INFLUENCE OF ATMOSPHERIC TELECONNECTION PATTERNS ON PRECIPITATION AND UPWELLING

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INFLUENCE OF ATMOSPHERIC TELECONNECTION PATTERNS
ON PRECIPITATION ANDUPWELLING

• M. Gómez- Gesteira1, M. deCastro1, I. Alvarez1,
  M.N. Lorenzo1, A.J.C. Crespo and J.J Taboada2
• 1Grupo de Física de la Atmósfera y del Océano,
  Universidad de Vigo, Ourense, Spain
• 2METEOGALICIA
• E-mail mggesteira_at_uvigo.es

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Area under Scope
44 N
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43.5 N
?
43 N
Ekman Transport
Ekman Transport
Ekman Transport
Ekman Transport
Ekman Transport
42.5 N
Miño River
42 N
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Precipitation and Miño River discharge M.
deCastro et al., Climate Research 32 (2006)
Rain- Gauge Station Mean Precipitación DJF (mm)
FONSAGRADA (FONS) 372.83
MONTEDERRAMO (MONT) 619.24
FOLGOSO DE CAUREL (FOLC) 607.40
VAO (VAO) 421.91
O BOLO (BOLO) 301.00
MONFORTE DE LEMOS 'E.AGRICOLA' (MOF1) 308.28
CASTRO DE REI (CREI) 437.46
SAN ESTEBAN (SEST) 456.52
AIRA PADRON (AIRP) 688.65
PUEBLA DE BROLLON (PDBR) 349.39
SEOANE DO COUREL (SEOC) 583.82
VEIGA DE BRAÑAS (VEIB) 670.37
SEQUEIROS (SEQU) 342.52
ACIVEIROS (ACIV) 443.90
TRIVES 'SAN JUAN DEL RIO' (TRIV) 388.71
PARAMOS-GUILLAREI (PAGU) 680.60
ORENSE 'GRANJA DIPUTACION' (OURE) 302.04
MONFORTE 'A PINGUELA' (MOF2) 252.23
PUEBLA DE BROLLON 'VEIGA' (PDBV) 389.52
SARRIA 'GRANXA BARREIROS' (SARR) 475.00
ALLARIZ (ALLA) 329.79
LUGO 'COLEGIO FINGOI' (LUGO) 371.13
Frieira
?
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Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Mean monthly flow (Miño River) (Data from
October 1970 to September 2005)
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C.C.0.88
Normalized precipitation DJF (blue) y and river
discharge (red) (Data from 1976 to 1997)
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Correlation between modes and river discharge
Index Correlation
NAO -0.54 (2)
SCAND 0.63 (1)
EA/WR -0.46 (1)
EA 0.40 (0)
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Evolution of the correlation between modes and
river discharge
Running period (22 years)
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Variability of Upwelling Conditions
Data 1966- 2005
Zonal Ekman transport
In Western Iberian Peninsula UI -Qx Qx lt 0
upwelling favorable Qx gt 0 upwelling
unfavorable
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Upwelling Conditions
Days per month under upwelling favorable
conditions
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Atmospheric patterns vs Qx during the wet season
(NDJF) M. deCastro et al., Jornal Marine Systems
72 (2008)
Correlation between atmospheric modes and Qx from
1966 to 2005.
EA NAO EA/WR POL SCAND
Qx (NDJF) 0.65 -0.19 0.16 -0.16 0.12
significance level gt 95
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EA Pattern Evolution
EA gt 0 associated to southerly winds at Galician
shelf
Qx Anomaly Evolution
Positive values from 1983 on, which result in
upwelling unfavorable conditions
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SLP composites
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Atmospheric patterns vs summer UISST M. deCastro
et al., Climate Research 36 (2008)
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Atmospheric patterns vs UISST
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Summary

• Precipitation/river discharge depend on several
  indices (NAO, SCAND, EA/WR, EA)
• The dependences is not stationary

• Winter upwelling in Galician region depends on EA
• Winter upwelling tends to decrease during the
  last decades

• Summer upwelling depends on EA and NAO along the
  Western Iberian Coast
• Dependence on NAO decreases northward

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Thanks!!!
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Dates UIAM (ºC) EA
Sep 88 -2.23 0.7
Sep 94 -2.52 -0.5
Aug 96 -1.89 0.6
Aug 98 -2.29 2
Sep 98 -2.06 0.4
Oct 98 -1.97 1.2
Aug 01 -2.07 2.6
Aug 02 -2.76 0.2
Sep 05 -2.08 1.7
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NAO and EA . Map of Correlations with
precipitation departures
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Correlación Modos vs. Precipitación
DEF coeficientes invernales de correlación de los
distintos índices de teleconexión y la
precipitación de las estaciones situadas (Octubre
1976 - Septiembre 1997)
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Correlación Modos vs. Precipitación
Variación interanual de los modos promediados a
DEF (línea roja) y las precipitaciones (línea
azul) (Octubre 1976-Septiembre 1997)