1 / 57

Outline

Outline. How do we define space weather? How do we observe it? What drives it (solar activity and solar phenomena)? Which are the impacts on: the atmosphere and technological sysytems? How can we forecast it? What service exist? Today’s space weather. The Sun. Diameter:

london
Télécharger la présentation

Outline

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Outline • How do we define space weather? • How do we observe it? • What drives it (solar activity and solar phenomena)? • Which are the impacts on: the atmosphere and technological sysytems? • How can we forecast it? • What service exist? • Today’s space weather.

  2. The Sun Diameter: 1 390 000 km (109 x Earth) Mass: 1.99x1030 kg (330 000 x Earth) Density: Core 151x103 kg/m-3 Average 1.41x103 kg/m-3 The Sun consits of: H (≈ 90%) Helium (≈ 10%) C,N,O ( ≈ 0.1%) Temperature: Core 15 million Photosphere 5800 K Chromosphere 4300-104K Corona 1-30 million K 4 protons --> He + 2 positrons + 2 neutrinos + 2 fotons (26.2 MeV)

  3. When the solar magnetic field emerges thru the solar suface sunspots appear

  4. Chromosphere Prominence Solar flare The chromosphere in H-alpha

  5. TRACE

  6. The solar corona seen at solar eclipses

  7. The heating of the solar corona

  8. Coronal mass ejections

  9. CMEs cause the most severe space weather effects • Halo CMEs are most geoeffective • Mass: 5-50 billion tons • Frequency: 3.5/day (max), 0.2/day (min) • Speed: 200-2000 km/s

  10. Solar flares and sun quakes

  11. The solar wind • Predicted from comet studies in 1940 ties • Theoretically predicted by Parker 1959 • Measusred in situ 1960

  12. The source of the fast solar wind

  13. Solar wind Typical values V: 450km/s N: 5particles/cm3 T: 105 K B: 5nT The solar wind consists of protons, electrons and 3-4% alpha particles

  14. Computation of the coronal magnetic field Daily observations of the solar photospheric magnetic field at WSO are used for computation of the coronal magnetic field according to the ”potential field model”.

  15. Computed Br at R=2.5Rs

  16. The heliospheric current sheet

  17. The solar wind Fast halo CME with solar flares and solar proton events Fast continuous solar wind from coronal holes Heliospheric current sheet The solar wind Bz, V, and n determine the effect of the solar plasma.

  18. Earth’s response • Geomagnetic disturbances • Aurora • Ionospheric disturbances • Climate and weather changes

  19. Earth’s magnetosphere and current systems

  20. Geomagnetic storms

  21. Earth’s magnetosphere and ionosphere

  22. Aurora oval

  23. Aurora during severe solar storms Aurora was observed in Italy 6-7 April and on July 15-16, 2000! The aurora observed in Stockholm

  24. Space weather effects on technological systems

  25. Satellite anomalies

  26. Satellite anomalies of July 14-16, 2000 event The proton event caused problems for ACE, SOHO, Ørsted, Japanese X-ray satellite, star trackers on board commercial satellites. Proton flux (pfu) > 10 MeV, 24000 pfu (July 15, 12.30 UT). Third largest! Largest 43 000 pfu, (March 24, 1991). Second 40 000 pfu (October 20, 1989).

  27. Solar proton events are dangerous to man in space Mars Between Apollo 16 and 17 a proton event occurred, which should have been deadly to the astronautes within 10 hours (i.e. above 4000 mSv).

  28. Radiation risks and aviation The radiation exposure is doubled every 2.2 km. Solar flares can increase the radiation by 20-30 times. Pilots get cancer more often than average. The intensive solar flare of April 2, 2001, which caused major communication problems also made Continental Airlines to change their route between Hong Kong and New York. New EU law: Pregnant (aircrew) should not be exposed to more than 1 (1-6) millisievert/year

  29. Power systems are effected at times of geomagnetic storms This severe electrojet caused the failure of Quebec’s power system March 13-14, 1989. A transformer damaged in Main USA. One of the generators of OKG’s (Sydkraft’s) nuclear plants was heated due to the geomagnetically induced current in March 13-14 1989.

  30. Workshops arranged by us Workshops on ”Artificial Intelligence Applications in Solar-Terrestrial Physics” were held in Lund 1993 and 1997.

  31. Artificial neural networks The basic element of every ANN is an artificial neuron or simply a neuron (which is an abstract model of a biological neuron (nerve cell)).

  32. Download Lund Dst model in Java and Matlab The ARMA filter is obtained by adding auto-regressive terms to a MA filter.The partial recurrent network (Elman) becomes identical to a linear ARMA filter if it is assigned linear activations functions.

  33. Our scientific approach

  34. Real-time test of Dst forecasts

  35. Test Dst forecasts

  36. Applications

  37. Applications

  38. Applications

  39. Real-time forecasts and warnings based on KBN Solar input data Solar observations with SOHO make warnings 1-3 days ahead possible. Solar wind observations with ACE make accurate forecasts 1-3 hours ahead possible.

  40. ESA/Lund Space Weather Forecast Service Package

  41. Near and farside solar activity from MDI/SOHO observations

  42. Latest information on arrival of halo CME at L1

  43. Latest info on forecasts of satellite anomalies (SAAPS)

  44. Latest information on forecasts of Kp, Dst, AE and GIC

  45. Our GIC Pilot ProjectAn application at implementation stage

  46. Today general forecast service is given by RWCs within ISES ISES Director: D. Boteler Deputy Director: H. Lundstedt Secr. for World days: H. Coffey Secr. Space Weather: J. Kunches WWW for Satellites: J. King

  47. RWC - SwedenISES

  48. The October 14 -November 6 events:It all started with no sunspots • No sunspots (R=24) • Aurora observed in Southern Sweden (Gothenburg, Lund) • Media got interested • SOHO/MDI far side images had told me Large ARs were to come

  49. Many radio and newspaper interviews followed and AR 484 entered

  50. Then came the AR 486, October 28 event • Even more interviews • Warnings and reports were sent to power industry • Discussions with power operators

More Related