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Thunderstorm Tracking and Nowcasting using 3D Lightning and Radar Data in Southern Germany. Vera Meyer [1] - vera.meyer@zamg.ac.at, H. Höller [2], H.-D. Betz [3] , K. Schmidt [2]. [1] Central Institute for Meteorology and Geodynamics, Hohe Warte, Vienna
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Thunderstorm Tracking and Nowcastingusing 3D Lightning and Radar Data in Southern Germany • Vera Meyer [1] - vera.meyer@zamg.ac.at, • 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 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. 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 MOTIVATION
IC IC IC CG CG LIGHTNING TYPES • 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) -15 °C 0 °C MOTIVATION
LINET 3D-Visualisierung high-precision lightning detection. ‚NORMAL STORM‘ ‚SEVERE STORM‘ cloud lightning cloud-to- ground lightning MOTIVATION
lightning-cell MUNICH AIRPORT cell track total lightning cloud lightning cloud-to-ground lightning time 14:45 15:00 15:15 15:30 THUNDERSTORM TRACKING and NOWCASTING • temporal evolution of LIGHTNING cell parameters MOTIVATION
lightning-cell MUNICH AIRPORT cell track cell nowcasts total lightning cloud lightning cloud-to-ground lightning time 14:45 15:00 15:15 15:30 now prognosis THUNDERSTORM TRACKING and NOWCASTING • temporal evolution of LIGHTNING cell parameters MOTIVATION
INTRODUCTION • GOAL: to assess the usability of 3D total-lightning data for thunderstorm nowcasting separately and in combination with other data sources (radar) 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 INTRODUCTION
cell evolution 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 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 INTRODUCTION
RESEARCH DOMAIN and OBSERVATION PERIOD May – September 2008 INTRODUCTION
ec-TRAM – tracking and monitoring of electrically charged convective cells NOWCASTING APPROACH ec-TRAM combines cell informations from independently tracked lightning- and radar-cells METHOD
ec-TRAM – tracking and monitoring of electrically charged convective cells NOWCASTING APPROACH ec-TRAM • 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 3 min minimum distance 6 km METHOD 3 3
NOWCASTING APPROACH ec-TRAM • combines the cell informations of lightning cells and radar cells 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 Rad-TRAM [Kober,2009] lightning-cell li-TRAM [Meyer,2010] cell assignment via spatial overlap 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 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) METHOD 5
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER 25 June 2008 F radar sites x Fürholzen x POLDIRAD MUC Munich Airport M Munich R Regensburg A Augsburg P South Germany Austria 18 CASE STUDY
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER • Example rad-TRAM: • temporal evolution of selected parameters • radar-cell: • cell area [km²] 25 June 2008 CASE STUDY
TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER • Example li-TRAM: • temporal evolution of selected parameters • lightning-cell: • cell area [km²] • TL [cnt/cell] • CG [cnt/cell] • IC [cnt/cell] 25 June 2008 CASE STUDY
area [km²], discharge frequency [cnt/cell] TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER 25 June 2008 • 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] 22 CASE STUDY
area [km²], discharge frequency [cnt/cell] TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER • 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] onset 23 CASE STUDY
area [km²], discharge frequency [cnt/cell] TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER • 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] cellsplitting 24 CASE STUDY
area [km²], discharge frequency [cnt/cell] TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER • 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] intensification 25 CASE STUDY
area [km²], discharge frequency [cnt/cell] TEMPORAL EVOLUTION of ec-TRAM CELL PARAMETER • 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] 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] VERIFICATION
30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] Lifetime = 40 min PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS 2 CASE STUDIES
30 May 2008 lightning-cell No 137 I 2 3 cell area [km²] lightning frequency per cell [cnt/cell] PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS cell growth Lifetime = 40 min 2 CASE STUDIES
30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS mature stage Lifetime = 40 min
30 May 2008 lightning-cell No 137 4 5 6 E cell area [km²] lightning frequency per cell [cnt/cell] PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS cell dissipation Lifetime = 40 min 2 CASE STUDIES
25 May 2008 lightning-cell No 6 30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] cell area [km²] lightning frequency per cell [cnt/cell] Lifetime = 40 min PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS Lifetime = 145 min 2 CASE STUDIES
25 May 2008 lightning-cell No 6 2 3 4 5 I 30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] cell area [km²] lightning frequency per cell [cnt/cell] Lifetime = 40 min PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS cell growth Lifetime = 145 min 2 CASE STUDIES
25 May 2008 lightning-cell No 6 30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] cell area [km²] lightning frequency per cell [cnt/cell] Lifetime = 40 min PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS mature stage Lifetime = 145 min 2 CASE STUDIES
-6 25 May 2008 lightning-cell No 6 -2 E -4 -5 -3 30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] cell area [km²] lightning frequency per cell [cnt/cell] Lifetime = 40 min PARAMETER CORRELATIONS of 2 LIGHTNING-CELL TRACKS cell dissipation Lifetime = 145 min 2 CASE STUDIES
PARAMETER MEANS • lightning frequency versus cell area • 10 km² area intervals • 10 200 completely assessed • lightning-cell entries cell area [km²] lightning frequency per cell [cnt/cell] TL mean IC mean TL MEAN IC MEAN TL fit 1 + 2 TL fit 1 + 2 TL fit 1 + 2 TL fit 1 + 2 CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS LIGHTNING-STATISTICS
cell area [km²] lightning frequency per cell [cnt/cell] TL mean IC mean TL MEAN IC MEAN TL fit 1 + 2 TL fit 1 + 2 TL fit 1 + 2 TL fit 1 + 2 160 km² CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS LIGHTNING-STATISTICS
IC mean discharge height per cell [km] cell area [km²] cell area [km²] lightning frequency per cell [cnt/cell] IC MEAN height TL MEAN IC MEAN TL fit 1 + 2 TL fit 1 + 2 fit 1 + 2 160 km² CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS LIGHTNING-STATISTICS
IC mean discharge height per cell [km] cell area [km²] cell area [km²] lightning frequency per cell [cnt/cell] IC mean height IC MEAN height TL MEAN IC MEAN TL fit 1 + 2 TL fit 1 + 2 fit 1 + 2 fit 1 + 2 160 km² 160 km² CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS NO ARTIFACT of the ALGRITHM LIGHTNING-STATISTICS
IC mean discharge height per cell [km] cell area [km²] cell area [km²] lightning frequency per cell [cnt/cell] IC MEAN height IC mean height TL MEAN IC MEAN TL mean IC mean TL fit 1 + 2 TL fit 1 + 2 TL fit 1 + 2 TL fit 1 + 2 fit 1 + 2 fit 1 + 2 160 km² 160 km² CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS NO INFORMATION about TEMPORAL CELL EVOLUTION LIGHTNING-STATISTICS 9
25 May 2008 lightning-cell No 6 I E E I 30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] cell area [km²] lightning frequency per cell [cnt/cell] CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS Lifetime = 145 min Lifetime = 40 min LIGHTNING-STATISTICS 10
25 May 2008 lightning-cell No 6 I E E I 30 May 2008 lightning-cell No 137 cell area [km²] lightning frequency per cell [cnt/cell] cell area [km²] lightning frequency per cell [cnt/cell] CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS Lifetime = 145 min Lifetime = 40 min LIGHTNING-STATISTICS 10
frequency [-] lightning-cell lifetime [min] FREQUENCY DISTRIBUTION of LIFE-TIMES short-lived cells long-lived cells LIGHTNING-STATISTICS
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 LIGHTNING-STATISTICS
lightning frequency per cell [cnt/cell] relative frequency cell area [km²] cell area [km²] CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS RELATIVE AMOUNT to STATISTICAL MEAN total lightning long-lived cells short-lived LIGHTNING-STATISTICS
lightning frequency per cell [cnt/cell] cell area [km²] CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS total lightning cell type short-lived cells short-lived growth decease DISCUSSION
lightning frequency per cell [cnt/cell] cell area [km²] CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS total lightning long-lived cells cell type maturity long-lived cells growth decease DISCUSSION
Lightning frequency per cell [1/km²] IC mean discharge height per cell [km] cell area [km²] cell area [km²] IC mean height TL mean IC mean TL fit 1 + 2 TL fit 1 + 2 fit 1 + 2 total lightning SCATTER! SCATTER! CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS DISCUSSION 48
lightning frequency per cell [cnt/cell] cell area [km²] CORRELATION STATISTICS of LIGHTNING-CELL PARAMETERS INFORMATION about STORM TYPE (lifetime, intensity) and TEMPORAL EVOLUTION! long-lived cell type short-lived short-lived long-lived cells DISCUSSION
lightning-cell MUNICH AIRPORT cell track cell nowcasts total lightning cloud lightning cloud-to-ground lightning time 14:45 15:00 15:15 15:30 now prognosis THUNDERSTORM TRACKING and NOWCASTING • temporal evolution of LIGHTNING cell parameters Ad MOTIVATION