Microscopic bits of metal – nanoparticles, a thousand times smaller than the thickness of a human hair – have been touted as a biotechnology and manufacturing miracle. Among many other applications, they can be used to keep the smell out of sweaty gym clothes, to treat wastewater, and they are being considered as a way to deliver cell-specific cancer drugs. However, as a recent experiment shows, the very properties that make nanoparticles so valuable in killing harmful and unpleasant bacteria also kill ocean phytoplankton that regulate the climate and are the base of the oceans’ food chain.

The study – whose lead author is Robert Miller of the Bren School of Environmental Science and Management at University of California Santa Barbara – was published on January 20, 2012 in the online journal PLoS One. It is called “Titanium Dioxide (TiO2) Nanoparticles Are Phototoxic to Marine Phytoplankton.” Miller and his colleagues conducted an experiment showing that even normal levels of ultraviolet light (UV) from sunshine are enough to cause titanium dioxide nanoparticles suspended in seawater to kill phytoplankton.

Phytoplankton. Image Credit: NOAA

Nanoparticles. Photo courtesy of UCLA

Phytoplankton are very small marine organisms (most are too small to be seen with the unaided eye) that regulate the global climate by taking up vast quantities of carbon dioxide, or CO2, from the atmosphere via photosynthesis. They also serve as the first link in the oceans’ food chain. Phytoplankton that are not eaten by other marine creatures end up sinking into the deep ocean, which is one of the only ways carbon is taken out of the atmosphere and naturally stored for thousands of years.

Titanium dioxide is by far the most commercially used nanoparticle. About 70% of all pigments use titanium dioxide, and it is a common ingredient in products such as sunscreen and food coloring. Titanium dioxide is therefore likely to enter estuaries and oceans, for example from industrial discharge, and new studies such as Miller’s have focused on measuring the impact of metal nanoparticles on marine life like phytoplankton.

Nanoparticles are highly reactive with oxygen after exposure to ultraviolet (UV) light. This reaction gives nanoparticles significant antimicrobial properties, which is why they are effective against your smelly gym clothes.

Meanwhile, nanoparticles suspended in water can easily attach to phytoplankton cell membranes. Damage to plankton occurs when titanium dioxide is electronically excited due to energy from UV light. Electrons from the nanoparticle react with surrounding water to form reactive oxygen species (ROS), which are very potent oxidizers that damage cell membranes and degrade proteins and organic compounds within a cell.

It is well established that titanium dioxide – as well as zinc oxide (ZnO) – exposed to artificially high levels of UV is electronically excitable and toxic to cells. However, the experiment by Robert Miller and his colleagues showed that normal levels of UV from sunshine can excite titanium dioxide nanoparticles suspended in seawater, kill phytoplankton, and lead to population crashes of some phytoplankton species in a laboratory setting.

While nanoparticles are thought not to be entering marine ecosystems yet in large quantities, this experiment is proof of concept that phytoplankton populations are highly vulnerable to damage from nanoparticles.

In an email, Dr. Miller told EarthSky that:

This could mean less support for ocean food webs, which includes fisheries and marine mammals. It could also impact the global carbon cycle – less phytoplankton production could mean less CO2 taken out of the atmosphere, and less carbon sequestered on the ocean floor.

They (nanoparticles) could aggregate with each other and with natural particles and settle to the seafloor, where they would affect bottom-dwelling organisms. We’re also working on that question.

Dr. Lucas Thompson, an Assistant Professor of Chemistry at Gettysburg College and an expert in metal nanoparticle applications, but not an author on Miller’s study, stated that nanoparticles still hold tremendous promise with some caveats. He said:

These nanoparticle interactions can be harnessed to fight cancer or to help deliver drugs in a controlled manner.

However, it must be noted that these same interactions can prove to be toxic if not carefully managed. This study highlights some of the potentially devastating effects that careless disposal of nanomaterials could have on the marine environment.

Bottom line: An experiment led by Robert Miller of the University of California Santa Barbara indicates that even normal levels of ultraviolet light (UV) from sunshine are enough to cause titanium dioxide nanoparticles suspended in seawater to kill phytoplankton, in a laboratory setting. The study – called “Titanium dioxide (TiO2) Nanoparticles Are Phototoxic to Marine Phytoplankton” – was published on January 20, 2012 in the online journal PLoS One.

Scientists revealed their discoveries about dark deep-sea “black smoker” volcanic vents that might be Earth’s hottest. These vents are deeper than any seen before, five kilometers (over three miles) down in a rift in the Caribbean seafloor called the Cayman Trough. The undersea hot springs – which might be hotter than 450 C (842 F) – shoot a dark, smoky-looking jet of mineral-laden water more than a kilometer into the ocean above.

Despite these extreme conditions, the vents are home to creatures of a new species, eyeless shrimp with a light-sensing organ on its back. And having found yet more black smoker vents on an undersea mountain nearby, the researchers suggest that deep-sea vents may be more widespread around the world than anyone thought.

Black smoker vent at the Beebe Vent Field, five km deep in the Cayman Trough. Image Credit: University of Southampton/NOC.

Lost world of creatures at Antarctic deep sea vents

Reporting in the scientific journal Nature Communications, a team led by marine geochemist Doug Connelly of the National Oceanography Centre in Southampton (UK) and marine biologist Jon Copley of the University of Southampton has revealed details of the world’s deepest known black smoker vents.

During an expedition in April 2010 aboard the Royal Research Ship (RSR) James Cook, the scientists used the National Oceanography Centre’s robot submarine, Autosub6000, and a deep-diving vehicle, HyBIS, to locate and study the vents at a depth of five kilometers in the Cayman Trough.

The vents gush hot fluids unusually rich in copper. These jets send mineral-laden water four times higher up into the ocean than other deep-sea vents. Although the scientists were not able to measure the temperature of the vents directly, these two features indicate that the world’s deepest known vents may be hotter than 450 C (842 F), according to the researchers.

The team found a new species of pale shrimp congregating in hordes around the tall mineral spires of the vents. Lacking normal eyes, the shrimp instead have a light-sensing organ on their backs, which may help them to navigate in the faint glow of the deep-sea vents.

The Cayman shrimp is related to a species called Rimicaris exoculata, found at other deep-sea vents 4,000 kilometers away on the Mid-Atlantic Ridge. Elsewhere, at the Beebe Vent Field, the team saw hundreds of white-tentacled sea anemones lining cracks where warm water seeps from the sea bed.

New shrimp species and snake-like fish. Image Credit: University of Southampton/NOC

The researchers also found black smoker vents on the upper slopes of an undersea mountain called Mount Dent. Mount Dent rises nearly three kilometers above the sea floor of the Cayman Trough, but its peak is still more than three kilometers beneath the waves. Mount Dent formed when a vast slab of rock was twisted up out of the ocean floor by the forces that pull the plates of the Earth’s crust apart. Connelly said:

Finding black smoker vents on Mount Dent was a complete surprise. Hot and acidic vents have never been seen in an area like this before, and usually we don’t even look for vents in places like this.

Because undersea mountains like Mount Dent may be quite common in the oceans, the discovery suggests that deep-sea vents might be more widespread than previously thought.

The vents on Mount Dent are also thronged with the new species of shrimp, along with snake-like fish and previously unseen species of snail and a flea-like crustacean called an amphipod. Copley said:

One of the big mysteries of deep-sea vents is how animals are able to disperse from vent field to vent field, crossing the apparently large distances between them. But maybe there are more “stepping stones” like these out there than we realized.

Bottom line: Scientists revealed their discoveries about newly found dark “black smoker” volcanic vents deeper than any seen before, five kilometers down in the Cayman Trough, a rift in the Caribbean seafloor. The hot vents are teeming with thousands of a new species of eyeless shrimp that has a light-sensing organ on its back.

Via EurekAlerts

Debris washed to sea from the Tohoku tsunami that struck Japan this year – following the 9.0-magnitude earthquake on March 11, 2011 – has added some millions of tons of weight to the Great Pacific Garbage Patch and is now sweeping toward the California coast, which it might reach sometime in 2013. But the first U.S. landfall for the debris will happen sooner, according to predictions by scientists at the National Oceanic and Atmospheric Administration.

Carey Morishige is the Pacific Islands Regional Coordinator for the NOAA Marine Debris Program. She spoke to NOAA's Making Waves podcast about debris from the 2011 Japan tsunami.

The Japanese debris – which NOAA scientists say is partially submerged beneath the ocean surface and dispersed over a wide area – will come “fairly close” to the Northwest Hawaiian Islands in northern hemisphere winter 2011/2012.

In other words, it could be any day now.

That’s according to Carey Morishige of the NOAA Marine Debris Program. NOAA’s National Ocean Service Making Waves podcast released an interview with her on December 16, 2011.

Shortly after the March 2011 earthquake and tsunami struck, large fields of debris could be seen floating in the ocean. But very soon, the debris fields had dispersed. Some is now floating below the ocean surface. Some has surely been broken into small bits by sunlight, wind and water. Morishige said:

As of April 14 [2011], we were not able to track that debris anymore because of the fact that it dispersed so much. The satellite imagery we have access to right now is not able to detect a single piece of debris floating in the ocean.

Debris floats in Pacific Ocean shortly after March 2011 Japanese earthquake and tsunami. The debris field soon dispersed and can no longer be seen or tracked. But computer models suggest it is still heading toward Hawaii and the U.S. West Coast. Image Credit: U.S. Navy

Yet computer models indicate the debris is still floating, with its path largely determined by currents and wind. The models also indicate the debris is fanning out into a wider and wider area. But there’s still a lot of uncertainty over exactly what is floating, where it’s located now, and when and where (or even if) it will make landfall. NOAA researchers have now teamed up with the U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, and other partners to coordinate data collection activities. There are also ways the public can help: look for the email address at the bottom of this post.

Top five natural disasters of 2011

Exactly what’s in this debris? Is any of it radioactive? Carey Morishige said radioactivity is probably not an issue since the tsunami carried most of the debris seaward before the failure of Japan’s Fukushima Daiichi nuclear reactor.

However, as it receded from Japan’s coastline, the tsunami washed much of whatever was loose in the inundation zone into the ocean. That includes whole boats, pieces of smashed buildings, appliances, and plastic, metal, and rubber objects of all shapes and sizes. Some of this debris sank, and some floated out to sea. The Japanese government estimated that the tsunami generated 25 million tons of rubble, but not all of that debris is headed our way, and statements in the media earlier this year that “20 million tons” of debris are headed for U.S. shores are “unfounded,” Morishige said.

Another shot of debris in the ocean, taken shortly after the 2011 Tohoku tsunami that devastated a coast of Japan. Image Credit: U.S. Navy

So what exactly is the danger? Without knowing exactly what’s in the debris, Morishige said, it is hard to estimate the danger. But her team will be looking for hazardous materials, for example. In a worst-case scenario, Morishige said, boats and other heavy objects could wash ashore in sensitive areas, damage coral reefs, or interfere with navigation in Hawaii and along the West Coast. The best-case scenario is that most of the debris will break up, disperse and eventually degrade.

Ocean currents - specifically the North Pacific Gyre - will carry the floating debris from Japan to the U.S. West Coast and back again. Image Credit: NOAA

Ocean currents are now guiding the fate of the Japanese debris. Morishige said:

… it’s going to go from Japan, across the North Pacific, skimming the top of the Northwest Hawaiian Islands, down the West Coast with the California currents, and then back across the North Pacific towards the main Hawaiian islands.

Computer models predict the debris will likely reach the California coast sometime in 2013, then head back across toward the main Hawaiian islands, reaching the islands sometime around 2015.

Morishige said experts are hoping to obtain real-time information from air flights or from very high resolution satellite imagery. She said:

Then we would know for sure that what our models are predicting is actually where the debris is ending up.

She said that the public can help address this problem in two ways. The email for both activities is mdsightings (at) gmail.com. First, you’re travelling by ship anywhere in the North Pacific Ocean and spot floating marine debris, you can report what you saw, and when and where you saw it. Second, if you live along the U.S. West Coast, Hawaii, or Alaska, you can track marine debris over time along the shoreline. Use the email above to request a copy of NOAA’s marine debris shoreline survey field guide.

Bottom line: Debris washed to sea by the major tsunami that struck Japan following the March 11, 2011 earthquake is making its way across the North Pacific Ocean. Scientists at NOAA believe it will pass close to Hawaii in winter 2011/2012 – in other words, soon. This debris is partially submerged and dispersed, and it is no longer visible. NOAA is hoping to get some real-time sightings of the debris. The public can help, too.

Ocean acidification is a change in ocean pH (acid-alkali proportion) caused by increased emissions of CO2 (carbon dioxide) in our modern world. In November of 2011, marine ecologist Joan Kleypas of the National Center for Atmospheric Research will receive a prestigious Heinz Award for her work on this subject. She published a groundbreaking paper on ocean acidification in the journal Science in 1999, alerting both policymakers and scientists to the issue. Kleypas now works mainly to combat – and help prevent – the effects of ocean acidification on coral reefs. She told EarthSky:

Image Credit: NASA

People wrote me after this paper was published and said you’re wrong, I know you’re wrong – and I’m going to prove you’re wrong. And I actually took comfort in that. But the rebuttals never came. As people looked closely at the pieces of evidence and they looked at the chemistry, they slowly came on board to realize that this is a serious issue.

Dr. Kleypas told us that excess CO2 from the atmosphere makes the oceans more acid – and reduces the amount of carbonate available for some ocean creatures to form their shells. She said:

When we think about a lot of marine organisms – things like corals, clams, oysters, things like hard shells, those shells are made of calcium carbonate. If you reduce the amount of carbonate in the ocean, you reduce the ability of the organisms to secrete their shells.

We often refer to it as being similar to osteoporosis. There are just fewer of the building blocks to build those shells.

Image Credit: NOAA

Kleypas’ focus is on coral reef preservation. She said many corals can’t build up as fast as Earth’s increasingly acidic oceans are breaking them down. Her work involves such things as whether marine algae can remove carbon dioxide from local waters at reef sites. She’s also using computer modeling to figure out which reefs are most likely to benefit from the setup of marine protection zones – because a healthy, undisturbed balance of organisms makes the corals more likely to survive global changes. She told EarthSky:

Most of the work I do is sort of modeling changes at the local scale and at the global scale. One of the big issues with coral reefs in climate change is … how much carbon dioxide is too much carbon dioxide for reef building? A reef is there because it produces more carbon than is removed. It’s amazing, if you ever visit a reef, you’ll see many things are chewing on the reef and breaking it down. Corals have to work hard to build that reef. You can see a balance. If they can’t produce as much calcium carbonate, then at some point these corals may be there but they’re not building a reef any longer.

In some cases, where there are marine algae growing in the reefs, those algae actually absorb carbon dioxide from the water, which can reduce the effects of ocean acidification, at least at the local level.

She said the idea of introducing corals that have been genetically modified to survive high acidity is also on the table. And she explained part of her work involves helping scientists figure out thresholds or “tipping points” for coral reef degradation.

Understanding what the thresholds are is very important because our policymakers are interested in just how high CO2 concentrations can get in the atmosphere. So our information about ecosystem function – it really gives them a guideline of creating future standards of carbon dioxide emissions.

Kleypas said she’s optimistic about her line of research

I like to call these nature’s masterpiece. If we lose coral reefs we’re really losing something that nature took millions of years to produce …

Image Credit: Jim Maragos/U.S. Fish & Wildlife Service

The green plumes shown in these images is the worst algae bloom North America’s Lake Erie has experienced in decades. The bloom is primarily microcystis aeruginosa, an algae that is toxic to mammals, according to the Great Lakes Environmental Research Laboratory. These images were acquired by the The Landsat-5 satellite in early October, 2011. The reasons for this year’s giant bloom are complex, say scientists, but might be related to a rainy spring and invasive mussels.

Image credit: NASA

The Landsat-5 satellite acquired the top image on October 5, 2011. Vibrant green filaments extend out from the northern shore. Several days of calm winds and warm temperatures allowed the algae to gather on the surface. The bloom intensified after October 5, and by October 9—when the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite acquired the lower image—the bloom covered much of the western basin.

Algae blooms were common in the lake’s shallow western basin in the 1950s and 60s. Phosphorus from farms, sewage, and industry fertilized the waters so that huge algae blooms developed year after year. The blooms subsided a bit starting in the 1970s, when regulations and improvements in agriculture and sewage treatment limited the amount of phosphorus that reached the lake.

Microcystis aeruginosa produces a liver toxin, microcystin, that commonly kills dogs swimming in infected water and causes skin irritation for people. Richard Stumpf, an oceanographer with the National Oceanic and Atmospheric Administration, measured 50 times more microcystin in Lake Erie in the summer of 2011 than the World Health Organization recommends for safe recreation. Stumf said:

This is considered the worst bloom in decades, and may have been influenced by the wet spring. Heavy snow fell in the winter and spring, followed by record-setting rainfall in parts of the Lake Erie watershed in April. The rain and melting snow ran off fields, yards, and paved surfaces, carrying an array of pollutants into streams and rivers—including phosphorus from fertilizers. More rain and runoff resulted in more phosphorus, and as in earlier decades, that nutrient nourished the algae in the lake.

But the rainy spring may not be the whole story, says Colleen Mouw, a researcher at the University of Wisconsin-Madison. Lake Erie has been invaded by zebra- and quagga mussels, carried into the lake in the ballast of ships. The mussels are bottom feeders, and they do a good job cleaning the water. They remove so many particles that Lake Erie is very clear in the spring and early summer. But zebra and quagga mussels don’t like microcystis. Mouw said:

They selectively feed on other phytoplankton species, removing competitors so microcystis can thrive.

As the mussels digest, they release phosphate and ammonia into the water, and these nutrients give microcystis an additional boost. When microcystis blooms develop, they create a green scum on the surface of the water that is visible from space.

Though not directly toxic to fish, the bloom isn’t good for marine life. After the algae dies, bacteria break it down. The decay process consumes oxygen, so the decay of a large bloom can leave “dead zones,” low oxygen areas where fish can’t survive. If ingested, the algae can cause flu-like symptoms in people and death in pets. The bloom is one of the issues being discussed at Great Lakes Week, a meeting of government representatives from the United States and Canada being held October 11-14 in Detroit, Michigan.

Bottom line: In early October, 2011, NASA’s Landsat satellite captured images of the worst algae bloom Lake Erie has experienced in decades. The bloom is primarily microcystis aeruginosa, an algae that is toxic to mammals. The reasons for this year’s giant bloom might be related to a rainy spring and invasive mussels.

Read more from NASA’s Earth Observatory

Improved digital map of Earth wows the world

Getting enough fresh water is an increasing challenge in Southern California – both because of the growing population and climate change-induced weather events, like drought.

That’s according to Susan Leal. She’s an associate of the School of Engineering and Applied Science at Harvard University, and co-author of the book, Running Out of Water. She told EarthSky:

When we were researching solutions to improve access to freshwater, we looked for solutions that were proven, solutions that could be replicated around the globe.

Image Credit: Greg Reigler Photography

Leal said one such solution is for more places to recycle wastewater. In the 1990s, Southern California’s Orange County was pumping in most of its freshwater from the northern part of the state – hundreds of miles away. Orange County water officials realized this wasn’t sustainable. Leal said:

What they decided to do was recycle their own wastewater. They took water from their sewer plants, and took it through a very intricate treatment system, so that the water they produced was pristine level, like distilled water. And then they put it back into their underground reservoirs.

When that water sprang up again, locally, it could be treated and used just like any other tap water, she said. That’s still happening today.

And it is proven to be a wonderful boon for the county – it is not in dire straits as some of its surrounding counties.

The same strategy is being used half a world away in Singapore, Leal said, which has a similar water scarcity issue, and an increasing population.

Leal talked more about freshwater access solutions for agriculture, which accounts for up to 70% of the world’s freshwater use. She said workable water solutions exist when it comes to agriculture, too – she discovered adjustments made to sprinkler systems on farms, for example, that cut down on a farm’s water use by as much as 20 percent.

We also looked at proven solutions around agriculture. They are available, whether it’s for growing cotton, or rice. It’s not only the crops you choose, but it is also how you grow them. And what we were able to determine is that they are very low cost – meaning these solutions can pay for themselves.

We’ve seen them work, for example, in Imperial County, also in Southern California. It was once a desert, and was flooded accidentally in the early 1900s, and it became one of the large agricultural valleys in the United States, and in the world. In fact, they say that half the winter vegetables in the U.S. come from this county. And what they found is with some fairly low-cost technology put in place, they could reduce the use of water, so they could easily grow the food with 10 percent less water. Which may not sound like much, but it could mean the difference between having food for three decades, instead of one.

We asked her what she meant when she said “low-cost technology.”

It might mean putting in certain types of drip irrigation. In the case of Nebraska, where they put in a certain type of sprinkler system, they used close to 20 percent less water than they would have originally. The supplies in their groundwater reservoirs was already diminishing.

Image Credit: Clearly Ambiguous

One of the most significant things she discovered in writing her book, Leal said, is that while good solutions exist for water challenges, they are not necessarily being implemented where they should be, sometimes because those solutions are cost-prohibitive.

She said this especially applies to wastewater treatment plants, which are having trouble keeping up with runoff into sewers from floods. She said flooding is on the rise because of global warming, which increases the frequency and fury of storms.

Storm surges overwhelm wastewater systems, so that the waste cannot be properly treated. And then it goes, without the proper treatment, into river, lakes, bays, and oceans, which of course can cause a public health problem, and definitely causes a problem with aquatic life.

She gave an example, explaining the challenges:

An example is if you were running a wastewater system in New York City, and you were having to process the wastewater coming out of Manhattan. With a storm surge, your systems could be overwhelmed. And you might have to build a bigger wastewater treatment system. These systems, especially for large cities, cost billions of dollars.

Rising sea level is another problem for wastewater treatment facilities, she said. If salt water gets into these facilities, it prevents them from working properly. Leal said:

For people that are running water utilities, whether it’s in the U.S. or in other parts of the world, it’s no longer an issue of “Is climate changing going to affect our water supply?” – it’s now to the point of: “What to do we have to do to adapt, to a climate that has been changing?”

Hear the 90 second EarthSky interview with Susan Leal on recycling wastewater as one solution to freshwater scarcity, (at top of page.)

A team of researchers used climate models to calculate the long-term outlook for rising sea levels in relation to the emission of greenhouse gases and pollution of the atmosphere.

How sea levels will change, based on four different pathways of human development and greenhouse gas pollution. The green, yellow and orange lines correspond to scenarios where it takes 10, 30, or 70 years before emissions are stabilized. The red line represents business as usual where greenhouse gas emissions increase over time. Image Credit: Aslak Grinsted

The study’s long-term calculations suggest that the sea will continue to rise in the coming centuries and it will most likely rise by 75 cm by the year 2100 and two meters by the year 2500.

The increasing emissions of greenhouse gases into our atmosphere are thought to contribute to global warming. A warmer world will have a higher sea level because as the land and lower atmosphere of the world warm, heat is transferred into the oceans. That heat causes sea water to expand, which then results in a rise in sea level. In addition, water from land-based ice such as glaciers and ice sheets may enter the ocean and contribute to sea level rise.

Aslak Grinsted, a researcher at the Center for Ice and Climate, the Niels Bohr Institute at the University of Copenhagen, was a lead author on the study, which was published in the scientific journal Global and Planetary Change in September, 2011. Grinsted said:

In the 20th century, sea level has risen by an average of 2 mm per year. But it is accelerating, and over the last decades the rise in sea level has gone approximately 70 percent faster. Even if we stabilize the concentrations in the atmosphere and stop emitting greenhouse gases into the atmosphere, we can see that the rise in sea level will continue to accelerate for several centuries because of the sea and ice caps’ long reaction time. So it would be 200 to 400 years before we returned to the 20th century level of a 2 mm rise per year.

In the 20th century, sea level rose by an average of 2 mm per year. But it is accelerating, and over the last decades the rise in sea level has gone approximately 70 percent faster, according to researchers. Photo credit: FaceMePLS

Grinsted collaborated with researchers from England and China to develop a climate model that is based on actual measurements of what happens to sea level depending on the emission levels of greenhouse gases and aerosols released into the atmosphere. They then used the model to predict the possible future outlook for rising sea levels.

The research group has made calculations for four scenarios:

A pessimistic one, in which greenhouse gas emissions continue to increase. In this scenario, sea levels will rise 1.1 meters by the year 2100 and will have risen 5.5 meters by the year 2500.

For the two more realistic scenarios, based on the emissions and pollution stabilizing, the results show a sea level rise of about 75 cm by 2100 and two meters by the year 2500.

But even in the most optimistic scenario, which requires dramatic climate change goals, major technological advances and strong international cooperation to stop emitting greenhouse gases and polluting the atmosphere, the model predicts that sea level would continue to rise. According to this scenario, by the year 2100 sea level will have risen by 60 cm, and 1.8 meters by the year 2500.

Bottom line: A recent study calculated that the sea will continue to rise in the coming centuries and it will most likely rise by 75 cm by the year 2100 and two meters by the year 2500. A international team of researchers used climate models to calculate the long-term outlook for rising sea levels in relation to the emission of greenhouse gases and pollution of the atmosphere.

Via EurekAlert

Arctic sea ice reached record lows in 2011

We might not be aware of how much water we use every day. That’s according to Charles Fishman, investigative journalist and contributing editor at Fast Company. Fishman interviewed dozens of water experts around the world for his new book, The Big Thirst. He told EarthSky:

Especially as people rise to the middle class, and in developed nations, there’s lots of hidden water use. An example is, in the United States, the average person, over the course of a day, uses 99 real gallons of water.

That is, 99 gallons of water for cooking, cleaning, and bathing. He talked about water use that we might not think about, or even know about.

Photo Credit: Argonne National Library

The electricity that each American uses just at home, just residential electricity per person, that electricity requires 250 gallons of water a day. So you use more than twice as much water just to keep your computer and light bulbs running and your refrigerator and your flat screen TV running as you do to actually take a bath and clean the dishes and go to the bathroom.

Fishman said challenges to our water supply will grow this century because of the effects of climate and a growing population.

In most of the the developed world, he said, we never think about our water supply – what’s required to get it to us, what’s required to clean it, what rainfall we’re depending on. But, he said, Australia is one portion of the developed world that does not take its water for granted. Fishman said:

As climate change takes hold, and in places with water scarcity, there’s no question about changing rainfall patterns. Australia is an example of a whole country that literally almost rain out of water because the rainfall pattern going back a hundred years – the colonialized history – shifted. And so the reservoirs and the rivers, and all the places people were used to getting their water from didn’t have the water that societies had become accustomed to…. As one elected official said to me: the reservoirs were built in all the wrong places.

Almost every Australian city has, at least temporarily, solved it’s water shortage, he said. Australia now converts ocean water into potable water. He said:

Almost every city has, at least temporarily, solved its water shortage by building huge expensive desalinization plants, reverse osmosis plants, Sydney-sized plants, where the guts of the plant cover a football field or more. And those work great, but they’re incredibly energy intensive, and so they’re expensive to operate, and they may contribute to what caused the problem in the first place…that is, you’re burning a bunch of fuel, and that causes climate change.

Reverse osmosis takes so much energy, he said, because water needs to be pushed through filtration membranes at very high pressure. It takes a lot of energy to build that pressure. To try to solve that problem, he said that experts at IBM are working right now on trying to filter water using carbon nano-tubes – very, very tiny carbon tubes – that would only require water to flow through them, not be pushed.

The better we understand our hidden water use, he said, the easier it will be for the public to make smart decisions about water use and conservation.

Martha Anderson, a research scientist at the U.S. Department of Agriculture, uses images from the Landsat satellite program to monitor water use and drought on U.S. farms with pinpoint accuracy, even at the scale of individual fields. As water availability becomes an increasingly critical issue worldwide, she said, it’s important to be able to monitor how much water is evaporated, how much is used, and where it is used. She spoke about monitoring our water use from space with EarthSky’s Jorge Salazar.

You measure what’s called evapotranspiration. What is evapotranspiration, and why is it important to measure evapotranspiration rates from space?

In agricultural landscapes, evapotranspiration, or ET as we call it for short, represents the total amount of water that’s used in the process of growing crops.

Evapotranspiration describes the exchange of water vapor between the land surface and the atmosphere. It’s made up of all the water that’s evaporated off of surfaces, and all water that’s used by plants in the process of photosynthesis. That’s the transpiration component. So, it’s evaporation plus transpiration.

We need to be able to monitor ET because it’s a really crucial part of the global water cycle. It’s the difference between rainfall – which is the water that is put into the land surface system – and the evaporative loss from the land surface. The process of ET lets us know how much water is left behind to do things like grow crops or provide drinking water or feed the regional streams and river systems.

Image Credit: Tomas Castelazo

So, if we can map ET accurately over large regions we can estimate soil moisture availability and how much water is being used for different purposes – for example agriculture and urban uses. We know that fresh water is becoming increasingly scarce worldwide. It’s going to become increasingly important that we be able to monitor this component of the water budget very accurately.

How does Landsat in space see how water is being used on an agricultural field?

Landsat has a number of imaging systems, and one of them collects radiation that is in the thermal waveband. Those are wavelengths that are longer than our eyes can see. All objects emit this kind of thermal radiation – the hotter the object, the stronger the thermal emission. Using these thermal waveband systems we can map out the temperature of the land surface remotely. With Landsat we can do this mapping at fine enough spatial resolution that we can detect temperature differences between different agricultural fields, and this is very useful.

Crops that are evaporating water with a very high rate of ET tend to be cooler because the evaporation is cooling down the surface. But as the crops become stressed the transpiration shuts down, the canopy starts to heat up, and we can detect those elevated leaf temperatures from space. So, with Landsat we can detect that a given field is maybe not as healthy as it should be.

Landsat Data Continuity Mission

How is the water use information that Landsat collects being used?

Landsat ET is being used operationally now – particularly in the western states, where water resources are getting increasingly tight and being depleted often at an unsustainable rate.

In Idaho, for example, water resource managers and water management districts are using Landsat ET to see if individual irrigators within irrigation districts are complying with their allocated water rights or if they’re using more water than they should be. They can determine this by looking at time sequences of the Landsat ET data.

Because we have a Landsat image archive extending back to the early 1980’s, we can make a time sequence of maps showing how water has been used historically over a landscape. That’s really critical information for negotiating water rights trades and interstate water compacts for example.

Farmers can use this information to figure out which fields need to be irrigated and by how much they need to be irrigated.

We can also study the trade-offs in water use between different users. For example, in some parts of the West you have irrigation occurring next to a stream that’s supporting important habitat – salmon spawning grounds, for example. We can use the Landsat ET to see how much the irrigated agriculture may be influencing the stream flow in these critical ecosystems.

Drought map for 2007: green shows areas where evapotranspiration is higher than average, and red shows areas with lower than average evapotranspiration

You’ve recently published work on how evaporation and transpiration by plants can be used to better understand drought using Landsat data. What did you find?

We know that when an area is experiencing drought, its ET is going to be necessarily lower. The soil is dry, there’s less water there available for the plants to use. These ET maps make excellent drought maps as well. You don’t need any ground-based rainfall data to make these maps because the drought signal is being conveyed by the thermal land surface temperature signal.

So, this is a really good way to map drought in countries that may not have the dense meteorological infrastructure that we have here in the U.S. – sparer rain gauges and Doppler radar systems. For example, in the Horn of Africa where they’re currently experiencing severe famine we’ve been able to apply these thermal techniques and make some very nice maps pinpointing the drought-affected regions.

The information from Landsat is freely available to anyone, right?

That’s right. And that’s a change that occurred just over the last couple of years. A new paradigm was developed – let’s distribute these images for free. It’s incredibly valuable information. People from the U.S., from other countries can access this imagery now free of charge.

And that’s enabled a whole new line of research, to be able to do times series analyses of how things are changing in different regions. How are urban regions expanding? How is water use changing in these expanding urban regions? How is water use changing as we convert land from natural vegetation into crop lands or housing developments? These are studies we can now do that we couldn’t do five years ago.

Our thanks today to the NASA and USGS Landsat Program, creating an unparalleled record of Earth’s changing landscapes.

San Diego County in California had a strong red tide this week, apparently peaking around September 28, 2011. The red tide – a discoloration of seawater caused by a bloom of tiny, toxic organisms known as red dinoflagellates – lit up the surf at night on San Diego beaches, via a phenomenon known as bioluminescence. Several videographers captured the strange light, visible at night in the breaking waves along San Diego shores.

This video – from cinemadv on YouTube – is short, but captures the phenomenon perfectly, although he (or she) commented the color was actually more greenish than blue. It was uploaded to YouTube on September 28, 2011.

This longer video comes from LoghanCall on YouTube. He wrote:

On September 28th, 2011, the “red tide” hit San Diego shores. The neon-blue waves are not digitally created or altered from their original form. This video was shot at Moonlight Beach in Encinitas, California and North Ponto Beach in Carlsbad, California.

The video above, uploaded to YouTube on September 27, is a bit dark, but you can see surfers in the bioluminescent surf. It’s from shuttrbg22.

Bioluminescent life forms – such as the tiny red dinoflagellates in the red tide shown in these videos – make their own light and carry it in their bodies. Fireflies are another, perhaps more commonly seen example. In the oceans of our world, though, many creatures are bioluminescent. Just as fireflies use their lit-up abdomens to send mating signals and other forms of communication, so bioluminescent creatures of the deep use their internal ability to create light to warn or evade predators, lure or detect prey, and communicate between species members.

Bottom line: During the last week of September, 2011, a red tide in southern California created bioluminescence along beaches near San Diego. The internally illuminated tide was seen for several nights, and some people captured good videos of the event.

Surf’s lighted up at San Diego beaches

Bioluminescent beaches photo gallery from SignOnSanDiego.com

Why do fireflies light up?

Humboldt squid washing up on southern California beaches

There’s no such thing as a jellyfish