The Antarctic Paradox

A phytoplankton bloom off the
coast of Argentina.

Recently I wrote about how the population of Antarctic krill has dropped by 80% over the last 40 years. I have to admit, I was feeling a bit depressed after writing that column. It seems that the natural world is forever being drop-kicked at the expense of progress. But are the two competing worlds forever destined to be in conflict? Maybe not.
   Let’s look a little closer at the problem of declining krill numbers. It’s paradoxical that there are vast areas of the Southern Ocean that contain plenty of nutrients to support phytoplankton growth, the primary food source for krill, yet we don’t see the growth that would normally be expected. These low-plankton regions near Antarctica are called HNLC areas because the have High Nutrient yet Low Chlorophyll.
   The main reason for this is a lack if iron in the water. Iron is an element that is required in trace amounts for photosynthesis to take place, but it is insoluble in sea water, making it a limiting nutrient for plankton growth.
   Over the last 20 years, there has been considerable research into the problem and it has been shown that phytoplankton growth can be stimulated by adding iron. Usually such iron fertilization occurs naturally by ocean current upwellings, wind-born dust being deposited over the ocean’s surface or iron-rich minerals being carried to the ocean by glaciers or icebergs. 
   And there is another potential benefit beyond boosting the bottom of the food chain. When Mount Pinatubo erupted in 1991, it deposited about 40,000 tons of iron-rich dust into the world’s oceans. What happened as a result was remarkable: over the next few years, phytoplankton blooms increased substantially, causing planetary carbon dioxide levels to drop and oxygen levels to increase. It was estimated that over a billion tons of CO2 was removed from the atmosphere.

   There are now plans underway to do this on a large-scale, commercial basis. However, there is considerable uncertainty and disagreement as to whether it will do more harm than good on a large scale. Some scientists remain skeptical about whether the process would remove carbon dioxide for the long term and what the ecological impact will be. Further experimentation is needed and one thing is for certain: future policies and carbon-offset markets will emerge, and possibly without a sound scientific basis. Iron fertilization should be considered along with any other geoengineering solution. And if it feeds a few more whales in the process, all the better.

A Strange Sight Over Moscow

On October 7th, 2009, a strange-looking formation was seen in the sky over Moscow. When it appeared, scores of supernatural enthusiasts speculated that it had been created be an alien spacecraft. Turns out, it was actually a hole-punch cloud. Because the center of the formation appears to be a falling streak of clouds, nepholologists call it a fallstreak hole. 
   A fallstreak hole is a large circular gap that can appear in cumulus clouds, usually at an elevation of six kilometers or more above the Earth. Such holes form when a cloud is made of both ice crystals and super-cooled water droplets that exist together in a delicate balance. When such a balance occurs, it only takes a slight disruption, such as a passing jet, to set off a chain reaction that transforms the super-cooled water droplets into ice which clings to existing ice particles. The quick build-up of ice falls from the cloud and dissipates the water, creating a void.

   Hole-punch clouds are rare, but when they do form, they’re large enough to be seen for many kilometers in every direction. Because they are so rare and have an unusual appearance, fallstreak holes are often mistaken for UFOs.
   Upon further investigation of the Moscow hole-punch cloud incident, it seems to have been inadvertently caused by the Russian Air Force—at the request of Yury Luzhkov, Moscow’s mayor—to test its cloud-seeding program. The idea was to fly over the approaching clouds and spray silver iodide into them. Moisture would quickly condense around the fine particles, creating snow much sooner than it would normally. 
   In theory, if the clouds shed enough precipitation before reaching the city, Moscow could avoid the usual heavy winter snowfalls for which they are so well known. Luzhkov said such efforts could save the city $4 million in snow-removal costs each year, and improve their quality of life during winter.
   But there was a problem: Mother Nature refused to cooperate. The pilots needed two weeks advance notice for maximum effectiveness, yet meteorologists had a hard enough time predicting snowfall two days in advance. So while Luzhkov blamed the hapless weathermen and promised to find a solution, Muscovites did not hold their breath. 

Bengal Tigers of the Sundarbans

The Sundarbans is a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site covering parts of Bangladesh and India. The region is densely covered by mangroves, and is the largest mangrove forest in the world. It is also one of the largest reserves for the Bengal tiger.
   The Sundarban forest lies in the expansive Bay of Bengal delta. Inland from the mangrove forest lies the seasonally flooded Sundarbans freshwater swamp. The Sundarbans is estimated to cover about 4,100 square kilometers and serves as a protective barrier against cyclone flooding. 
   A 2007 UNESCO report states that a likely 45-cm rise in sea level by the end of this century, along with other human-derived stresses, could lead to the destruction of 75% of the Sundarbans mangroves. 

A satellite image of the Sundarbans.

   The Sundarbans is intersected by a complex network of tidal waterways, mudflats and small islands of mangrove forests. Almost every part of the forest is accessible by boat. The fertile soil of the delta has been used for agriculture for centuries, with the forested regions dwindling to about one third the size that it originally measured some 200 years ago. What remains, along with the Sundarbans mangroves, is an important habitat for the endangered Bengal tiger. 
   Over the past century, the tiger population has fallen dramatically, and continues to decrease. Loss of habitat and poaching are the two most-serious threats to their survival.
   In 2006, the Indian government granted some of their most impoverished communities the right to own property in the forests, which brings them in conflict with the Bengal tiger. Tiger attacks in the Sundarbans kill from 50 to 250 people each year. Although precautions that were enacted in 2004 temporarily stalled the attacks, recently attacks have been on the rise. In 2007, Cyclone Sidr devastated the Bangladesh side of the swamp, depriving the tigers of their usual food sources and pushing them towards the more populated Indian side of the Sundarbans.

   Villagers tried wearing face masks on the back of their heads to confuse the tigers, which prefer to attack from behind. This worked for a while until the tigers figured it out, after which the attacks continued. Government workers wear strong padding on the back of the necks, similar to those worn by U.S. football players, to prevent the tigers from biting their spine. This is their favorite method of attack.
   Villagers in the area occasionally release livestock into the forest in order to provide an alternative food source for the tigers and discourage them from coming into the villages. The government subsidizes the project to encourage village participation.

If you enjoyed this article you might also want to read my article on the Siberian Tiger Project.

When the Lights Go Out

One of my readers posed the question: When I turn off the light in my bedroom at night, where does all the light go? Before we answer this, we need to make a few assumptions. Let’s assume that the bedroom is a perfect container: It has no windows for light to escape from and no cracks around the door so light can’t escape there either. Also, let’s say the walls are perfectly solid, and consist of a regular structure of atoms. Imagine a grid of hard spheres laying next to  each other. This is the surface of the walls. 
   First, we need to realize that light is a form of energy. While the light switch is on, it closes an electric circuit and electrons flow through the light bulb. The light bulb converts the energy from the electric current to light energy in the form of photons. Photons are tiny packet of electromagnetic energy and momentum. When you turn the light off, the circuit is broken, the energy stops flowing, and the light goes away. But where does it go?
   The photons travel across the room at the speed of light. When a photon hits the wall, its energy and momentum is either absorbed by the atoms in the wall, or are reflected to another wall where it again may get absorbed or reflected. One of the fundamental concepts of physics tells us that both energy and momentum are conserved, which means that an atom will get a small kick from absorbing a photon. It will move, and kick against its neighbor, etc. If enough photons get absorbed, this will result in the wall warming up slightly. So the light gets converted into thermal energy in the wall. This is what is meant by having a temperature. 
   If the wall were at absolute zero, these atoms do not move and are simply at rest, each one just touching the next. By saying that the wall has a temperature, we are really saying that it contains thermal energy. This thermal energy is the random vibration of the atoms around their equilibrium point. Such a vibration can travel through the grid of atoms in the form of a wave. One atom pushes the next, which pushes the next, etc. 
   When you turn off the light switch, the process just stops—the bulb stops generating photons, and the last set of photons hit walls until they’re all absorbed, all within a fraction of a second.

The Keystone Species of the Southern Ocean

A swarm of krill in the Southern Ocean

Worldwide there are about 85 species of krill, the largest of which is the Antarctic krill (Euphausia superba) which averages about five centimeters in length. Antarctic krill live in dense concentrations in the cold Southern Ocean. At any given time there are four or five billion individuals, and when they congregate for spawning they create a pink swarm so large that it can be seen from space.  
   Krill are crustaceans like crabs, shrimp and lobsters. But unlike their cousins that are bottom-feeders, krill are pelagic—they make their living in the open ocean. And unlike the plankton they feed on, krill are nektonic—they are able to swim independent of the ocean currents. 

The anatomy of the Arctic krill

   Antarctic krill feed on algae and phytoplankton that are suspended in the water column. They are preyed upon by nearly every Antarctic predator that exists. And if a predator doesn't eat krill, it feeds on the ones that do. A penguin's diet consists of nearly 100 percent krill. Blue whales rely on krill for almost all of their dietary requirement. During the summer months, an adult blue whale eats up to 40 million krill in a single day to fulfill its 1.5 million kilocalorie nutritional needs. Antarctic krill is the keystone species in the Southern Ocean, and without it, the ecosystem would collapse.
   Antarctic krill use intensive searching and rapid feeding techniques to take advantage of high plankton concentrations. Krill form dense schools that move horizontally in the water column when feeding. Krill spend their days avoiding predators in the cold depths of the Southern Ocean. At night, they drift up toward the surface to search for phytoplankton.

   Recent studies show Antarctic krill stocks have dropped by as much as 80 percent since the 1970s. Scientists attribute this decline in part to ice cover loss caused by global warming. This ice loss removes ice algae from the Southern Ocean which is a primary source of food for krill. NASA satellite data reveals that there has been continuous ice loss from Antarctica since 2002—more than 100 cubic kilometers of ice per year.

The Skies Near Mount Ranier

Located southeast of Seattle, Mount Rainier is the tallest volcano in the Cascade Range and the most topographically prominent mountain in the contiguous United States. Its summit is at an elevation of 4,392 meters and it has a topographic prominence of 4,027 meters. Because of this, many people from the Pacific Northwest are treated to the spectacular beauty of this snow-capped peak which dominates the landscape. But if you are really lucky, your view of Mount Ranier could be enhanced in some very unusual ways. 

A cloud shadow being cast from Mount Rainier. Photo by Nick Lippert.

   One way is by an amazing cloud shadow that only occurs with several factors happening concurrently. At the approach of winter, when the Sun rises farther to the south, it is possible for the first rays of light at sunrise to pass through a dip in the Cascade Range and catch the peak of Mount Ranier. If that sunrise is also accompanied by a cloud layer above the mountain, it will project a shadow onto the bottom of the cloud layer creating a spectacular cloud shadow. This could never happen in the Rockies because even though there are several peaks taller than Mount Ranier, none of them have the topographic prominence that is needed. And as the sun rises its light will scatter too much to cast a shadow behind it.

   Another strange yet beautiful cloud phenomenon that you can see near Mount Ranier is lenticular clouds. These are lens-shaped clouds that form at high altitude. Because of their smooth, saucer-like shape, lenticular clouds have been mistaken for UFOs. Lenticular clouds are formed when moist air travels vertically over the mountain and creates a standing wave pattern on the downwind side. Moisture condenses at the crest of the wave and evaporates at the wave trough, creating the characteristics lens shape. Even though the wind continues to move down the mountain, the lenticular cloud will remain stationary. Lenticular clouds can appear singly, or in clusters or stacks. Pilots will avoid lenticular clouds because of the dangerous wind shears that accompany them, but thrill-seeking hang gliders will use them to ride the wave for several kilometers.

A stacked lenticular cloud formation near Mount Ranier.

   At some point in the future Mount Ranier will give us the most-spectacular—yet terrifying—show of all: when it erupts. Even though Mount Ranier is quiet now and has been since the 1890s, geologists consider this stratovolcano to be episodically active, which means that it WILL erupt again at some point in the future. It’s for this reason, and the fact that Mount Ranier is located near a highly-populated area, that it was included as one of 16 “Decade Volcanoes” worthy of study in an attempt to reduce the severity of a future natural disasters. These Decade Volcanoes were studied as part of the United Nations International Decade for Natural Disaster Reduction during the 1990s.

Brocken Specter

Brocken specter as seen from 

the Golden Gate Bridge.

I love travelling through the mountains. The way the light plays off the mist in beautiful and sometimes eerie ways amazes me. If you're lucky enough to be at the right place at the right time, you might experience a rare and seemingly supernatural optical phenomenon called Brocken specter, named after the highest peak in the Harz mountains in Germany. 

   German Folklore dating back to the 17th century says that on the night of April 30 each year, exactly six months after Halloween, witches and sorcerers gather on the Brocken and revel with their gods as they await the arrival of spring. Among mountain climbers there is a superstition that a person who sees a Brocken specter will someday die on the mountain; local climbers have been so startled by the sudden appearance of a Brocken specter that they fall to their death, not realizing they are seeing their own harmless shadow.

Brocken specter from the 

Tanzawa Mountains in Japan.

   The Brocken specter appears when the setting sun casts a shadow from directly behind a climber at a higher altitude onto a cloud or mist at a lower altitude. When the shadow is cast upon a mist the sunlight surrounding it enters the suspended water droplets in the air and reflect back to the observer via diffraction, creating a rainbow-colored halo around the shadow's head. This halo is called solar glory. 

   The Brocken specter may appear to be huge because the fog hampers your depth perception. Only one's own shadow, seen in a mist, can converge with the antisolar point and combine with the solar glory to create the Brocken specter. Therefore, if you are travelling in a group you can only see your own Brocken specter.

Brocken specter from the Pamir Mountains of Tajikistan.