Space WeatherCauses and Consequences

An introduction to Space Weather

• What is it?• Where does it come from?• Who is impacted?

Rodney ViereckNOAA Space Environment Center

Boulder Colorado

Space Weather:

What is it?Space Weather refers to changes in the space environment near Earth

Earth

Sun

Sun: • Energy released in the form of…

• Light• Particles (electrons and

protons)• Magnetic Field

• Activity Cycles• 27 Days (solar rotation)• 11 years (solar cycle)• 22 years• 88 years• 208 years

Space Weather refers to changes in the space environment near Earth

Sun

Interplanetary Space:• Not quite a vacuum• Solar Wind

•Electrons and protons•Magnetic field

• Disturbances from the sun make waves in the solar wind

Interplanetary Space

Space Weather:

What is it?

Earth

Space Weather refers to changes in the space environment near Earth

Magnetosphere

Magnetosphere: • Created by Earth’s magnetic field• Deformed by the Solar Wind

• Not Quite a Vacuum•Particles (electrons and protons) trapped on magnetic field lines

Sun

Interplanetary Space

Space Weather:

What is it?

Earth

Space Weather refers to changes in the space environment near Earth

Magnetosphere

Sun

Interplanetary Space

IonosphereIonosphere: • Layer of electrons at the top of the

atmosphere (100 – 300 km up)• Formed when extreme ultraviolet

light from the sun hits Earth’s Atmosphere

• Critical in the reflection and transmission of radio waves

Space Weather:

What is it?

Earth

Other Space Weather Terms

• Solar Flare: An eruption on the sun that emits light (UV and x-rays) and often energetic particles.

• Energetic Particles: electrons and protons that have been accelerated to high speeds and can upset technological systems.

• Solar Wind: The outward flow of electrons, protons, and magnetic field from the sun.

• CME (Coronal Mass Ejection): A disturbance in the solar wind caused by an eruption on the sun.

• Geomagnetic Storm: The disturbance in the Near-Earth environment that can upset technological systems and also creates aurora.

• Radiation Storm: A large flux of solar energetic protons as measured near Earth that can upset technological systems .

• Radio Blackout: An enhancement in the lower ionosphere as a result of large x-ray flares that can upset technological systems .

The SunSolar Flares

The sun in X-rays From GOES 12

•Rotates every 27 days

•Has an 11-year cycle of activity

An Erupting Prominence

A Solar Flare

Image from NASA TRACE Satellite

Image from NASA SOHO Satellite Hill

Solar Photons (Light)

•Visible light (small slow changes)–Most of the energy output– Impacts climate

•UV light (medium slow changes)– Impacts ozone production and loss–May impact climate

•EUV light (large changes)–Affects radio communication–Affects navigation–Affects satellite orbits

•X-ray light (Can change by a factor of 1000 in five minutes)

–Affects radio communication

Solar spectrum

Solar variability

Atmospheric penetration

X-ray flare variability (minutes)

LeanX-Rays EUV

SEC Product for Radio Operators

Effect of Solar X-rays on D-Region and HF Propagation.

• D-Region Absorption Product based on GOES X-Ray Flux (SEC Product)– The map shows regions affected by the increased D-region ionization resulting

from enhanced x-ray flux during magnitude X-1 Flare

TJFR

Effect of Solar X-Ray Flares on D-Region of Ionosphere and HF Propagation

The map shows regions affected by the increased D-region ionization resulting from enhanced x-ray flux during magnitude X-1 Flares

CMEs (Coronal Mass

Ejections) in Interplanetary

Space• Solar flares send out – Light (mostly x-rays)– Energetic particles– Magnetic structures

• The CME disturbances propagate away from the sun but their paths are modified by the background solar wind and the sun’s magnetic field.

• Some of these disturbances reach Earth.

Images from NASA SOHO Satellite

Images from NASA SOHO Satellite

CMEs

Hill

MagnetosphereWhat happens when a CME hits Earth?

1. Solar wind is deflected around Earth2. Deflected solar wind drags Earth’s magnetic field with it3. Magnetic field lines “reconnect” and accelerate particles4. Accelerated particles follow field lines to Earth

Aurora is produced when particles hit Earth’s atmosphere

1. Solar wind is deflected around Earth

2. Deflected solar wind drags Earth’s magnetic field with it

3. Magnetic field lines “reconnect” and accelerate particles

4. Accelerated particles follow field lines to Earth

AuroraOuterRadiationBelt

InnerBelt

Onsager

Energetic Particle Effects

Spacecraft Systems

• Systems affected– Spacecraft electronics

• Surface Charging and Discharge

• Single Event Upsets• Deep Dielectric

Charging

– Spacecraft imaging and attitude systems

Polar Satellite Image Degradation

SOHO Satellite Image Degradation

Zwickl

Spacecraft Surface Charging (NASA animation)

Ionosphere

• The particle collide with the atmosphere and produce the Aurora and currents in the ionosphere

• As geomagnetic activity increases, the aurora gets brighter, more active, and moves away from the polar regions.

– Electric Power is affected

– Navigation Systems are affected

– Radio Communications are affected

Image from NASA IMAGE Satellite

Energetic Particle Effects

High Latitude HF Communications

Polar airline routes loose ground communications

• Alternate routes required• Uses more fuel• Flight delaysSample of Airline Flights

Affected:• 10/26/00: Lost of HF prior to 75N, re-

route off Polar route with Tokyo fuel stop. 15:00 flight now 20:30

• 11/10/00: Due to poor HF, ORD to HKG flown non-polar at 47 minute penalty

• 3/30/01-4/21/01: 25 flights operated on less than optimum polar routes due to HF disturbances resulting in time penalties ranging from 6 to 48 minutes

• 11/25/00: Polar flight re-route at 75N due to Solar Radiation, needed Tokyo fuel stop

• 11/26/00: Operated non-polar at 37 minute penalty due to solar radiation

• 11/27/00: Operated non polar at 32 minute penalty due to solar radiation.

• 11/28/00: Operated non-polar at 35 minute penalty due to solar radiation

Polar 2

Polar 3

Polar 1

Polar 4

Polar Airline Routes

North Pole Chicago

Hong Kong

Alaska

Radio BlackoutDuring

Particle Events

TJFR

Geomagnetic Storm EffectsMarch 1989

Hydro Quebec Loses Electric Power for 9 Hours

Transformer Damage

Electric Power Transformer

Geomagnetic Storm Effects

Aurora• Intensity and location depend on

strength of storm• Best time to view is around

midnight• No guarantee that aurora will occur

G5G3

G1

Photo by Jan Curtis, http://www.geo.mtu.edu/weather/aurora

NASA Animation

Sun to Earth

• An animation of a space weather event as it starts at the sun and end up at Earth– Solar Flare

• Light• Particles• CME

– Magnetosphere• Deflects the solar wind• Responds to the disturbance• Accelerates particles

– Ionosphere• Accelerated particles collide with the atmosphere

producing the aurora

Space Weather StormsTiming and Consequences

• At T = 0: A Flare and/or CME Erupts on the Sun

• 8 Minutes later: First blast of EUV and X-Ray light increases the ionospheric density

– Radio transmissions are lost

– Navigation errors increase

• 30 min. to 24 hrs.: Energetic Particles Arrive

– Astronauts are at risk

– High altitude aircraft crew are at risk

– Satellites are at risk

– Radio transmissions are lost

• 1 to 4 Days: CME Arrives and energizes the magnetosphere and ionosphere

– Electric power is affected

– Navigation errors increase

– Radio communications are affected

Movie from NASA SOHO Satellite

What Controls the Size a Space Weather Storm?

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• The Size of Flare or CME–Big solar events tend to make big storms

• The Location of the flare site on the SUN

–If it is directed at Earth, it is more likely to make a storm

–If it toward the east side of the sun, the particles will arrive sooner

• The Direction of the Magnetic Field in the CME

–If the interplanetary magnetic field is southward, then there will likely be a big storm

Note, there does not have to be a solar flare or CME to create a geomagnetic storm

Space Weather Scales

• Three Categories

– Geomagnetic Storms(CMEs)

– Solar Radiation Storms(Particle Events)

– Radio Blackouts(Solar Flares)

CombsRabin

How Often Do Space Weather Storms Occur?

• Solar Cycle is about 11 Years

Radiation Storms1-4 per month at max

Geomagnetic Storms

3-5 per month at max

Radio Blackouts50-100 per month at max

Sunspot Number11-year cycle

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000Year

Eve

nts

Per

Mo

nth

Eve

nts

Per

Mo

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Eve

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Per

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Murtaugh

The Solar Cycles of the Past• Sunspots have been recorded for the last 400

years• Note that there were no sunspots for nearly

60 years after 1640• During the same period, it was very cold in

Europe. This is a period called “The Little Ice Age”

• Is there a Connection?• Recent studies say there is

Solar Maximum

SolarMinimum

Sun and Climate

• The sun is the primary engine for weather and the climate

• Very large climate changes (Ice ages) are known to be caused by changes in solar irradiance (amount and distribution of sunlight)

• The sun is likely responsible for much of the global warming… up to 1960s

NCAR Climate Model

Ammann: SORCE 2003

Summary

•Space Weather Storms come in three primary categories

•Each category arrives at a different time

•Each category affects different users and technologies

Radio Blackouts

Bursts of X-ray and EUV radiation

Radiation Storms

Energetic Particles(electrons and

protons)

Geomagnetic Storms

When the CME reaches Earth

Arrival Time

8 Minutes 30 min. to 24 hrs.

1 to 4 days

Systems Affected

Radio Comm.

Navigation

SatellitesAstronauts

AirlinesRadio Comm.

Electric Power

Radio Comm.Navigation