Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in - PowerPoint PPT Presentation

Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer 1 , Thomas Hauf 1 , Caroline Forster 2 1 Leibniz Universität Hannover, Institute of Meteorology and Climatology 2 DLR, Institute of Physics of the Atmosphere 25. November 2014 – 4th SESAR Innovation Days

Outline • Thunderstorms, motivation and nowcast data used • Methodology and results of the uncertainty analysis • Application in weather avoidance routing Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 2

Thunderstorms • Small scale phenomena – cell diameter: 5 - 50 km – life time: 20 - 60 min Source: http://www.bom.gov.au/storm_spotters/handbook/thunderstorms.shtml • After generation: further life cycle and movement is in principal predictable UNCERTAINTY • Prediction of onset? – generation mechanisms need to be forecasted: • deterministic components: orography, surface convergence lines • stochastic components: gravity waves, temperature inhomogeneities not predictable! Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 3

Motivation lead time approaching an event in time and space event Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 4

Rad-TRAM nowcast system Radar Tracking and Monitoring • Based on radar composit with timely resolution of 5 minutes • object-based (> 37 dBZ) • Pyramidal image matcher  displacement  life cycle: growth and decay of cells Further information: Tafferner, A., C. Forster, 2012: Weather Nowcasting and Short Term Forecasting, in Atmospheric Physics, U. Schumann (ed.), Springer Verlag Source: http://www.pa.op.dlr.de/MUCSOMMER/2012/ Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 5

Rad-TRAM nowcasts t+60 timely resolution: 5 minutes t+55 horizontal resolution: 2 km lead time … t+20 t+15 t+10 no further t+5 detection of this cell t t 0 t 5 t 10 t 15 time t 55 t 65 t 60 Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 6

Nowcast uncertainty determination METHODOLOGY & RESULTS Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 7

Methodology N t 30,forward N t 30,left Δ dist forward - 0 + - 0 + Δ dist left Frequency distributions Δ dist forward Δ = obs - nowcast Δ dist back N t 30,backward N t 30,right Δ dist right Δ dist back Δ dist right - 0 + - 0 + Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 8

Results 20120715 N t 30,forward N t 30,left Δ dist forward Δ dist left Cumulative distribution function Δ dist forward 90th percentile N N t 30,back t 30,right Δ dist right Δ dist back Δ dist right Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 9

Increase of uncertainty with lead time 20120715 60 min RIGHT LEFT lead time 17.14 km P 90,abs,60min 18.24 km 35 min observation is always larger than nowcast in 5 min direction right 1.98 km P 90,abs,60min 3.79 km Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 10

Increase of uncertainty with lead time 20120715 60 min RIGHT LEFT lead time 17.14 km 18.24 km 35 min 5 min 1.98 km 3.79 km Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 11

80% intervals in all directions 20120715 FORWARD, 35 min moving direction nowcast time: 35 min RIGHT, 35 min LEFT, 35 min BACKWARD, 35 min nowcast 10th and 90th 100 km percentile mean uncertainty Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 12

80 % intervals in all directions 20120715 moving direction 5 min 35 min 60 min Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 13

Differing results for different days/situations July 15th, 2012 July 15th & 10th, 2012 No characteristic distribution on right extent! Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 14

Separate uncertainty analysis 20120715 – propagation error Gravity center displacement (rel. to obs) 50 km 5 min moving direction 0 km 50 km distance in mov direction 50 km 35 min 50 km 50 km 60 min gravity center No systematic 50 km misplacement! 50 km 50 km distance lateral to mov direction Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 15

Separate uncertainty analysis 20120715 – extension error Extension difference in direction RIGHT 1 5 min 0 -30 km 0 30 km 1 35 min relative counts Δ dist left 0 0 -30 km 30 km Δ dist forward 1 60 min gravity center Relative small Δ dist back Δ dist right uncertainties 0 (P 90,rel,right,60min = 5.87 km) 0 -30 km 30 km distance Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 16

Correlated distances in separate analysis 20120715 Regular growth or shrinkage on both sides Equivalent correlation between FORWARD and BACKWARD deviations Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 17

Integrated uncertainty development 20120715 Regressions: Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 18

Integrated uncertainty development 20120715 Larger 90th percentiles for directions BACKWARD and RIGHT Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 19

Nowcast uncertainty determination APPLICATION IN WEATHER AVOIDANCE ROUTING Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 20

Add uncertainty margin around a nowcast 20120715 35 minutes nowcast of a point cell movement direction 90th percentile uncertainty margin Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 21

Add uncertainty margin around a nowcast 20120715 12 km ~ 1.3 ° movement direction Additional heading change 525 km at 480kt to that forced by the nowcasted cells extent. Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 22

Conclusion I • Spatial uncertainty determination method of nowcast cells considering extent and displacement – Isotropic behavior for both components – BUT: integrated uncertainty shows characteristic features Separate view Integral view Thank you for your attention! sauer@muk.uni-hannover.de Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 23

Conclusion II • Spatial uncertainty determination method of nowcast cells considering extent and displacement – Isotropic behavior for both components – BUT: integrated uncertainty shows characteristic features • Quantified rate of increasing uncertainty with lead time Thank you for your attention! sauer@muk.uni-hannover.de . Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 24

Conclusion • Spatial uncertainty determination method of nowcast cells considering extent and displacement – Isotropic behavior for both components – BUT: integrated uncertainty shows characteristic features • Quantified rate of increasing uncertainty with lead time • Uncertainty is even higher due to – new, not yet nowcasted cells – Other not yet considered statistics • dissipating cells • merged/splitted cells • Further analyses on different thunderstorm situations Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 25

THANK YOU Contact information: Manuela Sauer sauer@muk.uni-hannover.de Thomas Hauf hauf@muk.uni-hannover.de Caroline Forster caroline.forster@dlr.de Uncertainty Analysis of Thunderstorm Nowcasts for Utilization in Aircraft Routing Manuela Sauer et al. 4th SESAR Innovation Days, Madrid 26