Decadal variability in the austral summer precipitation over the Central Andes: Observations and the empirical-statistical downscaling model

The decadal variability in summer precipitation over the Central Andes (10°–30°S) is investigated from 1921 to 2010 using low-pass filtered time series of the central and eastern El Niño–Southern Oscillation (ENSO) Pacific (C and E) indices, the South Pacific Convergence Zone (SPCZ) index, the Atlan...

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Bibliographic Details
Published in:International Journal of Climatology
Main Authors: Sulca Jota, Juan Carlos, Takahashi, Ken, Tacza, José, Espinoza, Jhan-Carlo, Dong, Bo
Format: Article in Journal/Newspaper
Language:English
Published: Royal Meteorological Society 2022
Subjects:
Atlantic Ocean
Central and eastern ENSO
Central Andes
Decadal variability
Empirical-statistical downscaling model
SACZ
https://purl.org/pe-repo/ocde/ford#1.05.09
Austral
Indian
Nordeste
Pacific
North Atlantic
North Atlantic oscillation
Online Access:https://hdl.handle.net/20.500.12816/5312
https://doi.org/10.1002/joc.7867
Description
Summary:The decadal variability in summer precipitation over the Central Andes (10°–30°S) is investigated from 1921 to 2010 using low-pass filtered time series of the central and eastern El Niño–Southern Oscillation (ENSO) Pacific (C and E) indices, the South Pacific Convergence Zone (SPCZ) index, the Atlantic SST indices, Atlantic Multidecadal Oscillation (AMO) index, North Atlantic Oscillation (NAO) index, and ERA-20C reanalysis. Additionally, an empirical-statistical downscaling (ESD) model was built. A rotated empirical orthogonal function (REOF) analysis shows that the first leading mode of precipitation (RPC1) represents 38.2% of the total decadal variance. RPC2, RCP3, and RPC4 represent 18.8, 12.8, and 9.7% of the total decadal variance, respectively. Furthermore, RPC1 features highest loadings over most of the region. RPC2 features a dipole of highest loadings over the southernmost Bolivian Altiplano and lowest loadings over the northwestern Argentinian Andes. Conversely, RPC3 presents highest loadings over the eastern-central Bolivian Altiplano and northwestern Argentinian Andes. RPC4 features highest loadings over the southern Bolivian Andes. RPC1 and RPC3 wet summers are associated with moisture transport from the Amazon basin, but RPC1 features the strengthening upper-level Bolivian high-Nordeste low system over South America. Conversely, RPC2 and RPC4 wet summers are associated with local processes induced by southward displacement of the South Atlantic Convergence Zone and warm sea surface temperature (SST) anomalies over the Indian Ocean, respectively. According to the ESD model, the decadal variability in the central and eastern Pacific (CP and EP) and Atlantic Ocean reproduces the decadal component of the DJF precipitation over most of the Central Andes. Por pares

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