PREDICTING INTERPLANETARY PREDICTING INTERPLANETARY SHOCKS USING NEURALSHOCKS USING NEURAL

NETWORKSNETWORKS

A.İbrahim PALAA.İbrahim PALA

METU Aerospace Engineering DepartmentMETU Aerospace Engineering Department

Senior StudentSenior Student

21.12.200521.12.2005

OUTLINEOUTLINE

WHAT IS AN INTERPLANETARY SHOCK?WHAT IS AN INTERPLANETARY SHOCK?

WHAT IS A NEURAL NETWORK?WHAT IS A NEURAL NETWORK?

HOW THE NEURAL NETWORKS ARE HOW THE NEURAL NETWORKS ARE USED TO PREDICT THE USED TO PREDICT THE INTERPLANETARY SHOCKS?INTERPLANETARY SHOCKS?

CONCLUSIONCONCLUSION

INTERPLANETARYINTERPLANETARY SHOCKSSHOCKS

Charged particles areCharged particles are

constantly streamingconstantly streaming

outward from the Sun.outward from the Sun.

When events such asWhen events such as

Coronal Mass EjectionsCoronal Mass Ejections

(CMEs) occur on the Sun,(CMEs) occur on the Sun,

an Interplanetary (IP) shockan Interplanetary (IP) shock

may be generated. may be generated.

INTERPLANETARYINTERPLANETARY SHOCKSSHOCKS

TThe abrupt boundary he abrupt boundary formed at the front formed at the front of a plasma cloud of a plasma cloud moving much faster moving much faster than the rest of the than the rest of the solar wind, as it solar wind, as it pushes its way pushes its way through through interplanetary space. interplanetary space.

NEURAL NETWORKSNEURAL NETWORKS

NEURONSNEURONS

SYNAPSESYNAPSE

(INPUT->WEIGHTS) (INPUT->WEIGHTS)

COLLECTORCOLLECTOR

ACTIVATION ACTIVATION FUNCTION->OUTPUTFUNCTION->OUTPUT

NEURAL NETWORKSNEURAL NETWORKS CONSTRUCTING A NEURAL NETWORK BY CONSTRUCTING A NEURAL NETWORK BY

BRINGING LOTS OF NEURONS TOGETHER AND BRINGING LOTS OF NEURONS TOGETHER AND INTERCONNECTING AND TRAINING THEMINTERCONNECTING AND TRAINING THEM

SYSTEM PARALLELISM AND STRUCTURAL SYSTEM PARALLELISM AND STRUCTURAL DISTRIBUTION OF OVERALL FUNCTIONDISTRIBUTION OF OVERALL FUNCTION

->compensating the errors due to a ->compensating the errors due to a nonfunctional neuronnonfunctional neuron

GENERALIZATION AND LEARNING ABILITYGENERALIZATION AND LEARNING ABILITY

->giving meaningful outputs for also the ->giving meaningful outputs for also the non-trained inputsnon-trained inputs

PREDICTING THE ARRIVAL OFPREDICTING THE ARRIVAL OFIP SHOCKS BY NEURAL IP SHOCKS BY NEURAL

NETWORKSNETWORKSIP Shocks causes the incoming particle IP Shocks causes the incoming particle

flux observed at or near Earth to flux observed at or near Earth to increase by orders of magnitude.increase by orders of magnitude.

Sharp increases in particle intensity Sharp increases in particle intensity are called Energetic Storm Particle are called Energetic Storm Particle (ESP) events(ESP) events

PREDICTING THE ARRIVAL OFPREDICTING THE ARRIVAL OFIP SHOCKS BY NEURAL IP SHOCKS BY NEURAL

NETWORKSNETWORKSINPUTSINPUTS:: Observations Observations

from two ACE instruments:from two ACE instruments:

TheThe ElectronElectron, Proton, , Proton, andand AlphaAlpha MonitorMonitor (EPAM) (EPAM): : particle intensity at five particle intensity at five different energy levels. different energy levels. This data is used to This data is used to detect detect the onsetthe onset of an event, of an event, several days in advance, several days in advance, and to and to predict the ESP predict the ESP event / IP shock arrivalevent / IP shock arrival. .

PREDICTING THE ARRIVAL OFPREDICTING THE ARRIVAL OFIP SHOCKS BY NEURAL IP SHOCKS BY NEURAL

NETWORKSNETWORKSINPUTSINPUTS

TheThe Solar Solar WindWind ElectronElectron, Proton, , Proton, andand AlphaAlpha MonitorMonitor (SWEPAM) (SWEPAM): solar wind : solar wind plasma temperature, plasma temperature, density, and speed. density, and speed. This data is used to This data is used to detect the actual IP detect the actual IP shock arrivalshock arrival. .

PREDICTING THE ARRIVAL OFPREDICTING THE ARRIVAL OFIP SHOCKS BY NEURAL NETWORKSIP SHOCKS BY NEURAL NETWORKS((RealReal-time -time InterplanetaryInterplanetary ShockShock PredictionPrediction

(RISP) (RISP) SystemSystem ))TRAINING THE ARTIFICIAL NEURAL TRAINING THE ARTIFICIAL NEURAL

NETWORK TO PREDICT THE TIME NETWORK TO PREDICT THE TIME REMAINING UNTIL THE SHOCK ARRIVESREMAINING UNTIL THE SHOCK ARRIVES

TRAINED BY 37 OF THE 56 SELECTED TRAINED BY 37 OF THE 56 SELECTED SHOCKSSHOCKS

PERFORMANCE ASSESSED BY FORECASTING PERFORMANCE ASSESSED BY FORECASTING ARRIVAL TIME COUNTDOWNS FOR 19 ARRIVAL TIME COUNTDOWNS FOR 19 SHOCKS NOT USED DURING TRAININGSHOCKS NOT USED DURING TRAINING

PREDICTING THE ARRIVAL OFPREDICTING THE ARRIVAL OFIP SHOCKS BY NEURAL IP SHOCKS BY NEURAL NETWORKSNETWORKS

Particle intensities for test sequence 9. Predicted time until shock arrival.

REFERENCESREFERENCES www.physics.usyd.edu.au/~cairns/teaching/lecture11/www.physics.usyd.edu.au/~cairns/teaching/lecture11/

node5.html+interplanetary+shocks&hl=trnode5.html+interplanetary+shocks&hl=tr

http://www-spof.gsfc.nasa.gov/Education/wgloss.htmlhttp://www-spof.gsfc.nasa.gov/Education/wgloss.html

http://sd-www.jhuapl.edu/ACE/EPAM/RISP/

Vandegriff , J., Wagstaff, K., Ho , G., Plauger, J. Forecasting space weather: Predicting interplanetary shocks using neural networks. Adv.Space Res. 36, 2323-2327, 2005.

www.srl.caltech.edu/ACE/

Efe, M.Ö., Kaynak, O., Yapay sinir ağları ve uygulamaları, Bogazici University,2005