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Clouds make newer climate models more realistic, but also less certain

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June 24 (UPI) — Efforts to improve the precision with which climate models simulate cloud processes have yielded more realistic models. New research suggests these efforts have also introduced greater uncertainty, according to a study published Wednesday in the journal Science Advances.

When the latest generation of climate models started producing results last year, researchers noticed that several models were predicting higher amounts of warming than previous models. The results of the new models inspired news headlines that suggested global warming might be worse than previously thought.

As researchers with the Coupled Model Intercomparison Project, CMIP6, soon found out, a few of the latest generation of models predicted smaller levels of warming than previous models. To identify the cause of this uncertainty, CMIP6 researchers decided some historical context was needed.

One way to measure and compare the predictions of different climate models is by calculating the equilibrium climate sensitivity, or ECS.

“It’s kind of an abstract measure, but it’s one these metrics that has been around for a long time,” Gerald Meehl, a senior scientist at the National Center for Atmospheric Research, told UPI.

Essentially, scientists double the CO2 in a model and let the simulation run its course until the climate stabilizes. Each model — and each new generation of models — produces a narrow range of warming, between 1.5 to 4.5 degrees Celsius, or 2.7 to 8.1 degrees Fahrenheit.

“This kind of range has been out there for some time, and with each successive generation of models has produced about the same range in terms of degrees,” Meehl said. “With the latest generation of models, the average warming has stayed roughly the same, but the range has gotten bigger than ever — at both the low and the high end.”

When Meehl and his colleagues asked members of the groups responsible for the 39 new CMIP6 models why they thought the ECS value got bigger, most of them pointed to clouds.

To improve the accuracy of the latest generation of climate models, scientists have worked hard to simulate small-scale cloud processes. But these efforts have introduced a variety of new interactions between clouds and tiny particles called aerosols — interactions that can produce contradictory results.

“For example, if you have polluted air, particularly sulfur dioxide, that can influence clouds. Sulfur dioxide is emitted from cars and factories, and it goes into the air and forms sulfate aerosols,” Meehl said. “When you see the sky and it looks orange and hazy, chances are that a lot of that is caused by an abundance of sulfate aerosols.”

According to Meehl, these aerosols operate as cloud condensation nuclei. When these aerosols seed clouds, they seed clouds with a lot more tiny droplets.

“That increased number of small droplets makes the cloud brighter, and it’s going to reflect more sunlight and have a cooling effect,” Meehl said.

But this phenomena, now rendered more precisely in climate models, can also yield the opposite effect.

“On the other hand, you’ve formed all these droplets in the sky, but the aerosols absorb some sunlight, warm the air, and evaporate some of the droplets and that reduces the amount of clouds,” Meehl said. “That allows a little more sun into the system, and now you have a warming effect.”

Cloud-aerosol interactions are just one example of new simulated intricacies that offer both greater realism and greater uncertainty. According to Meehl, there are a variety of interacting processes involving a variety of different cloud types at different altitudes.

“With more interacting processes, your level of uncertainty can go up,” he said.

But ECS isn’t the only way to test and compare climate models. Most climate modelers prefer to use transient climate response, or TCR.

“You increase CO2 at 1 percent per year, compounded, until the time you double the amount of carbon dioxide, which is usually about 70 years,” Meehl said.

TCR works on a smaller timescale and works more like actual climate change. When scientists calculated the TCR range for the newest generation of climate models, they got the same average warming value but a smaller range.

Meehl and his colleagues shared the ECS and TCR values produced by the latest CMIP6 models in the new paper.

In addition to putting the latest generation of climate models into historical context, Meehl hopes the new study will inspire cloud modeling improvements.

“We’re doing a better job of simulating the clouds themselves, but now we have these different feedbacks that give you more uncertainty,” he said.

Now that researchers have highlighted this uncertainty, Meehl hopes climate research institutions and the climate modeling community will work to address the issue by directing more funds to relevant observational and analysis programs.

“You can’t simulate what you don’t understand,” Meehl said.

And to understand how exactly clouds will effect climate and vice versa, in the future, scientists need more robust observational programs and better satellite measurements.



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Apple recalls shipment of iPhone 6 Plus due to photo glitch

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CUPERTINO, Calif., Aug. 23 (UPI) — Apple has recalled a shipment of its iPhone 6 Plus due to a technological glitch that produces blurry photos in the device’s camera, the company announced.

The recall affects a small number of iPhone 6 Plus devices, Apple said in a statement, which have demonstrated a glitch in the iSight camera.

Apple said it’s “a component that may fail causing your photos to look blurry.”

Apple created a web page where users can enter their phone’s serial number to determine if they are affected by the recall.

The iPhone 6 and larger iPhone 6 Plus were released last September.



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‘Invisible’ words reveal common structure among famous stories

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Aug. 7 (UPI) — Storytelling requires a narrative arc, but the trajectory of a dramatic arc isn’t always obvious.

By tracing the abundance of “invisible” words — pronouns, articles and other short words — researchers were able to identify patterns shared by a diversity of stories, from Shakespeare to Spielberg, according to a study published Friday in Science Advances.

“Over the years, these ‘invisible’ words have been found to be related to a whole mess of psychological processes — how people use small words like articles and pronouns tell us about a person’s mental health, thinking style, their social status, and even how well they get along with other people,” study lead author Ryan Boyd told UPI.

“In many ways, it was a natural progression to look at what these words can tell us how the nature of stories,” said Boyd, a lecturer in behavioral analytics at the University of Leeds.

For the study, Boyd and his colleagues used a range of statistical techniques to analyze the abundance and distribution of invisible words in 40,000 fictional texts, including short stories, novels and movie scripts.

The analysis revealed a common structure — a so-called narrative curve — featuring three distinct phases.

During the “staging” phase, authors use prepositions and articles in greater abundance, peppering their prose with “a” and “the.” These words are more useful at the beginning, when authors must set the scene and provide the audience with basic information.

The middle phase is defined by plot progression, which is revealed by a greater abundance of auxiliary verbs, adverbs and pronouns — or interactional language. During this phase, “the house” from the staging phase becomes “her home” or “it.”

During the third phase, cognitive tension is ramped up as the narrative arc reaches a climax. As the author guides the reader or viewer through the process of conflict resolution, cognitive-processing words like “think,” “believe,” “understand” and “cause” begin to crop up in greater numbers.

Researchers found this three-phase narrative shape remained consistent, regardless of a stories length.

“A 25,000 word story has the same shape as a 250 word story,” said Boyd, lead author of the new study. “It seems, then, that we are able to do a good job of structuring our stories in an optimal way regardless of how much space we have to do it in.”

The researchers set up a website showing the shapes of staging, plot progression and cognitive tension in eight texts at The Arc of Narrative website.

The patterns left by invisible words proved both good and bad stories — tales spun by amateurs, as well as professionals — utilize similar structures.

“Our results confirm what people have long believed about stories,” Boyd said. “Like DNA, we knew about it long before we could actually see it and measure it. With these new methods, we are able to see and measure the ‘DNA’ of stories and understand them in more objective, scientific ways.”

According to Boyd, studying the patterns of stories can offer insights into cognitive processes unique to humans.

“What these story shapes seem to tell us is that we have, to some degree, evolved to process information in certain ways,” he said. “We need to understand the ‘who’ and ‘what’ in order to understand the ‘why’ of our everyday lives and the lives of others.”

The authors of the latest story are already mining text for other language patterns that might help researchers determine whether a story-teller is telling the truth, or perhaps reveal the secrets to a “good” story.



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Florida Current study confirms decline in strength of Gulf Stream

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Aug. 7 (UPI) — New research suggests the strength of the Florida Current, which forms the beginning of the Gulf Stream, has weakened considerably over the last century.

The findings, published Friday in the journal Nature Climate Change, corroborate the predictions of several models that suggest the Gulf Stream has slowed over the last several decades.

The Florida Current is a thermal ocean current that flows from west to east around the tip of Florida, joining the Gulf Stream off Florida’s east coast.

Scientists have been tracking the strength of the Florida Current since the early 1980s — not long enough to identify multi-decadal or centennial trends.

To better understand the current’s historical changes, Christopher Piecuch, researcher at the Woods Hole Oceanographic Institution in Massachusetts, decided to study the relationship between coastal sea level and the strength of near-shore currents.

While researchers have only been measuring the Florida Current for a few decades, scientists have been recording sea level data since the early 1900s. Piecuch was able to use the data to predict historic changes in the strength of near-shore currents.

“In the ocean, almost everything is connected,” Christopher Piecuch, sole author of the new study, said in a news release. “We can use those connections to look at things in the past or far from shore, giving us a more complete view of the ocean and how it changes across space and time.”

The statistical analysis performed by Piecuch showed the Florida Current and Gulf Stream are the weakest they’ve been during the last 110 years.

The findings are in agreement with ocean current models that suggest climate change has caused a slowdown of the Atlantic Meridional Overturning Circulation, of which the Gulf Stream is a part.

Piecuch said he hopes his research will help other scientists use coastal current data to study changes in bigger currents like the Gulf Stream.

“If we can monitor something over the horizon by making measurements from shore, then that’s a win for science and potentially for society,” he said.



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