1 / 28

Daniel Vila 1,2 , Luiz Augusto Toledo Machado 2 , Ines Velasco 3

SOME RELATIONSHIPS BETWEEN MESOSCALE CONVECTIVE SYSTEMS LIFE CYCLE AND OBSERVED RAINFALL OVER DEL PLATA BASIN. Daniel Vila 1,2 , Luiz Augusto Toledo Machado 2 , Ines Velasco 3. 1 Instituto Nacional del Agua , Ezeiza, Buenos Aires, Argentina 2 DSA, CPTEC-INPE, Cachoeira Paulista, Brasil

allegra-mcknight
Download Presentation

Daniel Vila 1,2 , Luiz Augusto Toledo Machado 2 , Ines Velasco 3

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SOME RELATIONSHIPS BETWEEN MESOSCALE CONVECTIVE SYSTEMS LIFE CYCLE AND OBSERVED RAINFALL OVER DEL PLATA BASIN Daniel Vila 1,2, Luiz Augusto Toledo Machado 2, Ines Velasco 3 1 Instituto Nacional del Agua, Ezeiza, Buenos Aires, Argentina 2DSA, CPTEC-INPE, Cachoeira Paulista, Brasil 3DCAyO, FCEN, UBA, Buenos Aires, Argentina

  2. OUTLINES • THE FORTRACC TECHNIQUE • USED DATA BASE • MAIN ALGORITM CHARACTERISTICS • TECHNIQUE APPLICATION: IGUAZU BASIN • CONCLUSIONS

  3. OUTLINES • THE FORTRACC TECHNIQUE • USED DATA BASE • MAIN ALGORITM CHARACTERISTICS • TECHNIQUE APPLICATION: IGUAZU BASIN • CONCLUSIONS

  4. DATA : GOES 8 (75º W, 0º ) imagery - channel 4 (10.7 μm, thermal infrared), - spatial resolution: 4 km x 4 km - temporal resolution: ½ hour (*) provided by Centro de Previsión del Tiempo y Clima (CPTEC) . • Period: December 2002 – January and February 2003 • Region: SHEM (Southern Hemisphere Scan)

  5. OUTLINES • THE FORTRACC TECHNIQUE • USED DATA BASE • MAIN ALGORITM CHARACTERISTICS • TECHNIQUE APPLICATION: IGUAZU BASIN • CONCLUSIONS

  6. Conex space generation (“clusters”). Temperature threshold T 235 K – Minimun Area AMIN 150 pix

  7. Tracking Methodology • Based on overlapped area between consecutive images (1/2 hour) • Minimum MCS size: 150 pixels • Regular tracking (continuity), (b) split y (c) merge. • White MCS: t - Purple MCS: t+Δt

  8. MCS displacement estimation • MCS growing evolution estimation

  9. TECHNIQUE VALIDATION OF INTERPOLATED IMAGENS: NOWCASTING USE

  10. TECHNIQUE VALIDATION OF INTERPOLATED IMAGENS: NOWCASTING USE Evolución temporal de la cantidad de píxeles pronosticados y observados para el tiempo de pronóstico de 30 minutos (izquierda) y 120 minutos (derecha) para el periodo 6 al 11 de enero de 2003

  11. OUTLINES • THE FORTRACC TECHNIQUE • USED DATA BASE • MAIN ALGORITM CHARACTERISTICS • TECHNIQUE APPLICATION: IGUAZU BASIN • CONCLUSIONS

  12. Monthly rainfall and mean number of pixels per image with temperature below 235 K

  13. Rain event from raingauge measurement: • RR > 25 mm/day - minimum area = 50000 km2 • or • RR > 75 mm/dayin (at least) one raingauge. • 17 day were selected • Rain event from satellite detection: • For those days classified as rain event from raingauge measurement, were selected all MCS (“famlies’) that affect the raingauge stations with rr > 25 mm/day • 32 families were selected Iguazu river basin: green dots are raingauge stations (daily accumulation)

  14. Mean brightness temperature (left) and brightness temperature anomaly (right) for selected cases.

  15. Mean trajectory of composite (32 MCS families). Green circle correspond to initial stage, box to maturity (maximum extension) and star to dissipation.

  16. Relative frequency of life time for rainy and non-rainy MCS (left) and life time – maximum extent scatter plot for rainy and non-rainy MCS.

  17. DIURNAL CYCLE MCS area expansion rate (in s-1*106) and minimum temperature diurnal cycle.

  18. Mean temporal evolution of families composition: size, minimum temperature and convective area (T < 210 K) for rain events(left) and non-rain events (right)

  19. Initial stage: mean area expansion – cooling rate and total life cycle

  20. Mean area and temperature evolution according to different life cycle duration

  21. Cooling rate ~ 12 K/hour 24-hour accumulation (left) and size and temperature evolution of selected MCS (right)

  22. OUTLINES • THE FORTRACC TECHNIQUE • USED DATA BASE • MAIN ALGORITM CHARACTERISTICS • TECHNIQUE APPLICATION: IGUAZU BASIN • CONCLUSIONS

  23. CONCLUSIONS • THE MEAN LIFETIME IS AROUND THREE TIMES LARGER FOR RAINFALL-ASSOCIATED MCS’S THAN THAT OF THE GENERAL MCS DATASET. • THE COOLING RATE DURING THE FIRST STAGES OF LIFE CYCLE (FROM 2-4 TO 6-8 HOURS) IS GREATER THAN THAT OF THE GENERAL DATASET, WHILE THE MINIMUM TEMPERATURE DURING THE FIRST DETECTION STAGE DOES NOT ALLOW TO DISTINGUISH THE EVOLUTION OF A GIVEN MCS. • AREA EXPANSION RATE AND COLD-TOP GROWTH HAVE A SIMILAR BEHAVIOR TO THE MINIMUM TEMPERATURE EVOLUTION, WITH LARGER VARIATIONS DURING THE PERIOD BETWEEN 2-4 HOURS AND 10-12 HOURS COMPARED TO THOSE OF THE FULL DATASET. • THE MCS’S REACH THE MINIMUM TEMPERATURE 1 – 2 HOURS BEFORE ACQUIRING THE MAXIMUM EXTENT.

  24. CONCLUSIONS • THE MEAN LIFETIME IS AROUND THREE TIMES LARGER FOR RAINFALL-ASSOCIATED MCS’S THAN THAT OF THE GENERAL MCS DATASET. • THE COOLING RATE DURING THE FIRST STAGES OF LIFE CYCLE (FROM 2-4 TO 6-8 HOURS) IS GREATER THAN THAT OF THE GENERAL DATASET, WHILE THE MINIMUM TEMPERATURE DURING THE FIRST DETECTION STAGE DOES NOT ALLOW TO DISTINGUISH THE EVOLUTION OF A GIVEN MCS. • AREA EXPANSION RATE AND COLD-TOP GROWTH HAVE A SIMILAR BEHAVIOR TO THE MINIMUM TEMPERATURE EVOLUTION, WITH LARGER VARIATIONS DURING THE PERIOD BETWEEN 2-4 HOURS AND 10-12 HOURS COMPARED TO THOSE OF THE FULL DATASET. • THE MCS’S REACH THE MINIMUM TEMPERATURE 1 – 2 HOURS BEFORE ACQUIRING THE MAXIMUM EXTENT.

  25. CONCLUSIONS • THE MEAN LIFETIME IS AROUND THREE TIMES LARGER FOR RAINFALL-ASSOCIATED MCS’S THAN THAT OF THE GENERAL MCS DATASET. • THE COOLING RATE DURING THE FIRST STAGES OF LIFE CYCLE (FROM 2-4 TO 6-8 HOURS) IS GREATER THAN THAT OF THE GENERAL DATASET, WHILE THE MINIMUM TEMPERATURE DURING THE FIRST DETECTION STAGE DOES NOT ALLOW TO DISTINGUISH THE EVOLUTION OF A GIVEN MCS. • AREA EXPANSION RATE AND COLD-TOP GROWTH HAVE A SIMILAR BEHAVIOR TO THE MINIMUM TEMPERATURE EVOLUTION, WITH LARGER VARIATIONS DURING THE PERIOD BETWEEN 2-4 HOURS AND 10-12 HOURS COMPARED TO THOSE OF THE FULL DATASET. • THE MCS’S REACH THE MINIMUM TEMPERATURE 1 – 2 HOURS BEFORE ACQUIRING THE MAXIMUM EXTENT.

  26. CONCLUSIONS • THE MEAN LIFETIME IS AROUND THREE TIMES LARGER FOR RAINFALL-ASSOCIATED MCS’S THAN THAT OF THE GENERAL MCS DATASET. • THE COOLING RATE DURING THE FIRST STAGES OF LIFE CYCLE (FROM 2-4 TO 6-8 HOURS) IS GREATER THAN THAT OF THE GENERAL DATASET, WHILE THE MINIMUM TEMPERATURE DURING THE FIRST DETECTION STAGE DOES NOT ALLOW TO DISTINGUISH THE EVOLUTION OF A GIVEN MCS. • AREA EXPANSION RATE AND COLD-TOP GROWTH HAVE A SIMILAR BEHAVIOR TO THE MINIMUM TEMPERATURE EVOLUTION, WITH LARGER VARIATIONS DURING THE PERIOD BETWEEN 2-4 HOURS AND 10-12 HOURS COMPARED TO THOSE OF THE FULL DATASET. • THE MCS’S REACH THE MINIMUM TEMPERATURE 1 – 2 HOURS BEFORE ACQUIRING THE MAXIMUM EXTENT.

More Related