Science Current Events | Science News | Brightsurf.com
 

Warm coronal loops offer clue to mysteriously hot solar atmosphere

May 30, 2008

Scientists at NASA reveal a new understanding of the mysterious mechanism responsible for heating the outer part of the solar atmosphere, the corona, to million degree temperatures.

"It has become clear in recent years that coronal heating is a highly dynamic process, but inconsistencies between observations and theoretical models have been a major source of heartburn. We have now discovered two possible solutions to this dilemma: energy is released impulsively with the right mix of particle acceleration and direct heating, or energy is released gradually very close to the solar surface," says James Klimchuk, an astrophysicist at the Goddard Space Flight Center's Solar Physics Laboratory in Greenbelt, Md. Klimchuk will present his team's findings on May 29 at the American Geophysical Union conference in Ft. Lauderdale, Fl.

X-rays and ultraviolet radiation from the solar corona affect Earth and its atmosphere. For satellites, this can be a real drag-literally. As Earth's atmosphere gets hotter, it expands and becomes denser at high altitudes. When this happens, satellites experience more drag, which changes their orbits. Accurately predicting this "space weather" gives satellite operators more time to respond to or avert problems that could potentially cause interruptions and outages.

In order for scientists to build realistic models of the corona, they "must understand coronal heating. It's the root cause of all this radiation," says Klimchuk.

A comparison of numerical simulations with imaging and spectral data from NASA missions reveals that the coronal heating mechanism is highly impulsive, or concentrated close to the solar surface, or both.

The corona is made up of loops of hot gas that arch high above the sun's surface. These loops can have a wide range of temperatures, many reaching several million degrees Kelvin, but those of intermediate temperature have proven the most difficult to explain. Impulsive energy bursts called nanoflares seem to be the key. "Nanoflares can release their energy in different ways, including the acceleration of particles, and we now understand that the right mix of particle acceleration and direct heating is one way to explain the observations," says Klimchuk.

Another possibility is that energy release happens very gradually, but very close to the sun's surface. In this case, a phenomenon called thermal nonequilibrium causes the loops to go through periodic fits of dynamic behavior. The latest computer simulations suggest that these solar temper tantrums may also be able to explain the observations.

Either way, accurate space weather forecasts rely on a good physical understanding of how the corona works. How the corona radiates depends entirely on its thermal structure, and its thermal structure depends entirely on its heating. Detailed studies of nanoflare heating and thermal nonequilibrium are taking scientists one step closer to understanding the Sun-Earth connection.

NASA/Goddard Space Flight Center


Related Solar Atmosphere Current Events and Solar Atmosphere News Articles


Hinode, IRIS, and ATERUI cooperate on 70 year old solar mystery
Solar physicists have captured the first direct observational signatures of resonant absorption, thought to play an important role in solving the "coronal heating problem" which has defied explanation for over 70 years.

New Ice Age may begin by 2030
The arrival of intense cold similar to the one raged during the "Little Ice Age", which froze the world during the XVII century and in the beginning of the XVIII century, is expected in the years 2030--2040.

Strong evidence for coronal heating theory presented at 2015 TESS meeting
The sun's surface is blisteringly hot at 10,340 degrees Fahrenheit -- but its atmosphere is another 300 times hotter.

This week from AGU: Undersea eruptions, Shale boom and ozone pollution, Titan's atmosphere
Saturn's moon Titan is the only moon in the solar system that has an atmosphere as thick as Earth's, consisting of more than 98 percent nitrogen, roughly 1.4 percent of methane, and smaller amounts of other gases.

NASA Spacecraft Provides New Information About Sun's Atmosphere
NASA's Interface Region Imaging Spectrograph (IRIS) has provided scientists with five new findings into how the sun's atmosphere, or corona, is heated far hotter than its surface, what causes the sun's constant outflow of particles called the solar wind, and what mechanisms accelerate particles that power solar flares.

NASA-Funded Rocket Has Six Minutes to Study Solar Heating
On Sept. 30, 2014, a sounding rocket will fly up into the sky - past Earth's atmosphere that obscures certain wavelengths of light from the sun -- for a 15-minute journey to study what heats up the sun's atmosphere. This is the fourth flight for the Very high Angular Resolution Ultraviolet Telescope, or VAULT, will launch from the White Sands Missile Range near Las Cruces, New Mexico.

Solar explosions inside a computer
Strong solar flares can bring down communications and power grids on Earth. By demonstrating how these gigantic eruptions are caused, ETH physicists are laying the foundations for future predictions.

Researchers Discover New Clues to Determining the Solar Cycle
Approximately every 11 years, the sun undergoes a complete personality change from quiet and calm to violently active. The height of the sun's activity, known as solar maximum, is a time of numerous sunspots, punctuated with profound eruptions that send radiation and solar particles out into the far reaches of space.

Best Evidence Yet For Coronal Heating Theory Detected by NASA Sounding Rocket
Scientists have recently gathered some of the strongest evidence to date to explain what makes the sun's outer atmosphere so much hotter than its surface.

Solving sunspot mysteries
Multi-wavelength observations of sunspots with the 1.6-meter telescope at Big Bear Solar Observatory (BBSO) in California and aboard NASA's IRIS spacecraft have produced new and intriguing images of high-speed plasma flows and eruptions extending from the Sun's surface to the outermost layer of the solar atmosphere, the corona.
More Solar Atmosphere Current Events and Solar Atmosphere News Articles

Ultraviolet and X-ray Spectroscopy of the Solar Atmosphere (Cambridge Astrophysics)

Ultraviolet and X-ray Spectroscopy of the Solar Atmosphere (Cambridge Astrophysics)
by Kenneth J. H. Phillips (Author), Uri Feldman (Author), Enrico Landi (Author)


The solar atmosphere, above the Sun's surface layers, reaches mega-kelvin temperatures and high levels of dynamic activity through processes involving a pervading magnetic field. This book explores one of the principal means of understanding the solar atmosphere, its ultraviolet and soft X-ray emission. The ultraviolet and X-ray spectra of the Sun's atmosphere provide valuable information about its nature - the heat and density of its various parts, its dynamics, and chemical composition. The principles governing spectral line and continuous emission, and how spectral studies lead to deductions about physical properties, are described, together with spacecraft instrumentation from Skylab, SolarMax, Yohkoh, SOHO, TRACE, and Hinode. With introductions to atomic physics and diagnostic...

Solar

Solar
by Ian McEwan (Author)


WINNER OF THE BOLLINGER EVERYMAN WODEHOUSE PRIZE FOR COMIC FICTION Michael Beard is a Nobel prize-winning physicist whose best work is behind him. A compulsive womaniser, Beard finds his fifth marriage floundering. But this time it is different: she is having the affair, and he is still in love with her. When Beard's professional and personal worlds collide in a freak accident, an opportunity presents itself for Beard to extricate himself from his marital mess, reinvigorate his career and save the world from environmental disaster. Ranging from the Arctic Circle to the deserts of New Mexico, this is a story of one man's greed and self-deception; a darkly satirical novel showing human frailty struggling with the most pressing and complex problem of our time.

Solar Energy: The Physics and Engineering of Photovoltaic Conversion, Technologies and Systems

Solar Energy: The Physics and Engineering of Photovoltaic Conversion, Technologies and Systems
by Olindo Isabella (Author), Klaus Jäger (Author), Arno Smets (Author), René van Swaaij (Author), Miro Zeman (Author)


This comprehensive textbook takes you through everything you need to know about solar energy from the physics of photovoltaic (PV) cells through to the design of PV systems for real-life applications. Solar Energy is an invaluable reference for researchers, industrial engineers and designers working in solar energy generation. The book is also ideal for university and third-level physics or engineering courses on solar photovoltaics, with exercises to check students’ understanding and reinforce learning. It is the perfect companion to the Massive Open Online Course (MOOC) on Solar Energy (DelftX, ET.3034TU) presented by co-author Arno Smets. The course is available in English on the nonprofit open source edX.org platform, and in Arabic on edraak.org. Over 100,000 students have already...

The Solar System

The Solar System
by Michael A. Seeds (Author), Dana Backman (Author)


With this newly revised Ninth Edition of THE SOLAR SYSTEM, the authors' goals are to help you use astronomy to understand science--and use science to understand what we are. Fascinating, engaging, and visually vibrant, this text will help you answer two fundamental questions: What are we? And how do we know?

Solar System: A Visual Exploration of All the Planets, Moons and Other Heavenly Bodies that Orbit Our Sun

Solar System: A Visual Exploration of All the Planets, Moons and Other Heavenly Bodies that Orbit Our Sun
by Marcus Chown (Author)


Based on the latest ebook sensation developed by Theodore Gray and his company Touch Press, this beautiful print book presents a new and fascinating way to experience the wonders of the solar system

Following the stunning success of both the print edition and the app of The Elements, Black Dog & Leventhal and Touch Press have teamed up again. Solar System is something completely new under the sun. Never before have the wonders of our solar system?all its planets, dwarf planets, the sun, moons, rocky Asteroid Belt, and icy Kuiper Belt?been so immediately accessible to readers of all ages.

Beginning with a fascinating overview and then organized by planet, in order of its distance from the sun, Solar System takes us on a trip across time and space that includes a front-row...

The Solar Sales Leap: Stop Knocking on Doors, Cold Calling, and Buying Leads and Start Using the Internet to Grow Your Solar Energy Business for the Long Term

The Solar Sales Leap: Stop Knocking on Doors, Cold Calling, and Buying Leads and Start Using the Internet to Grow Your Solar Energy Business for the Long Term
by Erik Curren (Author), Lindsay K. Curren (Editor), Lindsay K. Curren (Editor)


"In the rapidly changing PV industry, The Solar Sales Leap is a must-read for anyone involved in the task of marketing solar power to residential homeowners. Curren summarizes here what many PV installers are failing to recognize when trying to capture the attention of a qualified residential solar power prospect.”-- Joe Sadonis, Solar Consultant, Paradise Clean Energy The Solar Sales Leap will help anyone who works in marketing, sales, or management at a residential or commercial solar contractor to sell more solar with the powerful new tools of online outreach. These days, even while solar panels are getting cheaper and cheaper, the cost of acquiring a new solar customer remains high — around $3,000 on average for a residential installation, according to GTM Research. This raises...

The Solar System

The Solar System
by Michael A. Seeds (Author), Dana Backman (Author)


With this newly revised Eigth Edition of THE SOLAR SYSTEM, the authors' goals are to help you use astronomy to understand science--and use science to understand what we are. Fascinating, engaging, and visually vibrant, this text will help you answer two fundamental questions: What are we? And how do we know?

Giant Planets of Our Solar System: Atmospheres, Composition, and Structure (Springer Praxis Books / Geophysical Sciences)

Giant Planets of Our Solar System: Atmospheres, Composition, and Structure (Springer Praxis Books / Geophysical Sciences)
by Patrick G.J. Irwin (Author)


This book reviews the current state of knowledge of the atmospheres of the giant gaseous planets: Jupiter, Saturn, Uranus, and Neptune. The current theories of their formation are reviewed and their recently observed temperature, composition and cloud structures are contrasted and compared with simple thermodynamic, radiative transfer and dynamical models. The instruments and techniques that have been used to remotely measure their atmospheric properties are also reviewed, and the likely development of outer planet observations over the next two decades is outlined.

Solar Engineering of Thermal Processes

Solar Engineering of Thermal Processes
by John A. Duffie (Author), William A. Beckman (Author)


The updated, cornerstone engineering resource of solar energy theory and applications. Solar technologies already provide energy for heat, light, hot water, electricity, and cooling for homes, businesses, and industry. Because solar energy only accounts for one-tenth of a percent of primary energy demand, relatively small increases in market penetration can lead to very rapid growth rates in the industryâ??which is exactly what has been projected for coming years as the world moves away from carbon-based energy production. Solar Engineering of Thermal Processes, Third Edition provides the latest thinking and practices for engineering solar technologies and using them in various markets.

This Third Edition of the acknowledged leading book on solar engineering features: ...

Solar Photovoltaic Basics: A Study Guide for the NABCEP Entry Level Exam

Solar Photovoltaic Basics: A Study Guide for the NABCEP Entry Level Exam
by Sean White (Author)


Whether or not you are taking the NABCEP Entry Level Exam, learning the material covered in this book is the best investment you can make towards your place in the solar industry. This book explains the science of photovoltaics (PV) in a way that most people can understand using the curriculum which reflects the core modules of the NABCEP Entry Level Exam. Providing complete coverage of the NABCEP syllabus in easily accessible chapters, addressing all of the core objectives that will aid in passing the PV Entry Level Exam including the ten main skill sets: PV Markets and Applications Safety Basics Electricity Basics Solar Energy Fundamentals PV Module Fundamentals System Components PV System Sizing Principles PV System Electrical Design PV System Mechanical...

© 2016 BrightSurf.com