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after Woch et al., 1997

700-800 km/s. 400 km/s. after Woch et al., 1997. Slow solar wind from an equatorial coronal hole. Slow solar wind from a polar coronal hole. Low-speed wind models. Helmet-streamer. Blob-loop reconnection Wang et al. (1999). Expanding active region Nakagawa & Uchida.

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after Woch et al., 1997

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  1. 700-800 km/s 400 km/s after Woch et al., 1997

  2. Slow solar wind from an equatorial coronal hole Slow solar wind from a polar coronal hole

  3. Low-speed wind models Helmet-streamer Blob-loop reconnection Wang et al. (1999) Expanding active region Nakagawa & Uchida

  4. Relation between speed and coronal hole area The speed of the solar wind scales with the coronal hole area. [Nolte et al., 1976] Intermediate and slow streams originated in smaller coronal holes at low latitudes and from open field regions just outside coronal hole boundaries. [Neugebauer et al., 1998]

  5. Wang & Sheely model Magnetic field configuration smaller expansion high speed larger expansion low speed RADIAL DISTANCE after Wang and Sheeley, 1990

  6. from flux expansion factor in situ observation after Wang and Sheeley, 1990

  7. potential field neutral line A neutral line does not traverse through the minimum speed locus. after Crooker et al., 1997

  8. Slow SW from an equatorial small CH

  9. potential field neutral line ? ? after Kojima et al., 1999

  10. potential field neutral line ? ? after Kojima et al., 1999

  11. after Kojima et al., 1999

  12. after Kojima et al., 1999

  13. Hinode Continuous Upflow of Plasmas (Ti/Poly Filter)

  14. MHD simulation by Linker & Mikic ’99 V V N low density low speed from coronal hole

  15. after Kojima et al., 1999 Coronal hole model Helmet streamer model

  16. potential field neutral line A neutral line does not traverse through the minimum speed locus. after Crooker et al., 1997

  17. V Np φB

  18. V Np To 106K

  19. V Np Na/Np

  20. Solar Wind in CR 1897 (June 12 – July 10, 1995) Parameter Slow (HPS) Slow (seCH) Fast (leCH) VP [km/s] 343±12 323±9673±14 NP [cm-3] 11.7±3.3 10.2±0.6 3.2±0.5 TP [105 K] 0.39±0.14 0.55±0.112.20±0.39 TO [106 K] 1.85±0.24 1.99±0.191.42±0.13 Nα/ NP 0.009±0.003 0.031±0.0080.039±0.004

  21. Solar Wind in CR 1897 (June 12 – July 10, 1995) Parameter Slow (HPS) Slow (seCH) Fast (leCH) VP [km/s] 343±12 323±9673±14 NP [cm-3] 11.7±3.3 10.2±0.6 3.2±0.5 TP [105 K] 0.39±0.14 0.55±0.112.20±0.39 TO [106 K] 1.85±0.24 1.99±0.191.42±0.13 Nα/ NP 0.009±0.003 0.031±0.0080.039±0.004

  22. slow wind (SCH) coronal hole steady large

  23. Origin of slow SW(seCH) Coronal hole origin but ⇒ extra momentum source in lower corona Large NV High To (in seCH) Enhanced Heating in lower corona seCH StrongB (in seCH)

  24. Slow SW from a polar CH

  25. dependence on polar coronal hole scale size 1999 1991 2000 Oct. 1999

  26. SOHO/EIT 195 Å 1999/10/23 22:24 UT

  27. Small Polar Coronal Hole

  28. Wang & Sheely model Magnetic field configuration smaller expansion high speed larger expansion low speed RADIAL DISTANCE Energy/mass flux B=4~6 G Less magnetic energy after Wang and Sheeley, 1990

  29. Polar Low-speed Solar Wind at Solar Activity Maximum of Cycle 23 October 23, 1999 Ohmi et al. [2002]

  30. Polar Low-speed Solar Wind at Solar Activity Maximum of Cycle 22 June 27, 1990 Ohmi et al. [2001]

  31. 12G 4~6G 18G slower fast slower slow

  32. Wang & Sheely model Magnetic field configuration smaller expansion high speed larger expansion low speed RADIAL DISTANCE Energy/mass flux after Wang and Sheeley, 1990

  33. Magnetic Field in the Coronal Holes

  34. Density excess in slow wind source 300~3000 The slowest SW has f = 100~1000.

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