How El Niño plans to hijack monsoon 2015
Whether the monsoon starts off on time, whether the June, July, August and September rainfall averages are met, and whether the seasonal pattern of the monsoon is maintained are expectations that must now be set aside.
According to the Climate Prediction Center’s ENSO probability forecast, there is a 90% chance that El Niño conditions will prevail through June to August of the northern hemisphere and a more than 80% percent chance El Niño will last throughout all of 2015.
What this means, especially when record warm global atmospheric temperatures (because we in South Asia and our neighbours in East Asia have continued burned coal as if the resulting CO2 and soot simply doesn’t exist) are being set, is the remaining months of 2015 – the monsoon period included – will bring strange, dangerous and extreme weather. We have already seen that over the last week, with the death toll from the heat wave having crossed 550.
For the first time since 1998 – the year of the strongest El Niño on record, which played havoc with the world’s weather patterns and was blamed for 23,000 deaths worldwide – ocean temperatures in all five El Niño zones have risen above 1 degree Celsius warmer than normal at the same time. That is read by climatologists and ocean scientists as presaging an El Niño that is moderately strong to strong. The forecast models updated in May are now unanimous that El Niño is going to keep strengthening through the rest of 2015. (See also the official forecast from the USA’s government climate science agency.)
El Niño’s home is in the tropical eastern Pacific, but we in India need to watch the waters to our south very closely. New research published in the journal Nature Geoscience has examined records going back to 1950 and noticed that Indian Ocean absorbed heat at a low level until 2003. Thereafter, the excess oceanic heat in the Pacific Ocean found its way through the Indonesian archipelago and into the Indian Ocean. This is the gigantic reservoir of watery heat that is going to dictate terms to our summer monsoon, or what our school textbooks call the south-west monsoon.
It is a worry for the entire South Asian region – India, Pakistan, Sri Lanka, Bangladesh, Nepal, the Maldives, Burma, Afghanistan and Bhutan. That is why when the Forum on Regional Climate Monitoring-Assessment-Prediction for Asia (FOCRA) issued its seasonal outlook for June to August 2015 it predicted weaker than normal Indian summer and East Asian monsoons. Precipitation over land is influenced by external factors such as the El Niño Southern Oscillation (the ENSO), the ‘Indian Ocean Dipole’, the ‘Arctic Oscillation’, and so on.
There may be a “timely onset” of the monsoon, as the venerable IMD is used to saying, but that doesn’t mean our troubles are over. Far from it.