FYFD

Tag: ocean

  • Oceans Could “Burp” Out Absorbed Heat

    Oceans Could “Burp” Out Absorbed Heat

    Earth’s atmosphere and oceans form a complicated and interconnected system. Water, carbon, nutrients, and heat move back and forth between them. As humanity pumps more carbon and heat into the atmosphere, the oceans–and particularly the Southern Ocean–have been absorbing both. A new study looks ahead at what the long-term consequences of that could be.

    The team modeled a scenario where, after decades of carbon emissions, the world instead sees a net decrease in carbon–which could be achieved by combining green energy production with carbon uptake technologies. They found that, after centuries of carbon reduction and gradual cooling, the Southern Ocean could release some of its pent-up heat in a “burp” that would raise global temperatures by tenths of a degree for decades to a century. The burp would not raise carbon levels, though.

    The research suggests that we should continue working to understand the complex balance between the atmosphere and oceans–and how our changes will affect that balance not only now but in the future. (Image credit: J. Owens; research credit: I. Frenger et al.; via Eos)

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  • Rip Currents and Hurricanes

    Rip Currents and Hurricanes

    When it comes to the beach, looks can be deceiving. That calm-looking water to the side of big crashing waves may actually be a rip current that carries water back out to the ocean. Rip currents are a result of conservation of mass; just as waves carry water to the shore, something has to carry that incoming water back out to the ocean. Depending on the local topography, that outflow could be below the water surface, creating an undertow, or along the surface, as a rip current.

    Even when far offshore, hurricanes can trigger unexpected and strong rip currents, largely because they create bigger waves that travel shoreward. Those waves can also change the depth and layout of the underwater shoreline, potentially exacerbating rip currents.

    For more on rip currents, including the latest guidance on how to escape one, check out this article. (Image credit: A. Marlowe; via SciAm)

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  • Baltic Bloom

    Baltic Bloom

    June and July brings blooming phytoplankton to the Baltic Sea, seen here in late July 2025. On-the-water measurements show that much of this bloom was cyanobacteria, an ancient type of organism among the first to process carbon dioxide into oxygen. These organisms thrive in nutrient- and nitrogen-rich waters. Here, they mark out the tides and currents that mix the Baltic. Zoom in on the full image, and you’ll see dark, nearly-straight lines across the swirls; these are the wakes of boats. (Image credit: M. Garrison; via NASA Earth Observatory)

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  • Artificial Reoxygenation

    Artificial Reoxygenation

    Phytoplankton blooms have blossomed in coastal waters around the world, driven by phosphorus and nitrogen in agricultural run-off. These large algal blooms deplete oxygen in the water, creating dead zones where fish and other marine life cannot survive. Typically, oxygen makes its way into the ocean at the surface, where breaking waves trap air in bubbles that, when tiny enough, dissolve their oxygen into the water. But this process mainly helps surface-level waters, and without means to circulate oxygen-rich water down to the depths, the low-oxygen state persists.

    Artificial reoxygenation is a possible countermeasure. Either by bubbling oxygen directly into deeper waters or by pumping surface-level water downward, we could increase oxygen levels in the water column. So far, though, artificial reoxygenation’s success has been limited; tests in a few bays and estuaries show that it’s possible to reoxygenate the water, but the effects only last as long as the artificial mechanism remains active. Stop the pumps and bubblers and the water will revert to its low-oxygen state in just a day. Even so, the measures may be worthwhile on a temporary basis in some places while we adjust agricultural practices and try to mitigate warming. (Image credit: Copernicus Sentinel/ESA; via Eos)

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  • Upwelling at Cabo Frio

    Upwelling at Cabo Frio

    The shores of the Brazilian state of Rio de Janeiro boast turquoise waters, white sands, and green lagoons, but European explorers discovered the waters around one promontory were unusually cold, leading to the name Cabo Frio. The chilly waters can be 8 degrees Celsius cooler than nearby surface temperatures, thanks to cold water upwelling near the coast. The upwelling is wind-driven; the dominant northeasterly winds push water out to sea, allowing colder waters to rise from the deep. (Image credit: L. Dauphin; via NASA Earth Observatory)

    A map of sea surface temperatures near Cabo Frio in Brazil.
    A map of sea surface temperatures near Cabo Frio in Brazil.
  • Why Sea Foams

    Why Sea Foams

    Seawater froths and foams in ways that freshwater rarely does. A new study pinpoints the ocean’s electrolytes as the reason bubbles resist merging there. By studying the final moments before bubbles coalesce in both pure and salt water, researchers found that dissolved salts slow down the drainage of the thin film of liquid between two bubbles. Once the film reaches a 30-50 nanometer thickness, its electrolyte concentration causes a difference in surface tension that slows the outward flow of liquid in the film. That keeps the film in place longer and makes bubbles form foams instead of merging or popping. (Image credit: P. Kuzovkova; research credit: B. Liu et al.; via APS Physics)

  • “Fade”

    “Fade”

    Stingrays swim over rippled sands in this award-winning image from photographer Gregory Sherman. Above this peaceful vista, waves break and a dramatic skyscape looms. It’s the regular back-and-forth of the waves that shapes the ripples of sand. The rays can also use the sand for cover; note the remnants of sand atop a few of these rays, and then see how they hide themselves. See more winners from the Underwater Photographer of the Year awards in this gallery. (Image credit: G. Sherman/UPY 2023; via Colossal)

  • How Large Particles Get in Sea Spray

    How Large Particles Get in Sea Spray

    When bubbles burst at the ocean’s surface, they eject droplets that can carry high concentrations of contaminants like pollutants, viruses, and microplastics. Previous theories posited that only particles smaller than the microlayer surrounding the bubble could make their way into these drops, but new work shows otherwise.

    As bubbles rise to the surface, they carry particles on their surface, collecting them to a concentration that’s even higher than the surrounding seawater. But which particles make it into the air depend on the details of what happens when the bubble pops. Previously, researchers assumed that the thin microlayer of fluid surrounding the bubble was uniform, but that turns out not to be the case. As the bubble pops, some regions of the microlayer stretch and thin, while others grow thicker. The thicker the microlayer, the larger the particles it can pull along. In their single-bubble experiments, the researchers found that 15- and 30-micrometer plastic beads — representing oceanic microplastics — appeared in high concentrations in ejected droplets.

    This animated simulation shows how fluid along the edge of a bubble makes its way into ejected droplets. Green particles indicate fluid from the left half of the bubble; blue shows fluid from the right side.
    This animated simulation shows how fluid along the edge of a bubble makes its way into ejected droplets. Green particles indicate fluid from the left half of the bubble; blue shows fluid from the right side.

    Environmental scientists are keen to understand these mechanisms because they link our oceans and atmosphere, potentially affecting rainfall, pollution spread, and epidemiology. (Image, video, and research credit: L. Dubitsky et al.; via APS Physics)

  • Turning the Beach Pink

    Turning the Beach Pink

    Lab experiments and numerical simulations can only take us so far; sometimes there’s no substitute for getting out into the field. That’s why a beach in San Diego turned pink this January and February, as researchers released a safe, non-toxic dye into an estuary. The goal is to understand how small freshwater sources mix with colder, saltier ocean waters when they meet in the surf zone. Differences in temperature and salinity both affect the waters’ density and, therefore, how they’ll combine, especially in the face of the turbulent surf. Using drones, distributed sensors, and a specially-outfitted jet ski, the researchers collect data about how the dye (and therefore the estuary’s water) spreads over the 24 hours following each dye release. Check out their experiment’s site to learn more. (Image credits: E. Jepsen/A. Simpson/UC San Diego; via SFGate; submitted by Emily R.)

  • Inhibiting Marine Lightning

    Inhibiting Marine Lightning

    Thunderstorms over the ocean have substantially less lightning than a similar storm over land. Scientists wondered whether this difference could be due to lower cloud bases over the ocean or differences in the cloud droplets’ nuclei. But a new study instead implicates coarse sea spray as the deciding factor. By tracking the full lifetime of storm systems through remote sensing, the team found that fine aerosols can increase lightning activity over both land and ocean. But adding coarse sea salt from sea spray reduced lightning by 90% regardless of fine aerosols. With sea salt in the mix, clouds seem to develop fewer but larger condensation droplets, providing less opportunity for the electrification necessary to generate lightning. (Image credit: Z. Tasi; research credit: Z. Pan et al.)