Ocean Action Hub

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Bacteria from the ocean floor could be influencing Arctic weather

18 Nov 2019 -There’s more to clouds than you might think.

18 Nov 2019 - Scientists have identified a surprising new mechanism that could be affecting cloud formation and weather patterns in the Arctic: bacteria from the ocean floor.

When tiny, plantlike ocean microbes known as phytoplankton die, their bodies sink to the bottom of the sea, becoming food for bacteria residing there. New observations made in the Bering and Chukchi seas off the coast of Alaska suggest that under the right conditions, these algae eaters are sloshed to the surface and from there are wafted into the air.

Once airborne, seafloor bacteria may become seeds that promote the growth of ice crystals, an important step in the formation of Arctic clouds.

“Clouds are super important in the Arctic,” said Jessie Creamean, an atmospheric scientist at Colorado State University and lead author of new research published in mid-July in Geophysical Research Letters.

“They regulate the surface and atmospheric temperatures, affecting sea ice, ecology, shipping, Arctic climate and weather. And we just have a really poor understanding of how they form,” Creamean said.

Prior research from the Southern Ocean as well as laboratory experiments suggest that ocean microbes can enhance cloud formation. To investigate whether that holds true in the Arctic, Creamean and several of her co-authors embarked on a NOAA-funded research cruise through the Bering and southern Chukchi seas from late August to mid-September 2017. Over the course of several weeks, the researchers collected samples of seawater and aerosols suspended about 20 meters (66 feet) above the ship.

They measured the abundance of what are known as ice-nucleating particles, which seed clouds. They also took stock of seawater chemistry and chlorophyll concentrations, an indicator of phytoplankton abundance.

At first, Creamean said, she simply was hoping to get a baseline sense of the distribution of cloud-seeding particles in the ocean and atmosphere. But on Aug. 29, as their ship passed through the Bering Strait, the researchers measured particularly high levels of them. Through a combination of DNA analysis and microbial culturing, they determined that the airborne particles were mostly bacteria.

CONTINUE READING: https://www.washingtonpost.com/weather/2019/11/15/bacteria-ocean-floor-could-be-influencing-arctic-weather/

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New U.N. climate report: Monumental change already here for world’s oceans and frozen regions

25 Sept 2019 - Growing coastal flooding is inevitable, and damage to corals and other marine life has already been unleashed. But scientists say the world still has time to avert even more severe consequences.

25 Sept 2019 - Growing coastal flooding is inevitable, and damage to corals and other marine life has already been unleashed. But scientists say the world still has time to avert even more severe consequences.

Climate change is already having staggering effects on oceans and ice-filled regions that encompass 80 percent of the Earth, and future damage from rising seas and melting glaciers is now all but certain, according to a sobering new report from the United Nations.

The warming climate is killing coral reefs, supercharging monster storms, and fueling deadly marine heat waves and record losses of sea ice. And Wednesday’s report on the world’s oceans, glaciers, polar regions and ice sheets finds that such effects foreshadow a more catastrophic future as long as greenhouse gas emissions remain unchecked.

Given current emissions levels, a number of serious effects are essentially unavoidable, says the report of the Intergovernmental Panel on Climate Change (IPCC).

Hundred-year floods will become an annual occurrence by 2050 in some cities and small island nations, according to the IPCC. Several of those cities are in the United States, including its second largest, Los Angeles.

“What more evidence do we need?" said Eric Garcetti, LA’s mayor, in response to the report. "These are our streets flooding, these are our homes burning, and in cities, we know this is real, and this is not just about resilience, it’s about adaptability.”

If emissions continue to increase, global sea levels could rise by more than three feet by the end of this century — about 12 percent higher than the group estimated as recently as 2013. Melting glaciers could harm water supplies, and warming oceans could wreck marine fisheries.

“As a result of excess greenhouse gases in the atmosphere, the ocean today is higher, warmer, more acidic, less productive and holds less oxygen,” said Jane Lubchenco, a former administrator of the National Oceanic and Atmospheric Administration (NOAA). “The conclusion is inescapable: The impacts of climate change on the ocean are well underway. Unless we take very serious action very soon, these impacts will get worse — much, much worse.”

More than 100 scientists from around the world contributed to the latest report by the IPCC, which comes on the heels of several other warnings the group has issued recently. Last fall, the IPCC said the world must make rapid, far-reaching changes to energy, transportation and other systems to hold warming below an increase of 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, a key threshold in the Paris climate agreement.

CONTINUE READING: https://www.washingtonpost.com/climate-environment/2019/09/25/new-un-climate-report-massive-change-already-here-worlds-oceans-frozen-regions/

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New science suggests the ocean could rise more — and faster — than we thought

26 Oct 2017 - Climate change could lead to sea level rises that are larger, and happen more rapidly, than previously thought, according to a trio of new studies that reflect mounting conce

26 Oct 2017 - Climate change could lead to sea level rises that are larger, and happen more rapidly, than previously thought, according to a trio of new studies that reflect mounting concerns about the stability of polar ice.

In one case, the research suggests that previous high end projections for sea level rise by the year 2100 — a little over three feet — could be too low, substituting numbers as high as six feet at the extreme if the world continues to burn large volumes of fossil fuels throughout the century.

“We have the potential to have much more sea level rise under high emissions scenarios,” said Alexander Nauels, a researcher at the University of Melbourne in Australia who led one of the three studies. His work, co-authored with researchers at institutions in Austria, Switzerland, and Germany, was published Thursday in Environmental Research Letters.

The results comprise both novel scientific observations — based on high resolution seafloor imaging techniques that give a new window on past sea level events — and new modeling techniques based on a better understanding of Antarctic ice.

The observational results, from Texas and Antarctica, examine a similar time period — the close of the last Ice Age a little over 10,000 years ago, when seas are believed to have risen very rapidly at times, as northern hemisphere ice sheets collapsed.

Off the Texas coast, this would have inundated ancient coral reefs. Usually, these reefs can grow upward to keep pace with sea level rise, but there’s a limit — one observed by a team of scientists aboard a vessel called the Falcor in 200 foot deep waters off the coast of Corpus Christi.

These so-called drowned reefs showed features that the researchers called “terraces,” an indicator of how the corals would have tried to respond to fast rising sea levels. Because the organisms must maintain access to a certain amount of sunlight, they would have tried to grow higher to keep up with fast rising seas — but they wouldn’t have been able to do so over a very large area. 

CONTINUE READING: https://www.washingtonpost.com/news/energy-environment/wp/2017/10/26/new...

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