Evaluation of Patterns of Climatic Drivers; Tropical Systems and the El Niño Southern Oscillation, in the Generation of Extreme Precipitations, (Case Northern Peru)

Abstract

In the year of 2017, extreme rainfall occurred in the Northern Zone of Peru, generating more than one hundred thousand victims, the worst climatic tragedy experienced in Peru since the 90s. This climatic event was attributed to the occurrence of El Niño Southern Oscillation (ENSO), but nevertheless the values of the Oceanic El Niño Index "ONI", did not show signs of sea surface temperature anomalies. For this reason, the main objective of this research is to determine the occurrence of this Meteorological Phenomena that cause extreme rainfall. The methodology includes the use of the Oceanic El Niño Index (ONI) to analyze the Pacific Sea Surface Temperature Anomalies (TSM) in the occurrence of ENSO; 82-83, 97-98 and 2015-2016, to later analyze the 2017 climatic event. Currently, two types of Niños are known: "Classic or Canonical" El Niño occur in all El Niño regions (1, 2, 3 and 4). "El Niño Modoki", (includes La Niña events) occurs in the Niño regions (3.4). From the analysis of the "ONI" values (region 3.4) for the month of January 2016, it was 2.5 generating El Niño Modoki. In January 2017, the "ONI" value was -0.3 generating the Niña Modoki. This sequence of El Niño and La Niña (region 3.4), generated the Coastal Niño of 2017 (Region 1.2), also producing the occurrence of tropical air masses that increased the precipitation. Similarly, in the present research the hypothesis is raised that the triggering process in the generation of these climatic events is the orbital position of the Earth at its closest point to the Sun, ie the Perihelion.

Key-words: ENSO, ONI , Niño Modoki, Niña Modoki.