Stories tagged The Water Cycle, Weather and Climate

Feb
01
2016

Long before computers, the Weather Channel and the internet, humans needed weather forecasts. Farmers and sailors particularly needed to know if storms were approaching. Over time, various folklore forecasts, often in the form of short rhymes, were devised and passed down through the generations. Although memorable, the folklore forecasts are of uneven quality—some good, others bad.

Groundhog Day is an example of predicting the weather based on folklore. If the groundhog comes out of its hole and sees its shadow, we are in store for forty more days of winter. Of course, after February 2, there are only 47 days left of astronomical winter – which ends on or about March 21!

The roots of Groundhog Day go back to the 6th century. February 2 is forty days after Christmas and is known as Candlemas. On this day, candles that are used for the rest of the year are blessed. This is also about the mid-point in winter, in meteorological not astronomical terms. The forecast rhyme goes:

"If Candlemas Day is bright and clear
There’ll be two winters in that year;
But if Candlemas Day is mild or brings rain,
Winter is gone and will not come again."

If the day is bright and clear, the groundhog “sees” his shadow and we have more winter. Of course, the weather conditions on February 2 at single locations like Punxsutawney, PA or Sun Prairie, WI tells us nothing about the weather for the rest of the winter season. As for accuracy - the “predictions” made by the various rodents involved in this annual event are correct about 40% of the time – vastly inferior to what is delivered by modern science. Right or wrong, they are fun community celebrations.

Feb
26
2014

Is it possible to deflate hurricanes by wind energy?: Huge wind turbines off the coast of Denmark show a small-scale version of an off-shore wind farm that could sap the energy of hurricanes and tropical storms.
Is it possible to deflate hurricanes by wind energy?: Huge wind turbines off the coast of Denmark show a small-scale version of an off-shore wind farm that could sap the energy of hurricanes and tropical storms.Courtesy Leonard G.
A new study claims that positioning large, off-shore wind farms in the path of oncoming tropical storms and hurricanes can reduce the damage those storms inflict. The extra electricity they produce is just an added bonus.

The study's findings contend that "tens of thousands of turbines can lower a hurricane's wind speed up to 92 mph and reduce its storm surge up to 79%."

But is it realistic to think that such a big wind operation could actually be built? Currently there are no operating water-based wind farms in the United States. The largest off-shore wind turbine sites being considered for construction have about 200 turbines planned. Those facilities are being planned off the coasts of Texas and New England. There are small-sized off-shore wind plants in Europe and China.

But if a huge wind operation was feasible, the study estimated that such a plant would have saved a lot of damage in the 2005 Hurricane Katrina in New Orleans. Somef 78,000 wind turbines — each 50 feet tall — could have slowed Katrina's wind speeds up to 78 mph and cut its storm surge up to 79%, the report from Stanford University said.

What do you think? Is this an idea ahead of its time? Is it pie – make that blowing pie – in the sky? Share your thoughts here with other Science Buzz readers.

Jan
07
2014

Dude, what's the wind chill?: The first wind chill calculations were made in Antarctica, but not by penguins.
Dude, what's the wind chill?: The first wind chill calculations were made in Antarctica, but not by penguins.Courtesy Frank Hurley
As we're nearing the end of this polar vortex-driven, bone-chilling weather, it's a good time to review exactly what is wind chill and how the wind chill index is calculated.

Q: What is wind chill?
A:
It's the term used to describe the rate of heat loss on the human body resulting from the combined effect of low temperature and wind. As winds increase, heat is carried away from the body at a faster rate, driving down both the skin temperature and eventually the internal body temperature. Wind does not change the temperature of the air. If a thermometer is placed outside, it will read the same temperature regardless of whether it's a windy day or a calm day. It simply "feels" colder because the heat that we give off is immediately blown away.

Q: Has this always been calculated the same way?
A:
No. And it's good to keep that in mind as we've gone through some record-breaking cold temps. Old records for wind chills might not be the records we once thought they were.

Q: Why is that?
A:
In 2001, the National Weather Service implemented a new wind chill Temperature Index. The new index will usually be warmer than what you would have expected with the old index. The new wind chill temperature Index uses updated science and technology and new forms of computer modeling to provide a more accurate indication of the impact of wind on how it feels outside.

Q: Can I figure conversions between the new and old wind chill formulas?
A:
Yes you can. Click here to get to an online wind chill calculator. You'll need to know the air temperature and wind speed of the place you want to figure the wind chill for. This web link also has
charts that show the differences between the old and new calculations.

Q: How can I protect myself when there are high wind chills?
A:
Here are some good tips courtesy of the Weather Chennal
• Wear layers of loose-fitting, lightweight, warm clothing. Trapped air between the layers will insulate you. Outer garments should be tightly woven, water repellent, and hooded.
• Wear a hat, because 40 percent of your body heat can be lost from your head.
• Cover your mouth to protect your lungs from extreme cold.
• Mittens, snug at the wrist, are better than gloves.
• Try to stay dry and out of the wind.

May
21
2013

More details are starting to emerge from the enormous tornado to rip through Oklahoma yesterday. Wind speeds were measured over 200 miles per hour. As of Tuesday morning, authorities had put the death toll at 24 but rescue crews were continuing to sort through the rubble looking for more casualties.

Here are a couple YouTube posts from storm chasers who were on the scene for yesterday's devastating tornado in Moore, Oklahoma. Listening to their voices, you can really get a feel for the huge magnitude of this tornado.

Oklahoma tornado paths: Three tornadoes have taken vary similar courses near Oklahoma City in the past 15 years.
Oklahoma tornado paths: Three tornadoes have taken vary similar courses near Oklahoma City in the past 15 years.Courtesy Oklahomanick
This map shows that three major tornadoes have taken very similar paths through this section of Oklahoma in the past 15 years, all occurring in May. The May 3, 1999 tornado killed 36 people and was rated EF-5, the strongest ranking on the tornado scale. The May 8, 2003 tornado was rated EF-4, but no one was killed. It is almost a certainty that the 2013 tornado will also be rated EF-5.

Click here to access an interactive slider graphic showing before and after aerial views of the destroyed Plaza Towers Elementary School building.

Satellite view: This satellite image shows the storm system that spawned the deadly tornado.
Satellite view: This satellite image shows the storm system that spawned the deadly tornado.Courtesy NOAA
NOAA (National Oceanic and Atmospheric Administration) captured this image of the storm system that spawned the tornado that hit Moore, Oklahoma. The storms’ violent updrafts sucked in air that shot up 40,000-50,000 feet or more into the atmosphere. The bubbly white structures you see in the image are known as overshooting cloud tops and are textbook features of violent thunderstorms.

A couple months ago, USA Today reported on global climate change's impact on tornadoes. You can read it here. Trying to draw conclusions about the impacts to this type of weather is twisted, to say the least.

Weather.com's Greg Forbes surveys the damage and gives his insights on the strength of the Oklahoma tornado.

Minnesota-based meteorologist Paul Douglas today gives some great analysis, and some amazing radar images, in the Start Tribune today on why this storm turned out to be so big and powerful. He also reviews the good and the better weather apps to have on your phone or mobile device to help you know when bad weather is coming.

Storm shelter: This commercially made storm shelter made of steel can hold up to six people.
Storm shelter: This commercially made storm shelter made of steel can hold up to six people.Courtesy Survive-a-storm
National Geographic shares information about how uncommon it is for tornadoes to hit developed, populated areas along with some of the basic science on what makes tornadoes occur.

USA Today reports that the phone is ringing off the hook for this tornado shelter sales company. A 4-by-6 steel shelter that can hold up to six people runs about $4,000. The demand is highest in the southern states where most homes are built without basements.

And here's the link to MDR's earlier post on the tornado, showing its movement in time lapse photography.

Apr
22
2013

People from all walks of life are fascinated by weather and make routine measurements. The “Cooperative Network” operated by the National Weather Service (or NWS) is a network of several thousand volunteers from across the country that routinely make and report weather observations. This Coop has operated continuously since 1890. The group includes about 9,000 weather observes who systematically measure high and low temperatures, rainfall and snow accumulation every day. These observations are archived at the National Climatic Data Center and are a large part of the historical weather record of the country.

Another group, the Community Collaborative Rain, Hail and Snow networks, or CoCoRaHS, includes 15,000 volunteers who help measure and report precipitation type and amounts every day. Observations of precipitation by a large group of volunteers are critical to understanding storms as precipitation varies widely from place to place even in a single storm. Such observations are useful for assessing flooding hazards and rapid snow melting. You can join CoCoRaHS at http://www.cocorahs.org.

There are also tens of thousands of citizens that serve as NWS severe weather spotters. The NWS relies on these storm spotters, along with radars, satellites and other data to supply observations that help in NWS’ decision making process of issuing and verifying severe weather warnings. The NWS is always looking for volunteers to help get the word out about severe storms. You can find out more about this group and sign up for classes and become a trained spotter at http://www.crh.noaa.gov/mkx/?n=spotters. It is a good class to take as we approach severe weather season.

So, if you enjoy making weather observations, join one of these groups and be one of the nation's weather observers!

Mar
12
2013

Hotter and hotter: This daily temperature map from space shows hotter areas in red, cooler areas in blue. The past century has seen a growing amount of red across the globe.
Hotter and hotter: This daily temperature map from space shows hotter areas in red, cooler areas in blue. The past century has seen a growing amount of red across the globe.Courtesy NASA/JPL
Here's another log to throw on the figurative global climate change fire: a new study shows that recent temperatures are significantly higher than most years since the last ice age some 11,000 years ago. And the trends show that by the end of this century, we'll likely set an all-time high.

Like me, you're probably wondering how researchers can know how cold or warm things were in that time span. Thermometer-measured temperature records only date back to the late 1800s. But temperature information can be gleaned from other datable sources, such as tree rings and isotope ratios in cave formations. Long-chain organic molecules in shells of sea-based microorganisms that settled at the bottom of oceans have also provided temperature clues.

Hockey stick graph: If you were to graph the global temperature data from the last 11,000 year, it would look much like a prone hockey stick, with temperatures of the last 100 years spiking up sharply.
Hockey stick graph: If you were to graph the global temperature data from the last 11,000 year, it would look much like a prone hockey stick, with temperatures of the last 100 years spiking up sharply.Courtesy Ohkami
The new study aggregated data taken from 73 different studies from across the globe to try to get a better handle on overall temperature trends. And that trend shows that in the past century, which started with some of the lowest global temperatures since the last ice age, we've spiked up in recent years to see some of the highest temperatures recorded in that 11,000-year span. Charting that data on a graph over all those years shows a long horizontal line of slight variations ending with a sharp incline over the last century, hence the hockey stick analogy.

Feb
13
2013

The Science Museum of Minnesota is a partner with the University of Minnesota on its Islands in the Sun project, which is monitoring the urban heat island in the Twin Cities to find ways of lessening its effects through landscape design. More than half the global population now lives in cities and so there is urgent need to understand and mitigate urban heat islands, especially during heat waves when the risk of heat-related illness and mortality can increase dramatically.Islands in the Sun temperature sensor
Islands in the Sun temperature sensorCourtesy Courtesy Department of Soil, Water and Climate, University of Minnesota

Islands in the Sun is setting up temperature sensors throughout the Twin Cities Metro Area. This temperature network when completed will be one of the densest in the world. Would you like to be a part of this effort? Islands in the Sun is especially interested in volunteers willing to have a sensor installed on their property and who live in the following locations -- downtown Minneapolis, downtown Saint Paul, Saint Paul – east of Rice St, West Saint Paul, South Saint Paul, Mendota Heights, Inver Grove Heights, Eagan, Oakdale, Woodbury, Cottage Grove, northern Roseville, Arden Hills, and Plymouth.

Information about the sensor and its placement can be found here. If you are still interested after reviewing this information, then fill out and submit a volunteer form. Please note that your interest does not guarantee that a sensor will be installed because each site must meet certain criteria. If selected, a temperature sensor will be installed at a location on your property acceptable to you with the expectation that it will remain onsite collecting data for up to four years. A technician will visit the sensor every two to three months to download data.

Thanks for considering being a part of this ground-breaking research project.

Oct
30
2012

Sandy seen from space: This satellite photo shows the enormity of Sandy as she slammed into the east coast of the United States.
Sandy seen from space: This satellite photo shows the enormity of Sandy as she slammed into the east coast of the United States.Courtesy NASA
I'm always skeptical about storms that get a catchy nickname before they strike. The hype always seems to be more than the outcome. But Sandy (aka Frankenstorm) seems to be living up to her billing. After coming ashore the New Jersey/New York area early Monday evening, her path of destruction is wide and intense. As of noontime Tuesday, the fatality toll had risen to 33 people.

Here's a round up of news sources reporting the impact of this major storm.

Converging factors – A nice recap of the meteorological conditions that combined to make this storm so strong.

The pre-storm view from crew members aboard the International Space Station.

Slide show of photos from damage in the New York City area.

Slide show of photos of damage up and down the eastern seaboard.

Sandy vs. 'The Perfect Storm' – Minnesota-based meteorologist Paul Douglas offered this comparison between Sandy and the infamous "Perfect Storm" that struck in 1991:

In some ways, Sandy will be much like "The Perfect Storm" of 1991, when the remnants of Hurricane Grace interacted with a cold front that moved through the Northeast. As tropical system (strengthened by the warm ocean waters) merged with the cold front, it became more of an typical Mid-Latitude Cyclone (strengthened by the large temperature difference across the front). Interestingly, the center of the storm (minimum central pressure of 972mb) stayed off shore and caused massive damage (estimated to over 200 million dollars with 13 dead). This storm (hybrid Sandy) is expected to MAKE landfall; some models forecasting the central pressure down near 950mb, much lower than that of 1991. You can read more of his insights on Sandy here.

In Chicago today, big waves – Sandy's stretching into the midwest, picking up 20-foot waves on Lake Michigan in Chicago.

Expanded reporting of the final hours of the HMS Bounty – the replica of a historic tall ship which sank off the coast of North Carolina Monday.

Top 10 rejected storm names – and on a lighter note, Dave Letterman goes low-tech to share rejected names for this super storm.

Oct
16
2012

A plankton bloom: Not the new bloom off of Canada, but this is what it looks like. The green stuff in the water is sucking up carbon dioxide and doing ... we don't know exactly what else yet.
A plankton bloom: Not the new bloom off of Canada, but this is what it looks like. The green stuff in the water is sucking up carbon dioxide and doing ... we don't know exactly what else yet.Courtesy NASA
Have you ever wanted to change the world? Of course you have. Who hasn’t? Even JGordon, world renowned for being more or less satisfied with his immediate surroundings, keeps a list of Things I Will Change When I Am King.

Some sample items from the list:
31: No more cake pops. What a joke.
54: Round up the jerks, make them live on Jerk Island.
55: Make sure Jerk Island isn’t actually an awesome place to live.
70: Transform Lake Michigan into biggest ball pit. Cover dead fish with plastic balls.
115: More eyepatches.
262: Regulate burps.

I think you get the idea. As Tears for Fears almost said, everybody wants to change the world.

And we do change it. We change it in a huge way. Cumulatively, the tremendous force of the human race has drastically altered the face of the planet, from oceans to atmosphere. But a lot of that change is sort of accidental; we don’t mean to affect the acidity of the oceans or warm the atmosphere, but we like driving around, making things, using electricity, and all that, and the byproducts of these activities have global effects that we can’t always control.

The notion that we could control these effects is called geoengineering. So we’re accidentally causing global warming … what if we could engineer a global solution to actively cool the planet. We’re causing ocean acidification … what if we could chemically alter the oceans on purpose to balance it out? The trick would be to balance out the positive effects of geoengineering with the potential side effects … if we could even figure out what those side effects are.

Geoengineering is necessarily a really large-scale thing, so for the most part it’s been limited to theoretical projects. But it’s been pointed out that some geoengineering projects would be within the capabilities of not just international bodies or individual countries, but corporations or even wealthy individuals. The Science Museum of Minnesota even has an exhibit on just this possibility: What would you do if you had the wealth to literally change the world?

But there are rules against that sort of thing, and it’s potentially really, really dangerous. So no one would actually do it in the real world ever, right?

Wrong!

Apparently someone did do it. Back in July.

A guy named Russ George, in partnership with a First Nations village, is thought to have dumped about 100,000 kilograms of iron sulfate into the ocean off the Western Coast of Canada. Why iron sulfate? Because iron sulfate is an effective fertilizer for plankton, the microscopic plant-like things in the ocean. The idea is that if you could cause massive growth in plankton, the plankton would suck up a bunch of carbon dioxide from the atmosphere before dying and falling the ocean floor, taking the CO2 with it.

The first part of the plan seems to have worked: satellites have detected an artificial plankton bloom about 6,200 square miles large off the west coast of Canada (which is how the operation was discovered).

George was hoping to make money selling carbon credits gained from the CO2 captured by the plankton, and he convinced the First Nations group involved to put about a million dollars into the project, telling them that it was meant to help bolster the area’s salmon population.

The thing is, it’s really hard to say what dumping almost half a million pounds of iron sulfate into the ocean will do, besides capture some CO2. And, what’s more, it looks like it was illegal: conducted as it was, the operation violates the UN’s Convention on Biological Diversity and the London convention on dumping wastes at sea. Whoops.

So does this spell the end for individually funded geoengineering projects? Or has George’s scheme just opened the door for similar operations?

And, more importantly, is this a good thing or a bad thing? Are people like George taking big steps toward addressing human-caused global change? Or are they creating what I like to call “Pandora’s Frankenstein*”?

Weigh in in the comments, and let us know what you think!

(*My friend Pandora has a pet chinchilla named Frankenstein, and he is horrible. I can’t wait until that chinchilla dies.)

Aug
22
2012

Mississippi River: Water levels in 2012 have dropped to record lows after a season of extreme flooding in 2011.
Mississippi River: Water levels in 2012 have dropped to record lows after a season of extreme flooding in 2011.Courtesy Mark Ryan
What a difference a year can make. The water levels of the Mississippi River this year are at their lowest on record, yet just last year, in the spring of 2011, extreme flooding of Ol’ Muddy was a source of deep concern for those living along its eroding banks.

NASA’s Earth Observatory page shows the striking difference in the river’s appearance near Memphis using two Landsat satellite images taken a year apart. One photograph shows the river in August of 2011 just after the river returned to its pre-flood levels. But if you compare it to a more recent image, its obvious that water levels have gone the opposite direction from flooding. The site conveniently allows you to combine the two views into a single image with a scroll bar you can manipulate back and forth over to see “then and now” differences (just click on the "View Image Comparison" button below the photos).

The lower levels of 2012 have allowed the US Army Corp of Engineers to patch and reinforce some of the levees built along the river to hold back flood waters, but tons of sediment from last year’s floods have reshaped river traffic corridors, reducing barge holding capacities and adding additional shipping costs.

SOURCE
NASA’s Earth Observatory site