(AGENPARL) – sab 24 giugno 2023 A weekly compendium of media reports on science and technology achievements
at Lawrence Livermore National Laboratory. Though the Laboratory reviews
items for overall accuracy, the reporting organizations are responsible for
the content in the links below.
….. LLNL Report, June 23, 2023
El Niño is part of a normal fluctuating pattern in the equatorial Pacific
Ocean, wherein warm water rises to the surface. Image by Adobe Stock.
… Oceans are in hot water https://mashable.com/article/why-oceans-warming
Water can absorb colossal amounts of heat, and Earth’s seas soak up more
than 90% of the heat trapped on the planet by human activities, mostly from
the burning of primordial fossil fuels that release extreme amounts of CO2
into the atmosphere. Normal fluctuations in ocean climate patterns, combined
with such continuous background warming, is largely what's now driving
anomalously high, or extreme, sea surface temperatures around the globe.
Without our ocean absorbing the lion’s share of excess heat, the land, ice,
and atmosphere would have warmed more, leading to further intensified heat
waves, droughts, deluges and other extremes.
“Every time we wake in the morning, we should be saying thanks to the ocean
for doing its job,” said Paul Durack, an oceanographer at the Lawrence
Livermore National Laboratory who researches the ocean and its role in global
climate variability and change. “The global ocean provides a key climate
service.”
Read More https://mashable.com/article/why-oceans-warming
LLNL scientists used molecular dynamics simulations to determine how humidity
controls the rate of atmospheric corrosion in aluminum. Image by Adobe Stock.
… New research is corrosive
https://www.materialsperformance.com/news/2023/06/research-lab-explores-connection-between-humidity-and-corrosion
Scientists at Lawrence Livermore National Lab performed simulations using
Ruby, one of the Lab’s supercomputers, to uncover physical mechanisms that
explain why humidity controls the rate of atmospheric corrosion of aluminum
metal.
Accurate predictions of aluminum component lifetimes depend on assessments of
corrosion rates. Engineering-scale models used for making system-level
lifetime predictions are expressed in terms of coupled physical and chemical
mechanisms including sorption, transport and chemical reactions. These
mechanisms are inherently multiscale, which complicates both model form
development and calibration. 
Rates for atmospheric aluminum corrosion depends on relative humidity, which
measures the amount of water present as vapor around the part. Understanding
which processes give rise to these rate effects can help constrain the form
of engineering lifetime models in terms of fundamental physical parameters.. 
To better understand how aluminum ions behave under confinement in water on
surfaces, the team turned to all-atom molecular dynamics (MD) simulations for
insights. MD makes comparatively few assumptions regarding how atoms interact
and directly simulates a trajectory of atomic motions that can be
post-processed to obtain material property data. 
From their simulations, the team observed that aluminum ions tend to localize
near the air-water interfaces and were completely absent near the oxide. This
phenomenon was attributed to both the surface polarization of the water film
and the rigid, ice-like phase of water that forms near the oxide surface. 
Read More
https://www.materialsperformance.com/news/2023/06/research-lab-explores-connection-between-humidity-and-corrosion
Climate change, caused by the burning of fossil fuels, has increased the
frequency and intensity of California wildfires. The Palisades fire was a
wildfire that burned in Topanga State Park, in the Pacific Palisades
neighborhood near Los Angeles on May 14, 2021. Photo by Amir AghaKouchak/UC
Irvine.
… California fires it up
The recent decades long surge in catastrophic wildfires in California is
almost entirely due to climate change, according to a recent study.
“We show that nearly all of the observed increase in burned area in
California over the past half-century is attributable to human-caused climate
change,” said study co-author Don Lucas, a scientist from Lawrence
Livermore National Laboratory.
Scientists say human-caused climate change is caused by the burning of fossil
fuels such as oil, coal and gas, which release greenhouse gases such as
carbon dioxide and methane into the atmosphere and has caused global air and
ocean temperatures to rise to levels that cannot be explained by natural
factors.
Along with fueling extreme weather events such as floods and hurricanes,
it’s also impacted the extent and severity of wildfire seasons in the U.S.
“Climate change, primarily caused by the burning of fossil fuels, is
increasing the frequency and severity of wildfires not only in California but
also all over the world,” the state of California's Air Resource Board
said.
Read More
Green algae isn’t always the best diesel production alternative. Image by
Adobe Stock.
… Biofuel isn’t always the greenest
New research using real-world data casts doubt on the energy efficiency of
diesel alternatives that come from phytoplankton.
Biofuels made from algae have had their time in the sun, with years of highly
publicized investments from fossil fuel companies, such as Exxon and Chevron,
and studies showing potential for the energy source to replace fossil fuels.
New research suggests, however, that biodiesel derived from microalgae may
actually emit more carbon during production and use than petroleum-based
diesel.
The biofuel’s poor performance is due to its manufacturing process, which
requires more energy than the final product can produce.
Xavier Mayali, an algae biofuel researcher at Lawrence Livermore National
Laboratory, who was not involved in the study, thinks that microalgae could