Today when the United Progressive Alliance
(UPA) government, in its second term, is suffering from low credibility, a
failed monsoon could well become a political tipping point. The scars of a
failed monsoon and the ensuing hardships are hard to erase in the minds of
voters especially when the next elections are simply one season away. The
constant litany from the India Meteorological Department (IMD) of a “normal
monsoon” only pushes decision makers to a slumber that they need to be woken up
from, if rural India’s distress is to be minimised.
This angst over whether the monsoon will bring
rains has become an annual occurrence but the sad reality is that the
weathermen are just not able to predict its arrival, spatial distribution and
departure accurately. They are not to be blamed since the science of the
monsoon remains a black box, a mystery that has not been understood despite
huge developments.
Indeed, it is high time Indian scientists
collectively told the government that since they can’t forecast the extremes,
it is really meaningless to forecast the monsoon. The need of the hour is to go
back to the drawing board to first understand the phenomenon of the monsoon and
then, if ever we understand it, attempt to forecast it.
Issue of models
Forecasting the southwest monsoon is not
easy. Till date in the 137 year history of the IMD, which operationally
forecasts the monsoon, it has never succeeded in correctly predicting the
extremes. In a rare and candid admission Dr. Laxman Singh Rathore,
director-general of the IMD, New Delhi, for the first time admitted that
“prediction of extreme events is a problem since models [they use] tend to
normalize things.”
This means that despite best efforts, the IMD will never be
able to forecast a drought or flood for the country as a whole.
To put this in perspective, in the last 137
years the Indian weather office has never ever been able to predict a drought.
Look at the basic statistics. In the last 100 years, more than 85 per cent of
the time the monsoon has been normal. So the chances of a normal monsoon are
always high. In the last two decades, the IMD has invariably only forecast
“normal” monsoons despite the huge variations India has witnessed in bad years
like the massive flooding of 1994, and the droughts of 1987, 2002, 2004 and
2009.
Experts say a forecast is only good if it
can pick up early signals and warn of impending hazards so that policymakers
and farmers in particular can prepare for the worst while hoping for the best.
To make a point in its self-praise, the IMD always points out that from 1989 to
2000, 11 years in a row, it predicted a “normal”
monsoon and it “turned out to be normal.”
But a closer examination reveals that more often than not, even in this “golden
period” their prediction was also actually way off the estimated margin of
error allowed in the model itself.
The flaw possibly lies in the statistical
model that the IMD uses to make its predictions. The current model is still not
good enough. A numerical model considered more accurate is still cooking.
Interestingly, for the 2012 season, the new numerical model imported from the
United States actually predicts a surplus.
Interestingly, the world over, scientists
find it very tough to forecast weather patterns months in advance, so in a way
it is commendable that the IMD puts its reputation on the block and makes an
operational monsoon forecast. Most others only do this as an academic exercise.
According to India’s leading atmospheric scientist, J. Srinivasan of the Indian
Institute of Science,
“no agency in the world has ever been able to
predict an ensuing drought or flood for the Indian region.”
So should we not stop giving lollipops of a
“normal” monsoon to the people?
Understanding the monsoon
The southwest monsoon is that life giving
phenomenon which releases on the Indian land mass 80 per cent of the total
annual of 105 cm of rainfall that India receives. Every year between June and
September, moisture laden winds blowing in from the Indian Ocean rejuvenate the
parched Indian countryside. The monsoon arrives without fail, but forecasting
it months ahead is a nightmare.
Much more difficult is to give early estimates
of when the breaks are likely to occur during the season. Farming, especially
crop sowing, is very dependent on the timing of the rainfall. In any given
year, if rainfall climbs more than 10 per cent above a long-term monsoon
average, floods ensue. If it declines more than 10 per cent below average, a
drought is declared. Slippage in either direction brings misery. For example, a
drought in 2002 shrank India’s GDP by an estimated 5.8 per cent.
It may come as a surprise but the monsoon
arrives without fail and has never delivered less than 60 cm of rain in the
last 137 years of official records. But its spatial and temporal variation is
vast, a fact which befuddles scientists.
“Every year the monsoon is peculiar in its
own way,” says Dr. Srinivasan. “We need to understand how the clouds develop
during the monsoon and how they are born and how they die and this we need to
understand very badly because due to global warming, monsoon is going to change
and we need to know how it will change.”
Now in an effort to erase the blemish of not
forecasting the monsoon accurately, the Ministry of Earth Sciences (MoES) is
launching a new five year “monsoon mission” at the cost of about $75 million to
better understand this complex ocean and atmospheric phenomenon. The monsoon of
2011 was an eye-opener for forecasters. The IMD had forecast that it would be a
bad monsoon with rains possibly being less than 90 per cent of the long-term
average, but at the end of the season, the rains turned out in excess of the
long period average. Hence, in a first of its kind admission as part its end of
season report, it said that it was “not
very accurate” in its forecasts.
“The monsoon remains a scientific mystery,”
admits Madhavan Rajeevan, a monsoon specialist, in the MoES, adding, “We are
accumulating more questions than answers.”
Shailesh Nayak, a geologist and secretary in
the MoES says,
‘‘understanding the monsoon will be major
priority in the next five years.”
In this new Monsoon Mission, efforts will be
made to understand it using the numerical models developed by the United
Kingdom Meteorological Office and the American model called Climate Forecast
System developed by National Centers for Environmental Prediction (NCEP) that
combine data from ocean, atmosphere and land for providing long range
forecasting. Mr. Nayak admits that “current
prediction capabilities are inadequate” and an effort will be made to
improve high performance computing.
The Indian Institute of Tropical
Meteorology, Pune will take the lead in deciphering the seasonal forecasts,
while trying to predict the active and break periods of the monsoon. Mr. Nayak
says the bottleneck is a shortage of trained scientists. According to his
estimate, in the next five years India needs about 1,200 skilled
meteorologists. There are only about 350 now.
It is also widely acknowledged that even
though the monsoon is a repetitive annual event, accurately predicting the
natural variations is like finding a path through a minefield because the chaos
of the tropical oceans and atmosphere is very hard to understand, let alone
model and forecast.
