RT Journal Article T1 A chronology of El niño events from primary documentary sources in northern Peru A1 García Herrera, Ricardo Francisco A1 Díaz, H. F. A1 García, R. R. A1 Prieto, M. R. A1 Barriopedro Cepero, David A1 Moyano, R. A1 Hernández Martín, Emiliano AB The authors present a chronology of El Niño (EN) events based on documentary records from northern Peru. The chronology, which covers the period 1550-1900, is constructed mainly from primary sources from the city of Trujillo (Peru), the Archivo General de Indias in Seville (Spain), and the Archivo General de la Nacion in Lima (Peru), supplemented by a reassessment of documentary evidence included in previously published literature. The archive in Trujillo has never been systematically evaluated for information related to the occurrence of El Niño-Southern Oscillation (ENSO). Abundant rainfall and river discharge correlate well with EN events in the area around Trujillo, which is very dry during most other years. Thus, rain and flooding descriptors, together with reports of failure of the local fishery, are the main indicators of EN occurrence that the authors have searched for in the documents. A total of 59 EN years are identified in this work. This chronology is compared with the two main previous documentary EN chronologies and with ENSO indicators derived from proxy data other than documentary sources. Overall, the seventeenth century appears to be the least active EN period, while the 1620s, 1720s, 1810s, and 1870s are the most active decades. The results herein reveal long-term fluctuations in warm ENSO activity that compare reasonably well with low-frequency variability deduced from other proxy data. PB American Meteorological Society SN 0894-8755 YR 2008 FD 2008-05 LK https://hdl.handle.net/20.500.14352/50976 UL https://hdl.handle.net/20.500.14352/50976 LA eng NO © 2008 American Meteorological Society. This work was supported by a grant from the NOAA Climate Program Office’s Climate Change Data and Detection element. J. Castañeda assisted with document identification activities in the Archivo de la Libertad. G. Fernández and E. González searched supplementary information in the Archivo General de Indias. J. A. García discussed a preliminary version of the manuscript. ONERN supplied meteorological information from northern Peru. Three anonymous reviewers provided helpful comments, which improved the original manuscript. NO NOAA Climate Program Office’s Climate Change Data and Detection element DS Docta Complutense RD 10 abr 2025