Saturday, August 20, 2016

Sea level can drive temperature change--this is weird but it explains a lot.

Scientists have long tried to calculate sea level rise from estimates of temperature rise, but now researchers believe they can work the other way.

They think they can predict global temperatures from sea level change.

Based on their calculations, they figure air temperatures will be up half a degree, Fahrenheit, by the end of this year (2016) from 2014. Half a degree in two years; that’s a lot.

It indicates a higher-than usual rise in global atmospheric temperatures, which is bad news. But the research also helps explain a long period of low temperature rise a decade ago--a slowdown that critics of climate theory used to suggest global warming was a hoax. More on that at the end of this post.

The new paper. Pacific sea level rise patterns and global surface temperature variability, is published in the journal Geophysical Research Letters. It was written by Cheryl Peyser, Jianjun Yin and Julia Cole of the Department of Geosciences, University of Arizona, and Felix Landerer of NASA’s Jet Propulsion Laboratory in Pasadena. 

“We find a significant and robust correlation between the east-west contrast of dynamic sea level in the Pacific and global mean surface temperature variability on both interannual and decadal time scales,” they wrote, with typical scientific impenetrability.

The fact that sea level rise and atmospheric temperatures are linked is no surprise. Warmer weather causes polar ice and glaciers to melt, adding water to the seas. Rising atmospheric temperature transmits energy into the ocean, and warmer water expands. Both thing make sea levels go up.

But apparently it works the other way, too. Changes in ocean temperature patterns impact the atmosphere. When you think about it, that makes perfect sense. 

Science Daily summarizes the new paper here.

“We're using sea level in a different way, by using the pattern of sea level changes in the Pacific to look at global surface temperatures -- and this hasn't been done before," Peyser said.

They found that when sea levels in the western Pacific rise more than usual, worldwide surface temperature rise slows. And when sea levels drop in the Western Pacific but go up in the eastern Pacific, global air temperatures jump. Apparently that’s because a lot of ocean heat is lost back to the atmosphere.

Water appears to slosh back and forth across the Pacific east to west and west to east. Strong tradewinds pushing water westward is part of that sloshing phenomenon. (Sloshing back and forth may not be the best analogy, since some of the sea level rise isn’t from movement of water but from the expansion in volume of warmed water. But it helps visualize the activity.)

There was a period from about 1998 to 2012 when conservative pundits were touting a slowdown in global temperature rise as proof that climate change wasn’t happening. It now turns out that slowdown was associated with a dramatic slosh to the west, when sea levels in the western tropical Pacific were significantly higher than average global sea level change.

Now it’s sloshing back, and atmospheric temperatures are rising faster again. 

The research helps explain why atmospheric temperature rise slows and speeds up at various times.

“Our research shows that the internal variability of the global climate system can conceal anthropogenic global warming, and at other times the internal variability of the system can enhance anthropogenic warming,” said paper co-author Yin.

© Jan TenBruggencate 2016

Sunday, August 14, 2016

A chance to experience life on Mars. Interested?

Want to experience life on Mars?
The University of Hawai`i, through a NASA-funded research project, is offering the opportunity to be a mock Barsoomian.

But consider carefully.

(Image: Bedrock in the central uplift area of an impact crater on Mars. Credit: NASA.)

There will be isolation. There will be space suits. But there are unlikely to be blasters, little green men or much in the way of excitement.

The Hawai`i Space Exploration Analog and Simulation (HI-SEAS) program at the Hawai`i state university is looking for people willing to spend eight months in relative isolation, as part of a program to figure out how humans respond to extreme conditions. 

Participants would spend most of their eight-month mock-Martian period in a geodesic dome at 8,200 feet on the side of Mauna Loa. The program calls it “an isolated Mars-like environment.”

A group of people will live together in tight quarters, separated from humanity, to help our space agency understand for a real Mars mission what kinds of people they should pick, what mixes of sexes they need, what kinds of stuff they need to help keep them sane, and so forth.

“These types of studies are essential for NASA to understand how teams of astronauts will perform on long-duration space exploration missions, such as those that will be required for human travel to Mars. The studies will also allow researchers to recommend strategies for crew composition for such missions, and to determine how best to support such crews while they are working in space,” HI-SEAS says.

It’s not for everyone, but in many ways, it’s not a whole lot different than the ocean voyages that brought foreigners to Hawai`i two centuries ago. Missionary Lucy Thurston spent 157 days on her 1819-1820 voyage from New England to Kawaihae. A little over 5 months. 

HI-SEAS is currently planning two eight-month missions, one January to September 2017 and one January to September 2018.

Actually, eight months isn’t all that long. A group of mock Martians is, as this is written, completing a 12-month stay at the dome. It is HI-SEAS Mission Four. They get out at the end of August 2016.

The first such long-stay experiment was for four months, then another four-monther, then eight months, followed by the current year-long stay. Right now, there are six folks living in the 1200-square-foot dome.

Interested? A preliminary application form is here.

Some of the preliminary requirements are these:

“Applicants must be between 21 and 65 years of age. They must be tobacco-free, able to pass a class 2 flight physical examination, and able to understand, speak and write fluently in English. They must meet the basic requirements of the NASA astronaut program (i.e. an undergraduate degree in a science or engineering discipline, three years of experience or graduate study, etc.); in addition, they will be evaluated for experience considered valuable in the program, such as experience in complex operational environments.”

© Jan TenBruggencate 2016

Friday, August 5, 2016

Wanna stay mentally alert as you age? Exercise both the body and the brain.

If you want to keep your wits about you as you age, you need to work those wits—but you also need to work your body.

Exercise, particularly aerobic exercise is very important to brain function. That’s been known for some time, and the evidence keeps building. 

As far back as 2004, a Hawai`i study found that elderly adults who walk a lot have lower rates of dementia. The report in the Journal of the American Medical Association reviewed tests done on hundreds of elderly men, comparing their physical activity with rates of dementia.

“Our findings suggest that physically capable elderly men who walk more regularly are less likely to develop dementia,” wrote the authors of the study, Walking and Dementia in Physically Capable Elderly Men.

The Mayo Clinic Proceedings in 2011 stated the case clearly: “A rapidly growing literature strongly suggests that exercise, specifically aerobic exercise, may attenuate cognitive impairment and reduce dementia risk,” Mayo wrote. 

Scientific American was in there, too, with the headline, “Aerobic exercise bulks up hippocampus, improving memory in older adults.”

A 2010 study in the Proceedings of the National Academy of Science said regular aerobic exercise increased the size of the hippocampus, a part of the brain that tends to shrink with age. 

“Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2” years, said this study.  

A 2014 study showed that specifically in elderly women, exercise increased the size of the hippocampus—the part of the brain associated with verbal memory and learning. 

That study, from the British Journal of Sports Medicine is here

A Finnish study in February of this year, 2016, found similar results: “Aerobic exercise, such as running, has positive effects on brain structure and function, for example, the generation of neurons (neurogenesis) in the hippocampus, a brain structure important in learning. 

That study, done on rats rather than humans, in the Journal of Physiology is here

And this article in the New York Times argues that it needs to be aerobic exercise, not just muscle-building work. 

Most of the work indicates that the effect of exercise isn’t huge but it’s real. 

Still, physical activity isn’t everything. You also need to exercise the brain directly.

The American Psychological Association says specific kinds of brain training can help stave off dementia. But not all brain training.

“The mistake some people make is thinking that all brain training is the same. Lumping all brain training together is like trying to determine the effectiveness of antibiotics by looking at the universe of all pills, and including sugar pills and dietary supplements in that analysis. You’ll find that some work and some do not. To then conclude that brain training does not work — or is not yet proven—is based on flawed analysis.” So says Jerri Edwards, PhD, of the University of South Florida, who led a study on the subject, published by APA, above.

Another study suggests intensive learning can actually cause chemical changes in the brain, increasing the amount of a protein that helps protect against memory loss, and even Alzheimer’s Disease.

"You're keeping the machinery going. It makes sense that the more time spent intensely focused on learning, the more your brain is trained to process information and that doesn't go away. That intense kind of learning seems to make your brain stronger," said Auriel Willette, an assistant professor of food science and human nutrition at Iowa State University. 

© Jan TenBruggencate 2016

Wednesday, August 3, 2016

Need to abandon Earth? Here are 49 alternative planets.

If we needed to abandon the planet we now know where to go—or at least where to look.

University of Hawai`i astronomers have helped identify dozens of planets that are the right size and the right distance from the sun, to potentially sustain life as we know it.

(Image: Habitable zones around different suns. Credit: Chester Harman. View a large version here.)

Astronomers from the Kepler Habitable Zone Working Group, which includes Nader Haghighipour of the University of Hawai’i Institute for Astronomy, writing in the Astrophysical Journal, have described 49 such planets.

Each is within a sun’s habitable zone—not too hot, not too cold—and is less than twice the radius of the Earth, which is required to have a rocky planet. The habitable zone is defined as that zone in which a rocky planet can have liquid water on its surface—something many Earth life forms require.

The team used NASA’s Kepler space observatory to identify the potential new human home planets. But they are also very cautious—just because it’s the right size and in the right zone doesn’t necessarily mean it actually is habitable. But it provides a first step.

“The HZ is primarily a target selection tool rather than any guarantee regarding habitability,” the authors write.

This also doesn’t address how we’d get there. Most such planets, even with technology far advanced from ours, could not be reached within the lifetimes of humans.

An abstract of the paper is here.

A press release on the report is here.

The authors of the paper are Stephen R. Kane, Michelle L. Hill, James F. Kasting, Ravi Kumar Kopparapu, Elisa V. Quintana, Thomas Barclay, Natalie M. Batalha, William J. Borucki, David R. Ciardi, Natalie R. Hinkel, Lisa Kaltenegger, Franck Selsis, Guillermo Torres and Hachichipour. 

© Jan TenBruggencate 2016