India's Monsoon

What is a monsoon, anyway?

Though the term “monsoon” is defined slightly differently among various meteorological bodies, it is widely accepted as referring to the seasonal patterns of surface winds, caused by the movement of semi-permanent high and low pressure areas.

These semi-permanent pressure areas which influence India’s Southwest Monsoon (winds blowing from the southwest direction) are known as the Pak-India Low; Monsoon Trough; Tropical Easterly Jet; Tibetan High; and Mascarene High.

The intensity and positioning of each of these systems impacts both short (1-3 day) and medium range (4-10 day) forecasts. And these systems are related: if the Monsoon Trough intensifies, the Mascarene High will likely intensify 24 to 48 hours after, followed by an intensification of the Tibetan High and Tropical Easterly Jet after an additional 24 to 48 hours. This particular phase takes roughly one week to complete—and can happen several times over the four-month monsoon period—and if it intensifies at each stage, results in a stronger monsoon.

The Pak-India Low is conceptually the starting point of the monsoon cycle. The Thar Desert of northwest India is one of the hottest places on Earth, with summer temperatures capable of soaring beyond 50°C (122°F), and the warm air aloft creates a low pressure area over the region. Moisture streams from the Indian Ocean flow towards this low in a cyclonic flow, which is clockwise north of the Equator, pulling in winds from the southwest and west. These moisture-filled winds carry towards the subcontinent until hitting the Himalayas, which block them from moving into Asia. 

At the southern tip of the Indian peninsula, winds divide into the two branches of the monsoon: the Arabian Sea Branch and the Bay of Bengal Branch. The Arabian Sea Branch travels northwards up the Western Ghats mountain range, which runs adjacent to India’s west coast. The Western Ghats partially block the Arabian Sea Branch’s eastward movement, but the fact that the mountain range ends before the states of Gujarat and Rajasthan allow those two to receive significant rainfall from the system.

The Bay of Bengal branch travels over the Bay of Bengal (framed by India on the west and Southeast Asia on the East) towards Northeast India. This system travels along the Eastern Ghats mountain range, but the fact that the Eastern Ghats are lower than the Western ones means that these mountains are capable of blocking less this branch’s movement. It therefore continues on to Bangladesh and Myanmar, which are both very much dependent upon this branch’s associated rains. 

Ultimately, the two branches reunite over the Gangetic Plain, in northern India, and merge into one, though much of the moisture has already been exhausted at this point.

The above describes only the Southwest Monsoon, which is the most important monsoon phenomenon to the subcontinent. The East Asian monsoon, for example, occurs at roughly the same time as the southwestern one, and brings seasonal rains to Southeast and East Asia. 

This year’s monsoon

The southwest monsoon is responsible for more than three quarters of India’s total rainfall. These rains are the lifeblood of India’s agricultural economy, especially given the fact that about 60 percent of Indian farmland is rain-fed as access to irrigation remains very much limited. This dependence upon rain-fed systems means that not only is total rainfall an important determinant of agricultural success—but so is the pattern of such rains, as uneven, ill-timed or changeable precipitation has a negative impact on agricultural production.

Monsoon-season crops, referred to as kharif crops, are responsible for a significant share of total agricultural production and include rice, millet, corn, groundnut, pigeon pea, soybean, cotton and wheat. Because kharif crops are largely sown upon the start of the rains, erratic rainfall at the start can force farmers to plant their seed prematurely, or hinder their ability to adequately prepare their land, or negatively impact crop growth. And while the effect of inadequate rainfall is particularly obvious when examining the kharif crop, precipitation patterns during the summer months also impact the ability to successfully sow winter, or rabi, crops during the secondary growing season which runs roughly from October through March. 

The onset of the monsoon rains varies by region, as does the dependence upon these rains for successful agricultural production. States such as Chhattisgarh, Kerala, and Maharashtra are heavily dependent on the seasonal rains, while Punjab and Haryana are comparatively less so. But the monsoon’s overall importance to the Indian economy can hardly be overstated: the governor of the Reserve Bank of India, Duvvuri Subbarao, called himself “hostage to monsoon,” given a weak monsoon’s inflationary potential. Similarly, the country’s current President (and former Finance Minister) Pranab Mukherjee famously stated that the monsoon was the “real” finance minister of India.

Much before the onset of the rains, prominent forecasters, like the India Meteorological Department (IMD), predicted that there was a strong possibility of below-average rainfall.

In April, the IMD released its predictions that the probability of deficient monsoon rains (<90 percent of the long period average) was 33 percent; the probability of below normal rains (90-96 percent of the average) was 35 percent; of normal rains 28 percent (96-104 percent), of above normal rains 3 percent (104-110 percent), and excess rains (>110 percent) just 1 percent.

The elevated probability of below-normal or deficient rainfall was particularly unwelcome this year, given that last year’s rains were 12 percent below their long period average, and that residents were particularly eager for relief from an uncharacteristically extreme heat wave that was blamed for up to 2,500 deaths in the country. 

By the first week of June, IMD released a statement indicating the probability that this year’s monsoon rains would be deficient had doubled to 66 percent, and that they were likely to amount to only 88 percent of average monsoon season rainfall (model error of ±4 percent). The probability that the rains would be below normal (90-96 percent of the average) was adjusted to 27 percent—which in turn meant that the probability of a normal monsoon was slashed.

Rains materialized early in June with massive, above average downpours that encouraged farmers to sow early. Overall, the month of June had strong rainfall: 189.5 millimeters, against the average of 163.5mm. This may have assuaged some fears, and even led to victorious-sounding headlines, but experts remained extremely cautious. While the rains were welcome, June is the least significant monsoon month: the 163.5 mm of expected rainfall in June is far less than the 288.9 mm expected in July, or the 261.0 mm expected in August, or even the 173.5 mm in September.

In the first few weeks of July, rainfall throughout much of the country was relatively weak. Towards the end of the month however, precipitation picked up—and in some parts of the subcontinent, it did so with a vengeance. In the Western states of Rajasthan and Gujarat, deadly floods claimed more than 100 lives, and in the Eastern state of West Bengal, dozens more were killed by a separate inundation. For India as a whole, July ended up falling short of rainfall expectations, with total precipitation amounting to roughly 83 percent of the historical average for the month.

And while the preceding months had allowed for muted optimism, or at least the potential for an only a slightly bad monsoon season, August proved to be the worst month of all. The month has culminated in nearly a 22 percent rainfall deficit—making it the third-driest August since 1993.

The outlook for September is glum enough to make a full recovery unlikely, with IMD representative indicating in the first days of the month that the monsoon deficit is likely to widen slightly (by one or two percent). One important thing to note is that total precipitation is not the only important aspect of the monsoon rains—their regional distribution and timing are also extremely important. And fortunately, in these two aspects at least, this year’s monsoon has not been too bad. 

In terms of overall precipitation, however, the deficit has been worst thus far in the South Peninsula, where rainfall has been 22 percent lower than the long period average. Central India is the next worst hit, with 16 percent below average rainfall, followed by Northwest India which is down 12 percent. East and Northeast India have had rainfall roughly on par with the long period average (down 1 percent).

Despite the optimistic chatter especially from media sources, that the “positive” Indian Ocean Dipole (IOD) could neutralize the negative effects of El Niño on the monsoon, such an outcome is unlikely. A positive IOD can indeed potentially mitigate against the impact of a strong El Niño, as it means that the waters in the Western tropical Indian Ocean are warmer than the eastern ones, and can create more moisture flow opportunities and favorable winds. Or to put it simply, a positive IOD can encourage more rainfall in the subcontinent.

Although optimistic reports indicated that the IOD was positive in June and July, the oscillation was technically in neutral phase, as neither June nor July anomalies met the +0.4°C threshold to qualify as positive events. August IOD just met the positive qualification with an anomaly of +0.4 Centigrade. And with the monsoon forecasted to begin its retreat within the next few weeks, it is highly unlikely that a borderline IOD could reverse these effects. 

Global impact

As a one billion-person market that is both a top producer and top consumer of many agricultural items, India’s rains (or lack thereof ) have global repercussions.

India is not only the world’s second-largest producer and consumer of rice, but is also typically a top-5 exporter of the grain. Much of India’s exported grain is destined for Saudi Arabia, Iran, Bangladesh, and West Africa (especially Benin, Senegal, and Nigeria). And while growers are holding out hope for good September capable of supporting a successful rice harvest, it is still unclear as to whether that will happen. This may translate into reduced rice exports from India—a fact which, when coupled with the potential for reduced output from top exporter Thailand (also due to erratic rainfall), may place upward pressure on global rice prices. 

And while a global sugar glut has kept prices of that commodity low over the past several months, sizeable rainfall deficits in top Indian sugar producing states Maharashtra and Uttar Pradesh have analysts concerned about their output potential. Excessive rainfall in Brazil, also related to El Niño, may also threaten the country’s overall sugar output.

Pulses are a vital agricultural group for India—so much so that it has blocked the exportation of pulses, other than chickpeas, since 2006. The country is a top producer of several pulse varieties, and still the largest importer of pulses, when considered as one group. India is also a major importer of soybean oil, despite being a major producer of the crop. A poor monsoon performance may, therefore, mean, an uptick in Indian imports of items including pigeon peas and lentils (which it mostly sources from Myanmar), as well as soybean oil (which it mostly gets from Argentina and Brazil).

India has a long history of instituting export bans for crops like wheat, rice, pulses and cotton, and has even put in place restrictions for goods like vegetable oils and onions. A weak monsoon performance, and the associated weak crop performance may lead the Indian government to restrictive export measures, as it has in the past.

Dealing with unpredictability

India is better equipped today to handle weak monsoons than it has ever been before. And the Indian government appears committed to stepping up its investment in its agricultural sector.

The Indian government has indicated its intention to step up its satellite crop monitoring system designed to enable something closer to precision agriculture—through the updated system, farmers would get, via their mobile phones, geographically tailored agricultural advice on issues including seed varietals and fertilizer types.

In July of this year, the government announced a nearly $8 billion investment over five years, which will boost access to irrigation in the subcontinent and establish an online market through which farmers can sell their goods. 

Over the past three decades, India has tried repeatedly to implement a farm insurance scheme, building and scrapping ineffective programs. Even still, the current scheme is widely criticized as having bad design, remaining inaccessible to the poorest farmers, and having the potential to trap farmers in cyclical debt. Earlier this year, the government announced its Unified Package Insurance Scheme, a holistic approach to farmer insurance (insurance would cover crops, livestock, agricultural equipment, and health). The new system may hold promise yet, but it is unclear as to what its implementation timeline will look like.

Although India is clearly ramping up its, and its farmers’, capacity to better deal with bad weather, it will have to act quickly. Climate change is predicted to make weather across the subcontinent only more erratic: if the earth warms by 4°C by the end of the century, which is what scientists predict will happen if no major measures are taken to combat climate change, there will be both more extreme droughts, and more extreme floods. An extreme wet monsoon, which currently happens only once every 100 years, could happen once every 10. 

Conclusions

The subcontinent has been waiting for and watching this year’s monsoon rains with baited breath. And forecasters maintain that like last year, this year’s season will disappoint. While two back-to-back poor rainfall years are certainly a blow for the country’s agricultural sector, it may ultimately help highlight the urgency with which the subcontinent needs to make itself less dependent on what will be an increasingly undependable season.