Post on 15-Dec-2015
transcript
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Short-term space weather forecast
A.A. Petrukovich
Space Research Institute, Russian Academy of Sciences
with contributions from G.N.Zastenker, V.M.Linkin, N.A.Eismont
What is space weather ?
Why is it important ?
Short-term forecast- concept - quality- real-time system
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Sun is a very stable starSun is a very stable star
Total solar energy fluxTotal solar energy flux - - SOLAR CONSTANTSOLAR CONSTANT 1.5 1.5 kWkW per per 1 1 sqsq. . mm..
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active sunactive sun: : ~0.1% solar ~0.1% solar constantconstant
cycle cycle with 11 (22) yearswith 11 (22) years
energy from heat is accumulatedenergy from heat is accumulated
in extra magnetic field and releasedin extra magnetic field and released
sun spotssun spots
solar flaressolar flares
coronal mass ejectionscoronal mass ejections
geomagnetic stormsgeomagnetic storms
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3. Subsequent coronal mass ejection:
1. Sunspot – signature of extra magnetic energy
2. Solar flare in soft X rays – explosive release of energy
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Summary of solar emissions
1. Solar UV - variable
2. Solar X-ray - sporadic from solar flares
3. Solar cosmic rays - sporadic from solar flares
4. Solar wind and interplanetary magnetic field
- permanent flow thermal expansion of solar plasma
- magnetic clouds sporadic from solar flares
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Solar wind & interplanetary magnetic field interactwith Earth magnetic field
Steady solar wind flow create magnetosphere from the pure dipole
Everyday interplanetary variations create geomagnetic activityenergy from solar wind powers up magnetospheric dynamics
Magnetic clouds – anomalously intense solar wind and IMF create geomagnetic storms
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Earth is inside an electromagnetic system:energy of geomagnetic storm is measured by megatons of TNT
All sorts of radiation andElectromagnetic influence:
Radio, satellites, …, humans
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Spacecraft effects
Electrostatic discharge on spacecraft surface
Radiation damage to electronics
Radiation threat to crews,Especially future interplanetary flights
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Telecommunications
In XIX cent. space weather effects were observed in wire telegraph lines
short wave telecom
radars
space telecom
GPS/GLONASS
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Effects on climate and biosphere ?Effects on climate and biosphere ?
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Summary of space weather
Space weather is due to solar activityand plasma environment of Earth
Sporadic intensifications “storms” are due to solar flares and magnetic clouds in solar wind affecting Earth
Space weather is basically “one for all” – storms are global
Monitoring and forecast are important for many technical systems in space and on ground
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Summary of forecast
long term (months and years) – cycle progression time-series analysis no hurry
mid term (weeks) – variability due to rotation (27 days) “recurrence”no hurry
flare warning (days & hours) – probability of a flare in given sunspot complexity analysis real time
short term (days & hours) – probability of magnetic storm after flare registration
propagation analysis real time
short term (hours) – storm development based on near Earth solar wind time series analysis real time
Physics-based models (requiring HPC) are not competitive currentlybut will be ?
Our interest
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Monitoring of interplanetary medium in front of the Earth is currently the only tool to provide reliable quantitative, but short-term, space weather forecast.
A L1 Sun-Earth libration point, 1.5 mln km from the Earth, is a convenient place with the lead time of a forecast of about 1 hour.
1 hour forecast >90% reliability
Solar light: 300 000 km/s: 8 min 3-day forecast 50% reliability
Solar stormSolar wind: 400-1000 km/s: 1.5-3 days Geomagnetic
storm
Libration point 1.5 mln km
150 mln km
solar wind-based short-term forecast: IKI studies
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reliability of the L1 monitor due to natural variability of solar wind
measurements of
solar wind and IMF
(1996-1999)
Wind (distant)
and
Interball (near-Earth)
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probability of different (by 15%) measurements of energy input ~VB2 to the magnetosphere
Petrukovich et al, JASTP, 2001.
magnetic storm (> 1016 J)
predictions are reliable,
while
substorm predictions
are uncertain.
! role of small variations
and discontinuities
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Geomagnetic indices AL and Kp (measures of magnetic fluctuations) are used as general indicators
Future or current indices might be estimated with real-time solar wind.
the main problem:significant scatter of
index(uncertainty of
magnetospheric dynamics)
with respect to solar wind input
solar wind driving function
~ VBns
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Unreliable measurements (marked by team)
error codes ACE in 2001
IMF 5.5% SW 20%
intervals > 20 min long
IMF 3.9%SW 3.9%IMF & SW 2.1%
major reserve: accept data even if it is flagged
ACE L1 monitoring
Internet availability errors add less than 1 %
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ACE data physical quality: real-time and final data compared
IMF clock anglewrong by 20-50o
in 1997-2004!
30% error in Bns!
ACE L1 monitoring
2001
corrected only in 2004
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NOAA/SEC
download& check
Activity estimates
Indexmodels
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Format &delivery
Consumer Blocks
Inte
rne
t
• download• data quality check and filling gaps• advection time to Earth
IKI solar wind forecast system
• activity estimates• specific predictions• product delivery
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Overview plots for “now” and +1 hour
Examples of general products
IKI solar wind forecast system
http://www.iki.rssi.ru/forecastsince 1999
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1 hour forecast >90% reliability
solar stormsolar wind: 400-1000 km/s: 1.5-3 days geomagnetic
storm
Libration point 1.5 mln km
3 mln km from Earth
2 hour forecast
Earth gravity larger than
solar gravity
solar gravity in balance with
Earth gravity
solar gravity in balance with Earth gravity +light pressure
future solar wind monitors
using micro satellites placing monitor further away from the Earth
Not so far to preserve forecast quality Solar sail is the only solution to keep spacecraft with Earth
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hardware
instruments:Magnetometersolar wind sensorCosmic ray sensor
total data flow ~100 bits/sec. Total scientific payload weight 2 kg
future solar wind monitors
"standing point" at 3 mln km
requires a spacecraft ~ 25 kg with solar sail ~1000 sq m or ~ 150 kg with solar sail ~6000 sq m
sails are made with thin polymer films
initial Solar sail deployment tests are underway world wide.
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Solar min in 2007
A 2004 forecast
What about a new solar cycle ?
A 2007 forecast
Solar min In 2008
A 2009 forecast
a very deepsolar minin 2009
Solar wind now on minimum
level in 50 years of observations
Grand solar minima
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Earth as space ecosystem
Life depends on Space:Earth climate driven by constant solar energy
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Life depends on Space:Earth climate driven by constant solar energy
Solar system climate: solar activity, solar evolution, orbit interactions
Earth as space ecosystem
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Galaxy climate: local interstellar medium and galactic cosmic rays
Life depends on Space:Earth climate driven by constant solar energy
Solar system climate: solar activity, solar evolution, orbit interactions
Earth as space ecosystem
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Short-term forecast is an important part of space weather services and is relatively novel technology
Real-time data analysis tools (image and time series processing)are necessary
Internet technologies are vital to create and use such forecast
•Proper data conditioning is an important task
CONCLUSIONS
Thank you !