Assertion (A) : According to the National Oceanic and Atmospheric Administration (NOAA), the El-Nino part of the cycle involves warmer than usual sea temperatures, great amounts of rainfall (in the Northern Hemisphere) and low atmospheric pressure. Reason (R) : The most extreme results of an El-Nino event have included flooding from Ecuador to the Gulf of Mexico, massive marine life die-offs in the Pacific, hurricanes in Tahiti and Hawaii, and concurrent droughts in many other parts of the world from Southern India to Australia to Central America. Codes

El Niño and La Niña are climate patterns in the Pacific Ocean that can affect weather worldwide.
During normal conditions in the Pacific ocean, trade winds blow west along the equator, taking warm water from South America towards Asia. To replace that warm water, cold water rises from the depths — a process called upwelling.

El Niño and La Niña are two opposing climate patterns that break these normal conditions. Scientists call these phenomena the El Niño-Southern Oscillation (ENSO) cycle.