Stories tagged weather

This made all the weekend news clips, but here's a little more extended version of the storm chaser video of the Wilkin County. Minnesota, tornado from Saturday.

Aug
08
2010

Russian wheat withers and burns

Plenty of wheat (Moscow)
Plenty of wheat (Moscow)Courtesy Chris
Fires and drought has destroyed so much of the wheat in Russia, that Prime Minister Vladimir Putin issued a ban on wheat exports for the rest of this year. Last year Russia exported more 17.5 million metric tons of wheat.

Surplus wheat in India is rotting

Pounding monsoon rains threaten to rot 17.8 million metric tons of wheat in India that are stored under tarps outdoors. Why they don't sell it at today's high prices or give it to the starving poor is supposedly explained in this quote:

Exporting the grain would be politically explosive because food inflation has been in the double digits for months. The government buying less wheat from farmers in a country where over half the population makes its living off the land is equally untenable. Selling more at subsidized prices to the poor is off the table because it would add to a swelling fiscal deficit. Associated Press

Wheat speculation will lead to higher food costs and starvation

The United States is having a bumper yield this year and global wheat stockpiles are high. So why have Chicago wheat prices nearly doubled since June?

We fear that excessive speculation on wheat by bankers has led to the price soaring. Speculators have bought unusually high numbers of wheat contracts in recent weeks." ABC News

Aug
08
2010

Here is a link to the BBC photo coverage of a devastating mud slide in China.

For videos, You Tube has a Chinese TV coverage of the Gansu, China landslide

In searching for links I discovered Dave's Landslide Blog by Dave Petley, who is the Wilson Professor of Hazard and Risk in the Department of Geography at Durham University in the United Kingdom. Check it out if you want to learn something.

Jul
24
2010

June continues 4 month trend of all-time record warmth

Warmest June ever
Warmest June everCourtesy NOAA
2010 just surpassed 1998 (Feb, Jul, Aug) for the most "warmest months" in any calendar year (NOAA via Science Digest

How hot and for how long?

The July 22 Scientific American asks if this is The New Normal? A week earlier they asked, "How Much Global Warming Are We Willing to Take?

The average temperature of the planet for the next several thousand years will be determined this century—by those of us living today

Anthropocene

A new report from the National Research Council concludes that emissions of carbon dioxide from the burning of fossil fuels have ushered in a new epoch where human activities will largely determine the evolution of Earth's climate.

Time to turn it down

I hope you will check out the links above and start to consider how our decisions will impact conditions on Earth for a long time.

Jun
28
2010

Tropical Storm Alex, which formed over the northwestern Caribbean Sea out of a westward-moving tropical wave on Friday and Saturday (June 26 and27), emerged overnight into the Bay of Campeche from the Yucatan Peninsula. Since emerging from that landmass as a tropical depression (signifying sustained winds weaker than 35 knots), it has strengthened back to Tropical Storm status. Current forecasts place it as a hurricane — possibly major — near the northern Mexico Gulf Coast later this week.

Jun
25
2010

Adios El Niño, Hello La Niña?: The Pacific has switched from warm (red) to cold (blue).
Adios El Niño, Hello La Niña?: The Pacific has switched from warm (red) to cold (blue).Courtesy NASA

How to measure ocean temperature

There are many ways to measure the temperature of an ocean. Oceans are big and temperatures at different locations vary. To get a sense of whether the ocean is warming or cooling, lots of spread out measurements need to be made.

  • Thermometers under buoys or ships Since about 1990 an extensive array of moored buoys across the equatorial Pacific Ocean has beamed temperature data from a 1 meter depth up to a satellite. Lots of ships are also recording their intake water temperatures but the depths and locations vary making this data harder to use.
  • Satellite remote sensing NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) SST satellites have been providing global SST (Sea Surface Temperature) data since 2000. Unlike buoys, the satellites can sense the surface temperature everywhere. The temp measured is of the surface only, though. The surface "skin" temp can be quite different than the temp of the water below because of things like evaporation, wind, sunshine, and humidity. Also, cloud cover prevents satellites from sensing surface temperatures.
  • Acoustic Tomography Sound, especially low frequencies, can travel long distances under water. Since the speed of sound under water varies with temperature, measuring how long sound takes to travel a certain distance will give you the average temperature of the water over that distance. Acoustic Thermometry of Ocean Climate (ATOC) is using trans-basin acoustic transmissions to observe the world's oceans, and the ocean climate in particular.
  • Ocean Surface Topography By bouncing microwaves off the the ocean surface and using GPS location, satellites can precisely measure the height of any spot on the ocean surface. Reasoning that water expands and contracts as it heats and cools, then so too would the height of the sea surface. I think Ocean Surface Topography is the easiest and best technique for measuring ocean temperature.
    In a 2005 study researchers compared satellite measurements of sea surface height in the northeast Pacific Ocean from 1993-2004 to recordings of sea surface temperature in the region during the same period. The sea surface height measurements proved to be as accurate as temperature measurements as indicators of ocean conditions resulting from long-term climate cycles as well as being more consistent. PhysOrg

El Niño and La Niña effect on hurricanes

Ocean temperature information is useful in predicting hurricane season severity and forecasting individual storm severity. The image above shows that the Pacific Ocean is changing from hot to cold.

A La Niña is essentially the opposite of an El Niño. During a La Niña, trade winds in the western equatorial Pacific are stronger than normal, and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. La Niñas change global weather patterns and are associated with less moisture in the air, resulting in less rain along the coasts of North and South America. They also tend to increase the formation of tropical storms in the Atlantic.

"For the American Southwest, La Niñas usually bring a dry winter, not good news for a region that has experienced normal rain and snowpack only once in the past five winters," said Patzert. NASA

May
23
2010

Climate science is hard

2010 (Jan - April) sets record for global warming
2010 (Jan - April) sets record for global warmingCourtesy NASA
Why can't scientists agree whether we are experiencing "global cooling" or "global warming" (Science Buzz covers both)?
I just spent a couple hours reading articles and comments about NASA's predicting that a new record global temperature will be set this year. Even though I have a degree in science education, I am overwhelmed by the complexity of the information.

  • Do temperatures taken down to 2000 meters below the surface give better results than down to 700 meters deep?
  • Are the thermometers used located too near the heated buildings?
  • How are large areas without temperature taking stations factored in?
  • One commenter questioned whether the heat contained by the ocean is measured in Joules per meter squared or joules per meter cubed (or should we use Watts per meter squared)?
  • What is the best way to measure a trend on a graph?

NASA scientists have this to say

Global warming trend: Anomaly means how much the temperature was above or below average.
Global warming trend: Anomaly means how much the temperature was above or below average.Courtesy NASA
NASA scientists just published a report on trends in global warming. Here is a link to a 34 page Goddard Institute for Space Studies (GISS) analysis of global surface temperature change Here is their conclusion and a graph from page 28.

Climate trends can be seen clearly if we take the 60-month (5-year) and 132-month (11-year) running means, as shown in Figure 21 for data through January 2010. The 5-year mean is sufficient to minimize El Nino variability, while the 11-year mean also minimizes the effect of solar variability. We conclude that there has been no reduction in the global warming trend of 0.15-0.20°C/decade that began in the late 1970s. pg 28

What I think

We have just had an extended period of minimum solar activity which should have had a cooling effect on the Earth (see our post Link between sunspots and weather explained). Increased solar activity will probably add even more energy. Warmer water means increased evaporation. Warmer air holds more moisture. So expect more extreme rainfalls (my sister experienced the Nashville flood of 2010) High temperatures mean higher energies so expect more violent weather (tornadoes and hurricanes).

Want more information?

Source article: Climate Progress

May
02
2010

Twister!: The Vortex2 project will study the causes, structure, and evolution of tornadoes.
Twister!: The Vortex2 project will study the causes, structure, and evolution of tornadoes.Courtesy 3aodia
The largest study ever of tornadoes is now underway in the central plains of the United States. Named Vortex2, the study will involve over 100 storm chasers from several countries and a fleet of movable weather equipment, including mobile weather stations, radar, and balloon launch platforms. Forty well-equipped vehicles will be crisscrossing the back roads of the Midwest throughout Tornado Alley, the area stretching between West Texas and southwestern Minnesota. Their mission is to closely track developing storms and find and gather information about tornadoes, one of Nature’s most destructive weather forces. (Last week’s devastating tornado in Yazoo City, Mississippi tore a path 1.75 mile wide and stayed on the ground for nearly 150 miles).

This is actually phase two of the study. Phase one began in the spring of 2009 which, unfortunately for the researchers, was an historically low period for tornadoes. There was one bright spot last year in Wyoming, where the storm chasers were well prepared and made what was probably the most thorough study of a tornado in history.

Vortex2 is funded by the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA).

The original Vortex project took place in 1994-95 with a follow-up four years later called Vortex-99. But Roger Wakimoto, director of the Earth Observing Laboratory at the National Center for Atmospheric Research, said those studies raised more questioned than they answered.

"We are still struggling to find out what actually triggers tornado generation," he said. "It's very difficult to get detailed data. These things are very transient."

Maybe this year things will be different, and questions about the how, why, when, and where of tornadoes will get answered. One interesting hypothesis the Vortex2 team hopes to settle is the one that claims tornadoes may actually start on the ground and reach up to the clouds, countering the popular notion that twisters descend from the sky. Support for this theory includes eyewitness reports of ground damage occurring prior to a funnel cloud’s arrival, and the fact that similar but less destructive phenomenon like dust devils and waterspout do just that, start on the ground and rise up into the sky.

Of course, there are plenty of other questions about the nature of tornadoes to answer, and the storm chasers hope to do so. But I have a feeling - with the Vortex2 team - the fun is all in the chase anyway.

LINKS

Vortex story at Forbes.com
More about Vortex2 on the Weather Channel website
Videos about Vortex2 at Worldnews.com (The tornado in a soap bubble video is great!)
Brief overview of tornadoes by George Pararas-Carayannis

Cumulonimbus Cloud Over Africa: High above the African continent, tall, dense cumulonimbus clouds, meaning "column rain"; in Latin, are the result of atmospheric instability.
Cumulonimbus Cloud Over Africa: High above the African continent, tall, dense cumulonimbus clouds, meaning "column rain"; in Latin, are the result of atmospheric instability.Courtesy NASA
Got this image from NASA's "image of the day" feature yesterday. Its beautiful, awe-inspiring. And also, a bit scary that these are the kinds of clouds associated with lightning, high wind speeds and tornadoes - things that can be fun (I love a good harmless thunderstorm) and also devastating. Learn more about cumulonimbus clouds here.