The growing uncertainty of El Nino conditions during the Indian Monsoon is keeping the weather agencies on the tenterhooks across the globe. The earlier consensus of a likely strong La Nina has shifted now to a state of divided opinion. Accordingly, whether more favourable conditions will actually form or appear in time for Monsoon rains, is a contentious issue.
Read to know, What is the impact of El Nino on Indian Monsoon
This El Nino is possibly one of the longest and strongest on record, wherein the Pacific temperature has remained above normal by more than 2˚C from fall of 2015 till now. As oceans are not good conductor of heat, they neither absorb nor release the heat quickly. More often, the declining trend of temperature is very gradual. In the last two weeks, Nino indices in the Pacific have dropped marginally. The mixed layer depth (MLD i.e. Sea surface to 50 meters below) and the thermocline (50 to 150 meters below sea surface) continue to be very warm. The images below will further substantiate this statement.
However, if we look into the image below we can see that below 150 meters, cooling has started and the phenomenon is also getting pushed eastward. This could be taken as a precursor to the likely cooling in the upper layers as well.
The past records do suggest a strong La Nina followed by strong El Nino but considering the present state, let us not be very optimistic about prospects of a big La Nina. Looks like, even the best of the drop rate may just suffice to reach a neutral ENSO at the time of onset of Monsoon.
Here’s a look at the surface temperatures anomalies in degree Celsius since the beginning of February:
It may be pertinent to state that weather pattern like El-Nino are not caused by climatic change. However, the rising ocean temperature by global warming are believed to impact their intensity and frequency. In the last two decades, there have been five El Nino years (1997, 2000, 2004, 2009 and 2015) and out of these, 2002 and 2009 had resulted in severe droughts.
Must watch: NOAA explains El Nino and La Nina phenomena
Two successive droughts of 2014 and 2015 almost rule out the climatological probability of yet another drought. But the intriguing question still remains - how good Monsoon 2016 is going to be.
Image credit - tripoto.com