Sunday, September 30, 2012

Hydrologic Oddities: Uphill Flowing Rivers

Water flows downhill under the influence of gravity and uphill under the influence of money. However, there was recently a case of the Mississippi River flowing backwards because of Hurricane Isaac on 28 August 2012.

The force of the Hurricane’s wind and storm surge piled up water at the mouth of the Mississippi. The force was so strong that it reversed the river’s flow, pushing water as far north as Baton Rouge. According to a US Geological Survey report, the storm made the river go backwards at 182,000 cubic feet per second (5,153 m^3/s), which is about as fast as it normally is going downstream.

Something similar happened during Hurricane Katrina. The river also did an about-face for a few hours during a major earthquake in 1812.


Escher's Waterfall

Friday, September 28, 2012

Tornado of Fire in Australia

The Daily Mail has an article about a video of a 30 meter high tornado in Australia. The tornado was made of fire and the most astonishing aspect was the duration of the event. Most such “fire devils” (as opposed to dust devils, which are small tornadoes that kick up dust) only last a few minutes, but this event lasted for over a half hour.  


The Daily Mail page contains a gallery of images

The videographer describes the scene like so:

'The weather was perfectly still and it was about 25 degrees celsius - it was an entirely uneventful day.

'Then the next thing a man is yelling 'what the hell is that?' and I turned around and saw a 30-metre fire tornado.

'I was about 300-metres away and there was no wind but the tornado sounded like a fighter jet. My jaw just dropped.'

Mr Tangey, who runs Alice Springs Film and Television, in central Australia, described it as a 'once in ten lifetimes experience'….

If I had known what was about to happen then I would have happily paid $1,000 to watch it.”

Wednesday, September 26, 2012

Two New Google Crisis Response Webpages

In addition to their work during the Bangkok floods of 2011, the Google Crisis Response Team assisted during the recent flood disasters in the US and the Philippines.

The Tropical Storm Isaac map combined information about the path of the storm (past and future) with weather data and recovery resources (e.g. evacuation routes, locations of shelters). The map contained YouTube videos about the storm and high resolution repeat photography for long sections of the Gulf Coast. 2304-hurricane-isaac

Screenshot from

The Philippines page includes a Person Finder. Users can either look for a certain person or contribute information about a person’s status. Similar to the other disasters, the Philippines page also showed maps of the flood extent and locations to get help.

Tuesday, September 25, 2012

10 Mottos for Travel and Life

Following my recent post drawing parallels between traveling and living skills, here are a few other things I’ve learned this year. Post your own travel mottos in the comments section below.

As long as you look like you know where you are going, no one will ask any questions. It also helps to know where you are going.

Where you look is where you will go. For example, if you are riding a motorbike and keep your eyes on a tree, you will unconsciously steer towards the tree and hit it.

Get food, water and sleep. Even if you are in the middle of a disaster, do not unnecessarily deprive your basic needs otherwise you will get cranky. I have snacked while being robbed.
Yes, there was a hippo but I was also thirsty. It's called multi-tasking.

Do not assume that the laws in other countries (or even your own) make sense. Also, wild animals are unpredictable and do not think like you. Nature and customs officers do not care about your preconceived notions.

Do not lie to a group of strangers about your ability to play an unusual musical instrument (e.g. a didgeridoo or a banjo). Inevitably, someone will find one and ask you to give a performance.

The worst case scenario rarely happens. If it does, at least you will get a good story out of it. Unfortunately, the best case scenario is also rare.

Meet locals and accept hospitality when offered. Tourism is about new places, travel is about new people. My most rewarding experiences this year have involved home-cooked meals.

This is better than any restaurant.

Set many small goals instead of a few giant goals. When it is all over, you do not want to feel you achieved nothing.

Go home before you feel you have to. Start your return journey before you get exhausted else you will not make it back.

Hold on tightly. Let go lightly...

and play with children along the way.

Monday, September 24, 2012

An Earthquake Made the River Rise

When I think of earthquakes and rivers, I imagine the scene in the Superman movie where Lex Luthor’s bomb sets off an earthquake and ruptures Hoover Dam.


Dambreak scene from the 1978 Superman Movie.

Natural disasters can cause problems with the cracking of structures, but earthquake-induced total failures of dams are relatively rare. That said, there are accounts of earthquakes happening after the construction of dams. Large lakes filling put new stresses on the landscape until conditions reach a breaking point. The filling of Lake Mead/Hoover Dam caused earthquakes. As you can imagine, there are karmic cases of large dams causing large quakes that damage the dams themselves (e.g. Hsinfengkiang in China in 1962, and at Koyna, in India in 1967).

More interesting are the effects that earthquakes have on the natural flow of rivers, some of which can be long lasting. About 10 years ago, scientists Montgomery and Manga collected examples of earthquakes changing the water levels in wells and rivers. They found “Detectable streamflow changes occur in areas within tens to hundreds of kilometers of the epicenter, whereas changes in groundwater levels in wells can occur hundreds to thousands of kilometers from earthquake epicenters.” Manga also helped write a book chapter on changes in rivers after earthquakes and highlighted the case of a 1989 California earthquake that made rivers come up from 4 to 24 times their original size for a period lasting weeks to months.

In 2010 the colossal magnitude 8.8 earthquake happened in Chile. According to studies published this summer, initially the river levels dropped but then, hours to days later, the rivers as much as quadrupled their original size. The shaking of the soils redistributed the groundwater up towards the surface and fairly soon plants started accessing this water for transpiration causing a larger fluctuation in the river between night and day.

There are also short-lasting (i.e. minutes to hours) dramatic changes in river flow. In 1812, the Mississippi River ran backwards following a magnitude 7 quake in 1812. Boatmen were jolted awake in the middle of the night to find themselves being washed upstream “at the speed of the swiftest horse” and having to hold onto their hats to keep them from flying off. There were accounts of sudden large holes opening in mid-river as much as 10 meters/33 feet deep with water spilling vertically into them.

Saturday, September 22, 2012

Heat Hunting in Australia (My Hottest Day)

The announcement about the fall of Libya’s hottest temperature record got me remembering about some adventure climatology I did a few years ago in Australia. I wanted to find the exact hottest spot in the city on the hottest day of the year. Can you guess where it was and how hot it was? Here are some excerpts from 2 events. First, infamous Black Saturday (7 February 2009). At the time, few realized the extent of the wildfires going on around Melbourne but we could see plumes of smoke from our apartment and had ash on our windows:

“Today was quite a day. Melbourne finally broke the all-time all-year maximum temperature record, 115.5 F/46.4 C. 

At the height of the heat at about 3:40pm I grabbed my personal thermometer and ran outside to see if I could find the hottest surface temperature (the "skin" temperature, the surface of the ground as opposed to the air temperature a couple feet off the ground which is what you see above) around our neighborhood.

In grad school in Arizona we would run out and see if we could fry an egg on the sidewalk on the hottest day of the year. Turns out you can't. Sidewalks aren't that hot, you need something like an motor oil stained manhole cover or the metal hood of a black car. Even then the best you can get is over-easy, a little less than totally runny. 

There's so many clich├ęs about heat... But they were all true, when I walked out into the 5% humidity and 50 km/hr winds, it was like being blasted in the face by a pizza oven wrapped in a sauna nestled in a box of hair dryers... on a tin roof... in Hades... with the heat on. Anyhow my thermometer is made to measure liquids so it wasn't quite designed for the task, but here's the best I could do today...

145.5 F/63 C. Hot damn! It was right outside our door actually, in front of a construction site, it's a large thick metal slab out in the street and the hottest temperatures were right in the middle. Later on I started to think I could do even better on some of the tram tracks going down the middle of Toorak Street... but then a confused policeman came along and rousted me.

Later on we had blackouts in our apartment. And Christine remarked that this might be the first time she hasn't felt cold. But the heat was over in 10 minutes, as you can see when the winds and my first showers came through.”

Then there was this event from 11 January 2010:

Today looked like it was going to be a scorcher, so this morning I called in sick with a terrible "cold". Right around 4:30 when it appeared like the airport temperature had reached its peak (110 F, 43C), I donned my cashmere wool overcoat and hat and set out.

First stop was the tram rails at Chapel and Toorak. In theory, a great spot, but I think I'm going to give up on this one. I only had the thermometer down for half a minute before the cars at the stoplight started to honk.

Where the construction site was last year, there's a skyscraper now. On the first floor is the Outpost Cafe, a high end coffee place that has a fancy contraption that makes a cup of coffee, one drip at a time over about 4 hours.

Those black metal plates below the windows were just about perfect and they had been facing the sun all day. As I got closer I saw that a couple flies had foolishly landed on the wall and were burnt to a crisp on the spot!

And the verdict is...

165 F/ 74 C, blowing away my record last year by over 11 degrees C! In theory, that really is hot enough to cook an egg (>158 F, 70 C).

Friday, September 21, 2012

Dead Heat: The Toppling of the World’s Hottest Temperature Record

Last week forecaster Jan Null sent out an announcement about how Death Valley has moved up into the top spot of (officially recorded) hottest place on earth:

The World Meteorological Organization (WMO) has stripped Libya of their world hottest temperature record; set at El Azizia on September 13, 1922. The “new” world record hottest temperature is now the 134 set at Greenland Ranch in Death Valley, CA on July 13, 1913. Here’s the Press Release. It was the tireless efforts of Chris Burt, author of Extreme Weather and the Weather Historian for Weather Underground, that helped spur the [World Meteorological Organization] to reexamine and ultimately delete the El Azizia record.


A photograph of the trading post at El Azizia, Libya taken in 1923

The old record fell because it was on old-style thermometer (even by 1922 standards) and was likely misread by a new observer on his second day at work. It was a hot day, but the record did not seem plausible when compared to other nearby stations reporting at the same time.

Chris Burt has an interesting blog with personal accounts and original investigation into this and other weather extremes. The blog includes a compelling 25 minute detective story documentary about the El Azizia record with dramatic accounts of the disappearance of the Libyan chief climatologist during last year’s revolution. There are also announcements in USA Today and Reuters.

Note that this record is for the hottest official air temperature recorded by a thermometer. There are measurements of the exact hottest place on earth (70 C/160 F surface temperature in the Lut Desert outside Kerman, Iran) but that is of the temperature of the ground as sensed by a satellite. Read more about my trip to that Iranian desert and its vast hand-dug underground canals.

Monday, September 17, 2012

Forecasts At the Airport (a Case Against Knowing Uncertainty)

The departure board at London Gatwick airport currently lists all flights as being on time. Some of these are probably lies, and knowing lies at that. 

When planes are delayed or cancelled, the passengers are only let in on this once there is virtual certainty that the flight will be off schedule. Even then, the passengers are updated through a slow creep in the numbers. First, a delay of five minutes is announced, then twenty and then…


When compared to what actually happens, these “predictions” are clearly biased. The forecasts are always too optimistic. Planes never leave earlier than the advertised times.

Someone in the airport (e.g. in the flight control tower) has unbiased information about when the planes will likely take off but there is a good reason to not give that data directly to the public.

Imagine a parallel universe without bias on the departure board, where half the planes leave early and half leave late. Passengers would check the board and perhaps some would decide they have enough time to get another coffee. It would be clearly upsetting to come back “on time” and discover the plane already left. People also get very mad when buses or trains run ahead of schedule.

A recent NYT article “The Weatherman Is Not a Moron” described the river-forecasting equivalent of such a catastrophic “missed the flight” scenario:

The Weather Service has struggled over the years with how much to let the public in on what it doesn’t exactly know. In April 1997, Grand Forks, N.D., was threatened by the flooding Red River … [The Weather Service] predicted that the Red would crest to 49 feet, close to the record…The waters, in fact, crested to 54 feet. It was well within the forecast’s margin of error, but enough to overcome the levees and spill more than two miles into the city… The Weather Service had explicitly avoided communicating the uncertainty in its forecast to the public, emphasizing only the 49-foot prediction. The forecasters later told researchers that they were afraid the public might lose confidence in the forecast if they had conveyed any uncertainty.

Times have changed….  

Since [the Grand Forks flood], the National Weather Service has come to recognize the importance of communicating the uncertainty in its forecasts as completely as possible… “No forecast is complete without some description of that uncertainty.” [said Max Mayfield] 

Still, just like how there are biases in flight departure times, there are biases in the weather forecasts:

In what may be the worst-kept secret in the business, numerous commercial weather forecasts are also biased toward forecasting more precipitation than will actually occur… For years, when the Weather Channel said there was a 20 percent chance of rain, it actually rained only about 5 percent of the time.

People don’t mind when a forecaster predicts rain and it turns out to be a nice day. But if it rains when it isn’t supposed to, they curse the weatherman for ruining their picnic. “If the forecast was objective, if it has zero bias in precipitation,” Bruce Rose, a former vice president for the Weather Channel, said, “we’d probably be in trouble.”

In flood forecasting, there seems to be a tolerance for false alarms. Occasionally crying wolf is not bad compared to letting the wolf in to make a big mess of everything (even if only once).

However, whose responsibility is it to make sure the wolf stays out? It is the airport’s responsibility to give good information to the passengers. It is the passenger’s responsibility to be at the gate on time. Similarly, the forecaster is not responsible for the flood damages, but he has a duty to provide good information to decision makers and the public. But don’t people with more information make better decisions? Is it fair to restrict what the public knows? Do more people catch their flights because they don’t know the whole story of what could happen?  

Max Mayfield said in the NYT article that “No forecast is complete without some description of… uncertainty.” Scientists (myself included) are falling over themselves to come up with new and better ways of quantifying forecast uncertainty; this is one of today’s most active research topics in hydrology (and meteorology and climate change). There are stacks of reports going back more than thirty years saying that forecasts that communicate uncertainty have more value than forecasts that only give one number (the river will reach 52 feet).

Some of the more informative alternatives include a credible range (there is a 90% chance that the river will reach between 48 and 55 feet) or the chance of a relevant threshold (there is a 35% chance of the river going above the levees) or an ensemble (any of the following scenarios could happen: 48 feet, 49 feet, 51 feet, 54 feet…).

Imagine the confusion and frustration if the airport departure board listed ensembles:

London to Paris, possible departure times include 8:30, 8:32, 8:37, 8:40, 8:55.

It may be entirely true that there is a “90% chance this flight will leave between 8:30 and 8:45” but is this enough information to help the user make a decision? Although ensemble forecasts are technically feasible, river forecasters often feel like they are shirking their duties by asking users to wade through a mass of possible scenarios. Yet, scientists bristle at the idea of giving users only one number. “You can’t pick one number, because that depends on the risk tolerance of the user and every user is different.” What is a conservative forecast for one user is risky for another.

For example, my return flight to London has a tight connection. The board of departures says “what is the earliest possible time that the planes could leave?” I could plan better if I knew the latest possible time the flight could leave (or, say, the chances of being delayed by more than 15 minutes). I could decide for myself if that was an acceptable risk. I resent not knowing.

But I’m not going to get that information however. Why not?

It is partly because most people are terribly inexperienced at thinking about chances in their daily lives. Answer this question: 

“I am 80% confident that the average distance between the centers of the earth and the moon is between ____ and ____ kilometers/miles.”

Try it. Write down your range. The answer is here.

So far, I have asked 40 scientists and operational forecasters to give their ranges. If people were good at quantifying their uncertainty then about 32 people (80%) would give ranges that contain the true distance. Instead, only 10 people (25%) have. This means that people (even those that predict for a living) give too narrow of a range and are overconfident in what they think they know.

Therefore, even if they were armed with the information “there is a 75% chance of the flight leaving in 10 minutes”, passengers would be largely unprepared to come up with the rest of the information necessary to make a good decision (e.g. in those 10 minutes, there is a 80% chance I could successfully get coffee, 90% chance of getting to the bathroom, 40% chance of getting both coffee and bathroom, and so on).

That said, with practice and feedback, people get better at sizing up risks. Once they learn that they are overconfident, people start to widen the range of their guesses. However, it takes some discipline to look back at past forecasts. Also, the feedback loop rarely closes in practice, especially if it is something that people do infrequently (e.g. navigate an unfamiliar airport, protect against an unprecedented flood).

But I’ll start the process by collecting my first data point. My flight was supposed to leave at 8:20. We touched off at 8:24. I probably wouldn’t have had time for another coffee.

Tuesday, September 11, 2012

The River Runs Red (Yangtze, China)

The Yangtze River at Chongqing has mysteriously turned scarlet this week. 


Amused locals are collecting souvenir bottles of the tomato juice-colored water.


The contrast is greatest where the polluted Yangtze (left) meets the Jialin (right).

No one is sure why the river has changed color, but this is not the first time something like this has happened. When a dye producing company dumped stocks into the Jain river, the result was described as “hellish”.


Blood-colored water in a separate incident on the Jian River in the city of Luoyang.

Monday, September 10, 2012

US Drought Impacts: From Power to Popcorn

Last week I met Andreas Weigel, a climate analyst with Cargill (a multinational food producing and processing company) and when I asked him about the drought, the response was an animated mix of awe and fear. With droughts causing failures in both the Russian and US harvests, all eyes are trained on the rainfall in Brazil. The Russian drought cost 1.2 billion dollars in agriculture losses and the impacts in the US will be several times that. Just the uninsured damage to cracking house foundations is on the order of 1 billion dollars.

parched-gulch-ab0ccc74e803a404967a861160a9d9f15497c50f-s3 A parched gulch in Missouri

Weigel was at the European Center for Medium Range Weather Forecasts seminar on seasonal forecasting, along with the top scientists and other analysts (from energy companies, banks and relief agencies, among others). The skill of the weeks-to-months ahead forecasts is modest, but even the slightest signal can help with planning or give a competitive advantage.

It is hard to declare victory for this year’s forecasts (indeed Climate Central highlights their failures: “the sea surface temperature pattern “would suggest drought,” but … forecasters completely missed the scale and scope of the disaster that has been unfolding during the past few months.”)

How bad is it? The drought maps leak red like the US has taken a slug to the gut. By some measures (e.g. area-wise) it’s the largest US drought in 50 years. It has been described as a “silent tsunami” sweeping across the country.


Map of drought over the US

What’s remarkable about drought is that it is so hard to picture. It is more about something not happening (the eerie silence of the grain processing plants, the stunted size of the crops), than something happening (torrents of water tumbling cars down a channel). It’s a creeping disaster that is easy to deny and slow to recover from. The fingers of the drought’s influence are likely touching your life, even overseas.

Some have said that there could be a shortage of popcorn. It is not like there will be empty shelves, but the quality will be lower and it will be more expensive. That said, popcorn has one of the highest markups of any product on the market. There are pennies worth of corn in a tub of movie popcorn- the box costs more than the product. Even then, what has ten times the markup of popcorn? Bottled water.

The rise in the price of corn will have a trickle down effect, perhaps making your monthly grocery bill about 20-30% more expensive. This will be magnified even further when it comes to prices of meat (because corn is used as animal feed). Right now farmers are selling off their animals in record numbers in anticipation of not being able to afford to feed them. The result is a lower price of meat in the short term because the supply is high, but the price will shoot up when those supplies run out.

The other major impact will be in energy production and prices. John Daly has some analysis at From that article:

“virtually all power plants, whether they are nuclear, coal, or natural gas-fired, are completely dependent on water for cooling. Hydroelectric plants require continuous water flow to operate their turbines. Given the drought, many facilities are overheating and utilities are shutting them down or running their plants at lower capacity. Few Americans know (or up to this point have cared) that the country’s power plants account for about half of all the water used in the United States. For every gallon of residential water used in the average U.S. household, five times more is used to provide that home with electricity via hydropower turbines and fossil fuel power plants, roughly 40,000 gallons each month.”

“”In summer you often get a double whammy. People want their air-conditioning and drought gets worse. You have more demand for electricity and less water available to produce it. That is what we are seeing in the Midwest right now, power plants on the edge”… In July U.S. nuclear-power production hit its lowest seasonal levels in nine years as drought and heat forced Nuclear power plants from Ohio to Vermont to slow output.”