phd project outline and risk analysis - division · 2019. 3. 26. · motivation solar cycle solar...
TRANSCRIPT
![Page 1: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/1.jpg)
PhD project outline and risk analysis
Simon Candelaresi
2009-11-24, Stockholm
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 1 / 14
![Page 2: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/2.jpg)
Overview
1 Motivation
2 Past and current work
3 Future work and outline
4 Risk analysis
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 2 / 14
![Page 3: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/3.jpg)
Motivation
Solar cycle
Solar winds: destruction of satellite, heazard for astronauts
Solar weather forecast
1d mean field simulation → global sun simulation (DNS)
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 3 / 14
![Page 4: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/4.jpg)
Past and current workMean field simulations
Axel Brandenburg and Piyali Chatterjee (MNRAS)One dimensional mean field dynamo
Question: Is magnetic helicity hindering dynamos (’alpha quenching’)?Answer: Yes. Remove it or let it diffuse through the equator.
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 4 / 14
![Page 5: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/5.jpg)
Past and current workTopological aspects
Fabio Del Sordo and Axel Brandenburg (PhysRevE)Topological aspects
Question: Does the topology change the dynamics?Answer: Depends on the helicity.
Hm =
∫A · B
= 2αφ1φ2
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 5 / 14
![Page 6: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/6.jpg)
Past and current workTopological aspects
3 flux rings: Result: Magnetic energy decaysslower with helicity.
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 6 / 14
![Page 7: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/7.jpg)
Past and current workTopological aspects
helicity = 0 helicity = 2
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 7 / 14
![Page 8: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/8.jpg)
Past and current workGauge invariance
Dhrubaditya Mitra, Piyali Chatterjee, Reza Tavakol and Axel Brandenburg(AN)Gauge invariance of magentic helicity fluxes in DNS
Magnetic helicity density A · B is gauge dependent.Weyl gauge Ψ = 0
pseude-Lorenz gauge ∇ · A + 1c2s
∂Ψ∂t
= 0
resistive gauge Ψ = η∇· A
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 8 / 14
![Page 9: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/9.jpg)
Past and current workGauge invariance
Result: Averaged magnetic helicity fluxes are independent of the gauge.
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 9 / 14
![Page 10: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/10.jpg)
Past and current workGauge invariance
Polarity reversal DNS:
Polarity reversal mean field:
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 10 / 14
![Page 11: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/11.jpg)
Future work and outline
linking number ⇔ helicityhigher order topological invariants ⇔ ?
Vishniac-Cho magnetic helicity flux (shear)
simulate the sun
solar wind
migrate simulations to GPUs (CUDA)
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 11 / 14
![Page 12: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/12.jpg)
Collaboration
Dhrubaditya Mitra (London)
Reza Tavakol (London)
Piyali Chatterjee (Stockholm)
Fabio Del Sordo (Stockholm
Axel Brandenburg (Stockholm)
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 12 / 14
![Page 13: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/13.jpg)
Risk analysis
Dependecne on aviable processing capacity.
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 13 / 14
![Page 14: PhD project outline and risk analysis - Division · 2019. 3. 26. · Motivation Solar cycle Solar winds: destruction of satellite, heazard for astronauts Solar weather forecast 1d](https://reader034.vdocument.in/reader034/viewer/2022052022/60375eb312ae9d6dfb021868/html5/thumbnails/14.jpg)
Thanks!
Thanks!
Simon Candelaresi () PhD project outline and risk analysis 2009-11-24, Stockholm 14 / 14