Centro Internacional para la Investigación del Fenómeno de El Niño I FORO DE PERSPECTIVAS CLIMÁTICAS PARA SUDAMÉRICA Guayaquil - Ecuador, 01 al 04 de Octubre 2012 Seminario - Taller Clima de Sud América Variabilidad Climática II: Imapactos regionales de ENSO Relator: Dr. René D. Garreaud www.dgf.uchile.cl/rene Departamento de Geofísica Universidad de Chile
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Variabilidad Climática II: Imapactos regionales de ENSOSeminario - Taller Clima de Sud América Variabilidad Climática II: Imapactos regionales de ENSO ... Major ENSO impacts . Wetter-JFMA
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Centro Internacional para la Investigación del Fenómeno de El Niño
I FORO DE PERSPECTIVAS CLIMÁTICAS PARA SUDAMÉRICA Guayaquil - Ecuador, 01 al 04 de Octubre 2012
Seminario - Taller Clima de Sud América
Variabilidad Climática II: Imapactos regionales de ENSO
Relator: Dr. René D. Garreaud www.dgf.uchile.cl/rene
Departamento de Geofísica Universidad de Chile
Interannual Precipitation Variability (UdW data)
Which regions exhibit large year-to-year variability?
Leadings modes of interannual (and longer) of atmospheric variability: ENSO – PDO(?) - AAO
Leadings modes of interannual (and longer) of atmospheric variability: ENSO – PDO(?) - AAO
Annual mean Precip/SAT regressed upon index of large-scale modes (50 years of data)
ENSO impacts on South America
Seasonal correlation between Precip/SAT and Multivariate ENSO Index (50 years of data)
Full references in Garreaud et al. 2009
Stronger upper- Level ST Jet
Climo. Storm Track
EN years Storm Track
H
Blocking High
Weakened ST High
H
Drier/Warmer DJF
Wetter-OND
Wetter-JJA
Drier-DJF
Colder
Interannual variability - Major ENSO impacts
Wetter-JFMA
Warmer - DJF
ENSO-related regional impacts
• Northern South America • Coastal Ecuador and Perú • Central Andes • Subtropical SA
Summer-Fall Precip: Average ∼ 0 EN ∼ 1000 – 4000 mm! Where? How come?
Horel & Cornejo-Garrido 1986
“the influx of lower-tropospheric air from the Pacific Ocean is critical in producing the heavy rains during the El Niño period. This is in contrast to a relatively widely-held belief in the region that the moisture source is from the Amazon Basin”
SYNOPTIC AND SPATIAL VARIABILITY OF THE RAINFALL ALONG THE NORTHERN PERUVIAN COAST DURING THE 1997-8 EL NIñO EVENT Michael W. Douglas1, Malaquias Peña2, Norma Ordinola3, Luis Flores3, Joshua Boustead4, and Jose Luis Santos5.
Central Andes Rainfall
* Closely tied to moisture availability * Wind aloft controls the transport of moisture towards the Altiplano
Interannual Variability Central Andes (Altiplano Region)
Interannual Variability
Climo
EN-LN
Choco Jet
Rutllant and Fuenzalida 1991: Synoptic explanation of increased CCh precipitation during EN years: blocking anticyclone shifts northward storm track and embedded frontal
systems
Background
Every EN/LN is different and it is superimposed on a slightly different background state. That produce changes in the
teleconnection patterns even in current climate…
ENSO-PDO interference
Non-ENSO-related regional impacts
• AAO impacts on southern SA •Amazon basin • NE Brazil
Annual mean Precip/SAT regressed upon index of large-scale modes (50 years of data)
Relationship between the southern annular mode and southern hemisphere atmospheric systems Michelle Simões Reboita; Tércio Ambrizzi; Rosmeri Porfírio da Rocha
Silvestri and Vera 2005
-0,80
-0,60
-0,40
-0,20
0,00
0,20
0,40
25 30 35 40 45 50 55SOIAAOSEP-AAO
Quintana & Aceituno 2012
Rojas et al. 2013
+ +
+
+ +
−
−
−
−
SE
B
WAT
Rainfall anomalies SST anomalies
−
−
+
+
−
−
Rainfall NE Brazil related to tropical Atlantic dipole
Un caso que trajo atención internacional: La sequia Amazónica del 2005
Condiciones de gran escala durante 4 sequias en Amazonía SST Z850
Intraseasonal variability in South America and MJO impacts
The Madden Julian Oscillation: Leading mode in the western tropical Pacific at intraseasonal timescales (30-60 days)
Observación y predicción de la OMJ
Índices diarios de la OMJ del Centro de Predicción Climática (CPC) del Servicio Meteorológico Nacional (NWS) de la NOAA (EE.UU.)