Space Weather

Effects and Consequences.

The case of MOPITT on board of Terra spacecraft.

Florian NichitiuDepartment of Physics, University of Toronto, Canada

July 2004-Frascati

Space Climate/Weather Space Climate/Weather refers to changes in the space environment and effects that those changes have on Earth and mankind’s activities.These affect Earth climate on various temporal and spatial scale as well as communications, navigation and many other space and ground based systems.

Space Climate or Climate in near-Earth space is characterized for long-term observations of space environment. Space Weather refers for short-term , very dynamic and highly variable conditions in the geo-space environment.

• Impact on Solar Physics ( with consequences even for fundamental particle physics; for example neutrino oscillation problem: SNO, Canada)

• It is important in order to improve our understanding of the Earth’s climate and weather in relation with (some time) controversial problem of signatures of solar activity variability in meteorological parameters, Earth’s atmosphere chemistry and long term trends in Earth’s Climate.

• Big impact on space technology.Need to have Space Weather nowcast and forecast . The very complex radiation effects on spacecraft systems and instruments, end even on Earth technology are influenced by Space Weather induced variations in the Earth’s space environment

Sun - Geospace environmentSources of Space Weather Sun : EM radiation & particle radiation Galactic Cosmic Rays

Indicators of Solar activity Solar and geomagnetic indices are used to describe the activity levels of the Sun and the disturbance of the geomagnetic field.

• Sun Spot Number(SSN)

• Solar Radio emissions : Flux of 10.7 cm ( Ottawa index). Are essential measurements of the total amount of thermal emissions from chromosphere and lower corona.The F107 index gives a good measure of the UV radiation output ( new E107).

There are suggestions that 10.7 cm flux is also an excellent indicator of magnetic activity

on the Sun.

• UV flux, irradiance.

• Magnetic indices ( aa, Ap, Kp, Dst, etc..).Geomagnetic indices typically describe the variations of the geomagnetic field over a certain time period.They provide a measure of the disturbance of the magnetosphere which has direct consequences for the charged particle space environment.

• Trapped proton and electron fluxes

• Galactic Cosmic Rays, protons of very high energy and neutrons fluxes.Flux periodicity correlated with IMF and erosion effect of Earth atmosphere via Solar activity.

Variations and periodicity Solar radiation as main element of space weather, varies at very different time scales.

due to solar activity due to Solar-Earth system

• ~27 days (Solar rotation)• ~11.2 years (Schwabe cycle, cycle of

solar activity)• ~22 years ( Hale cycle)

(magnetic cycle : the original magnetic polarity is restored every second 11-year)

• 80-90 years ( Gleissberg cycle) (seen by an enveloping curve of peaks of sunspot record)

• ~205 years (de Vries cycle): Sporer minima (AD 1420-1540) Maunder minima (AD 1645-1715)

• Seasonal variations (related with seasonal variations of geomagnetic activity --> variations of outer belt electron population); due to motions of the Earth around Sun (--> annual changes in the Earth’s atmosphere introduce seasonal modulation in low-altitude trapped proton population)

• Daily variations of Earth’s magnetic dipole (due to axial rotation of the Earth; angle between dipole and rotational axes ~11 deg.)

Longer cycles – important for effects related with Earth’s climate and long term trends

Space Radiation Environment

Electrons, protons and ions

Trapped by the Earth’s magnetic field :

Radiation Belts ( Van Allen Belts) e E< 2-3 MeV; p E< 200-300 MeV

Passing through the solar system :

Solar Wind ( e, p He4 ) E< 100 KeV Solar Particle Events mainly protons E = 1 - >100 MeV Galactic Cosmic Rays E up to TeV

Radiation Belts-Oct and Nov 1957 : Sputniks 1 & 2 ( SU)

-Jan 1958 : Explorer 1 ( US)

Expected rate 30 count/sec(Geiger-Muller counter;J van Allen)

& … zero count/sec !

-Explorer 2 =failed, BUT-March 25, 1958 Explorer 3: 30 /s ; increase to 128 /s (max on tape) then to zero c/s and again to 128. Near the perigee, back to expected 30c/sErnest Ray :“My God, space is radioactive !”

1) Circular motions with gyro-radius about the field line : T~ milliseconds2) Bounce back and forth along a field line.Reversing direction at a mirror point: T~ seconds.3) Drift of particles around the Earth: T~ one hour. Electrons drift to east, protons drift to west

A charged particle became trapped in those regions where the magnetic fieldlines are closed

There are two main belts:I- inner belt : e and p ( up to 2.4 Re)II- outer belt : e (2.8 – 12 Re)

Inner & outer belts

I II I

The Earth’s magnetic field is not symmetric

South Atlantic Anomaly ( also called Brazilian Anomaly or Capetown Anomaly) is a lowest magnetic field region located at 26S, 53W.

SAA is frequently said is due to the

The tilt of the dipole axis with respect to the rotational axis

And due to the displacementof the geomagnetic axis from the center of the Earth

Electrons AE-8 Protons AP-8

Radiation Belt Models

Plasma and Solar WindContinuous flux of particles ( e, p, He) from sun;(Expanding magnetized plasma generated by the Sun) -characterized mainly by speed and density.

Geomagnetic activity is controlled by the solar wind speed and IMF orientation. An important parameter:

Bz oscillation and a ‘turn’ to <0 values magnetic storm(Kp>5)

Electron enhancements- tendency to occur at the solar rotation period (27 days)

Strong correlation between electron precipitations (E>30 keV) at polar orbit and solar wind speed at 1 UA.-consequences for physico-chemistry parameters of the atmosphere.

Solar Energetic ParticlesSEP or SPE (Solar Proton Events)

( Solar Cosmic Rays)Origin: Solar flares and Coronal Mass Ejections (CME) p, e & He emitted by the sun in burst during ‘solar storms’ -energies > 10 MeV/nucleon -access to open magnetic fields of polar cap.Produce also : X-rays; gamma-rays, UV light burst and very fast wind flow which can inject protons into the trapping region ( even create ‘second proton belt’)

Fluence: from 10^5 to 10^11 part/cm^2

Duration of event: from one to several days

“Bastilia” Solar Event 14 July 2000

SPE Periodicity: Frequency spectra of solar proton fluence of Energy > 30 MeV periods of ~ 11 years and 3-4 years. Impossible to predict

-greater occurrence frequency during maximum solar activity- and during decline of cycle

NASA SOHO Image Solar Flare

Cosmic RaysGalactic Cosmic Rays: fully ionized particles of all stable elements (90% p ~7% He) Origin: galactic and extragalactic; Energies up to TeV Energy spectrum max at 0.3-1 GeV/nucleon The incoming charged particles are ‘modulated’ by the solar wind and IMF which decelerates and partially excludes the lower energy GCR from the inner solar system. There is a significant anticorrelation between solar activity and the intensity of the CR with E< 10 GeV.

Variations of proton counts E=80-215 MeV of MEPED detectoraboard the TIROS/NOAA spacecraft

Natural Albedo RadiationIs in fact the secondary radiation generated in the inner magnetosphere due to:

-nuclear reactions by GCR and SPE interactions with : - protons of the inner belt - and atoms of the atmosphere-secondary CR decay ( pions, muons..)This radiation component consists mostly of: - neutrons - e- and e+ - protons ( and antiprotons) , nuclei

There is also an anticorrelation between solar activity and the intensity ofsecondary radiation as a result of atmosphere expanding ( and increasing of nuclear interaction rate) during high solar activity.

Short term variations of Albedo Radiation

-When the Sun releases a large burst of matter and magnetic disturbance amagnetic storm which prevent many cosmic rays from entering the atmosphere.Forbush decrease detected bythe Inuvik neutron monitor at 23 Mar 1991.

“Solar cosmic rays” producedby a solar flare are recorded as a sharpincrease in secondary neutrons flux. The event of May 24, 1990 seenby Inuvik, Deep River and Goose Bay neutron monitors.

Low energy particles- correlated with SA

High energy particles- anti-correlated with SA

Solar Activity

Effects

on

Spacecraft

and

instruments

Solar irradiance- correlated with SA

Neutron Flux- anti-correlated with SA

Neutrons cosmogenic radionuclides (14C,10Be,36Cl) : extend record of Solar Activity : signal of past climate variations

Effects onEarth Climate

Radiation effect on spacecraft systems and instruments

Spacecraft anomalies: from -------- easily recovered to -------- total mission failure origin: -- engineering (operation fault, mechanism failure and ageing) -- space weather which simulate engineering faults— BUT not only

Based upon the effect upon the s/c :

Surface charging | Photonics noise Deep dielectric charging | Total dose effects Single Event Upset (SEU) | Material degradation Solar radio frequency interference | Spacecraft drag

Surface Charging

S/C immersed in a cool, dense plasma e, ions, secondary emitted particles: photoelectrons and backscattered electrons Gives net s/c potentialAnd this lead to discharges noise into the system; false command, change the physical characteristics of subsystems.Occurs predominantly during geomagnetic storms ( for K index >=6)NightDay transitions are especially problematic during storms: photoelectric effectis abruptly present/absent trip discharges

There is also a strong local time asymmetry: majority Surface Charging anomalies occur

during the night

Deep dielectric charging

Is a problem primarily for high altitude s/cRelativistic electrons (E> 1MeV) can easily penetrate s/c shielding and can build up charge where they come to rest ( in dielectrics). For high electron fluxduring extended period of time abrupt discharges deep in the s/c.Discharges appear to correlate well with long periods of high fluxes.

High fluxes of these electrons vary with 11 year Solar Cycle.This variation is dictated by the nature of the sun’s output and by the character of the solar wind incident on the magnetosphere.

Was also found that the equinoctial fluxes of electrons (this is an average over 7 years) were nearly a factor of three higher than the average solstice fluxes.

Example: Anik/Intelsat (Ca) : 1994 wheel controller 1998 lost all power from solar panel array

Single Event Upset (SEU)

SEU occur when a high-energy particle penetrates s/c shielding and hit a device causing a disruption. Effects can range from simple device tripping to component latch-up or failure. Hitting memory devices result in ‘bit-flip’.SEU are normally caused by GCR and SPE and high energy trapped particles.SEU rates increase with high fluxes, but the particle energy spectrum and arrival time seen by satellites varies with the location and nature of the event on the solar disk.

Distribution of SEU over entire CRRES mission(launched July 25, 1990; returned data for ~14 months)

SEU peak occurrence frequencycorresponds to the peak of ~50MeVprotons of the inner belt.

The shoulder in distribution correspond to the peak of the secondary proton belt(from 23 Mar 1991 solar storm).

SEU attributed to Cosmic Rays

MISR camera (3 Febr—16 Febr 2000) Before cover opened(proton hits cameras designed to detect visible light)

UoSAT-2 microsatelliteSEU- (recoverable) memory upsets(from Sept 1988 to May 1992)

Satellite anomalies over SAA

SOHO LASCO C2 & C3 Images

July 14, 2000- A powerful X class flare erupted from sunspot region

9077 at approximately 10:24- it was accompanied by a full halo coronal mass ejection that is Earth directed.

April 23 2003

Bastilia Solar Event– example of High Radiation Background anomaly

SSST 1 and SSST 2 Hitsthrough J anuary 15th, 2003

-90

-60

-30

0

30

60

90

-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180

E Longitude (deg)

Pond

SSST 1

SSST 2

-150 -100 -50 0 50-50

0

50

100

150

200

250

300

350

SS

ST

1 a

nd

SS

ST

2 a

no

ma

lie

s

SAA

-48.40 Width=30.105

Longitude

-80 -60 -40 -20 0 20

0

100

200

300

400

500

600

SS

ST1

and

SS

ST2

ano

mal

ies

SAA

-24.773 Width=15.316

Latitude

TERRASolid State Star

Tracker anomalies

High Background

Device Single Events (DSE) - anomalies – occurring in a piezoelectric accelerometer within the MOPITT

(Measurements Of Pollution In The Troposphere)

instrument aboard the Terra spacecraft.

- Piezoelectric accelerometer anomalies- Location of anomalies signals- Correlation with big Solar Particle Events- Correlation with Solar Activity ( Solar Sub maximum I and II)- Conclusions and consequences

The case of MOPITT

SAA

Sun

“Terra,” is the name of the Earth Observing System (EOS) flagship satellite, launched on Dec. 18, 1999. The mission is a vital part of NASA’s Earth Science Enterprise , helping us understand and protect our home planet

Terra s/c is in a sun-synchronous polar orbit.Orbital period=98.88 min.

Altitude=705 Km.25 Jun 2004 01:41:51.36

MOPITT instrument

The vibration level is measured by two piezoelectric accelerometers

-Cooler Compressor(vibrations for x,y,z)

-Cooler Displacer(vibrations for x,y,z)

MOPITT instrument is an infraredgas correlation radiometer.It operateswith eight channels : for CO and CH4.Infrared detectors need to be cooled toless than 100 K ( by Stirling Cycle Coolers with two Compressors and two Displacers mounted back to back).

0.1 0.2 0.3 0.4 0.5 0.616229.58

16229.60

16229.62

16229.64

16229.66

16229.68

16229.70

16229.72

16229.74

Tim

e (d

ays)

Vibration (N)

-250

-200

-150

-100

-50

0

50

100

150

200

250

Selection limit

Width=0.03 NAverage=018 N

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1

0.0

0.5

1.0

1.5

2.0

2.5

LOG

(N)

LOG(Vibration intensity)

Intensity (Vibration) distribution all events

A -0.48533 0.14097B -5.03397 0.44251

MOPITT Accelerometer anomalies

109.112 109.114 109.116 109.118 109.120 109.122 109.124 109.126

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Co

mp

resso

r Z

vib

rati

on

DOY 110 (2003)

DOY 109 (2003) Comp Z Vib

110.072 110.074 110.076 110.078 110.080 110.082 110.084

Comp Z Vib

Multi-component force measurementsKistler: K-Shear accelerometer.Sensing element: quartz crystal

-80-60

-40

-20

0-50

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-20

-10

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Nr

of E

vents

Location of MOPITT accelerometer anomalies

Total time: 993 days; Daily rate=1.06 ev/day

Total Nr events over SAA=567 ( 54%)SAA rate= 0.57 ev/day

MOPITT spend only 6.25% of time over SAA SAA rate=9.14 ev/day

South Atlantic Anomaly seen by MOPITT

MOPITT Accelerometer Anomalies are caused by the radiation environment

-150 -100 -50 0 50 100 1500

5

10

15

20

25South Pole events (Long >65S) 63.470

Width=77.913-65.721 Width=66.199

Nr

of

even

ts

Longitude

SAA events = 54 %Background = 20.4%Poles ( +/- 65 ) = 25.6 %; North/South (poles) asymmetry=0.43

-20 0 20 40 60 80 100 120 140 160-100

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Lati

tud

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Nr of events

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Nr

of e

vent

s

Longitude

MOPITT Accelerometer Anomalies in South Atlantic Anomaly region

-50 -40 -30 -20 -10 00

10

20

30

40

50

60

SAACenter Width---------------------------26.065 16.675

Nr o

f eve

nts

Latitude

-80 -70 -60 -50 -40 -30 -20 -10 00

5

10

15

20

25

30

35

40

45

SAA

Nr

of

even

ts

Longitude

Center Width--------------------------47.395 28.418

Day – Night Asymmetry SAA: Day/Night = 0.72 During the Night: Lat & Long widths increase with 2-3 deg.

0 200 400 600 800 10000.00E+000

5.00E+008

1.00E+009

1.50E+009

2.00E+009

2.50E+009

3.00E+009

Proton Flux p E>1 MeV p E>10 MeV

DOY (from 2000)

0

2

4

6

8

10

12

14

16

18

N1

Y3

N1Y2

Y1

DOY (from 2000)

DS

E d

aily

rat

e

0 200 400 600 800 10000

2000000

4000000

6000000

8000000

10000000

12000000

14000000

DOY (from 2000)

Y2Y1

Proton Flux

DS

E d

aily

rat

e

p E>100 MeV

0

2

4

6

8

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14

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18

Y3

Solar Protons EventsDetected by MOPITT accelerometer

0 200 400 600 800 1000 1200-2

0

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4

6

8

10

12

14

16

18

Average daily rate=

Daily Rate for Mopitt Accelerometer Anomalies

+/- 0.041861.05734

Dai

ly R

ate

DOY(from 2000)

Doy ( Date ) # of DSE < # >196 (July 14 2000) 8 1.03 Y1197 (July 15 2000) 11 1.03 Y1314 (Nov. 9 2000) 7 0.67 Y2634 (Sept 25 2001) 3 1.24 N1676 (Nov 6 2001) 16 1.59 Y3694 (Nov 24 2001) 3 1.78 N2

Y1

Y2

Y3

Solar Proton Events

Max p Flux [pfu] @

>10 MeV >100 MeV

Y1 Jul 14/15: 2000 24000 410

Y2 Nov 09: 2000 14800 347

N1 Sept 25: 2001 12900 31

Y3 Nov 06: 2001 31700 253

N2 Nov 24: 2001 18900 4

-Solar Proton Events ( from ftp://ftp.ngdc.noaa.gov/ ,

http://www.sel.noaa.gov/weekly/)

1 pfu = 1part/(cm^2 s sr)

MOPITT Accelerometer detect SPE at 6 Nov (during the second peak of proton flux)

even if the Solar Event start at 4 Nov

The Proton Monitor data consists of counting rates in a MicroChannel Plate (MCP).The PM MCP responds to secondaries generated by ions with incident energies > 50 MeV and electrons with incident energies > 2 MeV.

CELIAS/MTOF Proton Monitor on the SOHO Spacecraft

4-7 Nov 2001 22-25 Nov 2001

Seen by MOPITT Acc ( Y3)

NOT Seen by MOPITT Acc ( N2)

1386 1389 1392 1395 1398 1401 1404 1407 14100

2

4

6

8

DS

E/D

ay

DOY(2000)

DSE/Day

100

150

200

250

300

29 Oct 2003

F107

29 Oct 2003 Solar Proton Event

Max Proton Flux (pfu) > 10 MeV > 100 MeV 29/10 : 29500 186 30/10 : 3300 110

MOPITT DSE Total # # /Day 29/10 : 9 2.15 30/10 : 7 2.15

This SPE induced a high daily rate for MOPITT DSE on two consecutive days when, as in previous cases, the high energy component (>100 MeV) reaches a large value. These MOPITT DSEs are also located on the polar regions.

0 20 40 60 80 100 120

0.0

0.5

1.0

1.5

2.0

2.5p

+ (

#10^

10/c

m^

2)

Energy (MeV)

GOES-10 DataEvent Accumulated Fluence

Y1 Y2 Y3 N1 N2

30 35 40 45 500.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

SPE not dedected by Mopitt

SPE dedected by Mopitt

GOES-10 DataEvent Accumulated Fluence Y1

Y2 Y3 N1 N2

p+

(#1

0^10

/cm

^2)

Energy (MeV)

SPE detected by MOPITT. Energy dependence

0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2

2

4

6

8

10

12

14

16

18

20

N1N2

Y2

Y3

Y1

Mo

pit

t #

DS

E d

uri

ng

SP

E

SPE fluence (E> 15 MeV) (in units of 10^10 particles/cm^2)

(25 Sept. & 23 Nov 2001)

(9 Nov 2000)

(6 Nov 2001)

(14/15 July 2000) Correlation between number of DSE during SPEs and the SPE proton fluence for E> 15 MeV . Y# and N# refer to SPEs identified in previous Table .

The energetic particles detected by the MOPITT (piezoelectric) accelerometer are mainly high energy protons

-200 -150 -100 -50 0 50 100 150 200-100

-80

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0

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Night Day

La

titu

de

Longitude

Mopitt DSE location during intense SPE

MOPITT Accelerometer Anomalies during intense SPE

- are caused by high energy charged particles precipitating via ‘pole horns’. - more events during the Day

0 200 400 600 800 1000 1200

0

2

4

6

8

10

Nov 6, 2001

Nov 9, 2000

Jul 14 & 15, 2000

Event distribution over the poles

DS

E d

aily

rat

e

Doy (from 2000)

1965 1970 1975 1980 1985 1990 1995 2000 2005

0

50

100

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200

SC #21 SC #22 SC #23

SS

N

Year1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

-20

0

20

40

60

80

100

120

140

160

180

SS

N

Year

Double Solar Maximum Cycle #23

2000.0 2000.5 2001.0 2001.5 2002.0 2002.5 2003.0100

110

120

130

140

Year R

I SS

N

F1

0.7

160

170

180

190

200

0 20 40 60 80 100 12060

80

100

120

140

160

180

200

From 1997 (Solar Activity min)

Sol

ar R

adio

Flu

x F

10.7

cm

SI SSN

1997 1998 1999 2000 2001 2002 20030

20

40

60

80

100

120

140

The sun radio emission at a wavelength of 10.7 cm and sun spot number

Max of SC #23

F1

0.7

RI S

SN

Year

60

80

100

120

140

160

180

200

During High Solar Activity period ( II sub-max) the relative contribution of trapped particles in SAA decrease from ~70% to ~40%, Background remain almost constant(~20%) and Poles contribution increase (from ~15% to ~40%).This is a consequence of direct injection of more high energy particles (via poles) duringHigh Solar Activity.

Correlation with Solar activity

There is an overall increase ( ~ two times) of MOPITT DSE daily rate during the time period Nov 2001 – Feb 2002(second Solar sub-maximum)

0 200 400 600 800 1000 1200

0

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4

6

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12

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24

DOY (from 2000)

SAA Poles Bg

Mo

pit

t D

SE

(27

day

s av

erag

e)

First Sub_Max

Second Sub_Max

200 400 600 800 1000 12000.0

0.1

0.2

0.3

0.4

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Second Sub_Max

DOY (from 2000)

Bg contrib. Poles contrib. SAA contrib.

Rel

ativ

e co

ntr

ibu

tio

n

Correlation with Solar activity

MOPITT Accelerometer anomalies are

correlated with Solar Activity as shown by Solar centimetric Radio Flux : Ottawa index F10.7

0 200 400 600 800 1000 120040

60

80

100

120

140

First Sub_Max Second

Sub_Max

Mo

pit

t D

SE

ove

r S

AA

(27

day

s av

erag

e)

Smooth 27 average

DOY (from 2000)

SS

N (

Sm

oo

th 2

7 d

ays

aver

age)

0

2

4

6

8

10

12

14

16

18

20

22

24

SAA

0 200 400 600 800 1000 1200

120

140

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200

220

Second Sub_Max

First Sub_Max

Mo

pit

t D

SE

ove

r S

AA

(27

day

s av

erag

e)

Smooth 27 averageF10

.7 c

m (

Sm

oo

th 2

7 d

ays

aver

age)

DOY (from 2000)

0

2

4

6

8

10

12

14

16

18

20

22

24

SAA

With Sun Spot Number With 10.7 cm radio flux F10.7

Summary and conclusions Analysis of MOPITT anomalous accelerometer signals shows

a direct correlation of the DSE daily rate with solar activity, a Day/Night asymmetry caused probably by interaction of trapped particles with the neutral atmosphere, and a direct correlation with high intensity solar proton events (SPEs). The high energy particles – the source of anomalous accelerometer signals- are localized mainly in SAA region, but the polar regions, particularly the southern pole, are also regions of higher risk for satellites mainly during intense SPEs.

We have also found that at least during the Solar maximum, there is a correlation of the particle population responsible for DSEs in the piezoelectric accelerometer with solar activity as expressed better by the F10.7 than the SSN.

During the second sub-maximum of Solar Cycle SC23, the fraction of events over the poles relative to the SAA region increase, which mean that, probable there are more high-energy particles of non-trapped origin in this time interval, and a good proxy of Solar activity for this purpose is the F10.7 Solar Radio Flux index.

The paper: Solar Particle Events seen by MOPITT instrument by: F. Nichitiu, J.R. Drummond, F.Zou,R.Deschambault has been accepted for publication in Journal of Atmospheric and Solar-Terrestrial Physics

MOPITT mission and data analysis are supported by the Canadian Space Agency (CSA), Natural Sciences and Engineering Research Council (NSERC) and the National Aeronautics and Space Administration (NASA)

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Message : including Space Environment Sensors on satellites is a difficult idea to sell to management (because of cost/weight/power penalty) BUT with very good benefits