Comparison of the 2017 coastal El Nino with the 2015-2016 El Ni

Abstract

According to the Nino 3.4 index, the 2015-2016 El Nino was the strongest of the recent occurrences of El Ninos, but to the Nino 1+2 index in Ecuador- northern Peru, the index was approximately half scale compared to the 82-83 and 97-98 El Ninos. However, although the 2017 El Nino was not predicted through the Nino 3.4 Index, precipitation in the northern Peru was as large as the 97-98 El Nino, causing significant damage. The 82-83 and the 97-98 El Ninos are typical (Eastern Pacific) EP El Ninos, and the Equatorial Kelvin waves propagated to the South American coast, causing significant damage to the Peruvian coast. Recently, the trend of emergency of Central Pacific (CP) El Ninos has been increased. Since the 2015-2016 El Nino has matured, the characteristics of CP El Nino have been developed and reduced the impact on the Peruvian coast. The El Nino, which appeared in the Peruvian coast in 2017, was not characterized in the tropical central Pacific but was the local El Nino. This was caused by both the equatorial Kelvin waves and the weakening of Southeast trade winds caused by atmospheric abnormality for a short period of time. El Nino's impact on net primary production (NPP) in the Peruvian upwelling region was 16% lower than the normal NPP for the 2015-2016 El Nino, while the coastal 2017 El Nino decreased 30% in February and March 2017. However, the total decrease NPP quantity was 2.6 times larger for the 2015-2016 El Nino that the coastal 2017 El Nino.