1. Version 1.0, 14 May 2004 Slide: 1 APPLICATIONS OF METEOSAT SECOND GENERATION (MSG) FOG DETECTION Author:Jochen Kerkmann (EUMETSAT) (kerkmann@eumetsat.de) (kerkmann@eumetsat.de) Contributors:H. J. Lutz (EUMETSAT), P. Pylkkö (FMI), HP. Roesli (MeteoSwiss), D. Rosenfeld (HUJ)

2. Version 1.0, 14 May 2004 Slide: 2 Day-time Fog over Southern Germany 24 February 2003

3. Version 1.0, 14 May 2004 Slide: 3 IR10.8 channel not very useful for fog detection MSG-1 24 Feb 2003 11:00 UTC Channel 09 (IR10.8) 1 2 1 11 1=low-level fog or stratus 2=snow 3 = snow-free ground 2 13 3

4. Version 1.0, 14 May 2004 Slide: 4 Detection of fog during day-time much better with IR3.9 channel MSG-1 24 Feb 2003 11:00 UTC Channel 04 (IR3.9) 1=low-level fog or stratus 2=snow 3 = snow-free ground 3 3 1 1 2 1 2 1 1

5. Version 1.0, 14 May 2004 Slide: 5 Detection of fog during day-time also good with solar component of IR3.9 MSG-1 24 Feb 2003 11:00 UTC Channel 04r (IR3.9r) 1=low-level fog or stratus 2=snow 3 = snow-free ground 3 3 1 1 2 1 2 1 1

6. Version 1.0, 14 May 2004 Slide: 6 … or with the brightness temperature difference IR3.9 - IR10.8 MSG-1 24 Feb 2003 11:00 UTC Difference IR3.9 - IR10.8 1=low-level fog or stratus 2=snow 3 = snow-free ground 3 3 1 1 2 1 2 1 1

7. Version 1.0, 14 May 2004 Slide: 7 Detection of fog over snow surfaces with SEVIRI NIR 1.6 channel 24 Feb 2003, 11:00 UTC High reflectance (water clouds) Lower reflectance (ice clouds) Low reflectance (snow, sea) 3 3 1 1 2 1 2 1 1

8. Version 1.0, 14 May 2004 Slide: 8 Animation 1/5 3 1 1 2 2 2 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 4=lakes 4 MSG-1 24 Feb 2003 11:00 UTC Channel 03 (NIR1.6) Detection of fog over snow surfaces with SEVIRI NIR 1.6 channel

9. Version 1.0, 14 May 2004 Slide: 9 3 1 1 2 2 2 4 Animation 2/5 Detection of fog over snow surfaces with SEVIRI NIR 1.6 channel 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 4=lakes MSG-1 24 Feb 2003 11:15 UTC Channel 03 (NIR1.6)

10. Version 1.0, 14 May 2004 Slide: 10 3 1 1 2 2 2 4 Animation 3/5 Detection of fog over snow surfaces with SEVIRI NIR 1.6 channel 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 4=lakes MSG-1 24 Feb 2003 11:30 UTC Channel 03 (NIR1.6)

11. Version 1.0, 14 May 2004 Slide: 11 3 1 1 2 2 2 4 Animation 4/5 Detection of fog over snow surfaces with SEVIRI NIR 1.6 channel 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 4=lakes MSG-1 24 Feb 2003 11:45 UTC Channel 03 (NIR1.6)

12. Version 1.0, 14 May 2004 Slide: 12 3 1 1 2 2 2 4 Animation 5/5 Detection of fog over snow surfaces with SEVIRI NIR 1.6 channel 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 4=lakes MSG-1 24 Feb 2003 12:00 UTC Channel 03 (NIR1.6)

13. Version 1.0, 14 May 2004 Slide: 13 Non-detection of fog over snow surfaces with SEVIRI VIS0.6 amd VIS0.8 channels MSG-1, 24 Feb 2004, 11:00 UTC, VIS0.8 … close-up view over the Alps

14. Version 1.0, 14 May 2004 Slide: 14 Non-detection of fog over snow surfaces with SEVIRI HRV channel MSG-1, 24 Feb 2004, 11:00 UTC, HRV … close-up view over the Alps

15. Version 1.0, 14 May 2004 Slide: 15 Recommended RGBs for Monitoring of Day-time Fog MSG-1 24 Feb 2003 11:00 UTC RGB Composite R = NIR1.6 G = VIS0.8 B = VIS0.6 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 1 1 1 1 1 2 2 2 3

16. Version 1.0, 14 May 2004 Slide: 16 Recommended RGBs for Monitoring of Day-time Fog MSG-1 24 Feb 2003 11:00 UTC RGB Composite R = VIS0.8 G = IR3.9r B = IR10.8 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 1 1 1 1 12 2 2 3

17. Version 1.0, 14 May 2004 Slide: 17 Recommended RGBs for Monitoring of Day-time Fog MSG-1 24 Feb 2003 11:00 UTC RGB Composite R = VIS0.8 G = NIR1.6 B = IR3.9r 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 1 1 1 1 12 2 2 3

18. Version 1.0, 14 May 2004 Slide: 18 MSG-1 24 Feb 2003 11:45 UTC RGB Composite R = NIR1.6 G = HRV B = HRV Recommended RGBs for Monitoring of Day-time Fog 1=low-level fog or stratus 2=snow 3=thin mid-level cloud with water droplets (supercooled cloud) 1 3 2 1 2

19. Version 1.0, 14 May 2004 Slide: 19 Night-time Fog over France 14 July 2003

20. Version 1.0, 14 May 2004 Slide: 20 Detection of fog at night (and day) with IR3.9 - IR10.8 brightness temp. diff. MSG-1 14 July 2003 03:00 UTC Difference Image IR3.9 - IR10.8 Animation 1/4 2 1 3 1=low-level fog or stratus 2=clear ground 3=high-level clouds

21. Version 1.0, 14 May 2004 Slide: 21 MSG-1 14 July 2003 04:00 UTC Difference Image IR3.9 - IR10.8 Animation 2/4 2 1 1=low-level fog or stratus 2=clear ground 3=high-level clouds 3 Detection of fog at night (and day) with IR3.9 - IR10.8 brightness temp. diff.

22. Version 1.0, 14 May 2004 Slide: 22 MSG-1 14 July 2003 05:00 UTC Difference Image IR3.9 - IR10.8 Animation 3/4 2 1=low-level fog or stratus 2=clear ground 3=high-level clouds 1 3 Detection of fog difficult at dawn/dusk ! Detection of fog at night (and day) with IR3.9 - IR10.8 brightness temp. diff.

23. Version 1.0, 14 May 2004 Slide: 23 MSG-1 14 July 2003 06:00 UTC Difference Image IR3.9 - IR10.8 Animation 4/4 1 2 3 1=low-level fog or stratus 2=clear ground 3=high-level clouds Detection of fog at night (and day) with IR3.9 - IR10.8 brightness temp. diff.

24. Version 1.0, 14 May 2004 Slide: 24 Difference IR3.9 - IR10.8, 2:00 UTC HRVIS for comparison, 08:45 UTC MSG-1, 14 July 2003

25. Version 1.0, 14 May 2004 Slide: 25 Night-time Fog over S. Africa 24 April 2003

26. Version 1.0, 14 May 2004 Slide: 26 IR10.8 channel not useful for fog detection during night-time MSG-1 24 April 2003 02:00 UTC Channel 09 (IR10.8) 2 3 4 1 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds

27. Version 1.0, 14 May 2004 Slide: 27 IR8.7 channel also not useful for fog detection during night-time MSG-1 24 April 2003 02:00 UTC Channel 07 (IR8.7) 2 3 4 1 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds

28. Version 1.0, 14 May 2004 Slide: 28 IR3.9 channel also not useful for fog detection during night-time MSG-1 24 April 2003 02:00 UTC Channel 04 (IR3.9) 2 3 4 1 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds

29. Version 1.0, 14 May 2004 Slide: 29 MSG-1 24 April 2003 02:00 UTC Difference Image IR3.9 - IR10.8 1 2 3 4 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds Fog at night visible in IR3.9 - IR10.8 brightness temperature difference images

30. Version 1.0, 14 May 2004 Slide: 30 1 2 3 4 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds Fog at night less visible in IR8.7 - IR10.8 brightness temperature difference images MSG-1 24 April 2003 02:00 UTC Difference Image IR8.7 - IR10.8

31. Version 1.0, 14 May 2004 Slide: 31 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds MSG-1 24 April 2003 02:00 UTC Difference Image IR12.0 - IR10.8 1 2 3 4 Fog at night not visible in IR12.0 - IR10.8 brightness temperature difference images

32. Version 1.0, 14 May 2004 Slide: 32 1=low-level fog or stratus 2=clear ground 3 = thin mid-level clouds 4 = thick high-level clouds 1 2 3 4 MSG-1 24 April 2003 02:00 UTC RGB Composite R = IR12.0 - IR10.8 G = IR10.8 - IR3.9 B = IR10.8 Recommended RGB for Monitoring of Night-time Fog

33. Version 1.0, 14 May 2004 Slide: 33 Night-time Fog over Central Europe 25 October 2003

34. Version 1.0, 14 May 2004 Slide: 34 MSG-1 25 October 2003 02:00 UTC Channel 09 (IR10.8) IR10.8 channel not useful for fog detection during night-time 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds 1 12 2 3 3

35. Version 1.0, 14 May 2004 Slide: 35 IR8.7 channel also not useful for fog detection during night-time MSG-1 25 October 2003 02:00 UTC Channel 07 (IR8.7) 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds 1 12 2 3 3

36. Version 1.0, 14 May 2004 Slide: 36 MSG-1 25 October 2003 02:00 UTC Channel 04 (IR3.9) IR3.9 channel a bit better for fog detection during night-time, but... 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds 1 12 2 3 3

37. Version 1.0, 14 May 2004 Slide: 37 Fog: -8/-10 K (black) Ground: -4/-5 K (grey) … fog at night very well visible in IR3.9-IR10.8 temperature difference images MSG-1 25 October 2003 02:00 UTC Difference Image IR3.9 - IR10.8 12 2 1 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds 3 3

38. Version 1.0, 14 May 2004 Slide: 38 Fog: -4 K (dark grey) Ground: -2 K (light grey) … fog at night also well visible in IR8.7-IR10.8 temperature difference images MSG-1 25 October 2003 02:00 UTC Difference Image IR8.7 - IR10.8 1 1 2 2 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds 3 3

39. Version 1.0, 14 May 2004 Slide: 39 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds … fog at night not visible in IR12.0-IR10.8 temperature difference images 1 1 2 2 MSG-1 25 October 2003 02:00 UTC Difference Image IR12.0 - IR10.8 3 3

40. Version 1.0, 14 May 2004 Slide: 40 Recommended RGB for Monitoring of Night-time Fog MSG-1 25 Oct 2003 02:00 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8 1=low-level fog or stratus 2=clear ground 3 = thin Cirrus clouds 1 1 2 2 3 3

41. Version 1.0, 14 May 2004 Slide: 41 Night-time Fog over Southern Finland 29 October 2003

42. Version 1.0, 14 May 2004 Slide: 42 MSG-1 29 October 2003 02:00 UTC Channel 09 (IR10.8) 1 1 1 2 2 3 1=low-level fog or stratus 2=clear ground 3 = high-level frontal clouds 3 Fog at night not visible in IR10.8 images

43. Version 1.0, 14 May 2004 Slide: 43 MSG-1 29 October 2003 02:00 UTC Channel 07 (IR8.7) 1 1 1 2 2 3 1=low-level fog or stratus 2=clear ground 3 = high-level frontal clouds 3 Fog at night not visible in IR8.7 images

44. Version 1.0, 14 May 2004 Slide: 44 MSG-1 29 October 2003 02:00 UTC Channel 04 (IR3.9) 1 1 1 2 2 3 1=low-level fog or stratus 2=clear ground 3 = high-level frontal clouds 3 Fog at night hardly visible in IR3.9 images

45. Version 1.0, 14 May 2004 Slide: 45 MSG-1 29 October 2003 02:00 UTC Difference Image IR3.9 - IR10.8 Night-time fog is not well visible in IR3.9-IR10.8 temperature difference images over Scandinavia 1 1 1 2 2 3 1=low-level fog or stratus 2=clear ground 3 = high-level frontal clouds 3

46. Version 1.0, 14 May 2004 Slide: 46 1 1 2 2 MSG-1 29 October 2003 02:00 UTC Difference Image IR8.7 - IR10.8 1=low-level fog or stratus 2=clear ground 3 = high-level frontal clouds The IR8.7-IR10.8 temperature difference images give better results for fog detection at high latitudes 3 1 3

47. Version 1.0, 14 May 2004 Slide: 47 MSG-1 29 Oct 2003 02:00 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR8.7 B = IR10.8 Recommended RGB for Monitoring of Night-time Fog at high Latitudes 1=low-level fog or stratus 2=clear ground 3 = high-level frontal clouds 1 1 1 2 2 3 3

48. Version 1.0, 14 May 2004 Slide: 48 Night-time Fog over Central Europe 5 November 2003

49. Version 1.0, 14 May 2004 Slide: 49 MSG-1 5 November 2003 03:00 UTC Channel 04 (IR3.9) Fog at night not visible in IR window channels 33 2 1 1 2 1 3 1=low-level fog or stratus 2=clear ground 3 = high-level clouds

50. Version 1.0, 14 May 2004 Slide: 50 Fog at night not visible in IR window channels MSG-1 5 November 2003 03:00 UTC Channel 07 (IR8.7) 33 2 1 1 2 1 3 1=low-level fog or stratus 2=clear ground 3 = high-level clouds

51. Version 1.0, 14 May 2004 Slide: 51 Fog at night not visible in IR window channels MSG-1 5 November 2003 03:00 UTC Channel 09 (IR10.8) 33 2 1 1 2 1 3 1=low-level fog or stratus 2=clear ground 3 = high-level clouds

52. Version 1.0, 14 May 2004 Slide: 52 Fog: -7/-10 K (black) Ground: -4 K (grey) Fog at night well visible in IR3.9 - IR10.8 difference images MSG-1 5 November 2003 03:00 UTC Difference Image IR3.9 - IR10.8 1=low-level fog or stratus 2=clear ground 3 = high-level clouds 1 2 33 3 1 1 2

53. Version 1.0, 14 May 2004 Slide: 53 Fog: -8/-10 K (black) Ground: -5 K (grey) 1=low-level fog or stratus 2=clear ground 3 = high-level clouds 3 MSG-1 5 November 2003 03:00 UTC Difference Image IR3.9 - IR12.0 3 2 1 1 2 1 3 Fog at night also well visible in IR3.9 - IR12.0 difference images

54. Version 1.0, 14 May 2004 Slide: 54 Fog: -3/-4 K (dark grey) Ground: -1 K (light grey) 3 Fog at night also visible in IR8.7 - IR10.8 difference images 1=low-level fog or stratus 2=clear ground 3 = high-level clouds MSG-1 5 November 2003 03:00 UTC Difference Image IR8.7 - IR10.8 3 2 1 1 2 1 3

55. Version 1.0, 14 May 2004 Slide: 55 Fog: 0/+1 K (light grey) Ground: 0/+1 K (light grey) Fog at night not visible in difference IR12.0 - IR10.8 3 1=low-level fog or stratus 2=clear ground 3 = high-level clouds MSG-1 5 November 2003 03:00 UTC Difference Image IR12.0 - IR10.8 3 2 1 1 2 1 3

56. Version 1.0, 14 May 2004 Slide: 56 MSG-1 5 November 2003 03:00 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8 33 2 1 1 2 1 3 Recommended RGB for Monitoring of Night-time Fog 1=low-level fog or stratus 2=clear ground 3 = high-level clouds

57. Version 1.0, 14 May 2004 Slide: 57 Day-time Fog over Central Europe 5 November 2003

58. Version 1.0, 14 May 2004 Slide: 58 River Valley Fog as seen by Meteosat First Generation (MFG) Met-7, 5 November 2003, 08:00 UTC, VIS channel

59. Version 1.0, 14 May 2004 Slide: 59 MSG-1 5 November 2003 08:45 UTC Channel 12 (HRV) River valley fog can be better detected with the MSG HRV channel Mosel Valley Danube Valley

60. Version 1.0, 14 May 2004 Slide: 60 Kaiserstuhl (557 m) … and the MSG HRV channel gives more details MSG-1 5 November 2003 08:45 UTC Channel 12 (HRV)

61. Version 1.0, 14 May 2004 Slide: 61 1=low-level fog or stratus 2=clear ground 3 = high-level clouds 4 = snow MSG-1 5 November 2003 09:00 UTC RGB Composite R = NIR1.6 G = VIS0.8 B = VIS0.6 Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 4 4

62. Version 1.0, 14 May 2004 Slide: 62 1=low-level fog or stratus 2=clear ground 3 = high-level clouds 4 = snow MSG-1 5 November 2003 09:00 UTC RGB Composite R = VIS0.8 G = IR3.9r B = IR10.8 Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 4 4

63. Version 1.0, 14 May 2004 Slide: 63 1=low-level fog or stratus 2=clear ground 3 = high-level clouds 4 = snow MSG-1 5 November 2003 09:00 UTC RGB Composite R = VIS0.8 G = NIR1.6 B = IR3.9r Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 4 4

64. Version 1.0, 14 May 2004 Slide: 64 1=low-level fog or stratus 2=clear ground 3 = high-level clouds 4 = snow MSG-1 5 November 2003 08:45 UTC RGB Composite R = HRV G = HRV B = IR3.9i Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 4 4

65. Version 1.0, 14 May 2004 Slide: 65 Night-time Fog over Europe 9 November 2003

66. Version 1.0, 14 May 2004 Slide: 66 MSG-1 09 November 2003 03:15 UTC Channel 04 (IR3.9) Fog at night not visible in IR window channels 3 3 1 1 1 2 4 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds

67. Version 1.0, 14 May 2004 Slide: 67 Fog at night not visible in IR window channels MSG-1 09 November 2003 03:15 UTC Channel 07 (IR8.7) 3 3 1 1 1 2 4 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds

68. Version 1.0, 14 May 2004 Slide: 68 Fog at night not visible in IR window channels MSG-1 09 November 2003 03:15 UTC Channel 09 (IR10.8) 3 3 1 1 1 2 4 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds

69. Version 1.0, 14 May 2004 Slide: 69 Fog: -7/-10 K (black) Ground: -4/-5 K (grey) Fog at night visible in IR3.9 - IR10.8 difference images 3 3 1 1 1 2 4 MSG-1 09 November 2003 03:15 UTC Difference Image IR3.9 - IR10.8 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds Animation 1/6

70. Version 1.0, 14 May 2004 Slide: 70 Fog: -7/-10 K (black) Ground: -4/-5 K (grey) 3 3 1 1 1 2 4 MSG-1 09 November 2003 04:15 UTC Difference Image IR3.9 - IR10.8 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds Animation 2/6 Fog at night visible in IR3.9 - IR10.8 difference images

71. Version 1.0, 14 May 2004 Slide: 71 Fog: -7/-10 K (black) Ground: -4/-5 K (grey) 3 3 1 1 1 2 4 MSG-1 09 November 2003 05:15 UTC Difference Image IR3.9 - IR10.8 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds Animation 3/6 Fog at night visible in IR3.9 - IR10.8 difference images

72. Version 1.0, 14 May 2004 Slide: 72 Fog: -3/-4 K (grey) Ground: -4/-5 K (grey) Fog at dawn/dusk not visible in IR3.9 - IR10.8 difference images 3 3 1 1 1 2 4 MSG-1 09 November 2003 06:15 UTC Difference Image IR3.9 - IR10.8 Animation 4/6 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds

73. Version 1.0, 14 May 2004 Slide: 73 Fog: +2/+6 (light grey) Ground: -4/-5 K (dark grey) 3 3 1 1 1 2 4 MSG-1 09 November 2003 07:15 UTC Difference Image IR3.9 - IR10.8 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds Animation 5/6 Fog at daytime visible in IR3.9 - IR10.8 difference images

74. Version 1.0, 14 May 2004 Slide: 74 Fog: +6/+12 (light grey) Ground: -2/-3 K (dark grey) 3 3 1 1 1 2 4 MSG-1 09 November 2003 08:15 UTC Difference Image IR3.9 - IR10.8 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds Animation 6/6 Fog at daytime visible in IR3.9 - IR10.8 difference images

75. Version 1.0, 14 May 2004 Slide: 75 Fog: -3/-4 K (black) Ground: -1/-2 K (grey) 3 3 1 1 1 2 4 Fog at night also visible in difference IR8.7 - IR10.8 MSG-1 09 November 2003 03:15 UTC Difference Image IR8.7 - IR10.8 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds

76. Version 1.0, 14 May 2004 Slide: 76 Fog: 0/+1 K Ground: 0/+1 K Ocean: -1 K Fog at night not visible in difference IR12.0 - IR10.8 3 3 1 1 1 2 4 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high-level clouds MSG-1 09 November 2003 03:15 UTC Difference Image IR12.0 - IR10.8

77. Version 1.0, 14 May 2004 Slide: 77 MSG-1 9 November 2003 03:15 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8 3 3 1 1 1 2 4 Recommended RGB for Monitoring of Night-time Fog 1=low-level fog or stratus 2=cold clear ground 3 = warm clear ground (mountains) 4 = thin, high level clouds

78. Version 1.0, 14 May 2004 Slide: 78 Day-time Fog over Europe 9 November 2003

79. Version 1.0, 14 May 2004 Slide: 79 Low Stratus and River Valley Fog as seen by MFG Met-7, 9 November 2003, 08:00 UTC, VIS channel

80. Version 1.0, 14 May 2004 Slide: 80 MSG HRV channel gives more details on the fog... MSG-1 9 November 2003 08:15 UTC Channel 12 (HRV) River Valley Fog Fog/low stratus

81. Version 1.0, 14 May 2004 Slide: 81 MSG-1 9 November 2003 08:15 UTC Channel 12 (HRV) Fog/Low stratus with Gravity Waves … closer look at Denmark

82. Version 1.0, 14 May 2004 Slide: 82 MSG-1 9 November 2003 08:15 UTC RGB Composite R = NIR1.6 G = VIS0.8 B = VIS0.6 Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 3 1 1=low-level fog or stratus 2=clear ground 3 = high-level thick clouds 4 = high-level thin clouds 5 = snow 5 4 4 4

83. Version 1.0, 14 May 2004 Slide: 83 1=low-level fog or stratus 2=clear ground 3 = high-level thick clouds 4 = high-level thin clouds 5 = snow MSG-1 9 November 2003 08:15 UTC RGB Composite R = VIS0.8 G = IR3.9r B = IR10.8 Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 3 1 5 4 4 4

84. Version 1.0, 14 May 2004 Slide: 84 MSG-1 9 November 2003 08:15 UTC RGB Composite R = VIS0.8 G = NIR1.6 B = IR3.9r Recommended RGBs for Monitoring of Day-time Fog 1 2 3 1 1 2 5 3 1 1=low-level fog or stratus 2=clear ground 3 = high-level thick clouds 4 = high-level thin clouds 5 = snow 4 4 4

85. Version 1.0, 14 May 2004 Slide: 85 MSG-1 9 November 2003 08:15 UTC RGB Composite R = HRV G = HRV B = IR3.9 - IR10.8 Recommended RGBs for Monitoring of Day-time Fog 1 2 4 1 1 2 5 1 4 1=low-level fog or stratus 2=clear ground 3 = high-level thick clouds 4 = high-level thin clouds 5 = snow 2 3 4 1

86. Version 1.0, 14 May 2004 Slide: 86 Night-time Fog over Central Europe 11 November 2003

87. Version 1.0, 14 May 2004 Slide: 87 1. Sea surface 2. Land surface 3. Warm fog 4. Cool fog + stratus (-3 o C) 5. Supercooled water stratus (-13 o C) 6. Highly supercooled water stratus (-18 o C) 7. Cb with lightning 8. Thick cirrus 9. Thin cirrus 1 3 3 5 4 1 2 6 7 7 8 9 MSG-1 11 Nov 2003 03:00 UTC RGB Composite R = IR12.0 - IR10.8 G = IR10.8 - IR3.9 B = IR10.8 Recommended RGB for Monitoring of Night-time Fog

88. Version 1.0, 14 May 2004 Slide: 88 1 3 3 5 4 1 2 6 7 7 8 9 Recommended RGB for Monitoring of Night-time Fog MSG-1 11 Nov 2003 03:00 UTC Difference Image R = IR12.0 - IR10.8 1. Sea surface 2. Land surface 3. Warm fog 4. Cool fog + stratus (-3 o C) 5. Supercooled water stratus (-13 o C) 6. Highly supercooled water stratus (-18 o C) 7. Cb with lightning 8. Thick cirrus 9. Thin cirrus

89. Version 1.0, 14 May 2004 Slide: 89 1 3 3 5 4 1 2 6 7 7 8 9 MSG-1 11 Nov 2003 03:00 UTC Difference Image G = IR10.8 - IR3.9 1. Sea surface 2. Land surface 3. Warm fog 4. Cool fog + stratus (-3 o C) 5. Supercooled water stratus (-13 o C) 6. Highly supercooled water stratus (-18 o C) 7. Cb with lightning 8. Thick cirrus 9. Thin cirrus Recommended RGB for Monitoring of Night-time Fog

90. Version 1.0, 14 May 2004 Slide: 90 1 3 3 5 4 1 2 6 7 7 8 9 MSG-1 11 Nov 2003 03:00 UTC Difference Image B = IR10.8 1. Sea surface 2. Land surface 3. Warm fog 4. Cool fog + stratus (-3 o C) 5. Supercooled water stratus (-13 o C) 6. Highly supercooled water stratus (-18 o C) 7. Cb with lightning 8. Thick cirrus 9. Thin cirrus Recommended RGB for Monitoring of Night-time Fog

91. Version 1.0, 14 May 2004 Slide: 91 Day-time Fog over the Po Valley 20 November 2003

92. Version 1.0, 14 May 2004 Slide: 92 MSG-1, 20 November 2003, 11:00 UTC, HRV Channel

93. Version 1.0, 14 May 2004 Slide: 93 Night Fog darker than clear ground Dawn Fog and clear ground equal Day Fog brighter than clear ground 1 to 2 critical slots at dawn/dusk MSG-1, 20 November 2003 Difference IR3.9 - IR10.8

94. Version 1.0, 14 May 2004 Slide: 94 MSG-1, 20 November 2003, 00:00 UTC, IR3.9 - IR10.8 Click on the icon to see the animation (00:00-15:00 UTC, AVI, 15068 KB) !

95. Version 1.0, 14 May 2004 Slide: 95 SUMMARY

96. Version 1.0, 14 May 2004 Slide: 96 VIS0.6 and HRVIS: to disciminate between fog and ground (fog white, ground dark)VIS0.6 and HRVIS: to disciminate between fog and ground (fog white, ground dark) VIS0.8: less useful because of less contrast to vegetated areasVIS0.8: less useful because of less contrast to vegetated areas NIR1.6 and IR3.9: to discriminate between fog and snow (fog high reflectivity, snow low reflectivity)NIR1.6 and IR3.9: to discriminate between fog and snow (fog high reflectivity, snow low reflectivity) IR3.9 - IR10.8: fog large positive values; clear ground around 0 K (-5 K to +5 K)IR3.9 - IR10.8: fog large positive values; clear ground around 0 K (-5 K to +5 K) Detection of Fog/Low Stratus during Daytime

97. Version 1.0, 14 May 2004 Slide: 97 RGB 03-02-01: fog white-pinkish; clear ground greenish or reddish (depending in vegetation)RGB 03-02-01: fog white-pinkish; clear ground greenish or reddish (depending in vegetation) RGB 03-12-12: fog white-pinkish; clear ground reddishRGB 03-12-12: fog white-pinkish; clear ground reddish RGB 02-04r-09: fog white-pinkish; clear ground blueishRGB 02-04r-09: fog white-pinkish; clear ground blueish RGB 02-03-04r: fog whitish, clear ground greenish- bluishRGB 02-03-04r: fog whitish, clear ground greenish- bluish Detection of Fog/Low Stratus during Daytime

98. Version 1.0, 14 May 2004 Slide: 98 IR3.9-IR10.8: fog -10/-7 K; clear ground around -4 K (difficulties at high latitudes)IR3.9-IR10.8: fog -10/-7 K; clear ground around -4 K (difficulties at high latitudes) RGB 10-09 / 09-04 / 09: fog light greenish-yellowish; clear ground dark pinkishRGB 10-09 / 09-04 / 09: fog light greenish-yellowish; clear ground dark pinkish Detection of Fog/Low Stratus during Nighttime (Low and Mid Latitudes)

99. Version 1.0, 14 May 2004 Slide: 99 Detection of Fog/Low Stratus during Nighttime (High Latitudes) IR8.7-IR10.8: fog -4 K, clear ground around -1/-2 KIR8.7-IR10.8: fog -4 K, clear ground around -1/-2 K RGB 10-09 / 09-07 / 09: fog light greenish-yellowish; clear ground dark pinkishRGB 10-09 / 09-07 / 09: fog light greenish-yellowish; clear ground dark pinkish

100. Version 1.0, 14 May 2004 Slide: 100 IR3.9-IR10.8: fog detection difficult because of compensating effects (fog colder in IR3.9 than in IR10.8 because of lower emissivity, but reflection of solar radiation)IR3.9-IR10.8: fog detection difficult because of compensating effects (fog colder in IR3.9 than in IR10.8 because of lower emissivity, but reflection of solar radiation) IR8.7-IR10.8: fog -4 K, clear ground around -1/-2 K (only small difference between fog and clear ground, but works also at dawn/dusk)IR8.7-IR10.8: fog -4 K, clear ground around -1/-2 K (only small difference between fog and clear ground, but works also at dawn/dusk) Detection of Fog/Low Stratus at Dawn/Dusk

101. Version 1.0, 14 May 2004 Slide: 101 Detection of Fog/Low Stratus: Conclusion Less noisy than the difference IR3.9 - IR10.8 (works well also over Scandinavia)Less noisy than the difference IR3.9 - IR10.8 (works well also over Scandinavia) 24-hour capability with "constant" colour for fog/low stratus (unlike IR3.9-IR10.8 difference)24-hour capability with "constant" colour for fog/low stratus (unlike IR3.9-IR10.8 difference) High-level Cirrus above fog/low stratus can also be detected (combined with IR12.0-IR10.8 difference)High-level Cirrus above fog/low stratus can also be detected (combined with IR12.0-IR10.8 difference) In operational applications, the difference IR8.7-IR10.8 may be the best to detect fog/low stratus (day- and night), because of:

102. Version 1.0, 14 May 2004 Slide: 102 MSG-1, 9 November 2003, 00:15 UTC, Difference Image, IR8.7 - IR10.8 Click on the icon to see the animation (00:15-08:15 UTC, AVI, 10550 KB) !