#Stephanie Dutkiewicz

[xtruss]

Phytoplankton bloom in the Barents Sea on August 14, 2011. This image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite. Photograph By NASA, GSFC/Jeff Schmaltz/Modis Land Rapid Response Team

Climate Change Will Shift The Oceans’ Colors

In the next century, satellites will watch as the ocean's blues and greens intensify.

— By Sarah Gibbens | July 21, 2023

The color of deep blue oceans, shallow turquoise waters, and emerald green coasts is quickly changing as the planet warms, according to new research published in the journal Nature.

Analyzing 20 years of satellite data, the study's authors found that over half the world's ocean, 56 percent, experienced a shift in color. The cause? Changes in the density and distribution of plankton. These tiny organisms contain chlorophyll, the bright green pigment that helps plants make food from sunlight.

The recent study supports a similar prediction made by a Nature Communications study published in 2019 that modeled how phytoplankton will change as oceans continue to warm.

And while the new study used satellites to detect subtle changes in color, the prior research predicted significant changes by 2100, if the world keeps warming at its current pace.

Under a “business-as-usual” scenario in which greenhouse gas emissions continue unabated, the bluest subtropical zones of the ocean will become bluer, and greener regions along the equator and poles will become greener, that study found.

More than just an oddity, the changing color is a warning sign, say the 2019 study authors, of drastic global changes that will take place in a world warmed by climate change.

How The Ocean Gets Its Color

Sunlight penetrates over 600 feet below the surface of the ocean. Everything deeper is enshrined in darkness. Above that, most water molecules are capable of absorbing all colors except blue, which is why blue is reflected out.

Organic matter that blankets the surface of the ocean, like phytoplankton, changes this color. As the ocean warms, currents become more irregular, and the layers in the water become more stratified, meaning warm regions don't mix as easily with cold regions.

There are thousands of phytoplankton species, uniquely adapted to warm or cold water. As oceans continue warming, some species may die off, some will thrive, and others will migrate to different regions.

But just looking at chlorophyll alone, however, won't tell scientists how a warming climate is altering phytoplankton. Naturally occurring events like El Niños and La Niñas can influence how much phytoplankton is concentrated in a given area

Stephanie Dutkiewicz, an author on both papers and marine ecologist at the Massachusetts Institute of Technology, said in 2019 that models used to predict future changes in color factor phytoplankton life cycles and movements into naturally occurring ocean patterns.

The 2023 study revealed that many of these predicted changes have already occurred. Using light-measuring devices aboard NASA satellites, scientists observed that over half of the world covered by ocean already showed a measurable shift in blue and green wavelengths, an approximation for the amount of chlorophyll in a given region.

What Do These Changing Colors Mean?

It's too early to say for sure what effect these changing colors will have on the environment, but scientists think more ecosystems could be dominated by smaller-sized plankton in the future, according to a press release from the National Oceanography Center in the U.K., which supported the 2023 study.

The ocean has absorbed about a third of the world's carbon emissions, and marine life like kelp, seagrass, and algae play a critical role in helping pull that carbon out of the atmosphere.

But smaller algae could reduce that climate change-fighting power.

“Phytoplankton are the base of the marine food web. Everything in the ocean requires phytoplankton to exist," Dutkiewicz told National Geographic in 2019. "The impact will be felt all the way up the food chain."

#Youtube #The National Geographic #Climate Change #Sarah Gibbens #Oceans’ Colors #Phytoplankton Species #El Niños | La Niñas #Stephanie Dutkiewicz #Massachusetts Institute of Technology #NASA #Scientists #Oceanography Center U.K. 🇬🇧

[ammg-old2]

More than half of the world’s oceans have changed significantly in color over the past 20 years, with climate change as the likely cause, new research suggests. Oceans around the equator have shifted to a greener hue, a trend that cannot be explained by natural, year-to-year variability alone. 

“We are affecting the ecosystem in a way that we haven’t seen before,” B. B. Cael, an ocean and climate scientist at the National Oceanography Center in England, tells Nature News’ Alexandra Witze. 

The ocean’s color changes based on what’s found in its upper layers, according to a statement from MIT. Bluer oceans tend to have little life, while greener oceans have more phytoplankton—marine algae that photosynthesize. Phytoplankton are the base of the marine food web, serving as fuel for zooplankton and fish, which in turn are eaten by larger fish, seabirds and marine mammals.

But phytoplankton are also critical for combating the climate crisis. Researchers estimate the oceans absorb about 30 percent of the carbon dioxide produced by humans, largely thanks to the photosynthesis of these algae.

Different kinds of plankton reflect and absorb light in different ways, meaning that a shifting ocean color equates to a changing ecosystem, Cael tells Vice’s Becky Ferreira. Such changes could have a ripple effect on the entire food web and potentially even affect the ocean’s ability to store carbon, per CNN’s Jack Guy.

Cael and his colleagues examined data from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite, which has been monitoring ocean color for 21 years. The team looked at measurements from seven visible wavelengths and found that color shifts had occurred between 2002 to 2022 in 56 percent of the oceans, primarily around the tropics and subtropics. They published their findings Wednesday in the journal Nature. 

To determine whether the trend was related to climate change, the team turned to a model created by study co-author Stephanie Dutkiewicz in 2019, which simulated how the Earth’s oceans would respond under two scenarios: one with added greenhouse gases and one without. The results predicted in the greenhouse gas model aligned almost exactly with what the researchers found from real-world data—within 20 years, about half of the oceans significantly shifted in color, per the MIT statement.

“I’ve been running simulations that have been telling me for years that these changes in ocean color are going to happen,” Dutkiewicz tells MIT. “To actually see it happening for real is not surprising, but frightening. And these changes are consistent with man-induced changes to our climate.”

Though the team says climate change is to blame for the greener waters, the process within the oceans that’s causing this shift is still a mystery. Sea surface temperatures have increased, but the ocean areas that changed color were not the same as the specific regions that warmed at the surface, Cael tells Nature News. Instead, scientists suggest the trend comes from nutrient distribution—rising temperatures reduce the mixing between different layers of water and limit upwelling of nutrients. This, in turn, might alter which types of plankton can survive best.

The new findings “confirm suspicions” about how oceans are responding to climate change, Tammi Richardson, a phytoplankton researcher at the University of South Carolina who wasn’t involved in the study, tells New Scientist’s Madeleine Cuff. “It’s giving us much more solid evidence that the ocean is becoming greener, beyond the few data points that we’ve had historically.” 

While the MODIS satellite could pick up on the oceans’ shifting hue, scientists still aren’t sure whether these changes will ever be visible to the human eye. 

“If a big tipping point was reached in some places: maybe,” Dutkiewicz tells CNN. “Though you’d have to study the colors for a while to be able to pick up on the changes.”

#current events #climate change #global warming #environmentalism #ecology #oceanology #phytoplankton

[sweetobjectblizzard-blog]

Global warming is even changing the ocean’s color by 2100

Climate change is inevitable. In a recent study at MIT, it is understood that climatic change is causing a significant impact on the phytoplankton community affecting the ocean’s color intensifying blue and green regions.  Though the changes are not visible to mankind at least until the next few decades, satellites will detect the changes early on sending us the alarming signals for the changes in marine ecosystems.

A research paper recently said, by the end of the 21st century, more than 50 percent of the world’s oceans will shift in color due to climate change.

Also, the study suggests that blue regions, such as the subtropics will become bluer which means less phytoplankton in those waters compared to today. Some regions that are greener today, near the poles may turn even greener due to warm temperatures.

“The model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles,” says lead author Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change. “That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.”

“Since the late 1990s, satellites have taken continuous measurements of the ocean’s color. Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region. But Dutkiewicz says chlorophyll doesn’t necessarily reflect the sensitive signal of climate change. Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to “natural variability” normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.”

It is a clear sign of indication that climate change / global warming has a significant impact on marine ecosystems. But, what’s more, important for us to look at? What balances the whole equation? Chlorophyll?

“Chlorophyll is changing, but you can’t really see it because of its incredible natural variability,” Dutkiewicz says. “But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that’s where we should be looking in satellite measurements, for a real signal of change.”

“There will be a noticeable difference in the color of 50 percent of the ocean by the end of the 21st century,” Dutkiewicz says. “It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support. “

Source: MIT news

All-in-all, the shift may not be concerning at the moment. But the consequences might cause serious trouble for the generations to come. So, it is always important for us to be responsible for climate change and do our bit of work to protect our oceans.

#climate change #global warming #oceans #water #waternews

[unioncollegeespe]

Detrimental Effect of Global Warming and the Decrease of Phytoplankton in the World’s Oceans

In a recent study conducted by Stephanie Dutkiewicz, a marine ecologist at the Massachusetts Institute of Technology, it was discovered that an increase in global temperatures could alter the color of the world’s oceans, and be the catalyst for more concerning problems. In the study, it was found that global warming leads to an increase of acidity in our oceans, which has a harmful effect on populations of Phytoplankton—a key element to many marine ecosystems. These Phytoplankton are microscopic, photosynthesizing organisms that contain green pigment chlorophyll that gives the ocean its distinct blue-green color. A decline in the population of these microorganisms could cause our oceans to appear more blue than before—but thats not the worse part. Phytoplankton serve as the foundation of many saltwater, and freshwater basin ecosystems. Small sea creatures feed on phytoplankton, and are then consumed by larger fish, squids, and shellfish. In the end, a decrease in Phytoplankton will lead to a decrease in the amount of larger marine organisms that our society benefits from. If this is the case, people who rely on fisheries for income and protein, will suffer both economically and physically, which would be very problematic.��

In addition, Phytoplankton are able to absorb atmospheric carbon dioxide, similar to plants and trees. If the populations of these microorganisms decline, there will correspondingly be an increase in the amount of carbon dioxide in our atmosphere—which as we have learned, is not beneficial. 

Ultimately, global warming contributes to a multitude of concerning problems. Likewise, many of these problems have a snowball effect on other aspects of the environment. In other words, if one part of our environment is affected by global warming, it is inevitable that a number of other problems will follow. If our society acts passively towards these problems, it won’t be long before they get further out of our control and become detrimental to the world. 

https://www.nbcnews.com/mach/science/global-warming-will-cause-world-s-oceans-change-color-here-ncna968856

[toldnews-blog]

New Post has been published on https://toldnews.com/world/climate-change-blue-planet-will-get-even-bluer-as-earth-warms/

Climate change: Blue planet will get even bluer as Earth warms

Image copyright Getty Images

Image caption The blue ocean is likely to get more blue say scientists

Rising temperatures will change the colour of the world’s oceans, making them more blue in the coming decades say scientists.

They found that increased heat will change the mixture of phytoplankton or tiny marine organisms in the seas, which absorb and reflect light.

Scientists say there will be less of them in the waters in the decades to come.

This will drive a colour change in more than 50% of the world’s seas by 2100.

Phytoplankton play a hugely important role in the oceans.

As well as turning sunlight into chemical energy, and consuming carbon dioxide, they are the bottom rung on the marine food chain.

Image copyright Getty Images

Image caption Phytoplankton seen under a microscope

They also play an important role in how we see the oceans with our eyes.

The more phytoplankton in the water, the less blue the seas will appear, and the more likely they will be to have a greenish colour.

Previous research has shown that with warming, the oceans will see a reduction in phytoplankton in many places.

This new study models the likely impact these changes will have on the colour of the ocean and the planet as the world warms up.

“What we find is that the colour will change, probably not so much that you will see by eye, but certainly sensors will be able to pick up that there’s a change,” lead author Dr Stephanie Dutkiewicz from Massachusetts Institute of Technology (MIT) in Cambridge, US, told BBC News.

“And it will likely be one of the earliest warning signals that we have changed the ecology of the ocean.”

Image copyright NASA

Image caption As well as changes in the blue of the oceans, we are also likely to see changes in the green

The researchers point out that the changes are an indirect impact of climate change, as warming is affecting the circulation of the seas, this is changing the amount of food available for phytoplankton.

Another difference from previous studies is that this time, the researchers are looking solely at satellite measurements of reflected light from the phytoplankton.

In the past, scientists have used satellite measurements of chlorophyll, a light harvesting pigment found in phytoplankton, to try and understand the impact of climate change.

However they’ve had problems working out the difference between natural variability and human induced warming on this green pigment. They believe it will be 30-40 years before they can say for definite that climate change is having an impact on chlorophyll.

“What we’ve shown is that the colour in the blue green range is going to show that signal of change sooner, in some places in maybe the next decade,” said Dr Dutkiewicz.

“More of the ocean is going to show a change in colour over the next few decades than we would see in chlorophyll, the changing colour is going to be more of a warning signal.”

The researchers believe that the North Atlantic will be one of the first places to reflect the change – followed by locations in the Southern Ocean.

Image copyright Getty Images

Image caption Natural patterns seen on the Ukrainian river Dnepr covered by cyanobacterias as a result of phytoplankton evolution in hot seasons

The team modelled what would happen to the oceans by the end of this century if the world warmed by 3C, which is close to where temperatures are likely to be, if every country sticks to the promises they have made in the Paris climate agreement.

“There will be a noticeable difference in the colour of 50% of the ocean by the end of the 21st century,” Dr Dutkiewicz said.

“It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support. “

The team also believe that the world will see changes in some of the green shades seen in the oceans as well.

This will happen because some species of phytoplankton will respond well to a warmer environment and will create larger blooms of more diverse marine organisms. This is likely to show up with more green regions near the equator and the poles, the researchers say.

The study has been published in the journal Nature Communications.

[dorcasrempel]

Seeding oceans with iron may not impact climate change

Historically, the oceans have done much of the planet’s heavy lifting when it comes to sequestering carbon dioxide from the atmosphere. Microscopic organisms known collectively as phytoplankton, which grow throughout the sunlit surface oceans and absorb carbon dioxide through photosynthesis, are a key player.

To help stem escalating carbon dioxide emissions produced by the burning of fossil fuels, some scientists have proposed seeding the oceans with iron — an essential ingredient that can stimulate phytoplankton growth. Such “iron fertilization” would cultivate vast new fields of phytoplankton, particularly in areas normally bereft of marine life.

A new MIT study suggests that iron ferilization may not have a significant impact on phytoplankton growth, at least on a global scale.

The researchers studied the interactions between phytoplankton, iron, and other nutrients in the ocean that help phytoplankton grow. Their simulations suggest that on a global scale, marine life has tuned ocean chemistry through these interactions, evolving to maintain a level of ocean iron that supports a delicate balance of nutrients in various regions of the world.

“According to our framework, iron fertilization cannot have a significant overall effect on the amount of carbon in the ocean because the total amount of iron that microbes need is already just right,’’ says lead author Jonathan Lauderdale, a research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences. 

The paper’s co-authors are Rogier Braakman, Gael Forget, Stephanie Dutkiewicz, and Mick Follows at MIT.

Ligand soup

The iron that phytoplankton depend on to grow comes largely from dust that sweeps over the continents and eventually settles in ocean waters. While huge quantities of iron can be deposited in this way, the majority of this iron quickly  sinks, unused, to the seafloor.

“The fundamental problem is, marine microbes require iron to grow, but iron doesn’t hang around. Its concentration in the ocean is so miniscule that it’s a treasured resource,” Lauderdale says.

Hence, scientists have put forth iron fertilization as a way to introduce more iron into the system. But iron availability to phytoplankton is much higher if it is bound up with certain organic compounds that keep iron in the surface ocean and are themselves produced by phytoplankton. These compounds, known as ligands, constitute what Lauderdale describes as a “soup of ingredients” that typically come from organic waste products, dead cells, or siderophores — molecules that the microbes have evolved to bind specifically with iron.

Not much is known about these iron-trapping ligands at the ecosystem scale, and the team wondered what role the molecules play in regulating the ocean’s capacity to promote the growth of phytoplankton and ultimately absorb carbon dioxide.

“People have understood how ligands bind iron, but not what are the emergent properties of such a system at the global scale, and what that means for the biosphere as a whole,” Braakman says. “That’s what we’ve tried to model here.”

Iron sweet spot

The researchers set out to characterize the interactions between iron, ligands, and macronutrients such as nitrogen and phosphate, and how these interactions affect the global population of phytoplankton and, concurrently, the ocean’s capacity to store carbon dioxide.

The team developed a simple three-box model, with each box representing a general ocean environment with a particular balance of iron versus macronutrients. The first box represents remote waters such as the Southern Ocean, which typically have a decent concentration of macronutrients that are upwelled from the deep ocean. They also have a low iron content given their great distance from any continental dust source.

The second box represents the North Atlantic and other waters that have an opposite balance: high in iron because of proximity to dusty continents, and low in macronutrients. The third box is a stand-in for the deep ocean, which is a rich source of macronutrients, such as phosphates and nitrates.

The researchers simulated a general circulation pattern between the three boxes to represent the global currents that connect all the world’s oceans: The circulation starts in the North Atlantic and dives down into the deep ocean, then upwells into the Southern Ocean and returns back to the North Atlantic.

The team set relative concentrations of iron and macronutrients in each box, then ran the model to see how phytoplankton growth evolved in each box over 10,000 years. They ran 10,000 simulations, each with different ligand properties.

Out of their simulations, the researchers identified a crucial positive feedback loop between ligands and iron. Oceans with higher concentrations of ligands had also higher concentrations of iron available for phytoplankton to grow and produce more ligands. When microbes have more than enough iron to feast on, they consume as much of the other nutrients they need, such as nitrogen and phosphate, until those nutrients have been completely depleted.  

The opposite is true for oceans with low ligand concentrations: These have less iron available for phytoplankton growth, and therefore have very little biological activity in general, leading to less macronutrient consumption.

The researchers also observed in their simulations a narrow range of ligand concentrations that resulted in a sweet spot, where there was just the right amount of ligand to make just enough iron available for phytoplankton growth, while also leaving just the right amount of macronutrients left over to sustain a whole new cycle of growth across all three ocean boxes.

When they compared their simulations to measurements of nutrient, iron, and ligand concentrations taken in the real world, they found their simulated sweet spot range turned out to be the closest match. That is, the world’s oceans appear to have just the right amount of ligands, and therefore iron, available to maximize the growth of phytoplankton and optimally consume macronutrients, in a self-reinforcing and self-sustainable balance of resources.

If scientists were to widely fertilize the Southern Ocean or any other iron-depleted waters with iron, the effort would temporarily stimulate phytoplankton to grow and take up all the macronutrients available in that region. But eventually there would be no macronutrients left to circulate to other regions like the North Atlantic, which depends on these macronutrients, along with iron from dust deposits, for phytoplankton growth. The net result would be an eventual decrease in phytoplankton in the North Atlantic and no significant increase in carbon dioxide draw-down globally.

Lauderdale points out there may also be other unintended effects to fertilizing the Southern Ocean with iron.

“We have to consider the whole ocean as this interconnected system,” says Lauderdale, who adds that if phytoplankton in the North Atlantic were to plummet, so too would all the marine life on up the food chain that depends on the microscopic organisms.

“Something like 75 percent of production north of the Southern Ocean is fueled by nutrients from the Southern Ocean, and the northern oceans are where most fisheries are and where many ecosystem benefits for people occur,” Lauderdale says. “Before we dump loads of iron and draw down nutrients in the Southern Ocean, we should consider unintended consequences downstream that potentially make the environmental situation a lot worse.”

This research was supported, in part, by the National Science Foundation, the Gordon and Betty Moore Foundation, and the Simons Foundation.

Seeding oceans with iron may not impact climate change syndicated from https://osmowaterfilters.blogspot.com/

[chestnutpost]

Why the color of the oceans will change

Essentially, climate change will make the blues of the ocean bluer and the greens greener. Scientists figured this out by creating a global model that simulates the growth of a tiny creature that lives in the oceans and affects the color we see. Their research was published Monday in the journal Nature Communications.

The ocean looks blue or green to us because of a combination of how sunlight interacts with water molecules and with whatever else lives in that water.

The molecules in water absorb all but the blue part of the spectrum of sunlight, and the water reflects that blue color back. That’s the color we see.

The water looks greener when it has more phytoplankton, tiny, microscopic organisms that, like plants, can use chlorophyll to capture mostly the blue portions of the spectrum of sunlight. They then use photosynthesis to create the chemical energy they need to live. When there are more of these creatures in the water absorbing sunlight, they make the water look greener. Conversely, if there are fewer phytoplankton, the water looks bluer.

The creatures’ growth is dependent on how much sunlight, carbon dioxide and nutrients are around. Climate change is altering the ocean currents, meaning there will be fewer nutrients for phytoplankton to feed on in some areas, so there will be a decline in their number in those regions.

Since the 1990s, satellites have taken regular measurements of how much chlorophyll is in the ocean. Those levels can change because of weather events or because of climate change. But using those images to look at reflected light alone, the researchers in the new study could distinguish what is specifically due to climate change. And they noticed that there will be a significant shift in the color of the oceans much earlier than was previously predicted, just looking at chlorophyll changes.

The study predicts that the blues will intensify, most likely in subtropical regions where phytoplankton will decrease. These are areas near the equator like Bermuda and the Bahamas that are already quite low in phytoplankton.

Regions where there are a lot of nutrients, like in the Southern Ocean or parts of the North Atlantic, will see even faster-growing phytoplankton because those waters are warming with climate change. Those waters will look greener.

Climate change will bring a color change to half of the world’s oceans by the end of the 21st century, the study says. That’s bad for climate change on several levels: For one, phytoplankton remove about as much carbon dioxide from the air as plants and help regulate our climate, research shows. They are also key to other animals’ survival.

“The change is not a good thing, since it will definitely impact the rest of the food web,” said study co-author Stephanie Dutkiewicz, a principal research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “Phytoplankton are at the base, and if the base changes, it endangers everything else along the food web, going far enough to the polar bears or tuna or just about anything that you want to eat or love to see in pictures.”

The post Why the color of the oceans will change appeared first on The Chestnut Post.

from The Chestnut Post https://www.thechestnutpost.com/news/why-the-color-of-the-oceans-will-change/

[liputanviral-blog]

Pemanasan Global Membuat Laut Berubah Warna

Liputanviral - Warna biru pada lautan sebenarnya hanya ilusi dari mikroorganisme yang berhabitat di dalamnya. Namun warna biru tak selalu pertanda baik, karena hal tersebut juga berhubungan dengan semakin buruknya pemanasan global akibat perubahan iklim di dunia. Tim peneliti dari Massachusetts Institute of Technology memaparkan bahwa di masa depan lautan di dunia akan semakin biru, jika tidak ada kontrol atas perubahan iklim yang terjadi semakin drastis belakangan ini. Perubahan iklim membuat mikroorganisme berjenis fitoplankton melepaskan pigmen klorofil (zat hijau daun). Semakin biru atau semakin hijau air di lautan, maka semakin ramai fitoplankton yang berhabitat di dalamnya. Munculnya fitoplankton ini tergantung oleh paparan matahari, karbondioksida dan nutrisi yang berada di lautan. Perubahan iklim yang membuat air laut lebih menghangat bakal membuat fitoplankton bermunculan di lautan Atlantik Utara dan Antartika, sehingga perairan di sana bakal berwarna lebih hijau. Sementara perairan di Bermuda dan Bahama bakal lebih biru dari saat ini. "Perubahannya memang tak nampak oleh mata, namun secara sederhana perairan tropis bakal lebih biru dan perairan es bakal lebih hijau," kata salah satu peneliti, Stephanie Dutkiewicz. Tim peneliti lanjut mengatakan kalau perubahan ini akan lebih terlihat di penghujung abad ke-21. Selain berdampak buruk terhadap flora dan fauna lautan, perubahan di lautan juga bakal berdampak pada makhluk hidup di daratan, terutama manusia yang sering menyantap hasil laut. "Perubahan warna ini bukan hal yang baik, karena mempengaruhi rantai makanan," kata Dutkiewicz. Read the full article

#Laut #PemanasanGlobal #perubahaniklim #tipswisata #travel

[arunangur]

Photograph by NASA, GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team

By 2100, the ocean as we know it is likely to change colour. That was the conclusion of a study published Monday in the journal Nature Communications that modeled how phytoplankton will change as oceans continue to warm. Under a “business-as-usual” scenario in which greenhouse gas emissions continue unabated, the bluest subtropical zones of the ocean will become bluer, and greener regions along the equator and poles will become greener. More than just an oddity, the changing color is a warning sign, say the study authors, of drastic global changes that will take place in a world warmed by climate change.

Measuring colour

It's well known that seasonal changes regularly change water color, but warming oceans could be permanently altering the mosaics of blues and greens seen from space. Sunlight penetrates over 600 feet below the surface of the ocean. Everything deeper is enshrined in darkness. Above that, most water molecules are capable of absorbing all colors except blue, which is why blue is reflected out.

Organic matter that blankets the surface of the ocean, like phytoplankton, changes this color. Much of it contains chlorophyll, a green pigment that absorbs the sunlight plants need to make food. As the ocean warms, currents become more irregular, and the layers in the water become more stratified, meaning warm regions don't mix as easily with cold regions. There are thousands of phytoplankton species, uniquely adapted to warm or cold water. As oceans continue warming, some species may die off, some will thrive, and others will migrate to different regions. But just looking at chlorophyll alone, however, won't tell scientists how a warming climate is altering phytoplankton. Naturally occurring events like El Niños and La Niñas can influence how much phytoplankton is concentrated in a given area.

The research group instead used satellites to measure reflected light as a whole. Stephanie Dutkiewicz, the study's lead author, says the same model has previously been used to look at how warming oceans will change the behavior of phytoplankton. It factors phytoplankton life cycles and movements into naturally occurring ocean patterns. Using this same model, they then estimated how much light would be in a given region based on the number of organisms present. Their conclusion: half the world's oceans will have bluer blues and greener greens by 2100.

A business-as-usual scenario

“What was special about the model is it suggests the subtle shifts in color are an early warning sign,” says Dutkiewicz. “Phytoplankton are the base of the marine food web. Everything in the ocean requires phytoplankton to exist. The impact will be felt all the way up the food chain.” Their projections were based on the likelihood that the world will warm three degrees Celsius by 2100. Last November, the U.N. Meteorological Organization estimated that the Earth will warm anywhere between three and five degrees by the end of this century. Dutkiewicz says her model is based on a “much warmer world.” If significant changes are implemented, the ocean's color might remain the same. That would require significant cutbacks to greenhouse gas emissions created by burning fossil fuels.

[hudsonespie]

Study: Much Of The Surface Ocean Will Shift In Color By End Of 21st Century

Climate change is causing significant changes to phytoplankton in the world’s oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean’s color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.

Image Credits: news.mit.edu

Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.

The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world’s oceans will shift in color, due to climate change.

The study suggests that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton — and life in general — in those waters, compared with today. Some regions that are greener today, such as near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.

“The model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles,” says lead author Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change. “That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.”

Dutkiewicz’s co-authors include Oliver Jahn of MIT, Anna Hickman of the University of Southhampton, Stephanie Henson of the National Oceanography Centre Southampton, Claudie Beaulieu of the University of California at Santa Cruz, and Erwan Monier, former principal research scientist at the MIT Center for Global Change Science, and currently assistant professor at the University of California at Davis, in the Department of Land, Air and Water Resources.

Chlorophyll count

The ocean’s color depends on how sunlight interacts with whatever is in the water. Water molecules alone absorb almost all sunlight except for the blue part of the spectrum, which is reflected back out. Hence, relatively barren open-ocean regions appear as deep blue from space. If there are any organisms in the ocean, they can absorb and reflect different wavelengths of light, depending on their individual properties.

Phytoplankton, for instance, contain chlorophyll, a pigment which absorbs mostly in the blue portions of sunlight to produce carbon for photosynthesis, and less in the green portions. As a result, more green light is reflected back out of the ocean, giving algae-rich regions a greenish hue.

Since the late 1990s, satellites have taken continuous measurements of the ocean’s color. Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region. But Dutkiewicz says chlorophyll doesn’t necessarily have reflect the sensitive signal of climate change. Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to “natural variability” — normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.

“An El Niño or La Niña event will throw up a very large change in chlorophyll because it’s changing the amount of nutrients that are coming into the system,” Dutkiewicz says. “Because of these big, natural changes that happen every few years, it’s hard to see if things are changing due to climate change, if you’re just looking at chlorophyll.”

Modeling ocean light

Instead of looking to derived estimates of chlorophyll, the team wondered whether they could see a clear signal of climate change’s effect on phytoplankton by looking at satellite measurements of reflected light alone.

The group tweaked a computer model that it has used in the past to predict phytoplankton changes with rising temperatures and ocean acidification. This model takes information about phytoplankton, such as what they consume and how they grow, and incorporates this information into a physical model that simulates the ocean’s currents and mixing.

This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.

“Sunlight will come into the ocean, and anything that’s in the ocean will absorb it, like chlorophyll,” Dutkiewicz says. “Other things will absorb or scatter it, like something with a hard shell. So it’s a complicated process, how light is reflected back out of the ocean to give it its color.”

When the group compared results of their model to actual measurements of reflected light that satellites had taken in the past, they found the two agreed well enough that the model could be used to predict the ocean’s color as environmental conditions change in the future.

“The nice thing about this model is, we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change,” Dutkiewicz says.

A signal in blues and greens

As the researchers cranked up global temperatures in the model, by up to 3 degrees Celsius by 2100 — what most scientists predict will occur under a business-as-usual scenario of relatively no action to reduce greenhouse gases — they found that wavelengths of light in the blue/green waveband responded the fastest.

What’s more, Dutkiewicz observed that this blue/green waveband showed a very clear signal, or shift, due specifically to climate change, taking place much earlier than what scientists have previously found when they looked to chlorophyll, which they projected would exhibit a climate-driven change by 2055.

“Chlorophyll is changing, but you can’t really see it because of its incredible natural variability,” Dutkiewicz says. “But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that’s where we should be looking in satellite measurements, for a real signal of change.”

According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans. By the end of the century, our blue planet may look visibly altered.

“There will be a noticeable difference in the color of 50 percent of the ocean by the end of the 21st century,” Dutkiewicz says. “It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support. “

This research was supported, in part, by NASA and the Department of Energy.

Reference: news.mit.edu

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[kacydeneen]

Study: Climate Change Will Alter the Color of the Oceans

Climate change is causing a shift in the color of the oceans, an early indicator of important changes to marine ecosystems, according to a study done by MIT.

The change in temperature is having an effect on phytoplankton, microscopic organisms that live in the water and that absorb and reflect light wavelengths.

A model developed by the study’s researchers shows that by 2100, climate change will cause more than 50 percent of the oceans to change color. Even though the human eye may not be able to see the color adjustments, satellites will be able to to detect them.

“The model includes equations for what is happening in the atmosphere, how the atmosphere is moving around and being heated,” Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences, said. “It includes equations for how the ocean is moving, taking up heat and mixing up nutrients.”

The researchers take what they know about the real world to create a virtual world using those rules.

“We can also simulate the future, assuming things like how the CO2 content of the atmosphere is going to change and how humans will impact CO2 emissions,” she said.

The color of the ocean is dependent on how sunlights interacts with what is in the water. When there is no phytoplankton present, the ocean appears as deep blue from outer space. However, when there is a lot of phytoplankton, the ocean looks green because the chlorophyll in the phytoplankton absorbs the blue portions of sunlight in order produce more carbon for photosynthesis.

Phytoplankton live at the sunlit layer of the ocean, but to survive, they need nutrients from the bottom of the ocean. Natural causes, like an El Niño or La Niña, cause a fluctuation in the amount of nutrients that phytoplankton get and in turn, the color of the ocean to change.

Dutkiewicz’s previous studies show that changes in carbon emissions have a big impact on the phytoplankton. As the climate changes, not only does the color of the ocean change, but the food web that phytoplankton supports is affected

So why does this matter?

“The oceans modulate our climate in a very big way,” Amala Mahadevan, a physical oceanographer at Woods Hole Oceanographic Institution, said. “The oceans, thanks to phytoplankton which functions like a plant, take up about two thirds of the CO2 we put into the atmosphere because of the fossil fuels we are burning. The oceans are offsetting the effect of climate change for us. If they had not done that, our temperatures would be much higher.”

If phytoplankton change, the ocean would no longer absorb CO2 at the same rate.

“All other organism depend on phytoplankton, they are the base of the food chain in the ocean, Mahadevan said. “If you change the phytoplankton, you change everything, including the fish that you eat.”

Dutkiewicz stressed the need for satellites to be maintained by programs like NASA in order to continue to monitor the change of the color of the ocean.

“Just because you can’t see it, climate change is real and if we were to reduce the amount of greenhouse gasses we were admitting into the environment, it would reduce the impact of change that the model suggests,” Dutkiewicz said.

Photo Credit: Getty Images/EyeEm Study: Climate Change Will Alter the Color of the Oceans published first on Miami News

[shirlleycoyle]

Climate Change Will Alter the Color of Half of Earth’s Oceans by 2100

Half of Earth’s oceans will change color by 2100 as a result of warming global temperatures, according to a study published Monday in Nature Communications.

Blue ocean surfaces are expected to shift to a darker blue, said the authors, who were led by Stephanie Dutkiewicz, a principal research scientist and marine ecologist at MIT. Meanwhile, green-tinted marine habitats could become more intensely verdant.

The shifts in color will be the result of marine phytoplankton—microscopic organisms that live in the sunlit layers of the ocean—responding to the effects of human-driven climate change.

Phytoplankton uses the pigment chlorophyll to harvest solar radiation into energy, which bounces green rays back into the environment. As a result, large communities of phytoplankton act like a biological dye tinting the ocean surface green, while marine habitats that are depleted of phytoplankton are more of a navy blue color.

“There will be a noticeable difference in the color of 50 percent of the ocean by the end of the 21st century,” Dutkiewicz said in a statement. “It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support.”

Using computer models, the team projected that some blue regions of the ocean, including subtropical gyres, are likely to become bluer in the coming decades due to a reduced phytoplankton presence in the warmer waters. Meanwhile, phytoplankton blooms will become common in the water around Earth’s poles, suggesting those regions might have an emerald shade in the coming decades.

Monitoring ocean color could yield valuable insights into the effects of climate change on phytoplankton. Not only do these organisms make up the bedrock of aquatic food webs, their photosynthetic processes produce half the world’s oxygen and sequester about 10 gigatons of carbon into the deep ocean.

Read More: Climate Change Is Making Waves Stronger

Given how critical phytoplankton are to Earth’s life support systems, it’s alarming that rising sea temperatures have wiped out 40 percent of their population since 1950. If this trend continues, the marine food web could begin to collapse without its foundational food source. This would affect human reliance on marine species for food, sure, but it could also eventually make air less oxygenated (aka breathable) and cause runaway atmospheric carbon dioxide levels.

“Phytoplankton community structure, which strongly affects ocean optics, is likely to show one of the clearest and most rapid signatures of changes to the base of the marine ecosystem,” Dutkiewicz and her colleagues said in the paper.

The projected shifts might not be discernible to the naked eye, but satellites can detect them from space. Keeping tabs on this climate-related color change will enable scientists to estimate the health of the global phytoplankton population, which is crucial to the millions of species that depend on it.

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Climate Change Will Alter the Color of Half of Earth’s Oceans by 2100 syndicated from https://triviaqaweb.wordpress.com/feed/

[environmental-humanities]

Fun Nature Fact #4

We’re destroying the very bottom line of our ocean ecosystems.

That’s right.  We’re killing the plankton

Not that plankton... but also, yes, exactly that plankton.

Ocean acidification, the process were the oceans absorb carbon released into the atmosphere and converts it into carbonic acid, lowering the pH of the ocean, is going to have a wide variety of impacts on photoplankton and zooplankton.

These form the very basis of the ocean ecosystem.  Without plankton, nothing survives.  

Stephanie Dutkiewicz, who is a principle researcher for MIT said “A whole rearrangement of the [plankton] communities means something to both the food web further up, but also for things like cycling of carbon.”

If we don’t start controlling carbon outputs, we could watch the entire ocean die.

And it all starts with the plankton.

Source: Picturepest (flickr)

#plankton #zooplankton #ocean #acidification #climate #change #environment #issues #fun nature fact #this fact was a lot less fun #but still important #environmental #humanities #environmental-humanities #photoplankton

[dorcasrempel]

Study: Much of the surface ocean will shift in color by end of 21st century

Climate change is causing significant changes to phytoplankton in the world’s oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean’s color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.

Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.

The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world’s oceans will shift in color, due to climate change.

The study suggests that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton — and life in general — in those waters, compared with today. Some regions that are greener today, such as near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.

“The model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles,” says lead author Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change. “That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.”

Dutkiewicz’s co-authors include Oliver Jahn of MIT, Anna Hickman of the University of Southhampton, Stephanie Henson of the National Oceanography Centre Southampton, Claudie Beaulieu of the University of California at Santa Cruz, and Erwan Monier, former principal research scientist at the MIT Center for Global Change Science, and currently assistant professor at the University of California at Davis, in the Department of Land, Air and Water Resources.

Chlorophyll count

The ocean’s color depends on how sunlight interacts with whatever is in the water. Water molecules alone absorb almost all sunlight except for the blue part of the spectrum, which is reflected back out. Hence, relatively barren open-ocean regions appear as deep blue from space. If there are any organisms in the ocean, they can absorb and reflect different wavelengths of light, depending on their individual properties.

Phytoplankton, for instance, contain chlorophyll, a pigment which absorbs mostly in the blue portions of sunlight to produce carbon for photosynthesis, and less in the green portions. As a result, more green light is reflected back out of the ocean, giving algae-rich regions a greenish hue.

Since the late 1990s, satellites have taken continuous measurements of the ocean’s color. Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region. But Dutkiewicz says chlorophyll doesn’t necessarily have reflect the sensitive signal of climate change. Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to “natural variability” — normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.

“An El Niño or La Niña event will throw up a very large change in chlorophyll because it’s changing the amount of nutrients that are coming into the system,” Dutkiewicz says. “Because of these big, natural changes that happen every few years, it’s hard to see if things are changing due to climate change, if you’re just looking at chlorophyll.”

Modeling ocean light

Instead of looking to derived estimates of chlorophyll, the team wondered whether they could see a clear signal of climate change’s effect on phytoplankton by looking at satellite measurements of reflected light alone.

The group tweaked a computer model that it has used in the past to predict phytoplankton changes with rising temperatures and ocean acidification. This model takes information about phytoplankton, such as what they consume and how they grow, and incorporates this information into a physical model that simulates the ocean’s currents and mixing. 

This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.

“Sunlight will come into the ocean, and anything that’s in the ocean will absorb it, like chlorophyll,” Dutkiewicz says. “Other things will absorb or scatter it, like something with a hard shell. So it’s a complicated process, how light is reflected back out of the ocean to give it its color.”

When the group compared results of their model to actual measurements of reflected light that satellites had taken in the past, they found the two agreed well enough that the model could be used to predict the ocean’s color as environmental conditions change in the future.

“The nice thing about this model is, we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change,” Dutkiewicz says.

A signal in blues and greens

As the researchers cranked up global temperatures in the model, by up to 3 degrees Celsius by 2100 — what most scientists predict will occur under a business-as-usual scenario of relatively no action to reduce greenhouse gases — they found that wavelengths of light in the blue/green waveband responded the fastest.

What’s more, Dutkiewicz observed that this blue/green waveband showed a very clear signal, or shift, due specifically to climate change, taking place much earlier than what scientists have previously found when they looked to chlorophyll, which they projected would exhibit a climate-driven change by 2055.

“Chlorophyll is changing, but you can’t really see it because of its incredible natural variability,” Dutkiewicz says. “But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that’s where we should be looking in satellite measurements, for a real signal of change.”

According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans. By the end of the century, our blue planet may look visibly altered.

“There will be a noticeable difference in the color of 50 percent of the ocean by the end of the 21st century,” Dutkiewicz says. “It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support. “

This research was supported, in part, by NASA and the Department of Energy.

Study: Much of the surface ocean will shift in color by end of 21st century syndicated from https://osmowaterfilters.blogspot.com/