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SOUTH AMERICAN CLIMATE DYNAMICS - A GENERAL VIEW

SOUTH AMERICAN CLIMATE DYNAMICS - A GENERAL VIEW. Tércio Ambrizzi Department of Atmospheric Sciences University of São Paulo 1 ST IBERO-AMERICAN WORKSHOP ON CLIMATE DYNAMICS, CLIMATE CHANGE AND REGIONAL CLIMATE MODELING São Paulo, Brazil August 2007. Wind vector at high levels.

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SOUTH AMERICAN CLIMATE DYNAMICS - A GENERAL VIEW

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  1. SOUTH AMERICAN CLIMATE DYNAMICS - A GENERAL VIEW Tércio Ambrizzi Department of Atmospheric Sciences University of São Paulo 1ST IBERO-AMERICAN WORKSHOP ON CLIMATE DYNAMICS, CLIMATE CHANGE AND REGIONAL CLIMATE MODELING São Paulo, Brazil August 2007

  2. Wind vector at high levels Water vapor

  3. DJF Main Observed and Simulated Global Teleconnection Patterns

  4. JJA Main Observed and Simulated Global Teleconnection Patterns

  5. TROPICAL CONVECTION AND ROSSBY WAVE GENESIS

  6. Madden e Julian Oscillation and the generation of Rossby Wave OLR Wind Vector at 250 hPa

  7. Intraseasonal Variability (MJO) Composite evolution of 200-hPa velocity potential anomalies associated with MJO events and points of origin of tropical disturbances that developed into hurricanes or typhoons.

  8. Precipitation anomaly composites over the tropical Brazil associated to MJO events (mm) (Souza and Ambrizzi 2006)

  9. Daily Meridional Wind Anomaly (250 hPa) (Average between 40S – 50S) Rossby waves Life cycle between 6 and 14+ days

  10. RAY TRACING - SACZ MODE - NORTH 10/20 days 20/30 days 30/70 days OLR and wavenumbers 3, 4 e and 5 for each trajectory (Ferraz 2004)

  11. 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa 200 hPa ZCN 30/70 DAY +02 ZCN 30/70 DIA -18 ZCN 30/70 DIA -14 ZCN 30/70 DIA -12 ZCN 30/70 DIA -16 ZCN 30/70 DIA -10 ZCN 30/70 DIA -08 ZCN 30/70 DIA -06 ZCN 30/70 DIA -20 ZCN 30/70 DIA -04 ZCN 30/70 DIA -02 ZCN 30/70 DIA -01 ZCN 30/70 DIA +01 ZCN 30/70 DIA +0 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa 850 hPa (Ferraz 2004)

  12. South Atlantic Convergence Zone Event – 21 a 28/01/1997 Day 22 Day 21 Day 24 Day 23 Courtesy by Leila V. Carvalho

  13. South Atlantic Convergence Zone Event – Continue Day 26 Day 25 Day 27 Day 28

  14. Conceptual model of the SALLJ physical environment during the wet season (Marengo et al. 2004 - JC)

  15. SALLJEX PIBALS Radiosondes Enhanced precipitation gauge network NOAA/P-3 Missions

  16. EXTREME PRECIPITATION EVENTS AND LLJ 1° Case: EPE + LLJ 2° Case: EPE + LLJ 3° Case: EPE + LLJ 4° Case: LLJ without EPE over the areas A1, A2 or A3 Weykamp (2006)

  17. Divergence and Moisture flux integrated in the vertical Weykamp (2006)

  18. 1)19/02 LLJ (06Z) + EPE (A1) 2) 04/02 LLJ (06 e 12Z) + EPE (A2) 3) 21/01 LLJ (06 e 12Z) + EPE (A3) 4) 17/01 LLJ (12Z) without EPE 2 1 4 3 GOES 04/02/98 06Z GOES 17/01/98 12Z GOES 19/02/98 06Z GOES 21/02/98 06Z Some examples of each case for the 1998 summer Weykamp (2006)

  19. ATMOSPHERIC CIRCULATION SCHEMATIC PICTURES DURING CANONICAL EL NIÑO AND LA NIÑA CANONICAL EL NIÑO CANONICAL LA NIÑA (Ambrizzi et al 2004)

  20. INTER-EL NIÑOS VARIABILITY

  21. I = (Xi - Xi)/i ENSO episodes and the South American Regional Precipitation Seasonal Standardized index for the austral summer (DJF) and autumn (MAM) were calculated for the precipitation over key-areas of South America and the SSTa over the Niño 1.2, 3, 3.4 and 4 (Ambrizzi and Souza, 2003)

  22. Niños SSTa E Amazon NE Brazil SACZ SE South America Altiplano Ecuador Peru El Niño episodes and the South American Regional Precipitation during 1950-1990

  23. Niñas SSTa E Amazon NE Brazil SACZ SE South America Altiplano Ecuador Peru La Niña episodes and the South American Regional Precipitation during 1950-1990

  24. SLC – PACIFIC BOXES - DEC - MAY – EL NIÑO C B SVD E G (Coelho, Uvo and Ambrizzi, 2002 – TAC)

  25. SSTa for 4 EL NIÑOEVENTS Average over 4 events El Niño 82/83 El Niño 86/87 El Niño 97/98 El Niño 91/92 (Drumond e Ambrizzi, 2003)

  26. OMEGA ANOMALY (Magaña e Ambrizzi 2005)

  27. DJF ZONAL WIND AT 250 hPa

  28. STREAMFUNCION ANOMALY AND RAY TRACING FOR 4 EL NIÑO EVENTS Anomaly of Ψ

  29. Definition Climate Prediction Center AAO Positive Fase • To identify the leading teleconnection patterns in the atmospheric circulation, Empirical Orthogonal Function (EOF) was applied to the monthly mean 700-hPa height anomalies poleward of 20° latitude for the Southern Hemisphere, for the period 1979 to 2000. • The loading pattern of AAO is defined as the first leading mode from the EOF analysis. • Monthly AAO indices are constructed by projecting the monthly mean 700-hPa height anomalies onto the leading EOF mode. Both time series are normalized by the standard deviation of the monthly index (1979-2000 base period).

  30. Composites of SST and 200 hPa zonal wind (U200LF):Low-Frequency ( Retained Periods: above 365 days) Negative AAO Phase Positive AAO Phase SSTLF SSTLF U200LF U200LF (Carvalho, Jones, Ambrizzi, 2005 – JC)

  31. Teleconnection Patterns of U200 (Wallace and Gutzler 1981) (The strongest negative correlation with grid points from 90S – 40S ) • Equatorward shift of the Subtropical Jet • Weakening Polar Jet NEGATIVE • Strengthening of the Polar Jet • Poleward shift subtropical jet POSITIVE Westerly jets can act as Rossby waveguides for propagation from tropics to midlatitudes DIFFERENCE (Carvalho, Jones, Ambrizzi, 2005 – JC)

  32. Precipitation Anomaly (NCEP) Autumn Summer Winter Spring - AAO - AAO - AAO - AAO +AAO +AAO +AAO +AAO (Reboita, Ambrizzi & Rocha 2007)

  33. REOF Precipitation anomalies DJF 1950 to 2001 4th rotated mode - 6.6% of the total variance Drumond (2005) EN LN LN LN LN LN N EN N N EN LN EN LN EN EN ZCAS + 9 events 1951/52, 1956/57, 1959/60, 1964/65, 1967/68, 1978/79, 1984/85, 1986/87, 1988/89 ZCAS - 7 events 1957/58, 1970/71, 1972/73, 1976/77, 1980/81, 1983/84, 1997/98

  34. SACZ+ SACZ - Composite of DJF precipitation anomalies (mm.day-1) Composite of DJF SST anomalies (ºC) Composite of DJF 200hPa anomalous zonally asymmetric component of stream function (x 106m2/s) anomalies Drumond (2005)

  35. Low Frequency SST Variability modes related to the South American Monsoon System DJF SST Modes related to the SACZ - DJF SST Modes related to the SACZ + Drumond (2005)

  36. Em = Equatorial Mass Tm = Tropical Mass Em Pm = Polar Mass Tm Pm

  37. SEASONAL CYCLONE TRACKS AUTUMN SUMMER SPRING WINTER (Beu and Ambrizzi 2006)

  38. CYCLONES, ANTICYCLONES AND COLD AIR MASS (Pezza and Ambrizzi 2005)

  39. Generalized Frost (+σ) Day -3 Day -2 Phase coincidence Day -1 The anomalous 250hPa meridional wind component (ms-1) Day 0 (Muller et al 2005)

  40. Basic State +σ The anomalous 250hPa meridional wind component (ms-1) 14th day of integration • The importance of the phases coincidence: • Keeping the polar air advection over a large region • Provoking an intense decrease in the surface temperature (Muller and Ambrizzi 2007)

  41. GF +σ GF -σ Wind at 250 hPa BETA Ks (Muller and Ambrizzi 2007)

  42. SCHEMATIC CONCEPT OF POSSIBLE GENERALIZED FROST MECHANISM (Muller e Ambrizzi 2006)

  43. GRUPO DE ESTUDOS CLIMÁTICOS CLIMATE STUDIES GROUP THANKS FOR BEING HERE !!! WELCOME TO SÃO PAULO CITY, BRAZIL

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