Space Weather

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Space Weather Effects and Consequences. The
case of MOPITT on board of Terra spacecraft.
Florian Nichitiu Department of Physics,
University of Toronto, Canada July 2004-Frascati
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Space
Climate/Weather Space Climate/Weather refers to
changes in the space environment and effects
that those changes have on Earth and mankinds
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 Earths climate and weather
  in relation with (some time) controversial
  problem of signatures of solar activity
  variability in meteorological parameters, Earths
  atmosphere chemistry and long term trends in
  Earths 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 Earths space environment

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Sun - Geospace environment
Sources of Space Weather ? Sun EM radiation
particle radiation
? Galactic Cosmic Rays
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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.

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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
  --gt variations of outer belt electron
  population) due to motions
  of the Earth around Sun (--gt annual changes in
  the Earths atmosphere introduce seasonal
  modulation in low-altitude trapped proton
  population)
• Daily variations of Earths magnetic dipole
  (due to axial rotation of the
  Earth angle between dipole and rotational axes
  11 deg.)

Longer cycles important for effects related
with Earths climate and long term trends
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Space Radiation Environment
Electrons, protons and ions ?Trapped by the
Earths magnetic field Radiation Belts
( Van Allen Belts) e Elt 2-3 MeV

p Elt 200-300 MeV ?Passing through the
solar system Solar Wind ( e, p He4 )
Elt 100 KeV Solar Particle
Events mainly protons E 1 - gt100 MeV
Galactic Cosmic Rays E up to TeV
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Radiation Belts
-Oct and Nov 1957 Sputniks 1 2 ( SU)
-Jan 1958 Explorer 1 ( US)
(Geiger-Muller counterJ van Allen)
Expected rate 30 count/sec
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/s
• Ernest Ray

My God, space is radioactive !
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Inner outer belts
A charged particle became trapped in those
regions where the magnetic field lines are closed

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

I
II
I
There are two main belts I- inner belt e and
p ( up to 2.4 Re) II- outer belt e (2.8 12 Re)
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The Earths 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.
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SAA is frequently said is due to the
The tilt of the dipole axis with respect to the
rotational axis
And due to the displacement of the geomagnetic
axis from the center of the Earth
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Radiation Belt Models
Electrons AE-8
Protons AP-8
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Plasma and Solar Wind
Continuous 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 lt0 values ? magnetic
storm(Kpgt5)
Electron enhancements- tendency to occur at the
solar rotation period (27 days)
Strong correlation between electron
precipitations (Egt30 keV) at polar orbit and
solar wind speed at 1 UA. -consequences for
physico-chemistry parameters of the atmosphere.
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Solar Energetic Particles SEP 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 gt 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 105 to 1011 part/cm2 Duration
of event from one to several days
Bastilia Solar Event 14 July 2000
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SPE Periodicity
Frequency spectra of solar proton fluence of
Energy gt 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
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Cosmic
Rays Galactic 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 Elt 10
GeV.
Variations of proton counts E80-215 MeV of
MEPED detector aboard the TIROS/NOAA spacecraft
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Natural Albedo
Radiation Is 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 of secondary radiation
as a result of atmosphere expanding ( and
increasing of nuclear interaction rate) during
high solar activity.
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Short term variations of Albedo Radiation
-When the Sun releases a large burst of matter
and magnetic disturbance? a magnetic storm which
prevent many cosmic rays from entering the
atmosphere. Forbush decrease detected by the
Inuvik neutron monitor at 23 Mar 1991.
Solar cosmic rays produced by a solar flare are
recorded as a sharp increase in secondary
neutrons flux. The event of May 24, 1990
seen by Inuvik, Deep River and Goose Bay neutron
monitors.
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Effects on Spacecraft
and instruments
Low energy particles - correlated with SA
High energy particles - anti-correlated with SA
Solar Activity
Effects on Earth Climate
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
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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
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Surface Charging

• S/C immersed in a cool,
  dense plasma
• e, ions, secondary emitted particles
  photoelectrons and backscattered electrons
• 
  ? Gives net s/c potential
• And this lead to discharges ? noise into the
  system false command,
• 
  ? change the physical characteristics of
  subsystems.
• Occurs predominantly during geomagnetic storms (
  for K index gt6)
• Night??Day transitions are especially problematic
  during storms photoelectric effect
• is abruptly present/absent ? trip discharges

There is also a strong local time asymmetry
majority Surface Charging anomalies occur
during the night
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Deep dielectric charging
Is a problem primarily for high altitude
s/c Relativistic electrons (Egt 1MeV) can easily
penetrate s/c shielding and can build up charge
where they come to rest ( in dielectrics). For
high electron flux during 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 suns 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
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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.
SEU peak occurrence frequency corresponds to the
peak of 50MeV protons 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
Distribution of SEU over entire CRRES
mission (launched July 25, 1990 returned data
for 14 months)
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Satellite anomalies over SAA
UoSAT-2 microsatellite SEU- (recoverable) memory
upsets (from Sept 1988 to May 1992)
MISR camera (3 Febr16 Febr 2000)
Before cover opened (proton hits cameras designed
to detect visible light)
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Bastilia Solar Event example of High Radiation
Background anomaly
July 14, 2000- A powerful X class flare erupted
from sunspot region 9077 at approximately 1024-
it was accompanied by a full halo coronal mass
ejection that is Earth directed.
April 23 2003
SOHO LASCO C2 C3 Images
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TERRA Solid State Star Tracker anomalies High
Background
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The case of MOPITT
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
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Terra, is the name of the Earth Observing
System (EOS) flagship satellite, launched on Dec.
18, 1999. The mission is a vital part of NASAs
Earth Science Enterprise , helping us understand
and protect our home planet Terra s/c is in a
sun-synchronous polar orbit. Orbital period98.88
min. Altitude705 Km.
25 Jun 2004 014151.36
Sun
SAA
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MOPITT instrument
MOPITT instrument is an infrared gas correlation
radiometer.It operates with eight channels for
CO and CH4. Infrared detectors need to be cooled
to less than 100 K ( by Stirling Cycle Coolers
with two Compressors and two Displacers mounted
back to back).
The vibration level is measured by two
piezoelectric accelerometers
-Cooler Compressor (vibrations for x,y,z)
-Cooler Displacer (vibrations for x,y,z)
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MOPITT Accelerometer anomalies
Multi-component force measurements Kistler
K-Shear accelerometer. Sensing element quartz
crystal
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Location of MOPITT accelerometer anomalies
Total time 993 days Daily rate1.06
ev/day Total Nr events over SAA567 (
54) SAA rate 0.57 ev/day
South Atlantic Anomaly seen by MOPITT

MOPITT spend only 6.25 of time over SAA
? SAA rate9.14 ev/day
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MOPITT Accelerometer Anomalies are caused by
the
radiation environment
SAA events 54 Background 20.4 Poles ( /-
65 ) 25.6 North/South (poles)
asymmetry0.43
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MOPITT Accelerometer Anomalies in South Atlantic
Anomaly region
Day Night Asymmetry SAA Day/Night
0.72 During the Night Lat Long widths
increase with 2-3 deg.
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Solar Protons Events Detected by MOPITT
accelerometer
Y3
Y1
Y2
Doy ( Date ) of DSE lt
gt 196 (July 14 2000) 8 1.03
Y1 197 (July 15 2000) 11
1.03 Y1 314 (Nov. 9 2000) 7
0.67 Y2 634 (Sept 25 2001) 3
1.24 N1 676 (Nov 6 2001) 16
1.59 Y3 694 (Nov 24 2001)
3 1.78 N2
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Solar Proton Events
Max p Flux
pfu _at_
gt10 MeV gt100 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/(cm2 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
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CELIAS/MTOF Proton Monitor on the SOHO Spacecraft
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 gt 50 MeV and electrons with
incident energies gt 2 MeV.
4-7 Nov 2001
22-25 Nov 2001
Seen by MOPITT Acc ( Y3)
NOT Seen by MOPITT Acc ( N2)
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29 Oct 2003 Solar
Proton Event Max Proton Flux (pfu)
gt 10 MeV gt 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 (gt100 MeV)
reaches a large value. These MOPITT DSEs are
also located on the polar regions.
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SPE detected by MOPITT. Energy dependence
Correlation between number of DSE during SPEs
and the SPE proton fluence for Egt 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
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MOPITT Accelerometer Anomalies during intense SPE
- are caused by high energy charged particles
precipitating via pole horns. - more events
during the Day
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Double Solar Maximum Cycle 23
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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)
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)
during High Solar Activity.
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Correlation with Solar activity
With Sun Spot Number
With 10.7 cm radio flux F10.7
MOPITT Accelerometer
anomalies are correlated with Solar
Activity as shown by Solar centimetric Radio
Flux Ottawa index F10.7
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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.

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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
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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