El Nino & La Nina

El Niño is defined by prolonged warming in the Pacific Ocean sea surface temperatures when compared with the average value. El Niño and La Niña are opposite phases of what is known as the El Niño-Southern Oscillation (ENSO) cycle. The ENSO cycle is a scientific term that describes the fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific. The ENSO cycle, both El Niño and La Niña, causes global changes of both temperatures and rainfall

The first signs of an El Niño are a weakening of the Walker circulation or trade winds and strengthening of the Hadley circulation and may include

1.  Rise in surface pressure over the Indian Ocean, Indonesia, and Australia

2.  Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean

3.  Trade winds in the south Pacific weaken or head east

4.  Warm air rises near Peru, causing rain in the northern Peruvian deserts

La Niña is sometimes referred to as the cold phase of ENSO and El Niño as the warm phase of ENSO. These deviations from normal surface temperatures can have large-scale impacts not only on ocean processes, but also on global weather and climate. La Niña caused a drop in sea surface temperatures over Southeast Asia by 2 °C. It also caused heavy rains over Malaysia, the Philippines, and Indonesia. La Niña causes mostly the opposite effects of El Niño

2014 hottest year on record: US scientists

According to US scientists, year 2014 was the hottest year on record, with global average temperature increasing about 0.8 degrees Celsius since 1880. It was revealed by two separate analyses carried out by NASA and National Oceanic and Atmospheric Administration (NOAA).However, 2014’s record warmth occurred during an El Nino-neutral year.