Space Weather W. Dean Pesnell, Shea Hess Webber and Emilie Drobnes SDO Project Science and E/PO Team Members July 2006

Space WeatherSpace Weather

W. Dean Pesnell, Shea Hess Webber and Emilie Drobnes

SDO Project Science and E/PO Team Members

July 2006

NES/Space Weather 2

AgendaAgenda

• Presentation (60 minutes)– Space weather, solar activity, and why we study the

Sun today– Predicting Space Weather at the Earth and other

planets

• Three activities (75 minutes)– Solar telescopes– Scales of the solar system– Space Weather in the solar system

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Space WeatherSpace WeatherSpace Weather happens when the Sun sends out light, particles, and magnetic fields that hit objects in the solar system.

Flares: Bright flashes in the Sun’s corona. X-rays and EUV from flares affects the upper atmosphere of the Earth, satellites, and astronauts

CMEs: The “storms” of Space Weather, coronal mass ejections occur when material is driven off the Sun. Magnetic fields are carried into the heliosphere along with the particles. A prominence is often destroyed when a CME is created. Flares and CMEs are both “beamed”—

different planets will see different patterns.

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A flaring region observed by TRACE between July 14-17, 2000. Notice the motion of material and the many small brightenings that can be seen.

Pictures were made in light with a wavelength of 171 Å.

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A CME observed by LASCO on SoHO between July 14-17, 2000. Notice the interference of particles at the beginning of the movie and the several CMEs later.

Both flares and CMEs are “focused” and affect planets and satellites on one side of the Sun (or less). This complicates the study of Space Weather.



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Many technologies are affected by Space Weather

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Space WeatherSpace WeatherWhat is Space Weather?

Why study Space Weather?

How does Space Weather affect the Earth?

160 Years of Space Weather and what we use to study it!

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Solar Cycle in the EUVSolar Cycle in the EUV

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Solar Max. in the VisibleSolar Max. in the Visible



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We will discuss three areas affected by Space Weather


Everyday RadiationEveryday RadiationWe live in a world bathed with low-level radiation. Your daily dose is roughly 1 mrem/day = 0.4 µS/hr. This radiation comes from

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cosmic rays and radon decay. At the ground we see mostly muons (which where used to “prove” relativistic time dilation).

We measure the neutrons caused by cosmic rays at the South Pole.

Inexpensive gauges can shown some of the radiation that we live with everyday. This one does not measure neutrons or muons.

Recommended dose (sieverts)

Age Male Female

25 0.8 0.5

35 1.4 0.9

45 2.0 1.3

55 3.0 1.7


Astronaut SafetyAstronaut SafetyThese particles are also affect air crews in high-altitude flights.

Ionizing radiation harms humans and other life and may cause changes in the climate. Because most of the surface radiation is from cosmic rays, and cosmic rays are repelled by the solar magnetic field, solar activity protects us from this radiation source.

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The radiation dose is higher and more dangerous as you leave the Earth’s surface.

The radiation dose in a flight across the USA is roughly 4 the dose at the Earth’s surface.

The radiation dose in a Concorde was 100 the dose at the Earth’s surface.


Astronaut SafetyAstronaut Safety

In space, flare photons and energetic particles from CMEs can damage astronauts and equipment as they pass through each.

Space suits or space ships must protect against solar UV radiation and particles. On the surface we are protected by the Earth’s atmosphere and magnetic field. The importance of cosmic rays is reduced but still not understood. All Apollo missions occurred during a decline of solar activity.

The radiation dose is even higher and more dangerous when you orbit the Earth or travel to another planet in the solar system.

ISS Astronaut prepares for an EVA.

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CommunicationsCommunicationsDuring a flare the increases in the X-ray and extreme ultraviolet radiation changes the Earth’s atmosphere high above the surface.

Satellites use radio waves to send information to the ground (GPS, data, TV, phone calls.) Changes in the ionosphere will reflect the waves in different directions, distorting radio communications and navigation signals. We can use this to study Space Weather.


Satellite DragSatellite DragThe increase in X-ray and extreme ultraviolet radiation during solar maximum heats the Earth’s thermosphere. This causes the atmosphere to expand and deorbit satellites.

Skylab reentered early due to Space Weather

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The increased drag during solar maximum also helps to remove orbital debris, an increasing problem in low-Earth orbits.


Sudden Ionospheric Sudden Ionospheric Disturbances (SIDs)Disturbances (SIDs)

• VLF waves (3-30 kHz, = 10-100 km) are reflected by the increased electron density

• If you monitor a remote VLF station you can see the enhancements between you and the station


The inset graph shows my results compared with the satellite GOES-6. During the meridian passage of the Sun (and summertime) the sensitivity of the system can be as good as C-level flares. The transmitter location is Rugby, UK. It transmits continuously at 60 kHz. One use of SID monitors is to fill the gaps in the data of the GOES system.(This satellite is in eclipse from 8-9 UTC.) Another is provide real-time data to models of the upper atmosphere to help understand satellite drag and other effects of Space Weather.

SID Monitor of Gote Flodqvist in Farste, Sweden


Predicting Space Predicting Space WeatherWeather

Watching when and where flares and CMEs occur is one important part of predicting space weather. You must also measure the density, speed, and magnetic field of the solar wind as it moves from the Sun to the Earth. Predictions are for today, tomorrow, and next cycle.

Will Hubble reenter before 2015? 2025?


Predicting Space Predicting Space WeatherWeather

Watching the Sun is only one part of predicting space weather. You must also measure the response of the Earth. Until the telegraph and radio were invented, aurorae were the only visible sign of space weather.

In present times we want to know when communications will be affected, astronauts endangered, and what (or who) destroyed a spacecraft.

Aurorae are visible only at high latitudes. Aurora bands over Quartz Lake State Park, Alaska on taken on 6 September, 1996, ©Jan Curtis.


From Earth to MarsFrom Earth to MarsThe atmosphere of Mars changes with season and solar activity. To land on Mars using aerobraking requires us to know the solar activity and space weather at Mars. When leaving the Earth this is easy because we are behind Mars on the Sun. When landing we are ahead and need to predict activity on the side not visible from Earth.


AnalogyAnalogy1. Like regular weather, Space Weather has many facets and

complications.

2. Direct effects, such as flares and CMEs, are like the lightning and rain of weather. We guard against these effects by building things better.

3. Indirect effects, similar to needing windshield wipers, are still being discovered for Space Weather.


Possible ExercisesPossible Exercises• What is the magnetic declination for your location?• Use a model of the solar system to show why each planet

sees its own version of space weather. Easiest to show with flares, whose light travels in a straight line.

• Obtain a Sudden Ionospheric Disturbance (SID) monitor and see how space weather affects the air over your head.

• Use iron fillings to map out the field lines of bar and horseshoe magnets. Use the field probes to follow field lines. Compare these maps with EUV images of the Sun.

• Is the Earth’s magnetic field changing? • Can you see the aurora from your school? Why not?• Use pictures of the Sun, from the web or own telescopes, to

measure the rotation of the Sun.• Build a simple magnetometer and measure the changes in

the direction of the Earth’s magnetic field


How To Study the Sun?How To Study the Sun?Tracking the solar output is the best way to predict solar activity and space weather. Observations in narrow wavelength bands can measure the light, particles, and magnetic field output of the Sun. These measurements can be made with telescopes far from the Sun.

Measurements at the Sun are planned for 2020 or later. Perhaps one of your students can help design, build, and fly those satellites.

Large computer models are used to study the interior of the Sun. Right now they can simulate small parts of the Sun; soon they will model the entire convection zone-the source of the Sun’s magnetic field.

You can use your own equipment to look at the Sun, or go to Internet sites for data on today’s Sun.


SDO and the SunSDO and the SunThe Solar Dynamics Observatory (SDO) is the first Living With a Star mission. It will use telescopes to study the Sun’s magnetic field, the interior of the Sun, and changes in solar activity. Some of the telescopes will take pictures of the Sun, others will view the Sun as if it were a star.

SDO is scheduled for launch in August 2008. It will be put into a geosynchronous orbit over White Sands, NM.

Ours goals are to understand how solar activity is produced, how it affects our society, and to predict when the most destructive effects will happen.


SummarySummary1. Space Weather affects astronauts & satellites in space, radio

communications, satellite lifetimes, and power lines.

2. Space Weather is generated by the flares, CMEs, and other phenomena on the Sun.

3. The Sun’s magnetic field waxes and wanes with the solar cycle. As the Sun changes so does its ability to generate Space Weather.

4. SDO will measure the Sun’s light output and magnetic field continuously, allowing us to predict when the Sun will affect spacecraft and society.


Other ResourcesOther Resources• Sun-Earth Connection: http://sec.gsfc.nasa.gov

• Living With a Star: http://stargazers.gsfc.nasa.gov

• “Our Very Own Star: The Sun:” http://stargazers.gsfc.nasa.gov/epo/resources/Sun_booklet_English.htm

• Solar Dynamics Observatory: http://sdo.gsfc.nasa.gov

• Solar Heliospheric Observatory: http://soho.nascom.nasa.gov

• Space weather games and tools: http://www.spaceweathercenter.org

Check out the magneto mini golf

• Today’s Space Weather: http://www.spaceweather.com

• Space Weather Data: http://sec.noaa.gov


ProductsProducts

• UV Beads: http://www.teachersource.com

• Iron filings: http://sciencekit.com

• Windows on the Universe UV Activity: http://challenger.org/wotu/

• Interactive parallax program: http://www.astro.washington.edu/labs/parallax/solar.html

• SunWise School Program: http://www.epa.gov/sunwise/


Contact InformationContact Information

• W. Dean Pesnell: [email protected]

• Emilie Drobnes: [email protected]


Wanted, Day or Night: the Sun

Diameter: 1.4 million km (0.86 million miles, 110 Earth diameters)Mass: 2 1030 kg (2 nonillion kg, 330,000 times the Earth)Energy output: 4 1026 W (0.4 octillion W)Surface Temperature: 5770 K (10,420 ºF)Last Known Location: 150 million km (93 million miles) awayAKA: Old Sol, Die Sonne, Soleil, Sunce, Inti, Re, UTU, Helios

2004/07/09 Rz = 17

WARNING: The Sun is armed with very intense light. Approach with caution. Never look directly at the Sun without

protection.

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Playground SundialPlayground Sundial

Layout the area.

Draw an ellipse.

Transfer plan to ground.

Can be done in chalk or paint.

Understand true vs. magnetic North.

Distinguish solar vs. civil time.

Students must:

Documents

Space Weather W. Dean Pesnell, Shea Hess Webber and Emilie Drobnes SDO Project Science and E/PO Team Members July 2006