Showing posts with label NSF. Show all posts
Showing posts with label NSF. Show all posts

Thursday, September 24, 2009

Solar Winds are Blowing

This story has been sitting in my inbox for some time, but here is an excellent report that describes it all well.

A scientific assumption that has survived for perhaps a couple of centuries has just been shown false. That is how important this item is. We now need to properly map the solar wind for the next few decades to determine what correlations exist if any at all. And we also need to stamp all published research on sunspots and solar energy as pre 2009.

It is also exciting. We have discovered a significant variable that was assumed fairly stable or at least tied to an eleven year cycle to now be highly variable over much shorter time ranges. It may be actually linked directly to global weather effects.

Of course we will need to monitor the variation closely for a long time before we know anything but it is today a surprise to science and will cause all the text books to be rewritten even now.

Press Release 09-171

More to Solar Cycle Than Sunspots
Sun also bombards Earth with high-speed streams of wind

September 17, 2009

Challenging conventional wisdom, new research finds that the number of sunspots provides an incomplete measure of changes in the sun's impact on Earth over the course of the 11-year solar cycle. The study, led by scientists at the National Center for Atmospheric Research (NCAR) and the University of Michigan, finds that Earth was bombarded last year with high levels of solar energy at a time when the sun was in an unusually quiet phase and sunspots had virtually disappeared.

"The sun continues to surprise us," says lead author Sarah Gibson of NCAR's High Altitude Observatory. "The solar wind can hit Earth like a fire hose even when there are virtually no sunspots."

The study, also written by scientists at NOAA and NASA, is being published today in the Journal of Geophysical Research. It was funded by NASA and by the National Science Foundation, NCAR's sponsor.

"It is vitally important to realize that the 'quiet' sun really isn't all that quiet," says Rich Behnke, program director in NSF's Division of Atmospheric Sciences. "These high-speed streams of wind can affect many of our communications and navigation systems. And they can come at any time, during any part of the solar cycle."

Scientists for centuries have used sunspots, which are areas of concentrated magnetic fields that appear as dark patches on the solar surface, to determine the approximately 11-year solar cycle. At solar maximum, the number of sunspots peaks. During this time, intense solar flares occur daily and geomagnetic storms frequently buffet Earth, knocking out satellites and disrupting communications networks.
Gibson and her colleagues focused instead on another process by which the sun discharges energy. The team analyzed high-speed streams within the solar wind that carry turbulent magnetic fields out into the solar system.

When those streams blow by Earth, they intensify the energy of the planet's outer radiation belt. This can create serious hazards for Earth-orbiting satellites and affect global communications systems, while also threatening astronauts in the International Space Station. Auroral storms light up the night sky repeatedly at high latitudes as the streams move past, driving mega-ampere electrical currents a few hundred miles above Earth's surface. All that energy heats and expands the upper atmosphere. This expansion pushes denser air higher, slowing down satellites and causing them to drop to lower altitudes.

Scientists previously thought that the streams largely disappeared as the solar cycle reached minimum. But when the study team compared measurements within the current solar minimum interval, taken in 2008, with measurements of the last solar minimum in 1996, they found that the Earth in 2008 was continuing to resonate with the effects of the streams. Although the current solar minimum has fewer sunspots than any minimum in 75 years, the sun's effect on Earth's outer radiation belt, as measured by electron fluxes, was more than three times greater last year than in 1996.

Gibson said that observations this year show that the winds have finally slowed, almost two years after sunspots reached the levels of last cycle's minimum.

The authors note that more research is needed to understand the impacts of these high-speed streams on the planet. The study raises questions about how the streams might have affected Earth in the past when the sun went through extended periods of low sunspot activity, such as a period known as the Maunder minimum that lasted from about 1645 to 1715.

"The fact that Earth can continue to ring with solar energy has implications for satellites and sensitive technological systems," Gibson says. "This will keep scientists busy bringing all the pieces together."

Buffeting Earth with streams of energy

For the new study, the scientists analyzed information gathered from an array of space- and ground-based instruments during two international scientific projects: the Whole sun Month in the late summer of 1996 and the Whole Heliosphere Interval in the early spring of 2008. The solar cycle was at a minimal stage during both the study periods, with few sunspots in 1996 and even fewer in 2008.

The team found that strong, long, and recurring high-speed streams of charged particles buffeted Earth in 2008. In contrast, Earth encountered weaker and more sporadic streams in 1996. As a result, the planet was more affected by the sun in 2008 than in 1996, as measured by such variables as the strength of electron fluxes in the outer radiation belt, the velocity of the solar wind in the vicinity of Earth, and the periodic behavior of auroras (the Northern and Southern lights) as they responded to repeated high-speed streams.

The prevalence of high-speed streams during this solar minimum appears to be related to the current structure of the sun. As sunspots became less common over the last few years, large coronal holes lingered in the surface of the sun near its equator. The high-speed streams that blow out of those holes engulfed Earth during 55 percent of the study period in 2008, compared to 31 percent of the study period in 1996. A single stream of charged particles can last for as long as seven to 10 days. At their peak, the accumulated impact of the streams during one year can inject as much energy into Earth's environment as massive eruptions from the sun's surface can during a year at the peak of a solar cycle, says co-author Janet Kozyra of the University of Michigan.

The streams strike Earth periodically, spraying out in full force like water from a fire hose as the sun revolves. When the magnetic fields in the solar winds point in a direction opposite to the magnetic lines in Earth's magnetosphere, they have their strongest effect. The strength and speed of the magnetic fields in the high-speed streams can also affect Earth's response.

The authors speculate that the high number of low-latitude coronal holes during this solar minimum may be related to a weakness in the sun's overall magnetic field. The sun in 2008 had smaller polar coronal holes than in 1996, but high-speed streams that escape from the sun's poles do not travel in the direction of Earth.

"The sun-Earth interaction is complex, and we haven't yet discovered all the consequences for the Earth's environment of the unusual solar winds this cycle," Kozyra says. "The intensity of magnetic activity at Earth in this extremely quiet solar minimum surprised us all. The new observations from last year are changing our understanding of how solar quiet intervals affect the Earth and how and why this might change from cycle to cycle."

-NSF-

Media Contacts

Cheryl Dybas, NSF (703) 292-7734
cdybas@nsf.gov
David Hosansky, NCAR (303) 497-8611 hosansky@ucar.edu
Peter Weiss, American Geophysical Union (202) 777-7507 pweiss@agu.org

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2009, its budget is $9.5 billion, which includes $3.0 billion provided through the American Recovery and Reinvestment Act. NSF funds reach all 50 states through grants to over 1,900 universities and institutions. Each year, NSF receives about 44,400 competitive requests for funding, and makes over 11,500 new funding awards. NSF also awards over $400 million in professional and service contracts yearly.

Monday, June 15, 2009

Fossil Records On Insect Damage

I have no doubt that the evidence shown here is quite correct, but taking the inference as far as done here is pretty chancy on the basis of one fossilized snapshot.. Putting this is a more recent perspective, a few warming winters and I am talking about a couple of degrees, was sufficient to wipe out huge tracts of pine with the pine beetle. It really does not take very much for a shift here and there to act as a force multiplier in a given biome.

That evidence suggests that insect depredation is primarily a function of climatic conditions over decadal timelines. We already know that a single degree produces huge impact on crop placement and from this on insect populations.

The changes 55 millions of years ago were way more dramatic and decisive than anything the Holocene may ever throw at us so a radical change in insect populations was an inevitability then and that changing plant conditions show up in the fossil record is to be expected. It is nice to see it confirmed.

Why CO2 rose dramatically 55 millions of years ago is not well understood at all and it is way premature to attempt to link causes and effects. In fact the heating that took place may have been responsible for the sharp rise in the atmospheric CO2. In fact if we use that as our guide post, then we are left with either a close encounter with a star or with volcanics. The star proposition is already covered off with a known hundred thousand year orbit around Sirius that also shows us that the dwell time for such an event is simply too short for the events 55 millions of years ago.

That pretty well leaves super sized volcanic activity that was able to supply both heat and CO2. scenarios have been suggested and it will be eventually be sorted out.

Fossil Record Suggests Insect Assaults on Foliage May Increase with Warming Globe

June 12, 10:07 AM ·

The following is a press release from the National Science Foundation.

More than 55 million years ago, the Earth experienced a rapid jump in global carbon dioxide levels that raised temperatures across the planet. Now, researchers studying plants from that time have found that the rising temperatures may have boosted the foraging of insects. As modern temperatures continue to rise, the researchers believe the planet could see increasing crop damage and forest devastation.

The researchers, from Penn State, the Smithsonian Institution, the University of Maryland, the University of California, Santa Barbara, and Wesleyan University published their findings in the Feb. 11, 2008, Proceedings of the National Academy of Sciences.

"Our study convincingly shows that there is a link between temperature and insect feeding on leaves," said lead author Ellen Currano of Pennsylvania State University and the Smithsonian Institution. "When temperature increases, the diversity of insect feeding damage on plant species also increases."

With support from the National Science Foundation (NSF), Currano collected the study fossils from the badlands of Wyoming, gathering more than 5,000 fossil leaves from five sites representing time zones before, during and after the roughly 100,000 year temperature spike called the Paleocene-Eocene Thermal Maximum (PETM).

The researchers found that the PETM plants were noticeably more damaged than fossil plants before and after that period. The PETM plants, many of which are legumes -- the family that now includes beans and peas -- show damage with greater frequency, greater variety (such as mining, galling, surface feeding and other assaults) and a more destructive character than plants from the surrounding geologic time periods.

"This study shows that insects responded rapidly to a major change in climate during the PETM," said Enriqueta Barrera, program director in NSF's Division of Earth Sciences, which helped fund the project. "This is in agreement with previous findings by [co-author] Scott Wing of the Smithsonian Institution who found that plants that previously were common much farther south migrated northward at this time"

In order to test alternative reasons for the increased damage, the researchers looked at whether the plants in the analysis had key traits that made them more palatable to insects. However, after using established analytical techniques to measure various leaf structures in all of the specimens, the researchers concluded that the PETM plants do not appear to vary structurally from the plants in the rock layers above and below the temperature spike.

The researchers also looked to see if the insect species feeding on the leaves changed over the time period. The analysis showed that what changed was the abundance of insect species that are highly specialized in the type of plant they consume and the way they consume it, such as leaf miners and gallers - they are far more abundant in the PETM.

"We wanted to see whether the increase in insect damage during the PETM was because the leaves were less tough or more nutritious," said Currano. "There is no evidence to support this. Instead, we think that the warming allowed insect species from the tropics, particularly those that feed in a highly specific manner, to migrate north."

Biologists are already aware that insects in the tropics consume more plants and that warming temperatures are causing organisms to widen their ranges. In addition, research has shown that plants grown under higher concentrations of carbon dioxide (CO2) are less nutritious, so insects must eat more plant tissue to get the same sustenance. These earlier studies support the recent findings about the PETM.
Because food webs that involve plant-eating insects affect as much as three quarters of organisms on Earth, the researchers believe that the current increase in temperature could have a profound impact on present ecosystems, and potentially to crops, if the pattern holds true in modern times.

"This study represents a highly integrative approach, using well-studied systems, to model ecological dynamics during upcoming climate shifts," said William Hahn, a program director in NSF's Division of Graduate Education who supported Currano's work with a research fellowship. "The truly relevant description of past climate-change effects on plant-insect interactions, specifically the probability of increased insect damage to plants with rising temperatures, is a forward-looking approach that will help us prepare for the effects of future global warming," he added.

In addition to Currano's Graduate Research Fellowship, the research team was supported by grants from NSF's Division of Earth Sciences, as well as funding from the Roland Brown Fund of the Smithsonian's National Museum of Natural History, the Evolving Earth Foundation, the Paleontological Society, Penn State, the Petroleum Research Fund, the David and Lucile Packard Foundation and the University of Pennsylvania.