Latest news with #equator
Yahoo
15 hours ago
- Science
- Yahoo
As the ocean warms, a new study found it's also changing color
For thousands of years, writers have come up with increasingly creative ways to describe the 'wine-dark sea.' But a new study suggests that modern poets may be faced with a slightly different palette. A study published Thursday in the journal Science found that the ocean is changing color as it warms. By analyzing satellite data from 2003 to 2022, researchers from Duke University and the Georgia Institute of Technology noticed that waters near the equator were getting bluer, while areas near the poles were turning greener. Lead author Haipeng Zhou calls it 'this greener greens or bluer blues phenomenon.' The culprit, the paper suggests, is the teeny tiny plant-like creatures that form the building blocks of the marine food web — phytoplankton. Phytoplankton are filled with a green pigment called chlorophyll that allows them to absorb energy from sunlight through photosynthesis. As waters near the equator warm, they're less hospitable to the microscopic critters, so the water appears bluer. At the poles, the colder water is far more nutrient-dense, so there's lots more phytoplankton to go around, giving the waters a rich, green tinge. It's not a new phenomenon. There's a reason the Caribbean is known as the land of dazzling turquoise waters, while Arctic waters are a dark teal contrast to the ivory ice floes around them. But Zhou, who began the research at Duke University and completed it as a postdoctoral researcher at Georgia Tech, found that as the ocean warms, this phenomenon is getting stronger. Their study only looked at the open ocean, not coastal waters. Near the coast, there are plenty of complicating factors that make it hard to clearly point to phytoplankton as the main cause of color changes, like dirt and sand floating in the water, shifting winds, pollution or even seagrass die off. To understand the concentrations of phytoplankton, the research team relied on a National Oceanic and Atmospheric Administration database made up of samples scooped from various research cruises all over the world. This database, plus satellite imagery, helped show the color shift in different regions of the ocean. The changing levels of phytoplankton could be bad news for fish in the tropics, or for communities that rely on those fish. But it could also be a boon for their northern and southern cousins. 'We all know that phytoplankton is the bottom of the food chain. Any impact on phytoplankton will have impacts on its predators,' Zhou said. Phytoplankton need sun and nutrients to flourish, but when the ocean warms, the individual layers that make up the sea grow more stratified, so it's harder for phytoplankton to float up and down the water column to access the same light and nutrients they're used to, he said. So while scientists can clearly say that warmer waters lead to fewer phytoplankton, and they know that climate change is one of the main reasons the oceans are heating up, it's not clear if climate change is the reason for the color shift. 'We need longer records, 30 years, 40 years, to make us more confident whether it is linked to climate change or global variability,' Zhou said. The study only looked at about 20 years of data, which Zhou said is enough to confidently say that something has changed, but not long enough to know what caused that change. Other factors can and do affect water temperature, like the shift in trade winds over the Atlantic that led to a coral-killing marine heat wave in 2023. 'The study period was too short to rule out the influence of recurring climate phenomena such as El Niño,' wrote co-author Susan Lozier, Dean of the College of Sciences at Georgia Tech, in a statement. However, Zhou added, more research may very well find that this color-shifting trend continues into the future as human-caused climate change continues to heat up the oceans. 'The temperature of the water is rising. While there's no evidence showing that this progress will slow down, it's very likely we'll have warmer waters in the future, which means we'll have a continuous impact on the ocean ecosystem.' Correction: An initial version of this story incorrectly listed the start of the period analyzed on satellite as 2009. It was 2003.
Yahoo
17 hours ago
- Science
- Yahoo
The ocean is changing colors, researchers say. Here's what it means.
Warming waters are causing the colors of the ocean to change -- a trend that could impact humans if it were to continue, according to new research. Satellite data shows that ocean waters are getting greener at the poles and bluer toward the equator, according to a paper published Thursday in the journal Science. MORE: How penguin poop can help to mitigate climate change The change in hue is being caused by shifting concentrations of a green pigment called chlorophyll, which is produced by phytoplankton, Haipeng Zhao, a postdoctoral researcher and lead author of the paper, told ABC News. Phytoplankton are photosynthetic marine organisms. As algae, phytoplankton has photosynthetic pigments, which absorb green light and cause the waters around it to appear primarily green, Susan Lozier, dean of the College of Sciences at the Georgia Institute of Technology and co-author of the paper, told ABC News. Where phytoplankton are absent, the water appears blue. The researchers analyzed satellite data on the open ocean collected from 2003 to 2022 by a NASA instrument that combs through the planet every two days to measure light wavelength, according to the paper. The presence of chlorophyll in open ocean is a proxy for concentrations of phytoplankton biomass. The colors indicate how chlorophyll concentration is changing at specific latitudes, in which the subtropics are generally losing chlorophyll, and the polar regions -- the high-latitude regions -- are greening, the researchers said. MORE: Global sea level rose faster than expected in 2024, according to NASA analysis Green areas became greener, especially in the northern hemisphere, and blue regions "got even bluer," according to a press release by Duke University. "We borrowed concepts from economics called the Lorenz curve and the Gini index, which together show how wealth is distributed in a society," said Nicolas Cassar, the Lee Hill Snowdon Bass chair at Duke University's Nicholas School of the Environment, in a statement. "So, we thought, let's apply these to see whether the proportion of the ocean that holds the most chlorophyll has changed over time." The researchers examined how the patterns they observed were affected by variables like sea surface temperature, wind speed, light availability and mixed layer depth. Warming seas correlated with changes in chlorophyll concentration, they found. The other variables did not show any significant associations to chlorophyll concentration. However, the findings cannot be solely attributed to climate change, the authors said. The study period was too short to rule out the influence of recurring climate phenomena, Lozier said. "We haven't been able to observe the ocean for decades and decades, just because the satellite technology is pretty new," Lozier said. MORE: How marine biologists are using elephant seals as nature's 'artificial intelligence' After focusing his Ph.D. on regional studies in high-latitude oceans, Zhao said he was inspired to dive deeper to see whether oceans were transforming in color throughout the rest of the world. "The ocean has been warming, so there's a big question then about, what are the biological consequences of the ocean warming?" Lozier said. Several studies since the 1990s have documented enhanced greening on land, attributed to average leaf color increasing due to rising temperatures and other factors, according to the researchers. However, documenting such changes in the ocean has proven to be more difficult. The satellite images provide data on the chlorophyll production at the surface, but the picture is still incomplete, the researchers said. MORE: How to turn ocean waves into renewable energy If the trend continues, marine food webs could be impacted, the researchers said. Since phytoplankton are at the base of the food chain, it can be used to determine the presence of fish, too, Lozier said. A persistent decline in phytoplankton near the equator could cause a redistribution of the location of fisheries, the authors said. This could be especially impactful in low to middle-income nations, such as the Pacific Islands, that rely on commercial fishing for food and economic development, the authors said.
Yahoo
a day ago
- Science
- Yahoo
How did life survive 'Snowball Earth'? In ponds, study suggests
Earth has not always been so hospitable to live. During several ice ages, the planet's surface was almost completely frozen over, creating what has been dubbed "Snowball Earth". Liquid water appears to be the most important ingredient for life on any planet, raising the question: how did anything survive such frosty, brutal times? A group of scientists said Thursday that they had found an astonishing diversity of micro-organisms in tiny pools of melted ice in Antarctica, suggesting that life could have ridden out Snowball Earth in similar ponds. During the Cryogenian Period between 635 and 720 million years ago, the average global temperature did not rise above -50 degrees Celsius (-58 Fahrenheit). The climate near the equator at the time resembled modern-day Antarctica. Yet even in such extreme conditions, life found a way to keep evolving. Fatima Husain, the lead author of a new study published in Nature Communications, told AFP there was evidence of complex life forms "before and after the Cryogenian in the fossil record". "There are multiple hypotheses regarding possible places life may have persisted," said Husain, a graduate student at the Massachusetts Institute of Technology. Perhaps it found shelter in patches of open ocean, or in deep-sea hydrothermal vents, or under vast sheets of ice. The tiny melted ice pools that dotted the equator were another proposed refuge. These ponds could have been oases for eukaryotes, complex organisms that eventually evolved into multicellular life forms that would rise to dominate Earth, including humans. - Could aliens be hiding in ponds? - Melted ice ponds still exist today in Antarctica, at the edges of ice sheets. In 2018, members of a New Zealand research team visited the McMurdo ice shelf in east Antarctica, home to several such pools, which are only a few metres wide and less a metre deep. The bottom of the ponds are lined with a mat of microbes that have accumulated over the years to form slimy layers. "These mats can be a few centimetres thick, colourful, and they can be very clearly layered," Husain said. They are made up of single-celled organisms called cyanobacteria that are known to be able to survive extreme conditions. But the researchers also found signs indicating there were eukaryotes such as algae or microscopic animals. This suggests there was surprising diversity in the ponds, which appears to have been influenced by the amount of salt each contained. "No two ponds were alike," Husain said. "We found diverse assemblages of eukaryotes from all the major groups in all the ponds studied." "They demonstrate that these unique environments are capable of sheltering diverse assemblages of life, even in close proximity," she added. This could have implications in the search for extraterrestrial life. "Studies of life within these special environments on Earth can help inform our understanding of potential habitable environments on icy worlds, including icy moons in our Solar System," Husain said. Saturn's moon Enceladus and Jupiter's Europa are covered in ice, but scientists increasingly suspect they could be home to simple forms of life, and several space missions have been launched to find out more about them. ber/dl/js
Daily Mail
29-05-2025
- Health
- Daily Mail
The surprising science behind the colour of your eyes - and what it reveals about your personality
A viral TikTok video has revealed the remarkable science and deep symbolism behind eye colour - suggesting your eye shade might say more about you than you think. The clip, posted by user @snappybits2, explores how brown, blue and green eyes are shaped not only by biology but by history and light itself. According to the video, brown eyes are caused by a high concentration of melanin - the pigment responsible for colouring the skin, hair and eyes. In the iris, melanin acts as a shield that absorbs light rather than scattering it. 'Brown eyes pull light inward,' the narrator of the video explains. 'This is why brown eyes seem deeper, darker and more grounded.' The earliest humans had brown eyes, having evolved near the equator where the sun was most intense. 'Melanin wasn't just pigment. It was protection. Brown eyes were nature's built-in sunglasses, filtering out UV rays and reducing glare long before Ray Bans existed.' Today, over 70 per cent of the global population has brown eyes - a striking reminder of their evolutionary significance. The video describes the colour as 'not just a colour, but a legacy'. Culturally, brown eyes are often associated with warmth and reliability, but they've also been viewed as 'mysterious, serious, even intimidating.' This, it claims, is because 'brown eyes are hard to read. They don't change with the light. 'They don't flash with emotion the way lighter eyes sometimes do. They absorb rather than reveal.' But under certain lighting - low sun, candlelight, late afternoon haze - something remarkable can happen. 'Brown eyes start to glow… amber, honey, liquid gold,' the narrator continues. 'It's the melanin, again, scattering light just enough to reveal what's been hiding underneath 'In those moments, they feel ancient, like they're not just seeing you, they're remembering you. Unlike brown, blue eyes contain almost no melanin at all. Instead, what we perceive as blue is actually an optical illusion created by light scattering through layers of transparent iris tissue, a phenomenon known as Rayleigh scattering. 'There's no blue pigment inside the iris,' the narrator explains. 'What you're seeing is the light scattering through layers of tissue. 'It's the same reason the sky looks blue and sunsets bleed orange.' Every blue-eyed person on Earth, around 8 per cent of the population, shares a common ancestor. 'They trace their eye colour back to a single genetic mutation that occurred 6,000 to 10,000 years ago, somewhere near the Black Sea, in one human.' The mutation, found in the OCA2 gene, limited melanin production in the iris. 'Suddenly the eye didn't absorb light anymore, it scattered,' the video says. 'That one mutation spread from person to person, generation to generation, until millions now carry the glitch.' The result is eyes that aren't truly blue, but instead 'the colour of light's confusion.' Green eyes are the rarest of all, seen in just 2 per cent of the global population, making them less common than red hair or even being born with 12 fingers. They're described as a 'chemical contradiction, a perfect storm between biology and light'. To achieve green eyes, the body must produce just the right balance of melanin and a yellowish pigment called lipochrome, along with the scattering effect of light. 'Most people have too much melanin and their eyes come out brown. Some people have almost none, and their eyes appear blue,' the narrator explains. 'But green eyes need just enough melanin to darken the iris and just enough lipochrome to tint the light that bounces off it.' The video calls green eyes 'a rendered illusion so delicate that the smallest tweak in pigment breaks the effect entirely.' And they don't stay the same. 'Green eyes don't sit still. They shift in different lights - gold, jade, moss, steel. 'They look calm in the shade, then snap with energy and sunlight, like they've got a secret loaded behind the iris waiting to be triggered.' Green eyes, it says, are 'unstable beauty, an optical accident.' Whether a product of melanin's shielding power, a 10,000-year-old genetic glitch, or a collision of pigment and light, your eye colour might be revealing more about you than you ever realised.
CNA
26-05-2025
- Health
- CNA
Skincare-infused sunscreens that fight UV damage and boost skin health – can they really do it all?
When it comes to sunscreens, our demands are pretty high. It has to be lightweight (no one wants to deal with a tacky finish especially in Singapore's heat and humidity), leave no white cast (an ashy-grey hue is a big no), and have high SPF protection (Singapore sits near the equator where UV intensity is at its strongest). But these days, sunscreens are promising even more than just efficient UV protection. These are often packed with skincare ingredients that claim to help improve skin health and enhance skin repair, too. According to Dr Rachel Ho, an aesthetic doctor at La Clinic, evidence for sunscreen's role in preventing or delaying signs of ageing, such as hyperpigmentation and fine lines, is well established. Dr Angeline Yong, a dermatologist and medical director at Angeline Yong Dermatology, added: 'While sunscreen itself does not actively rejuvenate the skin in the way treatments like retinoids or lasers do, its role in preventing further damage is foundational for skin repair.' Think of the use of sunscreen as playing a 'supportive role for skin barrier functions and physiological repair mechanisms and any ongoing treatments to reduce signs of ageing', said Dr Ho. In short, regular sunscreen application is crucial as it not only prevents further skin damage but also allows skin to recover and maintain its health, which promotes a more youthful appearance over time, emphasised Dr Yong. These sunscreens can be also seen as multi-tasking products that can offer additional benefits because of the ingredients in them. And with consumers becoming savvier and more demanding, sunscreens – like serums and moisturisers – have also gone down the skinification (incorporating skincare ingredients) route. The new generation of sunscreens offer not just UV protection, they now come complete with efficient formulations that are designed to care for our skin inside and out by including skin-loving ingredients like hydrating and anti-ageing actives that can improve skin texture and appearance. Thus, these sunscreens can be also seen as multi-tasking products that can offer additional benefits because of the ingredients in them, added Dr Ho. CAN NEW-GEN SUNSCREEN REPLACE SKINCARE? Now that new-gen sunscreens are packed with skincare ingredients, does that mean that we can simplify our skincare routine by omitting other skincare products, like serums and moisturisers? 'If you would like to replace your skincare steps with a new-gen sunscreen, it's important to remember that while sunscreens with added skincare ingredients – like antioxidants like Vitamin E, niacinamide or reparative peptides – can support skin health, there are still limitations so you should manage your expectations,' said Dr Yong. The extent of benefits is variable and formula-dependent, as sunscreens with niacinamide listed at the bottom of its ingredient list are not the same as niacinamide serums that contain 5 per cent of the key active ingredient, added Dr Ho. This is because the benefits of these actives are secondary to the primary goal of UV blocking, explained Dr Yong. Thus, 'while some sunscreens may offer hydration or brightening properties, they shouldn't replace dedicated treatments for specific concerns'. Instead, assess your skin's needs and specific concerns to determine whether you can simplify your routine or if additional products are necessary for optimal skin health. SKIP YOUR SERUM OR MOISTURISER If your sunscreen is highly moisturising and you have normal, combination or oily skin. If your skin concerns are mild – a sunscreen with niacinamide and Vitamin E may replace a serum step as it can offer light hydration and a slight brightening effect, which is sufficient for general skin health maintenance. DON'T SKIP YOUR SERUM OR MOISTURISER If you have dry or dehydrated skin as most sunscreens don't provide enough long-term moisture. If you have specific skin issues like acne, hyperpigmentation or signs of ageing. This is because skincare actives in sunscreens are usually at lower concentrations and using a dedicated serum may be more effective. If your sunscreen delivers a matte finish because oil-free mattifying sunscreens can be drying. If you're dealing with a colder or drier climate. Layering a moisturiser not only helps with skin hydration, but can also protect the skin barrier as well. Consider these skincare ingredients in your new-gen sunscreen to boost skin health: Niacinamide: Soothes inflammation, brightens and supports skin barrier function. Antioxidants (Vitamin E, ferulic acid): Boosts UV protection by scavenging free radicals, providing an extra layer of protection against skin ageing. 6 SUNSCREENS THAT GO BEYOND UV PROTECTION 1. Re:erth Radiance Defense SPF50+/PA++++, S$65 This lightweight sunscreen also works hard to suppress the inflammation from the release of DAMPs (damage-associated molecular pattern) molecules that cause skin ageing. The secret lies in its blend of Japanese spring turmeric, carnosine, chestnut rose fruit, bilberry leaf and rose myrtle fruit extracts to brighten the skin tone, soothe the skin and reduce ROS (reactive oxygen species) that can damage skin's collagen and elastin. 2. Paula's Choice 5% Vitamin C Sheer Moisturizer SPF50, S$65 A sunscreen that doubles up as an anti-ageing moisturiser, it contains high SPF properties to protect against harmful UVA and UVB rays while also visibly brightening a dull complexion at the same time thanks to the 5 per cent vitamin C. Plus, the inclusion of algae-derived amino acids also helps strengthen the skin for a healthier complexion. Available at 3. Shiseido Perfect Sun Protector Lotion SPF50+/PA++++, S$70 Enriched with a new SynchroShieldRepair technology, this sunscreen strengthens its protective abilities when exposed to heat, water and even sweat, keeping you well-protected. In addition, it contains a unique Profesnse CEL complex that also helps firm the skin for a plumped and more youthful looking you. Available at Shiseido store and counters. 4. Bobbi Brown Intensive Serum UV Fluid SPF50+/PA++++, S$88 A skincare-packed sunscreen, it protects against UV, blue light and pollution while also helping to improve fine lines and skin firmness with the help of narcissus tazetta bulb extract and argireline peptides. In addition, it has cordyceps and ginseng to boost skin's vitality and reveal a brighter and more radiant complexion over time. Available at Bobbi Brown store and counters. 5. Lancome UV Expert Xtreem Shield SPF50+/PA++++, S$155 Leveraging on over two decades of expertise and inspired by advanced sport conditions, this sunscreen features a unique self-recovery UV technology that reforms UV protection even with friction or mechanical stress like rubbing, so skin stays well-protected. But that's not all, it also helps reduce the appearance of dark spots, enlarged pores and skin dullness too. Available at Lancome counters. 6. Augustinus Bader The Sunscreen SPF50/PA++++, S$205 Besides UV protection, this also helps boost skin's repair from external environmental stressors at the same time. Its exclusive TFC8 complex that's packed with vitamins and amino acids together with microalgae extract restore the skin and reduce the appearance of fine lines and wrinkles, while antioxidant-rich actives like raspberry seed and buriti oils, pomegranate flower, perilla leaf and Kakadu plum, to further enhance its photoprotective properties.
