Weather Vane. Eyes glued to Pacific, for monsoon clues

An extended ‘El Nino’ phase in the Pacific Ocean, which began in October-November-December of 2014, ran through all of 2015 and held sway until April-May-June 2016. During this spell, it masterminded two deficit-monsoon years on the trot (2014 and 2015) in India.

This may re-emphasise the link, however tenuous, between the periodic abnormal warming of waters in the East and Equatorial Pacific that lie spread out over thousands of km across the country’s international boundary, and the South-West monsoon, the lifeline of its farm economy.

Now, why should something that happens in the Pacific be of concern to India and its monsoon at all? The answer lies in the size, scale and enormity of climatic systems that this vast water body fathers and which respects no geographical boundaries as they move around wherever they wish over land or seas/oceans to stamp their firm imprint on local/regional weather/climate.

At 165.25 million square km in area, the Pacific forms the largest division of the World Ocean. It covers about 46 per cent of the planet’s water surface and about one-third of its total surface area, making it larger than all of the Earth’s land area combined.

Periodic anomalous warming of its eastern flanks creates lower atmospheric pressure, setting off evaporation and cloud building, which combine to build storms/cyclones/typhoons packing heavy rain and high winds.

In comparison, the western part of the ocean (which lies closer to India) cools, brings higher atmospheric pressure into play, suppresses cloud formation and rain, and generates dry conditions. This is called the El Nino (or, in Spanish, ‘little boy’).

Exactly the reverse happens in a La Nina (‘little girl’) phase when the warmth of the Pacific Ocean migrates to the western part and vice versa. As is usually the case in April (and pre-monsoon in India), the focus has once again shifted to the Pacific for signs of what it might ‘deliver’ this year.

Currently, the Pacific is in a ‘neutral’ phase as it emerges from a weak La Nina phase that set in the latter part of 2016, which also helped engineer the near-normal monsoon for India (though not so in South India).

Latest updates suggest that this weak La Nina phase has ended and the Pacific has started warming yet again. Available indications suggest that it could deliver a ‘little boy’ yet again. What he grows into is the million-dollar question. For instance, the Application Laboratory of Jamstec, the Japanese national forecaster, says it could be a ‘moderate-to-strong’ event, which puts it next in intensity only to the ‘strong’ event of 2015.

As already mentioned, before receiving average rains in 2016, India suffered back-to-back drought years for only the fourth time in over a century, hurting incomes and driving some farmers to suicide.

But even in 2016, the South of the country was denied its share thanks to a strong unfavourable (negative) phase of the Indian Ocean Dipole (IOD), which mimics El Nino-La Nina phase in its backyard. The forecast so far for the Indian Ocean this year tends to suggest a positive IOD phase, which favours a concurrent monsoon. What bears watching is whether this can help neutralise the impact of an El Nino in the Pacific just as it did in 1997, a strong El Nino year, as also in 2006.

El Nino is known to affect kharif output as 55-60 per cent of the country’s sown area is still rain-fed. In oilseeds, soyabean, groundnut and castor seeds may take a hit while among pulses, tur, urad and moong may be the worst affected. Sugarcane, cotton and rice also are likely to be affected.

The sowing of castor seed takes place in June-September and harvesting in November-March. El Nino can lower production of castor and lead to a rise in prices. The weather in Brazil, a big contributor to the global production, is another factor to watch out for. India and China are other major producers. With China consuming most of the castor seed it produces, India is a major exporter. Well-distributed rainfall from June to September is required for good growth of the cane crop. But an El Nino could cut down the production of sugarcane.

Sowing of cotton starts from June, and the progress of monsoon is critical in determining the short- to medium-term price trends. Late arrival, if any, of the monsoon could delay sowing and lower productivity.

An El Nino could bring about a fall in soyabean yield, which will lead to lower availability, in turn leading to a rise in prices of refined soya oil. Prices will also take cue from factors such as the onset of monsoon, sowing progress as well as condition of the soyabean crop and withdrawal of monsoon.

El Nino may hit rains in Indonesia and Malaysia, the world’s two-largest palm oil producers. Production and yield could take a hit, leading to a price spiral.

COMMENT NOW