Transcript Regionales Risiko konvektiver Extremwetterereignisse:

Thunderstorm Tracking and Nowcasting
using 3D Lightning and Radar Data
in Southern Germany
Vera Meyer [1] - [email protected],
H. Höller [2], H.-D. Betz [3] , K. Schmidt [2]
[1] Central Institute for Meteorology and Geodynamics, Hohe Warte, Vienna
[2] Deutsches Zentrum für Luft und Raumfahrt, Institut für Physik der Atmosphäre,
Oberpfaffenhofen, Deutschland
[3] Physics Department, University of Munich, Germany
1
Convection Week 2011, Session 3
PROJECT RegioExAKT
www.regioexakt.de
Regional Risk of Convective Extreme Weather Events:
User-oriented concepts for optimised thunderstorm nowcasting,
with focus on the needs of Munich Airport
Coordinator: Dr. Nikolai Dotzek
MUNICH AIRPORT
HEAVY RAIN
15 Juni 2007
40,5 l/m² zw. 18.00 –21.00 h
intense rain
hail
lightning strikes
wind gusts
etc.
2
HAIL DAMAGE
Boeing 737, Geneva 15
August 2003
MOTIVATION
LINET - Lightning Detection Network
- ‘total lightning’ detection
- 2008 app. 100 sensors in Central Europe
- magnetic field measurements
- TOA (time of arrival) method
- event-height parameter
comprehensive discrimination of ‘cloud’
and ‘cloud-to-ground’ lightning
3
MOTIVATION
LIGHTNING TYPES
IC
Abbreviations
IC (cloud lightning)
in-cloud, inter-cloud, intra-cloud,
cloud-to-air
-15 °C
IC
IC
0 °C
CG (cloud-to-ground)
cloud – to – ground
TL (total lightning)
sum (IC + CG)
CG
4
MOTIVATION
CG
LINET 3D-Visualisierung
high-precision lightning detection.
‚NORMAL STORM‘
‚SEVERE STORM‘
cloud lightning
cloud-to- ground
lightning
5
MOTIVATION
THUNDERSTORM TRACKING and NOWCASTING
lightning-cell
MUNICH
AIRPORT
cell track
temporal evolution of LIGHTNING cell parameters
total lightning
cloud lightning
cloud-to-ground
lightning
14:45
6
15:00
15:15
MOTIVATION
15:30
time
THUNDERSTORM TRACKING and NOWCASTING
lightning-cell
MUNICH
AIRPORT
cell track
cell
nowcasts
temporal evolution of LIGHTNING cell parameters
total lightning
cloud lightning
cloud-to-ground
lightning
14:45
15:00
15:15
now prognosis
7
MOTIVATION
15:30
time
INTRODUCTION
GOAL:
to assess the usability of 3D total-lightning data for
thunderstorm nowcasting
separately and in combination with other data sources (radar)
8
INTRODUCTION
INTRODUCTION
GOAL:
to assess the usability of 3D total-lightning data for
thunderstorm nowcasting
separately and in combination with other data sources (radar)
identification
tracking
prediction
9
INTRODUCTION
INTRODUCTION
GOAL:
to assess the usability of 3D total-lightning data for
thunderstorm nowcasting
separately and in combination with other data sources (radar)
identification
tracking
prediction
cell evolution
10
INTRODUCTION
INTRODUCTION
GOAL:
to assess the usability of 3D total-lightning data for
thunderstorm nowcasting
separately and in combination with other data sources (radar)
- develop a nowcasting method based on lightning information
- develop a method to compare lightning-cell information with information from
other data sources (radar)
verify lightning-cell properties in case-studies
evaluate the statistical information content of 3D lightning information
11
INTRODUCTION
RESEARCH DOMAIN and OBSERVATION PERIOD
May – September 2008
12
INTRODUCTION
NOWCASTING APPROACH ec-TRAM
ec-TRAM – tracking and monitoring of electrically charged convective cells
combines cell informations from independently tracked lightning- and radar-cells
13
METHOD
NOWCASTING APPROACH ec-TRAM
ec-TRAM – tracking and monitoring of electrically charged convective cells
DWD Radar Site Fürholzen (Munich)
2D reflecitvity maps, low level scan
domain
[200 km x 200 km]
resolution [1 km x 1 km], [5 min]
LINET lightning data, nowcast GmbH
3D TOA method in VLF/LF regime, IC/CG discrimination
2D discharge event maps
cell clustering: time interval
minimum distance
14
METHOD
3
3 min
6 km
NOWCASTING APPROACH ec-TRAM
combines the cell informations of lightning cells and radar cells
cell identification parameter (optimized)
radar-cells
lightning cell: threshold of 1 event
lightning data: amplitude |A| > 2.5 kA
Rad-TRAM
[Kober,2009]
radar cell:
threshold of 33 dBZ
lightning-cell
li-TRAM
[Meyer,2010]
cell assignment via spatial overlap
15
METHOD
4
NOWCASTING APPROACH ec-TRAM
combines the cell informations of lightning cells and radar cells
radar-cells
cell identification parameter
lightning cell:
threshold of 1 event
radar cell:
threshold of 33 dBZ
Rad-TRAM
[Kober,2009]
ec-cells
lightning-cell
ec-TRAM
[Meyer,2010]
li-TRAM
[Meyer,2010]
cell assignment via spatial overlap
16
METHOD
4
NOWCASTING APPROACH ec-TRAM
ec-cells
cell track
example: ec-TRAM nowcasting map (detail) with cell contours, tracks and prognoses of an
electrically charged ‚ec-cell‘.
radar cell: Reflectivity map (blue shaded) cell track (white line), actual cell contour (white polygons), cell
prognoses for 10 minutes (dark grey polygons), and 20 minutes (light grey polygons)
lightning cell: discharge events clustered for 3 minutes (green crosses) actual cell (red polygon)
17
METHOD
5
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
25 June 2008
F
P
South Germany
Austria
radar sites
x
Fürholzen
x
POLDIRAD
MUC
M
R
A
18
18
CASE STUDY
Munich Airport
Munich
Regensburg
Augsburg
19
19
LIFE CYCLE radcell AREA
20080625 Nr 7
500
400
[km2]
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
area
margin
merge
300
split
200
1 8:30
1 8:15
1 8:00
1 7:45
1 7:30
1 7:15
1 7:00
1 6:45
1 6:30
1 6:15
1 6:00
1 5:45
0
1 5:30
100
Example rad-TRAM:
temporal evolution of
selected parameters
25 June 2008
radar-cell:
-cell area
20
[km²]
CASE STUDY
LIFE CYCLE licell with LIGHTNING FREQUENCY
20080625 Nr 24
600
500
[km2], [cnt/cell]
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
area
f(TOT)
400
f(IC)
f(CG)
300
margin
merge
split
200
18:15
18:00
17:45
17:30
17:15
17:00
16:45
16:30
16:15
16:00
15:45
0
15:30
100
UTC time
Cluster: time= 3 min, dist=3.0 km
Example li-TRAM:
temporal evolution of
selected parameters
25 June 2008
lightning-cell:
-cell area [km²]
- TL
[cnt/cell]
- CG
[cnt/cell]
- IC
[cnt/cell]
21
CASE STUDY
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
radar-cell:
-cell area
[km²]
lightning-cell:
-cell area [km²]
- TL
[cnt/cell]
- CG
[cnt/cell]
- IC
[cnt/cell]
22
25 June 2008
area [km²], discharge frequency [cnt/cell]
Example ec-TRAM:
temporal evolution of
selected parameters
22
CASE STUDY
Example ec-TRAM:
temporal evolution of
selected parameters
radar-cell:
-cell area
[km²]
lightning-cell:
-cell area [km²]
- TL
[cnt/cell]
- CG
[cnt/cell]
- IC
[cnt/cell]
23
area [km²], discharge frequency [cnt/cell]
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
onset
23
CASE STUDY
Example ec-TRAM:
temporal evolution of
selected parameters
radar-cell:
-cell area
[km²]
lightning-cell:
-cell area [km²]
- TL
[cnt/cell]
- CG
[cnt/cell]
- IC
[cnt/cell]
24
area [km²], discharge frequency [cnt/cell]
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
cell splitting
24
CASE STUDY
Example ec-TRAM:
temporal evolution of
selected parameters
radar-cell:
-cell area
[km²]
lightning-cell:
-cell area [km²]
- TL
[cnt/cell]
- CG
[cnt/cell]
- IC
[cnt/cell]
25
area [km²], discharge frequency [cnt/cell]
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
intensification
25
CASE STUDY
Example ec-TRAM:
temporal evolution of
selected parameters
radar-cell:
-cell area
[km²]
lightning-cell:
-cell area [km²]
- TL
[cnt/cell]
- CG
[cnt/cell]
- IC
[cnt/cell]
26
area [km²], discharge frequency [cnt/cell]
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER
decease
26
CASE STUDY
VERIFICATION of LIGHTNING-CELL PROPERTIES
in CASE-STUDIES
lifetime series of ec-cell parameters were complemented with
3D polarimetric radar data (POLDIRAD) - not shown
lightning-cell parameters were found to
-evolve reasonably according to the current state of knowledge
-be in very good agreement with other case studies
[Klemp1987, Williams 1989 and 1999, Goodman 1988, Carey 1996, Lopez
1997, Mazur 1998, Altaraz 2003, Motley 2006, ...]
 reflect the actual storm dynamic
(intensification / weakening)
 li-TRAM has reasonable, consistent tracking performances
(comparable to rad-TRAM)
[Meyer, 2010]
27
VERIFICATION
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell area [km²]
Lifetime = 40 min
28
2 CASE STUDIES
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell growth
3
2
I
cell area [km²]
Lifetime = 40 min
29
2 CASE STUDIES
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
mature stage
cell area [km²]
Lifetime = 40 min
30
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell dissipation
4
5
6
E
cell area [km²]
Lifetime = 40 min
31
2 CASE STUDIES
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
25 May 2008
lightning-cell No 6
lightning frequency per cell [cnt/cell]
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell area [km²]
cell area [km²]
Lifetime = 40 min
32
2 CASE STUDIES
Lifetime = 145 min
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
25 May 2008
lightning-cell No 6
lightning frequency per cell [cnt/cell]
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell growth
4
I
23
cell area [km²]
cell area [km²]
Lifetime = 40 min
33
5
2 CASE STUDIES
Lifetime = 145 min
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
25 May 2008
lightning-cell No 6
lightning frequency per cell [cnt/cell]
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell area [km²]
cell area [km²]
Lifetime = 40 min
34
mature stage
2 CASE STUDIES
Lifetime = 145 min
PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS
25 May 2008
lightning-cell No 6
lightning frequency per cell [cnt/cell]
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
cell dissipation
-4
-2
E
-6
-3
cell area [km²]
cell area [km²]
Lifetime = 40 min
35
-5
2 CASE STUDIES
Lifetime = 145 min
lightning frequency per cell [cnt/cell]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
TL
TL mean
MEAN
IC MEAN
mean
IC
TL
TL fit
fit 1
1+
+2
2
TL
TL fit
fit 1
1+
+2
2
PARAMETER MEANS
lightning frequency versus cell area
-10 km² area intervals
-10 200 completely assessed
lightning-cell entries
cell area [km²]
36
LIGHTNING-STATISTICS
lightning frequency per cell [cnt/cell]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
TL
TL mean
MEAN
IC MEAN
mean
IC
TL
TL fit
fit 1
1+
+2
2
TL
TL fit
fit 1
1+
+2
2
160 km²
cell area [km²]
37
LIGHTNING-STATISTICS
TL MEAN
IC MEAN
TL fit 1 + 2
TL fit 1 + 2
160 km²
cell area [km²]
38
IC mean discharge height per cell [km]
lightning frequency per cell [cnt/cell]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
IC MEAN height
fit 1 + 2
LIGHTNING-STATISTICS
cell area [km²]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
TL MEAN
IC MEAN
TL fit 1 + 2
TL fit 1 + 2
160 km²
cell area [km²]
39
IC mean discharge height per cell [km]
lightning frequency per cell [cnt/cell]
NO ARTIFACT of the ALGRITHM
ICMEAN
mean height
IC
height
fit11 ++ 22
fit
LIGHTNING-STATISTICS
160 km²
cell area [km²]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
TL mean
MEAN
mean
IC MEAN
TL fit 1 + 2
TL fit 1 + 2
160 km²
cell area [km²]
40
IC mean discharge height per cell [km]
lightning frequency per cell [cnt/cell]
NO INFORMATION about TEMPORAL CELL EVOLUTION
IC MEAN
mean height
IC
height
fit 11 ++ 22
fit
LIGHTNING-STATISTICS
160 km²
cell area [km²]
9
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
I
E
cell area [km²]
Lifetime = 40 min
41
25 May 2008
lightning-cell No 6
lightning frequency per cell [cnt/cell]
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
I
E
cell area [km²]
Lifetime = 145 min
LIGHTNING-STATISTICS
10
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
I
E
cell area [km²]
Lifetime = 40 min
42
25 May 2008
lightning-cell No 6
lightning frequency per cell [cnt/cell]
lightning frequency per cell [cnt/cell]
30 May 2008
lightning-cell No 137
I
E
cell area [km²]
Lifetime = 145 min
LIGHTNING-STATISTICS
10
frequency [-]
FREQUENCY DISTRIBUTION of LIFE-TIMES
short-lived cells
long-lived cells
lightning-cell lifetime [min]
43
LIGHTNING-STATISTICS
LIFETIME REGIMES
short-lived
[ 15 min – 75 min ]
‚SINGLE CELLS‘
- lowly organized
- simply structured:
- simple life-cycles:
long-lived
1 updraft + 1 downdraft
growth – short maturity – decease
[ ≥ 80 min ]
‚MULITCELLS‘, ‚SUPERCELLS‘
- highly organized
- complexly structured
- complex life-cycles:
growth – elongated (fluctuating) maturity – decease
44
LIGHTNING-STATISTICS
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
total lightning
relative frequency
lightning frequency per cell [cnt/cell]
RELATIVE AMOUNT to STATISTICAL MEAN
long-lived
cells
short
-lived
cell area [km²]
45
LIGHTNING-STATISTICS
cell area [km²]
lightning frequency per cell [cnt/cell]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
total lightning
cell type
short-lived
cells
shortlived
cell area [km²]
46
DISCUSSION
lightning frequency per cell [cnt/cell]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
total lightning
long-lived cells
cell type
long-lived cells
cell area [km²]
47
DISCUSSION
TL mean
total
lightning
IC mean
TL fit 1 + 2
TL fit 1 + 2
SCATTER!
cell area [km²]
4848
IC mean discharge height per cell [km]
Lightning frequency per cell [1/km²]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
DISCUSSION
IC mean height
fit 1 + 2
SCATTER!
cell area [km²]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
lightning frequency per cell [cnt/cell]
INFORMATION about STORM TYPE (lifetime, intensity) and
TEMPORAL EVOLUTION!
long-lived
cell type
short-lived
shortlived
cell area [km²]
49
DISCUSSION
long-lived cells
THUNDERSTORM TRACKING and NOWCASTING
lightning-cell
MUNICH
AIRPORT
cell track
cell
nowcasts
temporal evolution of LIGHTNING cell parameters
total lightning
cloud lightning
cloud-to-ground
lightning
14:45
15:00
15:15
now prognosis
50
Ad MOTIVATION
15:30
time
TL MEAN
IC MEAN
TL fit 1 + 2
TL fit 1 + 2
cell area [km²]
51
IC mean discharge height per cell [km]
lightning frequency per cell [cnt/cell]
CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS
DISCUSSION
IC MEAN height
fit 1 + 2
3D information
from
2D cell tracking!
cell area [km²]
CONCLUSION
GOAL:
to assess the usability of 3D total-lightning data for thunderstorm nowcasting
separately and in combination with other data sources (radar)
3D lightning information with in-cloud and cloud-to-ground lightning
discrimination provides useful information about the storm dynamic and
developement and have the capacity to nowcast cell trends from the cell history
52
CONCLUSION and OUTLOOK
11
OUTLOOK
- test the usability of (specified) normalized cell life-cycles to derive trend
prognoses
- use cell trends from cell history to add trend prognoses to local prognoses
- test the quality of trend prognoses
- investigate cell parameter correlations with other data sources
(3D radar, satellite, ...)
53
CONCLUSION and OUTLOOK
11
OTHER possible APPLICATIONS
- parameterization of TL frequency with IC/CG ratio and mean IC height for
modelling [Price and Rind 1992, Allen and Pickering 2002]
- simulation of thunderstorm life-cycles with realistic discharge characteristics
?160 km²?
54
CONCLUSION and OUTLOOK
IC mean height
fit 1 + 2
THANK YOU
160 km²
cell area [km²]
55
IC mean discharge height per cell [km]
lightning frequency per cell [cnt/cell]
TL mean
IC mean
TL fit 1 + 2
TL fit 1 + 2
160 km²
[email protected]
cell area [km²]
Literature
K. Kober and A. Tafferner. Tracking and nowcasting of convective cells unsing
remote sensing data from radar and satellite. Meteorologiesche Zeitschrift,
10(1):75-84, 2009
V. Meyer, H. Höller, K.Schmidt, and H.-D. Betz. Temporal evolution of total lightning
and radar parameters of thunderstorms in southern Germany and its benefit for
nowcasting. Proceedings: 5th European Conference on Severe Storms, 2009
V. Meyer (2010): Thunderstorm Tracking and Monitorin on the Basis of Three
Dimenional Lightning Data and Conventional and Polarimetric Radar Data.
Dissertation, LMU München: Faculty of Physics
http://edoc.ub.uni-muenchen.de/12102/
56
[email protected]
POLARIMTRIC INFORMATION
POLDIRAD RHI 20080625, hydrometeorclassifications, 16:42h, azimuth = 52 °
sounding munich: 0 ° at 3.5 km, Tropopause at 10 km
57
57
ZEITLICHE ENTWICKLUNG VON ec-ZELL PARAMETERN
example:
radar-cell:
-cell area
[km²]
lightning-cell:
-cell area
- TL
- CG
- IC
[km²]
[cnt/cell]
[cnt/cell]
[cnt/cell]
polar. radar data
- hydrometeors
dBZ cell
graupel/hail
light rain H = 4 km
ground
heavy rain
58
area [km²], discharge frequency [cnt/cell]
25 June 2008