300 likes | 456 Views
Teleconnection Patterns and Seasonal Climate Prediction over South America The Final Chapter???. Tércio Ambrizzi and Rosmeri P. da Rocha University of São Paulo, São Paulo, Brazil. EUROBRISA 2010 – Barcelona, Spain. OBJECTIVE.
E N D
Teleconnection Patterns and Seasonal Climate Prediction over South America The Final Chapter??? Tércio Ambrizzi and Rosmeri P. da Rocha University of São Paulo, São Paulo, Brazil EUROBRISA 2010 – Barcelona, Spain
OBJECTIVE To analyze in detail 21 years of ECWMF seasonal forecast simulations using basic statistical methods and particularly the linear wave theory, in order to evaluate the seasonal forecast skill and its useful value
(1/3º x 1/3º and 0,83º lat x 1,25º lon) (1º x 1º and 1,25º lat x 1,825º lon) (Dawson et al 2010 – CD)
DATA AND METHODOLOGY • Climatological Data used : ECMWF/ERA40 – period 1982 – 2001 • ECMWF Coupled GCM – Hindcast Period – 1982 – 2001 – 11 ensemble • members – 6 months forecasting • The seasons are: DJF (Summer), MAM (Fall), JJA (Winter), • and SON (Spring) • To create the seasonal datasets it was used the third month of each • six months forecasting (PREV3) and three months seasonal forecasting (3MES) • Pearson linear correlation was used in some of the analyzes • The basic variables used in this presentation is Zonal (U) and Meridional • Wind (V) • Ray tracing analysis will be presented as well
PREV3 Autum 3MES Winter Spring Summer
REGIONS WHERE THE MODEL WILL BE VALIDATED CONSIDERING THE 3MES AND PREV3
Zonal and Meridional Seasonal Wind at 200 hPa for ERA 40 and 3MES inside the previous four regions ND ND Model superstimate the zonal wind and understimate the meridional wind CO CO SD SD RS RS
TOTAL AMPLITUDE OF U AND V WIND FOR EACH ENSEMBLE MEMBER AND EACH FORECASTING MONTH (RS BOX) U (200 hPa) V (200 hPa) U (850 hPa) V (850 hPa)
ZONAL AND MERIDIONAL WIND ERRORS FOR THE SUMMER MERIDIONAL WIND ZONAL WIND ND ND CO CO SD SD RS RS
ZONAL AND MERIDIONAL WIND ERRORS FOR WINTER ZONAL WIND MERIDIONAL WIND ND ND CO CO SD SD RS RS
ZONAL WINDA COMPOSITES FOR DJF AND JJA (200 hPa – m/s) JJA DJF ERA40 PREV3 3MES
ZONAL WIND CROSS SECTION AT 30o AND 50oS FOR 3MES AND DJF - JJA (m/s) DJF JJA 30oS 50oS
LATITUDINAL MEAN SEASONAL ZONAL WIND at 200 hPa - (m/s) MAM DJF JJA SON
ZONAL WIND ERRORS PREV3/3MES – ERA40 JJA DJF PREV3 3MES
STATIONARY WAVENUMBER (Ks) - DJF Ks Meridional cross section ERA40 120oE 120oW 3MES 65oW
STATIONARY WAVENUMBER (Ks) - JJA Ks Meridional cross section ERA40 120oE 180o 3MES 65oW
SEASONAL RAY TRACING ANALYSIS FOR WAVE NUMBERS=2 and 3 (WN=2-3) (ERA40 AND ALL 11 MEMBERS) WN2 WN3 DJF MAM JJA SON
SUMMER PRECIPITATION COMPARISON BETWEEN CMAP AND ERA40 CMAP ERA40 - CMAP ERA40
WINTER PRECIPITATION COMPARISON BETWEEN CMAP AND ERA40 CMAP ERA40 - CMAP ERA40
SEASONAL ZONAL MEAN PRECIPITATION (mm/day) CMAP DJF MODEL MAM SON JJA
SEASONAL PRECIPITATION COMPARISON BETWEEN CMAP AND MODEL FOR THE NORTHEAST BRAZIL“ND” CMAP Model El Niño years DJF MAM JJA SON
SEASONAL PRECIPITATION ANOMALIES IN THE NORTHEAST BRAZIL BOX (ND) – ALL ENSEMBLE MEMBERS MAM DJF SON JJA
SEASONAL PRECIPITATION COMPARISON BETWEEN CMAP AND MODEL AND SEASONAL PRECIPITATION ANOMALIES IN THE CENTER WEST BRAZILIAN BOX (CO) – ALL ENSEMBLE MEMBERS DJF MAM SON JJA
SEASONAL PRECIPITATION COMPARISON BETWEEN CMAP AND MODEL AND SEASONAL PRECIPITATION ANOMALIES IN THE SOUTHEAST BOX (SD) – ALL ENSEMBLE MEMBERS DJF MAM SON JJA
SEASONAL PRECIPITATION COMPARISON BETWEEN CMAP AND MODEL AND SEASONAL PRECIPITATION ANOMALIES IN THE SOUTH BOX (RS) – ALL ENSEMBLE MEMBERS El Niño DJF MAM SON JJA
summary • The GCM is not able to correctly represent the position of the maximum and minimum hemispheric zonal wind (large variability among the ensemble members) • There are considerable errors in the amplitudes of the zonal and meridional wind over different regions of South America. • The precipitation is overestimated in the hemispheric analysis but the model underestimate it in the different regions over South America. • Ray tracing analyzes clearly suggest that the model is not able reproduce the expected wave trajectory because it does not represent the Southern Hemisphere zonal wind variability. Bigger wavenumber larger variability among the trajectories.
FUTURE WORK • Repeat all previous analyzes for the Meteo Office and CPTEC hindcast data. • Select some specific years to analyze the atmospheric circulation over South America in order to determine some dynamical aspects of the model ensemble members and their deviation. We have to look more careful at ENSO years • A Scientific paper is underway containing the main results of the first part of this work • One M.Sc. Dissertation was concluded and the work was presented in some international conferences.
GRUPO DE ESTUDOS CLIMÁTICOS CLIMATE STUDIES GROUP THANK YOU FOR YOUR ATTENTION AND TO EUROBRISA FOR THE OPPORTUNITY TO WORK IN THIS PROJECT