APPLICATIONS OF METEOSAT SECOND GENERATION (MSG)

Version 1.0, 14 May 2004 Slide: 1

APPLICATIONS OFMETEOSAT SECOND GENERATION (MSG)

FOG DETECTION

Author:Author: Jochen Kerkmann (EUMETSAT)Jochen Kerkmann (EUMETSAT) ([email protected])([email protected])

Contributors:Contributors: H. J. Lutz (EUMETSAT), P. Pylkkö (FMI),H. J. Lutz (EUMETSAT), P. Pylkkö (FMI),HP. Roesli (MeteoSwiss), D. Rosenfeld (HUJ)HP. Roesli (MeteoSwiss), D. Rosenfeld (HUJ)


Day-time Fog over Southern Germany24 February 2003


IR10.8 channel not very useful for fog detection

MSG-124 Feb 200311:00 UTCChannel 09(IR10.8)

12

1

11

1= low-level fog or stratus

2= snow

3 = snow-free ground

2

13

3


Detection of fog during day-time much better with IR3.9 channel

MSG-124 Feb 200311:00 UTCChannel 04(IR3.9)


2= snow


3

3

1 1 2

1

2

1

1


Detection of fog during day-time also good with solar component of IR3.9

MSG-124 Feb 200311:00 UTCChannel 04r(IR3.9r)


2= snow


3

3

1 1 2

1

2

1

1


… or with the brightness temperature difference IR3.9 - IR10.8

MSG-124 Feb 200311:00 UTCDifferenceIR3.9 - IR10.8


2= snow


3

3

1 1 2

1

2

1

1


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)

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3

11 2

1

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1

1


Animation 1/5

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2

22


2= snow

3= thin mid-level cloud withwater droplets(supercooled cloud)

4= lakes

4 MSG-124 Feb 200311:00 UTCChannel 03(NIR1.6)

Detection of fog over snow surfaces with

SEVIRI NIR 1.6 channel


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11

2

22

4

Animation 2/5 Detection of fog over snow surfaces with



2= snow


4= lakes

MSG-124 Feb 200311:15 UTCChannel 03(NIR1.6)


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2

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4




2= snow


4= lakes



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 viewover the Alps


Non-detection of fog over snow surfaces with SEVIRI HRV channel

MSG-1, 24 Feb 2004, 11:00 UTC, HRV

… close-up viewover the Alps


Recommended RGBs for Monitoring of Day-time Fog

MSG-124 Feb 200311:00 UTCRGB CompositeR = NIR1.6G = VIS0.8B = VIS0.6


2= snow

3= thin mid-level cloud with water droplets

(supercooled cloud)

1

1

1

1

12

2

2

3



MSG-124 Feb 200311:00 UTCRGB CompositeR = VIS0.8G = IR3.9rB = IR10.8


2= snow


(supercooled cloud)

1

1

1

1 12

2

2

3



MSG-124 Feb 200311:00 UTCRGB CompositeR = VIS0.8G = NIR1.6B = IR3.9r


2= snow


(supercooled cloud)

1

1

1

1 12

2

2

3


MSG-124 Feb 200311:45 UTCRGB CompositeR = NIR1.6G = HRVB = HRV

Recommended RGBsfor Monitoring of

Day-time Fog


2= snow

3= thin mid-level cloud with water droplets (supercooled cloud)

1

3

2

1 2


Night-time Fog over France14 July 2003


Detection of fog at night (and day) withIR3.9 - IR10.8

brightness temp. diff.

MSG-114 July 200303:00 UTCDifference ImageIR3.9 - IR10.8

Animation 1/4

2

13


2= clear ground

3= high-level clouds



Animation 2/4

2

1


2= clear ground


3





Animation 3/4

2


2= clear ground

3= high-level clouds13

Detection of fog difficult at dawn/dusk !





Animation 4/4

1

2

3


2= clear ground





Difference IR3.9 - IR10.8, 2:00 UTC HRVIS for comparison, 08:45 UTC

MSG-1, 14 July 2003


Night-time Fog over S. Africa24 April 2003


IR10.8 channel not useful for fog detection

during night-time

MSG-124 April 200302:00 UTCChannel 09(IR10.8)

2

3

4


2= clear ground

3 = thin mid-level clouds

4 = thick high-level clouds


IR8.7 channel also not useful for fog detection

during night-time


2

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4


2= clear ground





during night-time


2

3

4


2= clear ground




MSG-124 April 200302:00 UTCDifference ImageIR3.9 - IR10.8

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3

4


2= clear ground



Fog at night visible inIR3.9 - IR10.8

brightness temperature difference images


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3

4


2= clear ground



Fog at night less visible in IR8.7 - IR10.8





2= clear ground




12

3

4

Fog at night not visible in IR12.0 - IR10.8




2= clear ground



12

3

4

MSG-124 April 200302:00 UTCRGB CompositeR = IR12.0 - IR10.8G = IR10.8 - IR3.9B = IR10.8

Recommended RGBfor Monitoring ofNight-time Fog


Night-time Fog over Central Europe25 October 2003


MSG-125 October 200302:00 UTCChannel 09(IR10.8)

IR10.8 channel not useful for fog detectionduring night-time


2= clear ground

3 = thin Cirrus clouds

11 2

2

3

3



during night-time



2= clear ground


11 2

2

3

3



IR3.9 channel a bit better for fog detection

during night-time,but ...


2= clear ground


11 2

2

3

3


Fog: -8/-10 K (black)Ground: -4/-5 K (grey)

… fog at nightvery well visible in

IR3.9-IR10.8 temperature difference images

MSG-125 October 200302:00 UTCDifference ImageIR3.9 - IR10.8

1 2

2

1


2= clear ground


3

3


Fog: -4 K (dark grey)Ground: -2 K (light grey)

… fog at nightalso well visible in



1 12


2= clear ground


3

3



2= clear ground


… fog at nightnot visible in


1 12

2


3

3


Recommended RGB for Monitoring of Night-time Fog

MSG-125 Oct 200302:00 UTCRGB CompositeR = IR12.0-IR10.8G = IR10.8-IR3.9B = IR10.8


2= clear ground


1 12

2

3

3


Night-time Fog over Southern Finland29 October 2003



1

1

1

2

2


2= clear ground

3 = high-level frontal clouds3

Fog at nightnot visible in

IR10.8 images



1

1

1

2

2


2= clear ground


Fog at nightnot visible inIR8.7 images



1

1

1

2

2


2= clear ground


Fog at nighthardly visible inIR3.9 images



Night-time fog is not well visible in

IR3.9-IR10.8 temperature difference images over

Scandinavia

1

1

1

2

2


2= clear ground



1

1

2

2



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


MSG-129 Oct 200302:00 UTCRGB CompositeR = IR12.0-IR10.8G = IR10.8-IR8.7B = IR10.8

Recommended RGB for Monitoring of Night-time Fog at high Latitudes


2= clear ground

3 = high-level frontal clouds

1

1

1

2

2

33


Night-time Fog over Central Europe 5 November 2003


MSG-15 November 200303:00 UTCChannel 04(IR3.9)

Fog at nightnot visible inIR windowchannels

3 3

2

11

21

3


2= clear ground

3 = high-level clouds




3 3

2

11

21

3


2= clear ground



Fog: -7/-10 K (black)Ground: -4 K (grey)

Fog at nightwell visible inIR3.9 - IR10.8

difference images

MSG-15 November 200303:00 UTCDifference ImageIR3.9 - IR10.8


2= clear ground

3 = high-level clouds1

2

33

3

1

1

2


Fog: -8/-10 K (black)Ground: -5 K (grey)


2= clear ground


3


3

2

11

21

3

Fog at nightalso well visible in

IR3.9 - IR12.0 difference images


Fog: -3/-4 K (dark grey)Ground: -1 K (light grey)

3 Fog at nightalso visible inIR8.7 - IR10.8

difference images


2= clear ground



3

2

11

21

3


Fog: 0/+1 K (light grey)Ground: 0/+1 K (light grey)

Fog at nightnot visible in

differenceIR12.0 - IR10.8

3


2= clear ground



3

2

11

21

3


MSG-15 November 200303:00 UTCRGB CompositeR = IR12.0-IR10.8G = IR10.8-IR3.9B = IR10.8

3 3

2

11

21

3



2= clear ground



Day-time Fog over Central Europe 5 November 2003


River Valley Fog as seen by Meteosat First Generation (MFG)Met-7, 5 November 2003, 08:00 UTC, VIS channel


MSG-15 November 200308:45 UTCChannel 12(HRV)

River valley fog can be better detected with the

MSG HRV channel

Mosel Valley

Danube Valley


Kaiserstuhl(557 m)

… and the MSG HRV channel gives more details




2= clear ground

3 = high-level clouds4 = snow

MSG-15 November 200309:00 UTCRGB CompositeR = NIR1.6G = VIS0.8B = VIS0.6


1

2

3

11

2

4

4



2= clear ground


MSG-15 November 200309:00 UTCRGB CompositeR = VIS0.8G = IR3.9rB = IR10.8


1

2

3

1

1

2

4

4



2= clear ground


MSG-15 November 200309:00 UTCRGB CompositeR = VIS0.8G = NIR1.6B = IR3.9r


1

2

3

1

1

2

4

4



2= clear ground


4 = snow

MSG-15 November 200308:45 UTCRGB CompositeR = HRVG = HRVB = IR3.9i

Recommended RGBsfor Monitoring of

Day-time Fog1 2

3

11

2

4

4


Night-time Fog over Europe9 November 2003




3

3

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1

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2= cold clear ground

3 = warm clear ground (mountains)

4 = thin, high-level clouds




3

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Fog at night visible inIR3.9 - IR10.8

difference images

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Animation 1/6



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Animation 2/6 Fog at night visible inIR3.9 - IR10.8

difference images



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Animation 3/6 Fog at night visible inIR3.9 - IR10.8

difference images


Fog: -3/-4 K (grey)Ground: -4/-5 K (grey)

Fog at dawn/dusk not visible in IR3.9 - IR10.8

difference images

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31

1

1

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4


Animation 4/6






Fog: +2/+6 (light grey)Ground: -4/-5 K (dark grey)

3

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Animation 5/6 Fog at daytime visible in IR3.9 - IR10.8

difference images


Fog: +6/+12 (light grey)Ground: -2/-3 K (dark grey)

3

31

1

1

2

4






Animation 6/6 Fog at daytime visible in IR3.9 - IR10.8

difference images



3

3

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1

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Fog at night also visible in difference

IR8.7 - IR10.8







Fog: 0/+1 KGround: 0/+1 KOcean: -1 K

Fog at night not visible in difference

IR12.0 - IR10.8

3

3

1

1

1

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4







MSG-19 November 200303:15 UTCRGB CompositeR = IR12.0-IR10.8G = IR10.8-IR3.9B = IR10.8

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4 = thin, high level clouds


Day-time Fog over Europe9 November 2003


Low Stratus and River Valley Fog as seen by MFGMet-7, 9 November 2003, 08:00 UTC, VIS channel


MSG HRV channel gives more details on the fog ...


River Valley Fog

Fog/low stratus



Fog/Low stratuswith Gravity Waves

… closer look at Denmark


MSG-19 November 200308:15 UTCRGB CompositeR = NIR1.6G = VIS0.8B = VIS0.6


1

2

3

1

1

2

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1


2= clear ground

3 = high-level thick clouds

4 = high-level thin clouds

5 = snow

544

4



2= clear ground



5 = snow

MSG-19 November 200308:15 UTCRGB CompositeR = VIS0.8G = IR3.9rB = IR10.8


1

2

3

1

1

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3

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544

4


MSG-19 November 200308:15 UTCRGB CompositeR = VIS0.8G = NIR1.6B = IR3.9r


1

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1

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1


2= clear ground



5 = snow

4

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MSG-19 November 200308:15 UTCRGB CompositeR = HRVG = HRVB = IR3.9 - IR10.8


1

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1

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5

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2= clear ground



5 = snow

2

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Night-time Fog over Central Europe 11 November 2003


1. Sea surface2. Land surface3. Warm fog4. Cool fog + stratus (-3oC)5. Supercooled water stratus (-13oC) 6. Highly supercooled water stratus (-18oC)7. Cb with lightning8. Thick cirrus9. Thin cirrus

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MSG-111 Nov 200303:00 UTCRGB CompositeR = IR12.0 - IR10.8G = IR10.8 - IR3.9B = IR10.8



1

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MSG-111 Nov 200303:00 UTCDifference ImageR = IR12.0 - IR10.8



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MSG-111 Nov 200303:00 UTCDifference ImageG = IR10.8 - IR3.9




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MSG-111 Nov 200303:00 UTCDifference ImageB = IR10.8




Day-time Fog over the Po Valley 20 November 2003


MSG-1, 20 November 2003, 11:00 UTC, HRV Channel


NightFog darker than

clear ground

DawnFog and clearground equal

DayFog brighter than

clear ground

1 to 2 critical slots at dawn/dusk

MSG-1, 20 November 2003Difference IR3.9 - IR10.8


MSG-1, 20 November 2003, 00:00 UTC, IR3.9 - IR10.8

Click on the icon tosee the animation

(00:00-15:00 UTC,AVI, 15068 KB) !


SUMMARY


• VIS0.6 and HRVIS: to disciminate between fog and VIS0.6 and HRVIS: to disciminate between fog and ground (fog white, ground dark)ground (fog white, ground dark)

• VIS0.8: less useful because of less contrast to VIS0.8: less useful because of less contrast to vegetated areasvegetated areas

• NIR1.6 and IR3.9: to discriminate between fog and NIR1.6 and IR3.9: to discriminate between fog and snow (fog high reflectivity, snow low reflectivity)snow (fog high reflectivity, snow low reflectivity)

• IR3.9 - IR10.8: fog large positive values; clear IR3.9 - IR10.8: fog large positive values; clear ground around 0 K (-5 K to +5 K)ground around 0 K (-5 K to +5 K)

Detection of Fog/Low Stratus during Daytime


• RGB 03-02-01: fog white-pinkish; clear ground RGB 03-02-01: fog white-pinkish; clear ground greenish or reddish (depending in vegetation)greenish or reddish (depending in vegetation)

• RGB 03-12-12: fog white-pinkish; clear ground RGB 03-12-12: fog white-pinkish; clear ground reddishreddish

• RGB 02-04r-09: fog white-pinkish; clear ground RGB 02-04r-09: fog white-pinkish; clear ground blueishblueish

• RGB 02-03-04r: fog whitish, clear ground greenish-RGB 02-03-04r: fog whitish, clear ground greenish-bluishbluish

Detection of Fog/Low Stratus during Daytime


• IR3.9-IR10.8: fog -10/-7 K; clear ground around -4 KIR3.9-IR10.8: fog -10/-7 K; clear ground around -4 K(difficulties at high latitudes)(difficulties at high latitudes)

• RGB 10-09 / 09-04 / 09: fog light greenish-yellowish; RGB 10-09 / 09-04 / 09: fog light greenish-yellowish; clear ground dark pinkishclear ground dark pinkish

Detection of Fog/Low Stratus during Nighttime (Low and Mid Latitudes)


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; RGB 10-09 / 09-07 / 09: fog light greenish-yellowish; clear ground dark pinkishclear ground dark pinkish


• IR3.9-IR10.8: fog detection difficult because of IR3.9-IR10.8: fog detection difficult because of compensating effects (fog colder in IR3.9 than in compensating effects (fog colder in IR3.9 than in IR10.8 because of lower emissivity, but reflection of IR10.8 because of lower emissivity, but reflection of solar radiation)solar radiation)

• 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(only small difference between fog and clear ground, (only small difference between fog and clear ground, but works also at dawn/dusk)but works also at dawn/dusk)

Detection of Fog/Low Stratus atDawn/Dusk


Detection of Fog/Low Stratus: Conclusion

• Less noisy than the difference IR3.9 - IR10.8Less noisy than the difference IR3.9 - IR10.8(works well also over Scandinavia)(works well also over Scandinavia)

• 24-hour capability with "constant" colour for fog/low 24-hour capability with "constant" colour for fog/low stratus (unlike IR3.9-IR10.8 difference)stratus (unlike IR3.9-IR10.8 difference)

• High-level Cirrus above fog/low stratus can also be High-level Cirrus above fog/low stratus can also be detected (combined with IR12.0-IR10.8 difference)detected (combined with IR12.0-IR10.8 difference)

In operational applications, the difference IR8.7-IR10.8In operational applications, the difference IR8.7-IR10.8may be the best to detect fog/low stratus (day- and night), may be the best to detect fog/low stratus (day- and night), because of:because of:


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) !

APPLICATIONS OF METEOSAT SECOND GENERATION (MSG)

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