There seems to be a significant confusion regarding the prevalence of El Nino conditions over equatorial Pacific Ocean. The weather agencies of different countries have come up with different conclusions on this.
While Japan’s Meteorological Agency (JMA), which is also the Asian arm of the World Meteorological Organisation (WMO), says El Nino conditions are prevailing and that there is an 80 per cent chance of El Nino phenomenon staying till spring season of 2019, the India Meteorological Department (IMD) says El Nino neutral conditions, which means it is neither El Nino (warming) nor La Nina (cooling), are currently prevailing in the equatorial Pacific Ocean. The IMD also issued a short-term forecast that the neutral conditions will remain for the next two weeks, but didn’t provide a picture on how the condition would pan out in the long term.
On the other hand, the Australian Bureau of Meteorology (ABM) has said though El Nino Southern Oscillation (ENSO) is in neutral phase, the sub surface of the ocean is still warm and El Nino conditions could be back later in 2019. The ABM also suggested that the current cooling of sea waters might be a result of Madden Julian Oscillation (MJO)-induced stronger trade winds.
As the MJO moves east, these winds will become weaker paving the way for more warming and possible development of El Nino. The Climate Prediction Centre of the National Oceanic and Atmospheric Administration (NOAA) also says, “El Nino is expected to form and continue through the Northern Hemisphere spring 2019.”
The El Nino/ENSO is a phenomenon that involves fluctuating ocean surface temperatures in the equatorial Pacific. It has a major influence on weather patterns over many parts of the world.
What if it continues?
If the El Nino continues into the spring and summer seasons, it might bring down the average rainfall during the 2019 monsoon and may cause warmer than usual summer temperatures.In the 135 years between 1880 and 2014, around 90 per cent of all evolving El Nino years have seen below normal rainfall and 65 per cent of them experienced droughts. In fact, six of the worst droughts in the country since 1871 have been triggered by El Nino—the most recent being in 2009.
Earlier, IMD had predicted the development of El Nino by the end of winters. On November 22, the agency said moderate El Nino Southern Oscillation (ENSO) conditions were prevalent in the equatorial Pacific Ocean region and the El Nino is likely to develop in the next two months. Further on December 3, it again stated equatorial sea surface temperatures (SSTs) were above average across most of the Pacific Ocean.
The impact of El Nino on global weather has gotten more intense as a result of climate change, according to a research paper published in the journal Geophysical Research Letters.
Its past
The last El Nino event that ended in 2016 had lasted for two years and caused heat waves all around the world, including India. The heat waves in 2015 and 2016 killed more than 2,500 people in India, and have been attributed to climate change which suggests that El Nino was intensified by global warming.
“The heat waves of 2015 and 2016 have been attributed to global warming with some confidence, particularly when considering a combination of temperature and humidity,” says Arpita Mondal, assistant professor at the Indian Institute of Technology, Bombay.
The severe El Nino had also caused massive coral bleaching in the Great Barrier Reef and droughts in parts of Africa, South East Asia and South America. This year, too, Australia has seen its worst drought in living memory. In regions like the New South Wales the drought is the worst in 400 years.