Tree ring reconstructed rainfall over the southern Amazon Basin

LOPEZ, LIDIO; STAHLE, DAVID; VILLALBA, RICARDO; TORBENSON, MAX; FENG, SONG; COOK, EDWARD

GEOPHYSICAL RESEARCH LETTERS

AMER GEOPHYSICAL UNION

Año: 2017

0094-8276

Moisture sensitive tree ring chronologies of Centrolobium microchaete have been developedfrom seasonally dry forests in the southern Amazon Basin and used to reconstruct wet season rainfalltotals from 1799 to 2012, adding over 150 years of rainfall estimates to the short instrumental record for theregion. The reconstruction is correlated with the same atmospheric variables that influence the instrumentalmeasurements of wet season rainfall. Anticyclonic circulation over midlatitude South America promotesequatorward surges of cold and relatively dry extratropical air that converge with warm moist air to formdeep convection and heavy rainfall over this sector of the southern Amazon Basin. Interesting droughts andpluvials are reconstructed during the preinstrumental nineteenth and early twentieth centuries, but thetree ring reconstruction suggests that the strong multidecadal variability in instrumental and reconstructedwet season rainfall after 1950 may have been unmatched since 1799