rgb applications for cloud microphysical analysis in ninjo
DESCRIPTION
RGB Applications for Cloud Microphysical Analysis in NinJo. Victor Chung SAAWSO Project Workshop April 22-24, 2013 National Lab for Nowcasting and Remote Sensing Meteorology MSC Ontario Environment Canada. Objective. - PowerPoint PPT PresentationTRANSCRIPT
RGB Applications for Cloud Microphysical Analysis in NinJo
Victor Chung
SAAWSO Project Workshop
April 22-24, 2013
National Lab for Nowcasting and Remote Sensing MeteorologyMSC Ontario
Environment Canada
Objective
To demonstrate how to use RGB imageries in NinJo to perform
daytime cloud microphysical analysis
Why do we need RGB?
...because you can see more with an RGB.....
Role of 3.9 µm in RGB
http://www.meted.ucar.edu/satmet/goeschan/print/6_2_4_3.htm
The microphysics RGB in NinJoMicrophysics (day) [0.67, 3.7-10.7, 10.7i]
RGB examples to differentiate between water and ice clouds
Color enhanced imagery at 10.7 µm.
A
B
CD
E
F
Color enhanced imagery at 3.7 µm
A
B
CE
D
F
Let us look at cloud masses A, D, E, and B
Cloud mass AAppearance in channel 10.7 and 3.7 µm
cold at IR but quite warm at NIR super-cooled water droplets
10.7µm
3.7 µm
T_10.7: -23 to -29 C
T_3.9: 12 to 20 C
Cloud mass A
Cloud mass AAppearance in RGB
Super-cooledwater droplets
RGB
Cloud mass D & EAppearance in 10.7 and 3.7 µm
E (-20 to -25 C)
D (-20 to -25 C)
E (-13 to -15 C)
D (~15 C)
10.7 µm
3.7 µm
D: cold at IR, warm at NIR Super-cooled droplets
E: cold at IR, cold at NIR Ice particles
Histogram Plots for 10.7 and 3.7 µm Channels for a Line Across Cloud Masses D and E
10.7 µm (IR) 3.9 µm (NIR)
Small temperatureRange at IR
Two distinct peak atNIR
Ice
Water
Cloud masses D & EAppearance in RGB
E
D
RGB E: ice
D: super-cooled water
Let us look at cloud mass B evolution from 19 to 21z
Cloud mass B evolution from 19 to 21Z(at 19Z)
Ice or water?10.7 µm 3.7 µm
0.65 µm RGB2
It is water!
Scatter Plots of 3.7 versus 10.7 µm Channels for an Area over Cloud Mass B at 19Z
IR well below freezingNIR warm waterConclusion: super-cooledcloud droplets
Histogram Plots for 10.7 and 3.7 µm Channels for an Area over Cloud Mass B at 19Z
10.7 µ 3.7 µm
Cloud mass B at 20ZIce nucleation is
underway!10.7 µm (IR) 3.7 µm (NIR)
RGB0.65 µm
Scatter Plots of 3.7 vs 10.7 µm Channels for an Area over Cloud Mass B at 20Z
Small IRspread
Large NIRspread
Ice nucleation in process(water drops + ice crystals)
Histogram Plots for 10.7 and 3.7 µm Channels for an Area over Cloud Mass B at 20Z
10.7 µm 3.7 µm
Cloud mass B at 21Z
10.7 µm 3.7 µm
0.65 µm RGB
Clouds consists of mainly ice crystals
Scatter Plots of 3.7 vs 10.7 µm Channels for an Area over Cloud Mass B at 21Z
More pixels with NIRtemperature shift toThe colder side
Histogram Plots for 10.7 and 3.7 µm Channels for an Area over Cloud Mass B at 21Z
10.7 µm 3.7 µm
Conclusion• The special characteristics of the 3.7 um allows us to create a useful
RGB for cloud microphysical analysis
• Several examples have been used to demonstrate how to use this RGB operationally to differentiate between water and ice clouds
• This RGB can be applied for summer storm analysis, for example ice nucleation and lightning
• This RGB can be used in conjunction with other icing products for better cloud icing detection
Water Ice
Thank You!
Questions?
Outline --- this slide will not be shown
Objective- To demonstrate how to perform cloud
microphysical analysis using RGB imageries in NinJo
IntroductionOpener
- With RGB imagery, you can see things that can not be seen with a single channel imagery
- Characteristics of 3.9 um and its role on RGB imagery
Topic- Use of RGB in NinJo for cloud microphysics analysis
Thesis (idea convey)- RGB imagery helps forecasters to monitoring
cloud microphysical properties- Good microphysical analysis helps detecting
icing, and convective storm analysis
The Body- A list of examples for cloud microphysical analysis
ConclusionRestate the thesis
- RGB should be used more for cloud top microphysical analysis to improve our weather monitoring capabilityAction for future works
- Real-time applications for summer and winter storms
- Use in conjunction with icing product