Satellite based instability indices for very short range forecasting of convection Estelle de Coning...
-
Upload
milton-lee -
Category
Documents
-
view
225 -
download
1
Transcript of Satellite based instability indices for very short range forecasting of convection Estelle de Coning...
![Page 1: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/1.jpg)
Satellite based instability indices for very short range forecasting of convection
Estelle de Coning
South African Weather ServiceContributions from Marianne Koenig (EUMETSAT)
1
![Page 2: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/2.jpg)
Content
• EUMETSAT MPEF products
• Satellite based instability indices (GII)
• GII validated over SA
• Summary
2
![Page 3: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/3.jpg)
EUMETSAT MPEF (Meteorological Products Extraction Facility)
• MPEF is part of the the source of the Meteorological Products provided by the MSG system
• The list of products to be extracted from the MSG imagery has been agreed by EUMETSAT member states
• As a general principle, the MPEF will extract products on a synoptic scale (< 100 km)
3
![Page 4: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/4.jpg)
Radiative Transfer Model (RTM)
SCE (scenes analysis)
Cloud Aanalysisint
SatelliteModel Data
AMV CLA CSR TH TOZ HPI CTH GII
Algorithm Overview
4
![Page 5: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/5.jpg)
MSG MPEF Products Baseline (distributed via GTS/EUMETCast/UMARF)
• Atmospheric Motion Vectors (AMV)• Calibration Monitoring (CAL-MON)• Clear Sky Radiance (CSR)• Clear Sky Reflectance Map (CRM)• Climate Data Set (CDS)• Cloud Analysis (CLA)• Cloud Top Height (CTH)• Global Instability Index (GII)• ISCCP Dataset (IDS)• Precipitation Index (PI)• Total Ozone (TOZ)• Tropospheric Humidity (TH)
Some internal Products: Sea Surface temperature (SST) Scenes Analysis (SCE) Radiative Transfer Model (RTM)
5
![Page 6: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/6.jpg)
Atmospheric instability: Using upper air ascents
• Traditionally, these indices are taken from temperature and humidity soundings by radiosondes.
• Instability indices are calculated using the vertical profile of moisture and temperature
6
![Page 7: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/7.jpg)
Atmospheric instability: Using NWP
• Since numerical weather prediction models can forecast these factors of the atmosphere, they can forecast the instability as well.
![Page 8: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/8.jpg)
Atmospheric instability: The Global Instability Index (GII)
• As radiosondes are only of very limited temporal and spatial resolution there is a demand for satellite-derived indices which can provide the information every 15 minutes!
• The basis of the GII methodology is:– Together with the satellite measured brightness
temperatures and some a priori information of the atmospheric profile (from the Numerical Weather Prediction model) a local profile is derived, and instability indices are computed from this local profile.
8
![Page 9: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/9.jpg)
History – USA and GOES• A global (Meteosat) coverage of instability information
(GII = Global Instability Indices) satellite product was one of the drivers of the channel definition on MSG
• Heritage: Similar products from the GOES Sounder, provided by CIMSS (Univ. Wisconsin)
Shades of brow stable air
Blue to yellow to red increasing instability
9
![Page 10: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/10.jpg)
MSG Channels
1 = VIS0.6 2=VIS0.8 3=NIR1.6 12=HRV
4=IR3.9 5=WV6.2 6=WV7.3 7=IR8.7
8=IR9.7 9=IR10.8 10=IR12.0 11=IR13.4
12 available channels on MSG, 4 in the solar spectral range (VIS), 8 in the infrared (IR)
10
![Page 11: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/11.jpg)
MSG channels we cannot use for a vertical profile of temperature and humidity
1 = VIS0.6 2=VIS0.8 3=NIR1.6 12=HRV
4=IR3.9 5=WV6.2 6=WV7.3 7=IR8.7
8=IR9.7 9=IR10.8 10=IR12.0 11=IR13.4
No temperature/humidity information in solar channels
Temperature information in IR3.9 mixed with solar contribution (during daytime)
Too much ozone information in IR9.7
11
![Page 12: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/12.jpg)
MSG channels useful for a vertical profile
5=WV6.2 6=WV7.3 7=IR8.7
9=IR10.8 10=IR12.0 11=IR13.4
Humidity information in various levels
12
![Page 13: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/13.jpg)
MSG Information Content
5=WV6.2 6=WV7.3 7=IR8.7
9=IR10.8 10=IR12.0 11=IR13.4
Humidity information in various levels
Information on surface temperature
13
![Page 14: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/14.jpg)
MSG Information Content
5=WV6.2 6=WV7.3 7=IR8.7
9=IR10.8 10=IR12.0 11=IR13.4
Humidity information in various levels
Information on surface temperature
Information on mid-level air temperature
14
![Page 15: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/15.jpg)
Retrieval Concept (1)
• From NWP: Forecast temperature and humidity profile: T(p), q(p)
15
![Page 16: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/16.jpg)
Retrieval Concept (1)
• From NWP: Forecast temperature and humidity profile: T(p), q(p)
Expected MSG brightness temperatures in 6 channels TB (MSG)
Radiative transfer model
16
![Page 17: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/17.jpg)
Retrieval Concept (1)
• From NWP: Forecast temperature and humidity profile: T(p), q(p)
Expected MSG brightness temperatures in 6 channels TB (MSG)
Radiative transfer model
Compare with measurements
TB(NWP) – TB(MSG) : The temperature differences are used to change the initial profile, Tn(p), qn(p)
17
![Page 18: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/18.jpg)
Retrieval Concept (1)
• Updated temperature and humidity profile: Tn(p), qn(p)
Expected MSG brightness temperatures in 6 channels TB (MSG)
Radiative transfer model
Compare with measurements TB
TB(NWP) – TB(MSG) : The temperature differences are used to change the initial profile
18
![Page 19: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/19.jpg)
Retrieval Concept (1)
In every iteration of this process we check:
Is (TB(NWP) – TB(MSG)) small?
If yes, the process is stopped and the last profile is taken as the “best” solution
19
![Page 20: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/20.jpg)
• MSG channels 5,6,( WV) 7,9,10 and 11 (IR) are currently used for calculations
• The GII product consists of a set of instability indices which describe the layer stability of the atmosphere:– K index, – Lifted Index, – Precipitable Water– KO Index– Maximum Buoyancy
• The retrieval of these parameters from satellite data is only possible under cloud-free conditions.
20
![Page 21: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/21.jpg)
21
![Page 22: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/22.jpg)
> 0 Thunderstorms unlikely
0 - -2 Thunderstorms possible – triggered needed
-3 - -5 Thunderstorms probable
-5 - -7 Strong/severe thunderstorms. Tornadoes possible
Lifted Index
Sturtevant (1995)
![Page 23: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/23.jpg)
0 – 15 No thunderstorms
16 – 19 Thunderstorms unlikely
20 – 25 Isolated thunderstorms
26 – 29 Widely scattered thunderstorms
30 – 35 Numerous thunderstorms
36 – 39 Thunderstorms very likely
40+ 100% chance of thunderstorms
Sturtevant (1995)
K-Index
![Page 24: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/24.jpg)
MSG MPEF Product: Global Instability Index (GII) example of PW
10
161416
12
34
41
14
15
13
21
13
52
59
35
Example of a total precipitable water retrieval, co-located radiosonde observations are also shown
24
![Page 25: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/25.jpg)
K Index for 08:45 UTC on 6 Nov 2005 from GII product
![Page 26: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/26.jpg)
MSG Convection RGB (Ch5-6,Ch4-9,Ch3-1) at 14:42 UTC on 6 Nov 2005
![Page 27: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/27.jpg)
CASE POD FARatio ACCURACY
15 Jan 2007 0.47 0.31 0.63
16 Jan 2007 0.91 0.42 0.65
17 Jan 2007 0.73 0.33 0.70
28 Dec 2006 0.83 0.21 0.81
4 Mar 2007 0.93 0.38 0.71
6 Oct 2007 0.48 0.04 0.76
6 Nov 2007 1.0 0.13 0.9
4 Jan 2008 0.88 0.32 0.74
AVERAGE 0.78 0.27 0.74
GII : Evaluation against lightning data: K index
![Page 28: Satellite based instability indices for very short range forecasting of convection Estelle de Coning South African Weather Service Contributions from Marianne.](https://reader035.fdocuments.in/reader035/viewer/2022081506/5697c02a1a28abf838cd80c0/html5/thumbnails/28.jpg)
Summary
• Satellite based instability indices make it possible to say something about atmospheric stability/instability for thunderstorm forecasting in areas where upper air ascents are not available
• Combining the vertical profile of the satellite data (using 6 channels) with the NWP profile, adds observation data (from satellite) to the NWP fields
• Satellite instability indices can be calculated every 15 min (MSG)
• Data sources should always be used to complement one another and not to replace one another.
28