1. Atmospheric transport and chemistry lecture I.Introduction II.Fundamental concepts in atmospheric dynamics: Brewer-Dobson circulation and waves III.Radiative transfer, heating and vertical transport IV.Stratospheric ozone chemistry V.The tropical tropopause VI.Climate gases VII.Solar variability I.The sun II.Solar radiation changes and ozone III.Solar particles and the middle atmosphere

2. The sun seen in the visible (by MDI on the SOHO satellite)

4. Planck‘s function (black-body radiation) deviation from Planck‘s function some structure

5. Internal structure of the sun The (assumed) zones within the sun:  core  radiative zone  convective zone  atmosphere

6. The core of the sun All energy is produced in the solar core, by nuclear reactions (fusion reactions of H) Inner core: composed of 4 He, no nuclear reactions Core edge: nuclear reactions of H, producing 4 He

7. Nuclear reactions at the core edge Proton-proton fusion chain to form 4 He

8. Nuclear reactions at the core edge Proton-proton fusion chain to form 4 He Proton-carbon fusion chain to form 4 He

9. Relative abundances of species in the sun

10. Relative abundances of species in the sun... and in the solar system

11.  the sun is formed of the debris of dead stars

12. Nuclear reactions at the core edge Energy is released in the form of radiation (  - rays).... and kinetic energy of the products

13. The (assumed) zones within the sun:  core  radiative zone  convective zone  atmosphere

14. Radiative zone Temperature and density are not large enough for nuclear reactions Radiation is transmitted from the core through the radiative zone – on it‘s way, it is absorbed and emitted many times, and loses energy

15. Convective zone Formation of convection zells – cooled by updraft of ‚hot‘ plasma parcels  moving plasma produces a strong magnetic field (‚dynamo effect‘), similar to the formation of the terrestrial magnetic field

16. The solar atmosphere Photosphere: ~ 1000 km small, forms the visible surface of the sun Chromosphere: several 1000 km Corona: several solar radii

17. The solar spectrum – the spectrum of the solar atmosphere

18. Temperature and density of the solar atmosphere Solar spectrum: black-body radiation of the photosphere

19. Spectrum of the solar atmosphere: black body radiation, emission and absorption at different T and p Low T: only ground-state of atoms is occupied  absorption

20. Spectrum of the solar atmosphere: black body radiation, emission and absorption at different T and p Low T: only ground-state of atoms is occupied  absorption High T: excited-states are occupied  emission

21. Spectrum of the solar atmosphere: black body radiation, emission and absorption at different T and p Low p: clearly defined lines High p: pressure broadening smears out lines

22. Spectrum of the solar atmosphere: black body radiation, emission and absorption at different T and p Clearly defined emission lines: hot, low density broad absorption feature: cold, high density

23. Temperature and density of the solar atmosphere Density is constant within the corona !Clearly defined emission lines: hot, low density broad absorption feature: cold, high density

24. Spectrum of the solar atmosphere: black body radiation, emission and absorption in the solar atmosphere Fraunhofer lines in the far UV: emission from the chromosphere and corona

25. Spectrum of the solar atmosphere: black body radiation, emission and absorption in the solar atmosphere in the near-UV: absorption in the photosphere Fraunhofer lines in the far UV: emission from the chromosphere and corona

26. The photosphere – the visible surface of the sun granules across the solar surface: top of convection zells

27. The photosphere – the visible surface of the sun Quiet sunActive sun dark sunspots in active regions

28. The photosphere – the visible surface of the sun Quiet sunActive sun dark sunspots in active regions light faculae around active regions

29. Sunspots and the solar 11-year (22-year) cycle Dark sunspots: cooler than the surrounding plasma

30. Sunspots and the solar 11-year (22-year) cycle

31. Sunspots are colder than the surrounding plasma associated with the solar magnetic field extend into the chromosphere and corona as brighter areas

32. Sunspots and the solar 11-year (22-year) cycle Sunspots are colder than the surrounding plasma  convection below sunspots is prohibited by the strong field extend into the chromosphere and corona as brighter areas  plasma is trapped within the strong outer field

33. The 11 – year sunspot cycle: the last 400 years Maunder minimum Solar minimum: low sunspot numbers, low solar activity Solar maximum: high sunspot numbers, high solar activity periodicity of 9 - 13 years

34. Distribution of sunspots across the solar disk: the butterfly diagramm

35. From the homepage of the Ulysses instrument (http://www.sp.ph.ic.ac.uk/~forsyth/reversals)

38.  the 11-year solar cycle is a 22 year solar magnetic cycle !

40. at the approach to solar max  the form of the corona changes  the brightness of the chromosphere increases  the surface of the chromosphere gets patchy

41. The sun‘s corona during an eclipse (1966): solar magnetic field and the brightness of the corona From: Kivelson and Russell, Introduction to Space Physics

42. Solar min: even surfaceSolar max: bright loops and dark patches across surface

43. Loops: plasma trapped in closed magnetic field lines

44. Closed loops in the solar magnetic field of the corona: prominences

46. The final fate of a prominence: eruption

47. Breaking and reconnection of the magnetic field lines above sunspots: solar coronal mass ejections flare associated with the CME large plasma bubble is hurled into space

48. Breaking and reconnection of the magnetic field lines above sunspots: solar coronal mass ejections flare plasma bulb

49. Evolution of a CME at the point where magnetic polarities change Low and Zhang, in: Solar variability and its effect on climate

51. Internal structure of the sun

52. SOHO image of a coronal mass ejection

54. The last 400 years of Solar Proton Events: McCracken et al., JGR, 2000 1989 1859 1893- 1896 „Space age“