ago, it was a sight that was never seen.
Being abandoned is a almost always fatal for a walrus pup. The moms dive into the water to find food – bottom-dwelling aquatic animals – for the pups. But if the ice isn’t thick and strong enough to support the adults, they little ones go hungry. Adult walruses can dive as deep as 600 feet to find food.
“We were on a station for 24 hours, and the calves would be swimming around us crying. We couldn’t rescue them,” said Carin Ashjian, a biologist at Woods Hole Oceanographic Institution.
That same research crew found a large pool of warmer ocean water surrounding the area with all the abandoned walrus pups. That water has a temperature of 44-degrees, which is about six degrees warmer than water temperatures taken at the same spot at the same time of year two years earlier.
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.)
Check back often for the latest predictions, forecasts, and discussion.
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.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.
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.
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.
