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 (2017), generating one hundred thousand victims, the worst climatic tragedy experienced in Peru since the 1990s. This climatic event was attributed to the occurrence of El Niño-Southern Oscillation (ENSO), but nevertheless the values ​​of the Oceanic Niño Index "ONI", did not show signs of sea surface temperature anomalies. For this reason one of the main objectives of the Study, is to determine the occurrence of this type of Meteorological Phenomena that cause extreme rainfall. The methodology used was the use of the “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 climate event of 2017.

Two types of El Niño, are currently known; Niño "Classic or Canonico"; occur in all Niño regions (1, 2, 3 and 4). 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 the Niño “Modoki”. In 2017 (January), the "ONI" value was -0.3, generating the Niña Modoki. This sequence of El Niño and La Niña (region 3.4), generated El Niño Costero of 2017 (Region 1.2), also generating the occurrence of tropical air masses that increased precipitation. In the same way in the present study the hypothesis arises, that the triggering process in the generation of these cllimatic event, is the orbital position of the Earth in its closest point to the Sun, that is to say the Perihelion.

Key-words: ENSO, ONI , Niño Clásico o Canónico, Niño Modoki, Niña Modoki, Niño costero