Thunderstorm Tracking and Nowcasting using 3D Lightning and Radar Data in Southern Germany

1

[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

Vera Meyer [1] - [email protected],H. Höller [2], H.-D. Betz [3] , K. Schmidt [2]

Convection Week 2011, Session 3

Thunderstorm Tracking and Nowcastingusing 3D Lightning and Radar Data in Southern Germany

2

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 AIRPORTHEAVY RAIN15 Juni 2007 40,5 l/m² zw. 18.00 –21.00 h

HAIL DAMAGE

Boeing 737, Geneva 15 August 2003

intense rainhaillightning strikeswind gustsetc.

MOTIVATION

3

LINET - Lightning Detection Network

- ‘total lightning’ detection

- 2008 app. 100 sensors in Central Europe

- magnetic field measurements

- TOA (time of arrival) method

- event-height parametercomprehensive discrimination of ‘cloud’ and ‘cloud-to-ground’ lightning

MOTIVATION

4

Abbreviations

IC (cloud lightning)in-cloud, inter-cloud, intra-cloud,cloud-to-air

CG (cloud-to-ground)cloud – to – ground

TL (total lightning)sum (IC + CG)

0 °C

-15 °C

CG CG

IC IC

IC

LIGHTNING TYPES

MOTIVATION

5

high-precision lightning detection.

‚NORMAL STORM‘

cloud lightning

cloud-to- ground lightning

MOTIVATION

LINET 3D-Visualisierung

‚SEVERE STORM‘

6

THUNDERSTORM TRACKING and NOWCASTING

temporal evolution of LIGHTNING cell parameters

cell track

MUNICH AIRPORT

lightning-cell

14:45 15:00 15:15 15:30

total lightningcloud lightningcloud-to-groundlightning

time

MOTIVATION

7

cell track

MUNICH AIRPORT

lightning-cell

cell nowcasts


14:45 15:00 15:15 15:30


time

now prognosis


MOTIVATION

8

GOAL:

to assess the usability of 3D total-lightning data forthunderstorm nowcasting

separately and in combination with other data sources (radar)

INTRODUCTION

INTRODUCTION

9

GOAL:



INTRODUCTION

INTRODUCTION

identificationtracking

prediction

10

GOAL:



INTRODUCTION

INTRODUCTION

identificationtracking

prediction

cell evolution

11

GOAL:



- 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

INTRODUCTION

INTRODUCTION

12 INTRODUCTION

May – September 2008

RESEARCH DOMAIN and OBSERVATION PERIOD

13 METHOD

ec-TRAM – tracking and monitoring of electrically charged convective cells

combines cell informations from independently tracked lightning- and radar-cells

NOWCASTING APPROACH ec-TRAM

14 3

DWD Radar Site Fürholzen (Munich)2D reflecitvity maps, low level scandomain [200 km x 200 km]resolution [1 km x 1 km], [5 min]

LINET lightning data, nowcast GmbH3D TOA method in VLF/LF regime, IC/CG discrimination

2D discharge event maps

cell clustering: time interval 3 min

minimum distance 6 km

ec-TRAM – tracking and monitoring of electrically charged convective cells


3METHOD

15


combines the cell informations of lightning cells and radar cells

cell assignment via spatial overlap

cell identification parameter (optimized)

lightning cell: threshold of 1 event

lightning data: amplitude |A| > 2.5 kA

radar cell: threshold of 33 dBZ

radar-cells

lightning-cell

4METHOD

Rad-TRAM

[Kober,2009]

li-TRAM

[Meyer,2010]

16


cell assignment via spatial overlap

cell identification parameter

lightning cell: threshold of 1 event

radar cell: threshold of 33 dBZ

radar-cells

lightning-cell ec-cells

combines the cell informations of lightning cells and radar cells

4METHOD

ec-TRAM

[Meyer,2010]

Rad-TRAM

[Kober,2009]

li-TRAM

[Meyer,2010]

17

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)

cell track

ec-cells


5METHOD

18

18

radar sites

x Fürholzen

x POLDIRAD

MUC Munich Airport

M Munich

R Regensburg

A Augsburg

P

F

25 June 2008

TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER

South Germany

Austria

CASE STUDY

19

19

20

15:3

0

15:4

5

16:0

0

16:1

5

16:3

0

16:4

5

17:0

0

17:1

5

17:3

0

17:4

5

18:0

0

18:1

5

18:3

00

100

200

300

400

500

[km

2]

LIFE CYCLE radcell AREA20080625 Nr 7

areamarginmerge

split


25 June 2008

Example rad-TRAM:

temporal evolution of selected parameters

radar-cell:-cell area [km²]

CASE STUDY

21

15

:30

15

:45

16

:00

16

:15

16

:30

16

:45

17

:00

17

:15

17

:30

17

:45

18

:00

18

:15

UTC timeCluster: time= 3 min, dist=3.0 km

0

100

200

300

400

500

600

[km

2],

[cn

t/ce

ll]

LIFE CYCLE licell with LIGHTNING FREQUENCY20080625 Nr 24

areaf(TOT)

f(IC)

f(CG)

margin

merge

split

25 June 2008

CASE STUDY


Example li-TRAM:


lightning-cell: -cell area [km²]- TL

[cnt/cell]- CG

[cnt/cell]- IC

[cnt/cell]

22

22


Example ec-TRAM:




[cnt/cell]- CG

[cnt/cell]- IC

[cnt/cell]

area

[km

²], d

isch

arg

e fr

equ

ency

[cn

t/ce

ll]

25 June 2008

CASE STUDY

23

23


area

[km

²], d

isch

arg

e fr

equ

ency

[cn

t/ce

ll]

onset

Example ec-TRAM:




[cnt/cell]- CG

[cnt/cell]- IC

[cnt/cell]

CASE STUDY

24

24


area

[km

²], d

isch

arg

e fr

equ

ency

[cn

t/ce

ll]

cell splitting

Example ec-TRAM:




[cnt/cell]- CG

[cnt/cell]- IC

[cnt/cell]

CASE STUDY

25

25


area

[km

²], d

isch

arg

e fr

equ

ency

[cn

t/ce

ll]

intensification

Example ec-TRAM:




[cnt/cell]- CG

[cnt/cell]- IC

[cnt/cell]

CASE STUDY

26

26


area

[km

²], d

isch

arg

e fr

equ

ency

[cn

t/ce

ll]

decease

Example ec-TRAM:




[cnt/cell]- CG

[cnt/cell]- IC

[cnt/cell]

CASE STUDY

27

VERIFICATION of LIGHTNING-CELL PROPERTIESin 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]

VERIFICATION

28

Lifetime = 40 min

30 May 2008lightning-cell No 137

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS

2 CASE STUDIES

29

Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

I

2

3

cell growth


2 CASE STUDIES

30

Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

mature stage


31

Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

4

5

6

E

cell dissipation


2 CASE STUDIES

32

Lifetime = 145 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]


Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

2 CASE STUDIES

33

Lifetime = 145 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

23

45I

cell growth


Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

2 CASE STUDIES

34

Lifetime = 145 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

mature stage


Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

2 CASE STUDIES

35

Lifetime = 145 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

-2

E

-4-5

-6

cell dissipation

-3


Lifetime = 40 min


cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

2 CASE STUDIES

36

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

TL fit 1 + 2

TL fit 1 + 2

TL meanIC mean

PARAMETER MEANS

lightning frequency versus cell area

-10 km² area intervals-10 200 completely assessedlightning-cell entries

TL fit 1 + 2

TL fit 1 + 2

TL MEANIC MEAN

CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS

LIGHTNING-STATISTICS

37

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

TL fit 1 + 2

TL fit 1 + 2

TL meanIC mean

TL fit 1 + 2

TL fit 1 + 2

TL MEANIC MEAN

160 km²



38

cell area [km²]IC m

ea

n d

isch

arg

e h

eig

ht p

er c

ell

[km

]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

TL fit 1 + 2

TL fit 1 + 2

TL MEANIC MEAN fit 1 + 2

IC MEAN height


160 km²


39


ea

n d

isch

arg

e h

eig

ht p

er c

ell

[km

]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

160 km²

fit 1 + 2IC mean height

160 km²

TL fit 1 + 2

TL fit 1 + 2


IC MEAN height


NO ARTIFACT of the ALGRITHM


40



ea

n d

isch

arg

e h

eig

ht p

er c

ell

[km

]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

160 km²

TL fit 1 + 2

TL fit 1 + 2

TL meanIC mean fit 1 + 2

IC mean height

160 km²

NO INFORMATION about TEMPORAL CELL EVOLUTION

TL fit 1 + 2

TL fit 1 + 2


IC MEAN height

9LIGHTNING-STATISTICS

41

Lifetime = 40 min Lifetime = 145 min



cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

I

EE

I



42

Lifetime = 40 min Lifetime = 145 min



cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

I

EE

I



43

FREQUENCY DISTRIBUTION of LIFE-TIMES


lightning-cell lifetime [min]

fre

que

ncy

[-] long-lived cellsshort-lived cells

44

LIFETIME REGIMES


short-lived [ 15 min – 75 min ]

‚SINGLE CELLS‘- lowly organized- simply structured: 1 updraft + 1 downdraft- simple life-cycles: growth – short maturity – decease

long-lived [ ≥ 80 min ]

‚MULITCELLS‘, ‚SUPERCELLS‘- highly organized- complexly structured- complex life-cycles: growth – elongated (fluctuating) maturity – decease

45

rela

tive

fre

que

ncy

cell area [km²]cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

total lightning

short-lived

long-lived cells

RELATIVE AMOUNT to STATISTICAL MEAN



46

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell] total lightning

cell type

growth

decease


short-lived cells

short-lived

DISCUSSION

47

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell] total lightning

cell type

long-lived cells

maturity


long-lived cells

growth

decease

DISCUSSION

4848

cell area [km²]

Lig

htn

ing

freq

ue

ncy

pe

r ce

ll [1

/km

²]

TL fit 1 + 2

TL fit 1 + 2

TL meanIC mean

SCATTER!

total lightning


ea

n d

isch

arg

e h

eig

ht p

er c

ell

[km

]

fit 1 + 2IC mean height

SCATTER!


DISCUSSION

49

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

long-livedcell type

long-lived cells

short-lived

short-lived

INFORMATION about STORM TYPE (lifetime, intensity) and TEMPORAL EVOLUTION!


DISCUSSION

50


cell track

MUNICH AIRPORT

lightning-cell

cell nowcasts

14:45 15:00 15:15 15:30


time

now prognosis


Ad MOTIVATION

51


ea

n d

isch

arg

e h

eig

ht p

er c

ell

[km

]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

TL fit 1 + 2

TL fit 1 + 2


IC MEAN height

3D informationfrom

2D cell tracking!


DISCUSSION

52

GOAL:

to assess the usability of 3D total-lightning data for thunderstorm nowcasting separately and in combination with other data sources (radar)

CONCLUSION

11CONCLUSION and OUTLOOK

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

53

- 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, ...)

OUTLOOK

11CONCLUSION and OUTLOOK

54

- 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

OTHER possible APPLICATIONS

CONCLUSION and OUTLOOK

?160 km²?

55


ea

n d

isch

arg

e h

eig

ht p

er c

ell

[km

]

cell area [km²]

ligh

tnin

g fr

equ

ency

pe

r ce

ll [c

nt/c

ell]

160 km²

TL fit 1 + 2

TL fit 1 + 2

TL meanIC mean fit 1 + 2

IC mean height

160 km²

THANK YOU

[email protected]

56

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 Physicshttp://edoc.ub.uni-muenchen.de/12102/

[email protected]

57

57

POLARIMTRIC INFORMATION

POLDIRAD RHI 20080625, hydrometeorclassifications, 16:42h, azimuth = 52 °

sounding munich: 0 ° at 3.5 km, Tropopause at 10 km

58

area

[km

²],

dis

char

ge

freq

uen

cy [

cnt/

cell

]

25 June 2008example:


lightning-cell: -cell area [km²]- TL [cnt/cell]- CG [cnt/cell]- IC [cnt/cell]

polar. radar data

- hydrometeors

ZEITLICHE ENTWICKLUNG VON ec-ZELL PARAMETERN

dBZ cellgraupel/hail

heavy rainlight rain H = 4 km

ground

Documents

Thunderstorm Tracking and Nowcasting using 3D Lightning and Radar Data in Southern Germany