Solar Particle Events in Aviation and Space. Günther Reitz Insitute of Aerospace Medicine German Aerospace Center, DLR, Cologne, Germany

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1 Solar Particle Events in Aviation and Space Günther Reitz Insitute of Aerospace Medicine German Aerospace Center, DLR, Cologne, Germany

2 Radiation Field in the Heliosphere LEO orbit

3 Fluxes of primary space radiation components inner Van Allen belt protons

4 The Earth Magnetic Field

5 Deflection and trapping of charged particles by the geomagnetic field

6 Vertical Cut-Off Rigidities in GV

7 Atmospheric Shielding - Particle Cascade

8 Charged Particle Count rate in dependence of Altitude

9 The Solar Cycle

10 The Solar Cyle

11 Solar corona and sudden release of a huge clouds of particles

12 Sourcle: NASA Source: Charlton et al. Solar energetic particle events (Solar Particle Events (SPE), Coronal Mass Ejections (CME)) probability of occurrence is correlated with the solar cycle

13 Integral energy spectra of historical worstcase solar particle events

14 What are flares and CMEs? Solar sources of major space weather disturbances: Flares & coronal mass ejections (CMEs) CMEs are huge clouds of magnetized plasma expelled from the solar corona to interplanetary space with velocities of ~100 km/s up to 3000 km/s. Flares manifest themselves as enhanced radiation across the whole electromagnetic spectrum due to heating and interaction of high-energetic particles with the solar atmosphere. Both flares and CMEs are powered by a sudden release of magnetic energy in the corona previously stored in non-potential (stressed) fields. Both may be associated with solar energetic particles (SEPs) : cause e.g. surface and internal charging on satellites; radiation hazard to astronauts

15 Solar Energetic Particles (SEPs)

16 Solar Flares and Coronal Mass Ejections

17 Space Weather Impact Drivers of Space Weather Coronal Mass Ejections (CMEs): Arrive 1-4 Days later Last a day or two Produce Geomagnetic Storms at Earth Systems Affected Radio Communications Navigations Electric Power Grids Pipelines High-Speed Solar Wind: Common During Solar Minimum Enhances Radiation Belts Systems Affected Satellite Charging Astronouts Solar X-Rays and EUV: Arrive in 8 Minutes Last minutes to hours Increases ionosphere density Increases neutral density Systems Affected: Radio Communications Navigation Satellite Orbits Solar Energetic Particles: Arrive in 30 Minutes to 24 hours Last several days Systems Affected: Astronauts Spacecraft Airlines Radio Communications

18 Measurements

19 Navigation camera image showing the surface scour marks and rocks on the rover s deck and RAD! RAD NASA/JPL-Caltech

20 MSL Radiation Assessment Detector

21 Radiation Assessment Detector (Cruise Measurements) SPE Exposures msv Jan March May 1.2 Daily GCR 1.84 msv

22 ISS Radiation measurements : Area Monitoring NASA ESA JAXA IMBP

23 1 / cm 2 s sr Count Rate (top panel) and Particle Fluxes on ISS GOES Satellite Measurements (bottom panel) DOSTEL count rate 1 / s cm th April GOES8 Proton Flux >= 100MeV DoY th April

24 Dose equivalent (µsv/day) Cummulative Dose Equivalent (msv) ISS TEPC During 2005 (Dose Equivalent Rate)

26 Increase and decrease of radiation exposure in 12 km due to GLE 65 and the following Forbush decrease

27 Calculations

28 Solare Worst Case particle event Space suit (0.3 g/cm 2 ) Equipment room (5 g/cm 2 ) Radiation shelter (10 g/cm 2 ) Skin Lens BFO Skin Lens BFO Skin Lens BFO Free Space Lunar Surface Exposure [Sv] Martian Surface

29 Determination of SEP spectrum Assume spectrum for Solar Energetic Particles at time t Calculate secondary particle fluences and Neutron- Monitor count rates related to GCR and SEP (PLANETOCOSMICS, GEANT4) ( stations Compare to measured count rates (~30 ( Minimization ) Adapt spectrum for SEP Calculate secondary particle fluences at aviation altitudes Conversion to radiation exposure

30 Neutron Monitor Network

31 GLE70: Primary proton spectra

32 Vortrag > Autor > Dokumentname > Datum Interplanetary space: GLE 70 on of Dec. 13, 2006 Organ dose equivalent H for 25 g/cm2 Al shielding Water sphere with NUNDO Water sphere with ICRPP NUNDO voxel (16-21 msv) ICRPP voxel (13-20 msv)

33 Vortrag > Autor > Dokumentname > Datum ISS orbit: GLE 70 on of December 13, 2006 Organ dose equivalent for 25 g/cm2 Al shielding Water sphere with NUNDO Water sphere with ICRPP NUNDO voxel ( msv) ICRPP voxel ( msv) Quality factor : Benghin et al.: DB-8: 0.32 mgy 0.67 mgy

34 GLE70: Dose rates at 200g/cm 2 ( 12km, FL390) Along 25 E Peak values of 4.5 to 5 times GCR background

35 GLE70: Dose Rates in FL390 (12km, 200g/cm 2 ) Prior to event 3.05 UTC 3.35 UTC

36 GLE70: Dose rates in high latitudes g/cm 200, 12km )FL390 2 ) FRA-LAX: 140 μsv (GCR=93μSv) JFK-PEK: 153 μsv (GCR=107μSv) ~50% Increase compared to GCR 12km GCR GCR+SEP

37 GLE 60 Dose equivalent at 300 g cm -2 (~10,000m) CERCLe Lantos et al. 12,200m

38 Comparison of Calculation and Measurement GLE 60 Courtesy: J.-F. Bottollier

39 Maximum Dose Equivalent in µsv of large SPE s above latitudes of 60 for different Flight levels GLE No. Solar Particle Event Flight level feet feet feet GLE 5 # Feb 23, GLE 42 Sept 29, GLE 43 Oct 19, GLE 44 Oct 22, GLE 45 Oct 24, GLE 60 April 15, GLE 68 Jan. 20, GLE 70 Dec 13, # estimated as 10 fold dose of the GLE42

40 Summary I SPE Exposures in Interplanetary Space AcuteExposures can exceed 1 Sv and are potentially life threatening, but risks are manageable by shielding measures Optimise shielding design, include storm shelters (material & thickness) Shielding should limit excessive exposure to prevent acute effects Optimise mission design duration timeline relative to solar activity cycle guarantied shelter accessibility Advance forecasting capabilities for solar particle events Exploration vehicles shielding should focus on SPE instead on GCR SPE Exposures in Low Earth Orbit Thanks to the high magnetic shielding of the ISS exposures higher than a couple of tenth of msv are not likely Astronauts are advised to move to higher shielding areas in case of a SPE Extravehicluar activities are prohibited

41 Summary II Civil airflight Altitudes Exposures are in the micosv range, nevertheless strong interest of air crew to monitor them accurately Only a few measurements available, next step: To equip more airplanes with monitor to optimize the coverage Calculations are necessary for an fast estimate of the exposure: Two models are available one using Models and one is based on Concorde measurements (SiGle) The combination of neutron monitor data analysis with the Geant4 applications MAGNETOCOSMICS and PLANETOCOSMICS is a suitable tool for dosage evaluations at aircraft altitudes during GLEs, in particular during highly anisotropic events (Univ. Bern; DLR) Additional fine-tuning is in progress, as well as the comparison action with the French SiGle

42 Chart 42 > Vortrag > Autor Dokumentname > Datum SPARES

43 di x 0, 0,,, b dr 0 C Count rate of C c s i SEP GCR i GCR i x x x Primary SEP spectrum Background count rate of Neutron Monitor i GCR C x Ci Relative count rate increase SEP GCR i GCR Ci i x modeled measured c c 2 i Minimize s(x) by adapting x! i Neutron Monitor i

44 GLE 70: Calculated Neutron Monitor Count Rates

45 Chart 45 > Vortrag > Autor Dokumentname > Datum GLE 68: Jan. 20, 2005 Courtesy: J.-F. Bottollier

46 Mission Doses from Galactic Cosmic Rays for Reference Scenarios

47 Exposures of Radiation workers surveillance of personal dosimeters by GSF for 2001 persons per dose unit / msv all workers medical 'industrial' source: bk1_1, 2001bk2_1, 2001sum_1.gif range and average of aircrew exposure annual equivalent dose / msv GSFannualexp2001.opj

48 Chart 48 > Vortrag > Autor Dokumentname > Datum Solar Forecast 1) To predict when the next CME-flare event will occur - we are still far from that. Needs better understanding and modeling of the basic physics 2) Given the observation of an event occurring on the Sun: predict its arrival time and effect on Earth Needs good input data (observations) Needs good understanding and modeling of interplanetary propagation and magnetosphere response Time scales: - Flare radiation: immediate - if we see it, it s here - SEPs from flares and CMEs: some ten minutes to days - CMEs: ~1 5 days

49 Space Radiation Environment

50 Comparison of estimated probabilities for human radiation deaths from extreme solar particle events with common terrestrial risks.

51 The three major components of ionising space radiation, galactic cosmic rays (GCR), solar particle-, and geomagnetically trapped radiation

Space Weather and Satellite System Interaction

Space Engineering International Course, Kyutech, 4 th Quarter Semester 2017 Space Weather and Satellite System Interaction Lecture 2: Space Weather Concept, Reporting and Forecasting Assoc. Prof. Ir. Dr.