Articles | Volume 42
Adv. Geosci., 42, 23–33, 2016
https://doi.org/10.5194/adgeo-42-23-2016
Adv. Geosci., 42, 23–33, 2016
https://doi.org/10.5194/adgeo-42-23-2016

  22 Mar 2016

22 Mar 2016

An assessment of El Niño and La Niña impacts focused on monthly and seasonal rainfall and extreme dry/precipitation events in mountain regions of Colombia and México

María Carolina Pinilla Herrera1,2 and Carlos Andrés Pinzón Correa2 María Carolina Pinilla Herrera and Carlos Andrés Pinzón Correa
  • 1Centro de Investigaciones en Geografía Ambiental – UNAM, Morelia, México
  • 2Fundación Natura, Bogotá, Colombia

Abstract. The influence of El Niño and La Niña on monthly and seasonal rainfall over mountain landscapes in Colombia and México was assessed based on the Oceanic Niño Index (ONI). A statistical analysis was develop to compare the extreme dry/precipitation events between El Niño, La Niña and Neutral episodes. For both areas, it was observed that El Niño and La Niña episodes are associated with important increases or decreases in rainfall. However, Neutral episodes showed the highest occurrence of extreme precipitation/dry events. For a better understanding of the impact of El Niño and La Niña on seasonal precipitation, we did a compound and a GIS analyses to define the high/low probability of above, below or normal seasonal precipitation under El Niño, La Niña and cold/warm Neutral episodes. In San Vicente, Colombia the below-normal seasonal rainfall was identified during El Niño and Neutral episodes in the dry season JJA. In this same municipality we also found above-normal seasonal rainfall during La Niña and Neutral episodes, especially in the dry season DJF. In Tancítaro México the below-normal seasonal rainfall was identified during La Niña winters (DJF) and El Niño summers (JJA), the above-normal seasonal rainfall was found during La Niña summers (JJA) and El Niño winters (DJF).

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Short summary
This paper reports the results of our study about the El Niño and La Niña impacts on local monthly and seasonal precipitation, and the occurrence of extreme dry/precipitation events on mountain regions exposed to several climate variability processes in Colombia and México. We did this research because we work on rural studies and this kind of climate analyses can be usefull for the development of strategies to improve crop production and resource management by local stackeholders and farmers.