Posts about weather

Yacouba Sawadogo – The Man Who Stopped the Desert

Quote from the video

Yacouba single-handedly had more impact on the soil conservation in the Sahel than than all the national and international researchers combined.

Dr. Chris Reij, Vrije University of Amsterdam.

As is normally the case making improvements in the real world is challenging and visionaries often face setbacks. Even when they have success that success is threatened by those that want to take the rewards but ignore the lessons. The clip above is a excerpt from the documentary film on his efforts.

Meet Yacouba Sawadogo – The Man Who Stopped the Desert

The simple old farmer’s re-forestation and soil conservation techniques are so effective they’ve helped turn the tide in the fight against the desertification of the harsh lands in northern Burkina Faso.

Over-farming, over-grazing and over population have, over the years, resulted in heavy soil erosion and drying in this landlocked West African nation.

Zai is a very simple and low-cost farming technique. Using a shovel or an axe, small holes are dug into the hard ground and filled with compost. Seeds of trees, millet or sorghum are planted in the compost. The holes catch water during the rainy season, so they are able to retain moisture and nutrients during the dry season.

According to the rules of Zai, Yacouba would prepare the lands in the dry season – exactly the opposite of the local practice. Other farmers and land chiefs laughed at him, but soon realized that he is a genius. In just 20 years, he converted a completely barren area into a thriving 30-acre forest with over 60 species of trees.

Yacouba has chosen not to keep his secrets to himself. Instead, he hosts a workshop at his farm, teaching visitors and bringing people together in a spirit of friendship. “I want the training program to be the starting point for many fruitful exchanges across the region

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How to Walk on Ice

infographic explaining how to walk on ice - walk like a penguin

Infographic by Tablet. Falling on ice leads to many injuries and even 60 deaths a year in the USA (about the number that will die due to tornados). The graphic encourages thinking like a penguin. Penguins walk well on ice (in some ways) and they also fall well.

Seeking to keep your weight well supported (short strides) is wise (and sliding instead of picking up your feet can help). Falling well is also important. It is basic physics, you want to lower your center of gravity if you are start to slip and avoid any excessive force (so sliding is better than trying to stick out your hand and support all your weight). The elderly are especially susceptible to injuries – avoiding taking direct shocks to the wrist, knees or hips is wise). It does seem kind of silly to learn how to fall but it is very helpful in avoiding injuries.

On sidewalks if you are going to fall and there is snow piled up off the sidewalk, falling into the pile of snow may well be softer than falling directly onto the sidewalk.

On ice you have lower friction so strategies that require friction are not useful – quick moves often rely on very sturdy bases (which are based on the friction of our shoe on for example concrete [which normally is good – though business shoes are not very good] and on ice [where it is very poor – sliding and gradual moves are better]).

Related: Falling SafelyMinistry of Silly WalksMake Crosswalks More VisibleWhy Wasn’t the Earth Covered in Ice 4 Billion Years Ago – When the Sun was DimmerScience Toys You Can Make With Your Kids

Circumhorizontal Arcs – Fire Rainbows – Cloud Rainbows

photo of rainbow in a cloud

Fire Rainbow, Johor Bahru by John Hunter

Yesterday afternoon I spotted this odd, colorful, spectrum seemingly in a cloud in Johor Bahru, Malaysia. The colors are similar to a rainbow but the prism effect takes on a bit different form than a rainbow as I learned with a bit of searching online. I added a short post to this blog, about the phenomenon a few years ago.

photo of a large cloud over Johor Bahru

Johor Bahru under a large cloud which is topped with a fire rainbow.

A circumhorizontal arc is an optical phenomenon – an ice-halo formed by plate-shaped ice crystals in high level cirrus clouds. They are also known as “fire rainbows,” if the cloud is at the right angle to the sun, the crystals will refract the sunlight just as when rainbow is created.

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A single spot in the Sahara that provides huge amounts of nutrients to the Amazon

The Bodélé depression: a single spot in the Sahara that provides most of the mineral dust to the Amazon forest

About 40 million tons of dust are transported annually from the Sahara to the Amazon basin. Saharan dust has been proposed to be the main mineral source that fertilizes the Amazon basin, generating a dependence of the health and productivity of the rain forest on dust supply from the Sahara. Here we show that about half of the annual dust supply to the Amazon basin is emitted from a single source: the Bodélé depression located northeast of Lake Chad, approximately 0.5% of the size of the Amazon or 0.2% of the Sahara. Placed in a narrow path between two mountain chains that direct and accelerate the surface winds over the depression, the Bodélé emits dust on 40% of the winter days, averaging more than 0.7 million tons of dust per day.

Even understanding how connected the global ecosystem is, research like this provides amazing reminders of those connections.

Related: The Amazon Rainforest Would Not Be Without Saharan Dust (podcast interview)Ancient Whale Uncovered in Egyptian DesertNigersaurusThe Sahara Wasn’t Always a DesertElusive Saharan cheetah and Sandcat

Finding Huge Sources of Energy Without Increasing Carbon Dioxide Output

Bill Gates talking about energy, and climate change, at TED. He is looking at a new type of nuclear reactor using as fuel, what is now nuclear waste.

The idea of Terrapower is that, instead of burning a part of uranium, the one percent, which is the U235, we decided, let’s burn the 99 percent, the U238. It is kind of a crazy idea. In fact, people had talked about it for a long time, but they could never simulate properly whether it would work or not, and so it’s through the advent of modern supercomputers that now you can simulate and see that, yes, with the right material’s approach, this looks like it would work.

And, because you’re burning that 99 percent, you have greatly improved cost profile. You actually burn up the waste, and you can actually use as fuel all the leftover waste from today’s reactors. So, instead of worrying about them, you just take that. It’s a great thing. It breathes this uranium as it goes along. So it’s kind of like a candle. You can see it’s a log there, often referred to as a traveling wave reactor. In terms of fuel, this really solves the problem. I’ve got a picture here of a place in Kentucky. This is the left over, the 99 percent, where they’ve taken out the part they burn now, so it’s called depleted uranium. That would power the U.S. for hundreds of years. And, simply by filtering sea water in an inexpensive process, you’d have enough fuel for the entire lifetime of the rest of the planet.

Related: Unless We Take Decisive Action, Climate Change Will Ravage Our PlanetMolten Salt Solar Reactor Approved by CaliforniaWind Power Capacity Up 170% Worldwide from 2005-2009Helium-3 Fusion Reactor

The Sahara Wasn’t Always a Desert

Green Sahara

For much of the past 70,000 years, the Sahara has closely resembled the desert it is today. Some 12,000 years ago, however, a wobble in the Earth’s axis and other factors caused Africa’s seasonal monsoons to shift slightly north, bringing new rains to an area nearly the size of the contiguous United States. Lush watersheds stretched across the Sahara, from Egypt to Mauritania, drawing animal life and eventually people.

by some 3,500 years ago the desert had returned. The people vanished.

The twilight of the Green Sahara around 4,500 years ago might have been the perfect time to be hunting at Gobero, said Carlo Giraudi, the team’s geologist. As water sources dried up throughout the region, animals would have been drawn to pocket wetlands, making them easier to kill. Four middens found on the dunes and dated to around that time included hundreds of animal remains, as well as fish bones and clamshells—not usually part of a herder’s diet. “The Green Sahara’s climate was rapidly changing,” said Giraudi, “but just before the lake dried up, the people at Gobero would have thought they were living in a golden period.”

There are many values of science: letting our curious minds learn, giving us cool robots and gadgets and letting us learn about the past (and thus about the ever-changing world we live in).

Related: Ancient Whale Uncovered in Egyptian DesertRare Saharan Cheetahs Photographed“Gladiator” tomb is found in Rome

Volleyball Sized Hail

photo of volleyball sized hail

On July 23, 2010, a severe thunderstorm struck Vivian, South Dakota, USA, a quiet rural community of less than 200. While there was nothing unusual about a violent summer storm, the softball (and larger)-sized hail that accompanied it was extraordinary. In fact, it led to the discovery of the largest hailstone ever recorded in the United States.

Once the thunderstorm passed, Vivian resident Les Scott ventured outside to see if there was any damage as a result of the storm. He was surprised to see a tremendous number of large hailstones on the ground, including one about the size of a volleyball. Scott gathered up that stone, along with a few smaller ones, and placed them in his freezer.

How does hail form?

  • Inside of a thunderstorm are strong updrafts of warm air and downdrafts of cold air.
  • If a water droplet is picked up by the updrafts…it can be carried well into colder zones and the water droplet freezes.
  • As the frozen droplet begins to fall, carried by cold downdrafts, it may partially thaw as it moves into warmer air toward the bottom of the thunderstorm
  • But, if the little half-frozen droplet get picked up again by another updraft and is carried back into very cold air it will re-freeze. With each trip above and below the freezing level our frozen droplet adds another layer of ice.
  • Finally, the frozen hail, with many layers of ice, much like the rings in a tree falls to the ground.

According to NOAA, the Kansas City hail storm on April 10, 2001 was the costliest hail storm in the U.S. which caused damages of an estimated $2 billion.

Image from NOAA

Related: 500 Year FloodsClouds Alive With BacteriaRare “Rainbow” Over IdahoWhy is it Colder at Higher Elevations?

Why Wasn’t the Earth Covered in Ice 4 Billion Years Ago – When the Sun was Dimmer

Climate scientists from all over the globe are now able to test their climate models under extreme conditions thanks to Professor Minik Rosing, University of Copenhagen. Rosing has solved one of the great mysteries and paradoxes of our geological past, namely, “Why the earth’s surface was not just one big lump of ice four billion years ago when the Sun’s radiation was much weaker than it is today.” Until now, scientists have presumed that the earth’s atmosphere back then consisted of 30% carbon dioxide (CO2) which ensconced the planet in a protective membrane, thereby trapping heat like a greenhouse.

The faint early sun paradox
In 1972, the late, world famous astronomer Carl Sagan and his colleague George Mullen formulated “The faint early sun paradox. ” The paradox consisted in that the earth’s climate has been fairly constant during almost four of the four and a half billion years that the planet has been in existence, and this despite the fact that radiation from the sun has increased by 25-30 percent.

The paradoxical question that arose for scientists in this connection was why the earth’s surface at its fragile beginning was not covered by ice, seeing that the sun’s rays were much fainter than they are today. Science found one probable answer in 1993, which was proffered by the American atmospheric scientist, Jim Kasting. He performed theoretical calculations that showed that 30% of the earth’s atmosphere four billion years ago consisted of CO2. This in turn entailed that the large amount of greenhouse gases layered themselves as a protective greenhouse around the planet, thereby preventing the oceans from freezing over.

Mystery solved
Now, however, Professor Minik Rosing, from the Natural History Museum of Denmark, and Christian Bjerrum, from the Department of Geography and Geology at University of Copenhagen, together with American colleagues from Stanford University in California have discovered the reason for “the missing ice age” back then, thereby solving the sun paradox, which has haunted scientific circles for more than forty years.

Professor Minik Rosing explains, “What prevented an ice age back then was not high CO2 concentration in the atmosphere, but the fact that the cloud layer was much thinner than it is today. In addition to this, the earth’s surface was covered by water. This meant that the sun’s rays could warm the oceans unobstructed, which in turn could layer the heat, thereby preventing the earth’s watery surface from freezing into ice. The reason for the lack of clouds back in earth’s childhood can be explained by the process by which clouds form. This process requires chemical substances that are produced by algae and plants, which did not exist at the time. These chemical processes would have been able to form a dense layer of clouds, which in turn would have reflected the sun’s rays, throwing them back into the cosmos and thereby preventing the warming of earth’s oceans. Scientists have formerly used the relationship between the radiation from the sun and earth’s surface temperature to calculate that earth ought to have been in a deep freeze during three billion of its four and a half billion years of existence. Sagan and Mullen brought attention to the paradox between these theoretical calculations and geological reality by the fact that the oceans had not frozen. This paradox of having a faint sun and ice-free oceans has now been solved.”

CO2 history iluminated
Minik Rosing and his team have by analyzing samples of 3.8-billion-year-old mountain rock from the world’s oldest bedrock, Isua, in western Greenland, solved the “paradox”.

But more importantly, the analyses also provided a finding for a highly important issue in today’s climate research – and climate debate, not least: whether the atmosphere’s CO2 concentration throughout earth’s history has fluctuated strongly or been fairly stable over the course of billions of years.

“The analyses of the CO2-content in the atmosphere, which can be deduced from the age-old Isua rock, show that the atmosphere at the time contained a maximum of one part per thousand of this greenhouse gas. This was three to four times more than the atmosphere’s CO2-content today. However, not anywhere in the range of the of the 30 percent share in early earth history, which has hitherto been the theoretical calculation. Hence we may conclude that the atmosphere’s CO2-content has not changed substantially through the billions of years of earth’s geological history. However, today the graph is turning upward. Not least due to the emissions from fossil fuels used by humans. Therefore it is vital to determine the geological and atmospheric premises for the prehistoric past in order to understand the present, not to mention the future, in what pertains to the design of climate models and calculations,” underscores Minik Rosing.

Full press release from the University of Copenhagen in Denmark.

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Backyard Scientists Aid Research

Backyard scientists use Web to catalog species, aid research

When a scientist caught onto her efforts, Jirachareonkul and a friend assembled about 20 volunteers — a group she calls the “Toad NUTS” — to collect data on the endangered Western Leopard Toad. The information they collect is being used in scientific research.

At a time when climate change and urbanization are poised to set off a new wave of extinction, some members of the scientific community are turning toward backyard biologists for the data they need to monitor ecosystems and protect struggling species.

Project BudBurst, out of Boulder, Colorado, aims to collect so much amateur data about plant species that scientists will be able to tell how climate change is altering the seasons in North America.

Technology is amplifying this passion for citizen science, which has been around since scientists started cataloging species. Researchers at several universities are working on iPhone applications and computer programs that could analyze digital photos of plant leaves and automatically identify the plant’s species.

The relationship between formal science and citizen science is similar to that between professional news reporters and bloggers; some scientists worry that the information coming in from nonprofessionals will be inaccurate, said John Musinsky, a senior director at Conservation International.

Great stuff. And you can get involved if you want. Just follow the links or search around the internet to find projects that interest you. These projects can be great ways to get kids involved in science.

Related: The Great Sunflower ProjectMonarch Butterfly Migration

Dealth of Artic Plankton a Warning on Warming

Death bloom of plankton a warning on warming by David Perlman

Vanishing Arctic sea ice brought on by climate change is causing the crucially important microscopic marine plants called phytoplankton to bloom explosively and die away as never before, a phenomenon that is likely to create havoc among migratory creatures that rely on the ocean for food, Stanford scientists have found.

Phytoplankton throughout the world’s oceans is the crucial nutrient at the base of the food web on which all marine life depends; when it’s plentiful, life thrives and when it’s gone, marine life is impossible.

“It’s a complex system,” Arrigo said in an interview, “but as the changes in ice cover throw the timing of phytoplankton abundance off, then the birds and animals whose brains have long been programmed to migrate north at specific times of the year will have missed the boat if there’s no nourishment for them when they get there.”

Every spring and summer, phytoplankton in the Arctic blooms richly in explosive pulses, nourished by nitrogen and phosphorous in the seawater, and when those chemicals are consumed, the blooms end, Arrigo said.

Related: Arctic System on Trajectory to New, Seasonally Ice-Free StateOcean Warming’s Effect on PhytoplanktonWhat’s Up With the Weather?posts related to oceans

Atlantic Hurricane Season 2008

photo of hurricane evacuation sign

Here is a nice post on weather and understanding data – Atlantic Hurricane Season 2008

A well-accepted metric which convolves storm frequency, intensity, and duration is called accumulate cyclone energy (ACE) and is calculated very simply: take the maximum sustained winds reported by the NHC every 6-hours for all storms (> 34 knots), square this value, and sum over the entire lifetime, then divide by 10,000. In 2007, even though there were also 15 storms, the ACE was only 72 compared to 132 for 2008 with the same number of named storms. This is partially because the storms in 2008 were much longer lived especially Bertha.

When encapsulated in the recent active period in North Atlantic activity (1995-2007), 2008 experienced normal or expected activity as measured by ACE. In terms of a long-term climatology, either the last 30 or 65 years, 2008 is clearly an above average year.

Data can’t lie but mistaken assumptions can lead you to form mistaken impressions. If you believe the number of named storms = hurricane activity and then are surprised that in fact there was many more days of hurricane activity it is not because the data lied but because you didn’t understand what the data represented.

Related: Data Based BlatheringDangers of Forgetting the Proxy Nature of DataWhat’s Up With the Weather?Saving Lives with Smarter Hurricane Evacuations