Courtesy Mark RyanIn Homer’s epic poem, the Odyssey , the ruler of wind Aeolus gives the hero Odysseus a leather bag containing all the winds except the west wind. Odyssus keeps its contents secret but his men grow suspicious that he’s withholding treasure from them so they open the bag while Odysseus sleeps. The unleashed winds nearly destroy their ship and send it off course to the other end of the world.
In aeolian geology (sometimes spelled eolian), scientists study how landforms are created by wind, either through transportation, sedimentation, or erosion. Sand dunes, dune migration, cross-bedding, and scouring are some of the ways wind can shape the landscape. On Earth, discernible wind patterns in deserts are plainly visible from space, and similar patterns have been seen on other planets, such as Mars, leading scientists to conclude that wind played a role in forming those same landscape features there.
This informative webpage illustrates how some of it works, and how wind can be a powerful shaping force.
This same force was at work this past weekend in Minnesota. As seen in the above video, a winter blizzard barreled across the state bringing with it the usual high winds, low visibility, and drifting and blowing snow.
Courtesy Mark Ryan
Courtesy Mark Ryan
Courtesy Mark Ryan
Courtesy Mark RyanAfter the weather system moved out, it left in its wake (besides a collapsed stadium and lots of white stuff to shovel) some very cool (and familiar) aeloian shapes and patterns in the snow.With the help of the low-angled winter sun and my trusty camera, I was able to capture some of these wind-borne creations.
The Associated Press reports that Mt. Merapi on the island of Java is pouring tons of hot ash, dust and smoke into the air in a massive eruption today. The volcano, one of world's most active, is located in the Ring of Fire, an area high in volcanic and seismic activity due to the extreme forces of plate tectonics that occur around the Pacific Ocean basin.
Merapi began erupting last week and has forced tens of thousands of villagers to evacuate the area. So far, the eruptions have killed nearly 40 people and burned several others, causing authorities to expand the danger zone from a 6-mile to 9-mile radius. Several flights in and out of local airports have been canceled due to the ash cloud. The recent eruption is the largest so far, and scientists think things could get worse.
To give you an idea of what's involved, here's a video showing a pyroclastic flow from an eruption last year on Mt. Merapi. From the looks of it, it's not something you want to try to outrun.
Courtesy Public domain (via Dartmouth)An outbreak of cholera in Haiti is causing doctors and other aid workers concern. Cholera is an infection of the intestines caused by Vibrio cholerae a bacteria often found in contaminated food or drinking water. The bacteria can spread through crowded and unsanitary areas via contact with feces of infected persons. Cholera outbreaks often take place in crowded and impoverished areas, or in war zones. Symptoms include severe abdominal cramps, watery diarrhea, vomiting and rapid dehydration. Left untreated, cholera can be deadly within 24 hours. When detected, treatment involves replenishment of lost fluids and electrolytes. Improved sanitation and personal hygiene practices such as frequent hand washing can help stop the spread of the disease. So far, cholera has killed more than 300 people in Haiti, and most of the nearly 4000 recorded cases have occurred in the region of Arbonite, a rural area unaffected by the 7.0 magnitude earthquake that devastated much of the country last January. The outbreak has been slowing lately, but officials are concerned it could still spread through the hundreds of refugee tent camps located in the overcrowded capital of Port-au-Prince.
Courtesy Wikimedia CommonsHundreds of people are still missing and feared drowned from the tsunami triggered by the large earthquake that struck Indonesia earlier this week. So far 340 deaths have been blamed on the 10-foot waves that washed over many of the tiny and remote islands in the Mentawai chain. The tsunami warning system set in place after 2004's devastating tsunami apparently malfunctioned due to vandalism to some of its expensive sensors. But local officials say the tsunami came on so quickly that even if they had been functioning the warnings would have been useless. Four hundred people are still missing, and several aftershocks, coupled with changing weather conditions have made search and rescue efforts difficult. Meanwhile, to the east on the island of Java, Mount Merapi, has erupted again and is adding to Indonesia's woes. Some scientists think the two disasters may be linked.
Alright, it's absolutely beautiful outside today. So what's up with this predicted flooding?
Remember all that rain the week of September 20th? (We got 2-4" here in the Twin Cities, but areas to the southwest of us got as much as 10".)
Courtesy National Weather Service
It all had to go somewhere, and that somewhere was the Minnesota River. Why does that affect us here in St. Paul? Take a look at another map:
Courtesy NASA (Landsat)
Remember: rivers don't necessarily flow south. The reddish line is the Minnesota River. The blue is the Mississippi. And that little blip just north of where the two rivers come together is downtown St. Paul. (The yellow elipse is the area of highest rainfall.)
All that rain is flowing right past us. And it should be impressive. The river's at 15.4' this morning (moderate flood stage), and predicted to crest at 18' (major flood stage) on Saturday morning. But the recent spate of lovely weather means that the flooding should pass quickly--today's prediction has the water level back under 17" by Monday morning.
St. Paul police have closed all the river roads and parks, and are discouraging people from walking down by the river. But you can get a stellar view of everything from outside the Museum on Kellogg Plaza, or inside the museum from the Mississippi River Gallery on level 5.
It's been a crazy couple of days of rain.
Courtesy National Weather Service
Forecasters say it's mostly over, although we can expect some rainfall through Saturday. But rain upstream swells the rivers downstream, and flood watches and warnings are in effect for much of Minnesota. Here in downtown St. Paul, the river is expected to rise about ten feet over the next week.
"1128 am CDT Fri Sep 24 2010
The Flood Warning continues for the Mississippi River at St Paul.
- At 10:15 am Friday the stage was 6.8 feet.
- Moderate flooding is forecast.
- Flood stage is 14.0 feet.
- Forecast... rise above flood stage by early Wednesday morning and continue to rise to near 16.4 feet by early Friday morning.
- Impact... at 18.0 feet... Warner Road may become impassable due to high water.
- Impact... at 17.5 feet... Harriet Island begins to become submerged.
- Impact... at 17.0 feet... secondary flood walls are deployed at St Paul Airport.
- Impact... at 14.0 feet... portions of the Lilydale park area begin to experience flooding.
- Flood history... this crest compares to a previous crest of 18.4 feet on Mar 24 2010."
Still with me? Then check out Buzz coverage of the March 2010 flood along the Mississippi.
Courtesy Paige Shoemaker
Next time you look at the clouds, shake your fist and yell at those jerks for making our lives difficult. You might look crazy, but somebody needs to tell those fools.
While it's relatively easy to model temperature changes over the last century thanks to detailed records, clouds are more tricky to understand because we don't have a similar history of cloud observations, and also because they are ornery. So in order to understand how clouds work, scientists are building a body of evidence to model cloud behavior and help show how clouds will impact our weather as well as our climate in the future. I believe they also plan to show those clouds who is the boss of them.
Like a child running loose in a toy store, hurricanes have always been difficult to predict because they can unexpectedly change direction. This confounds plans for evacuation, leading some people to leave areas that are never hit, leading others to stay put and potentially face nasty weather because they don't trust the meteorologist, and leading meteorologists to keep Advil in business. But since the 90s, our ability to predict where hurricanes will make landfall has become twice as accurate. This new prescience is due to the development and use of more accurate models of how clouds work, which is in turn due to better understanding of cloud dynamics and faster computers. How about that, punk clouds?
Intensity, however, remains elusive to model. (Shh, don't let them know we have a weakness!)
"While we pride ourselves that the track forecast is getting better and better, we remain humbled by the uncertainties of the science we don't yet understand," Schott said. "This is not an algebra question where there's only one right answer."
Despite being a "forecasting nightmare," Earl ended up hitting about where it was predicted to go. This means that the right people have been evacuated to avoid injury and fatality. That's right, stick your tail between your legs, Earl.
Connecting to climate
Short-term events such as hurricanes and other storms are difficult to predict, but climate change is a whole other world of uncertainty--again, thanks to those uncouth clouds. Climate scientists are developing new tools, such as satellite technologies that show how much light different cloud types reflect and models that demonstrate localized cloud processes. These approaches look specifically at certain groups of clouds and their patterns of change to add detail to older, larger models that look at climate over larger scales.
Courtesy Nic McPhee
The problem with the older models is that they have a low resolution that doesn't accurately represent clouds because the clouds are smaller than they can show. Think of it like Google maps--at the beginning, you're looking at the entire planet, or a whole continent--this is similar to older, low-res climate models. The new models are like zooming in on a city--you can see bus stops, restaurants, and highways. But you have to zoom out to see how these small pieces relate to the larger surroundings. In a similar way, the new high-res models are helping to inform older models--this type of work is called multiscale modeling.
Researchers at the Center for Multiscale Modeling of Atmospheric Processes (CMMAP) are developing this exact type of model. You can read about their advances here. This work is important because it brings insight into questions about whether clouds will reflect or trap more sunlight, which can have a big impact on the rate of global warming. It also helps us understand whether geoengineering projects that alter clouds will really have the intended effect. Plus it's just one more way we can pwn clouds.
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.
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
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
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.