Latest revision as of 18:43, 19 November 2023

[edit] In three sentences

The four-month monsoon [rainy] season normally begins from June 1 and ends on September 30. The Southwest Monsoon gives 70 per cent (of the entire year's) rains to the country, where agriculture still remains a major contributor to the GDP. June contributes 17% of the total rainfall, July 32%, August 28% and September 23%. (From PTI)

And three more sentences:

How long was the monsoon break in June, during the period 2010 to 2018?

2010: It was a 13-day break, the longest in June in the years 2010-18

2018: The monsoon did not move for 9 days after June 13.

And one more important fact:

India's Long Period Average rainfall is 880mm (1961- 2010).

[edit] A backgrounder

Here is how a monsoon is rated to be good, bad or normal
From: April 17, 2022: The Times of India

[edit] The overall picture

Monsoon usually reaches India's mainland by first week of June, May 29 2017: The Times of India

What causes monsoon?

Monsoon, which is the seasonal reversal in the wind direction, causes most of the rainfall received in India and some other parts of the world. The primary cause of monsoons is the difference between annual temperature trends over land and sea. The apparent position of Sun with reference to earth is not fixed -it oscillates from tropic of cancer to Capricorn through the equator. The heating leads to the creation of a low pressure region. The northeast and southeast trade winds converge in this low pressure zone which is also known as the Intertropical Convergence Zone (ITCZ). This low pressure region witnesses continuous rise of the moist wind from the sea surface to the upper layers of atmosphere, where the cooling causes the loss of moisture resulting into precipitation. It is observed that the rainy season of east Asia, Sub Saharan Africa, Australia and southern parts of North America coincides with the shift of the ITCZ towards these regions.

What causes Indian monsoon?

Thar Desert and adjoining areas of the northern and central Indian Subcontinent heats up during the hot seasons of sum mer. Because of the rapid solar heating mainly between April and May a lowpressure cell is created over the Indian subcontinent. To fill up this void, the moisture-laden winds from the Indian Ocean rush in to the subcontinent. The ITCZ, which is sometimes also referred as monsoon trough also shifts northwards towards the subcontinent causing monsoon rains which typically reaches subcontinent's mainland in the last week of May or the first week of June. The metdepartment declares the onset of monsoon over Kerala if 60% of the 14 enlisted stations falling in the states report a rainfall of 2.5mm or more for any two consec ll of 2.5mm or more for any two consec utive days falling after 10 May.

What are the ways to forecast monsoon?

Generally there are three main approaches used for long range forecast of the southwest monsoon in India. The first is the statistical method which uses the historical relationships between southwest monsoon and various global weath er parameters. The historical data is then used to forecast the onset of the monsoon.The second approach is the empirical method which uses time series analysis of past rainfall data. The third is the dynamical method which uses general circula tion models of atmosphere and oceans to predict the southwest monsoons. It is observed that the prediction models based on statistical approach have so far yielded most accurate results for the Indian monsoon. However none of the models can claim 100% accuracy because there are several factors like the correlations between the parameters, changing predictability of the model over a period of time.

Which method is used by our met-department to forecast monsoon?

Prior to 2002 IMD used to issue annual forecast using a model based on 16 parameter but it failed in 2002. Since 2003 two new models were introduced which instead of 16 used 8 and 10 parameters to forecast the southwest monsoon in India. Apart from this a two stage forecast system was also introduced--the first stage forecast was issued in mid April and an update or second stage by the end of June. This model also gave false predictions for 2004. Since 2007 a new forecast system using ensemble technique is being used to forecast monsoon. At present monsoon is predicted on the basis of five predictors including the sea surface temperature (SST) gradient between north Atlantic and north Pacific, Equatorial South Indian Ocean SST, East Asia Mean Sea Level Pressure, Northwest Europe Land Surface Air Temperature and Equatorial Pacific Warm Water Volume at designated times of the year. Instead of relying on one model with best possible forecast, the ensemble method uses inputs from the forecast of all models to calculate the final result.

[edit] Steven Clemens’ research

June 19, 2021: The Times of India

The Indian monsoon originates in distant waters and faraway lands before it travels here
From: June 19, 2021: The Times of India

Steven Clemens teaches earth, environmental and planetary sciences at Brown University. Speaking to Srijana Mitra Das at Times Evoke, Clemens discusses how a monsoon is made, the impacts of global warming on the rain — and why India’s monsoon is special:

What is the core of your research?

We look at ocean sediments that build up on the seafloor over time and examine their chemical, physical, isotopic and biological properties. Through these, we reconstruct changes in monsoon winds and rainfall across time.

Studying the monsoon is important because it’s one of the largest expressions of the movement of water and energy in the atmosphere on Earth. It is responsible for much of the rainfall that tropical and subtropical continental interiors receive and it’s shaped by very powerful meteorological, environmental and climatic drivers.

How is a monsoon actually made?

The location or the latitude and longitude of Africa, India and parts of Asia conspire such that when summer begins, these continental interiors start to heat up quite strongly. That creates low density air along the surface of these continents. This moves upwards into the atmosphere and creates a vacuum. This draws air masses inwards from the ocean into India.

Surface air masses are one reason why the South Asian monsoon is so strong — the unique geography of the Indo-Asian landmass confines and intensifies the circulation of these air masses, which further power the monsoon. With the Indian monsoon, the air masses originate in the southern hemisphere of the ocean and then, the vacuum pulls these up across the equator, into the Arabian Sea, where these air masses curve to the right into India. It thus draws a tremendous amount of moisture and energy from the southern hemisphere into Asia — that’s a unique component of monsoonal circulation in India, not shared by any other monsoon in the world.

What is the role of the Indian Ocean?

The Indian Ocean is absolutely central — most of the monsoon’s energy that’s released over India comes from the ocean. It’s extracted out of the waters and hidden in the atmosphere as latent heat. It’s expressed only when that moisture condenses and causes rainfall.

Are rising Co2 levels impacting this?

Numerous models find that increased Co2 levels will result in a warmer planet — this means more moisture in the atmosphere, which will cause increased rainfall in the South Asian monsoon. We have tested these predictions using sediment records off the coast of India and we’ve verified that indeed, with future Co2 increases caused by anthropogenic or human action, there will be more intense monsoon rain.

Importantly, there are two opposing forces at play here. Anthropogenic aerosols in the atmosphere over India decrease moisture and reduce the Indian monsoon’s strength. But alongside, rising Co2 is intensifying the monsoon. So, we have two forces pulling at opposite climatic ends. But I would predict increases in monsoonal rain in terms of mean annual rainfall levels.

Does solar radiation affect the monsoon?

Yes but in a different timescale. We examine changes in rainfall from 20,000 to 1,00,000-year cycles. In these timescales, there is a lot of variability associated with changes in Earth’s orbit and how much solar radiation comes into the system. Earth has three components of orbital-scale variants — the circularity of Earth’s orbit, the spin axis or tilt of the planet and the precision of that spin axis with respect to the sun, stars and the equatorial plane. All three change over time and alter the amount of solar radiation coming to a specific latitude by upto 12% even, which is a lot.

Such orbital scale variability becomes a huge driver of change in monsoon patterns over long timescales. In the short term, changes in solar exposure play a role in warming up the landmass — that’s how monsoon circulation is initiated. But other factors drive how strong or weak the monsoon is each year.

What are some of these factors?

Most weakened monsoons in India are associated with El Nino events or condensation being drawn away to the equatorial Pacific Ocean, with consequent effects on the Indian monsoon. Another factor is the Indian Ocean dipole or a difference in sea surface temperatures between opposite poles or parts of the ocean. A positive dipole phase means warmer sea temperatures in the western Indian Ocean, and cooler temperatures in the east. This has been causing high rainfall and floods in east Africa and droughts and heatwaves in Australia. With increased Co2 levels, temperature and circulation in the equatorial Pacific and Indian Ocean will have an even stronger impact on monsoons everywhere.

Can you tell us about monsoons in other places?

I’ll share a story. Some years ago, several scientists were at a seminar discussing the American monsoon. An Indian academic suddenly remarked, ‘You know, I work on the North American monsoon but I’m from India — now that really is a monsoon!’ This observation stayed with me. If you define a monsoon as the seasonal change in wind direction and rainfall, then there are monsoons all over tropical and subtropical areas. Even the south-west United States has a monsoon in this context, as do South America and Australia.

The monsoons are global but India’s monsoon is truly incredible — it is one of the most unique systems on Earth in terms of its energy, its intricate natural systems and its interrelationship with human society.

[edit] Kaustubh Thirumalai’s study

June 20, 2021: The Times of India

Million-year study shows warming will make Indian monsoons more extreme

Climate models have predicted that global warming will make monsoons in India wetter and more unpredictable. Now, a major new study has literally dug up evidence of South Asian monsoon’s behaviour over the last million years (during the Pleistocene, or ice age), using mud samples drilled from the Bay of Bengal bed to show that periods of rise in greenhouse gases and ice-sheet melts had indeed coincided with increased rainfall over the subcontinent in the past.
Kaustubh Thirumalai, a 33-year-old geoscientist at the University of Arizona who co-authored the study, talks to Amit Bhattacharya about the study’s implications for India’s rainy seasons in a warming world and his personal journey

What does this study of a million monsoon years tell us about the southwest monsoon system and its drivers during the Ice Age, which spanned over a million years?

Our study reconstructs Indian monsoon variability over the past million years using marine sediments from the northwest Bay of Bengal. Across this period of Earth’s history, global climate fluctuated between cold glacial states with extensive northern hemisphere ice-sheets, and warm interglacial states, such as the last 11,000 years, which coincided with the advent of agriculture. Linked to oscillations in Earth’s orbit, these ice age cycles were amplified by greenhouse gases and provide a clear testbed to understand how regional variability, including weather systems, respond to climate forcing and to changes in global temperatures over long timescales (multiple decades to centuries). Contrary to previous assertions that the southwest monsoon was only sensitive to summer solar radiation across this period, our results point to a dominant role for greenhouse gases and ice-sheet melt in shaping Pleistocene monsoon dynamics.

As a sedimentologist in the group, you helped analyse “tens of kilometres” of sediments brought up from the sea bed. How do core samples drilled from the bed of the Bay of Bengal reveal the story of the monsoons in the distant past? How were the samples collected?

Bay of Bengal seafloor sediments preserve a rich history of deposits of sediments from the Indian landmass via runoff from the world’s most powerful river systems, and also serve as an archive for microfossil shells and biomarkers of organisms that once lived at the surface of the ocean. These long-dead organisms carry within them the imprint of the monsoon in their lifespans, as an intense monsoon year leads to more freshwater flowing into the Bay of Bengal, which reduces salinity at the sea surface. The sediment cores were drilled in the Mahanadi Basin, northwest Bay of Bengal, from November 2014 to January 2015 by the JOIDES Resolution drilling vessel of the International Ocean Discovery Program — an intergovernmental organisation of which India is a key member as well. The ministry of earth sciences and IODP supported and collaborated in obtaining these samples of exceedingly high scientific value. The lead author, Steve Clemens, was also chief scientist on our expedition and has been working towards these scientific objectives for more than a decade.

[edit] Kerala and the monsoon

Sudha Nambudiri, May 18, 2021: The Times of India

Infographics and lead: Sajeev Kumarapuram

As the rest of the country reels from the blistering heat, the southern state of Kerala is transitioning from a summer month to a pre-monsoon one, when the skies cloud up and the air smells of impending rain.

Most Keralites know that if it’s hot and sultry outside, even for a week, the clouds will soon give way to showers, bringing down the mercury levels. While the southwest monsoon is still far-off for the rest of the country, the Indian meteorological department (IMD), the country’s official weather agency, indicates a near normal or above normal rainfall this time around, news that has been greeted with much enthusiasm by the local fishermen and farming community.

For Kerala, which is the entry point to the Indian summer monsoon, the indications usually begin by May and June 1 is almost always the declared date of its arrival.

This, of course, varies depending on the ocean-atmospheric conditions in May. Interestingly, even though IMD has announced varying dates this year for when the monsoon will hit most states – which depends on 70 per cent of its rainfall from it – it is still June 1 for Kerala. Till 2005, the IMD would calculate the daily rainfall from seven monitoring stations in Kerala to declare the onset of monsoon. From 2006, however, a new criterion was devised, based on the daily rainfall in 14 stations across Kerala and neighbouring areas, along with measuring the wind field and the outgoing long-wave radiation (OLR) over southeast Arabian Sea.

The first alert comes almost ten days before, when the clouds swelled with rain make their presence felt in the Andaman sea. This is when the IMD issues an approximate date for its arrival. The monsoon winds then continue to cover the rest of the country, from south to north, and from east to west, by July 15, and by September 1, it slowly starts withdrawing.

In the earlier decades, the monsoon would hit Thiruvananthapuram and Kollam waters first, accompanied by strong winds and heavy rainfall for three-four days, before June 1. Coasts would be cleared and beaches would be closed in those regions as the state would prepare for the monsoon. But today records show it has moved upwards to Kochi and central Kerala.

In its report, “Observed rainfall variability and changes over Kerala state”, the IMD climate research centre has found changes in the monsoon patterns in the 30 years from 1989-2018. It also notes that Kerala receives its highest rainfall in July (32.9 per cent) followed by June.

“The most notable change in the behaviour of the Indian summer monsoon is that there is a significant rise in heavy rains along with a steady decline in total monsoon rainfall. Basically, rainfall patterns have changed, and we are having longer dry spells with intermittent heavy rainfall events,” said Roxy Mathew Koll, senior scientist, centre for climate change research (CCCR), Indian Institute of Tropical Meteorology, Pune. “We find that this is due to rapid ocean warming that makes the monsoon circulation erratic.”

In recent years, monsoon trackers have been noting that the beginning of the monsoon is generally weak, but gradually picks up. Also, cyclonic systems forming in the Arabian Sea or the Bay of Bengal late May or early June are considerably affecting the monsoon circulation as well as the rainfall pattern.

“Arabian Sea has been witnessing the formation of cyclones along with the monsoon onset in Kerala,” said S Abhilash, associate professor, Advanced Centre for Atmospheric Radar Research (ACARR), Cochin University. “They disturb the basic monsoon state and, depending on the region of its formation, it can adversely affect the further northward progression of monsoon. Alternatively, when the cyclones form very close to the west coast and move parallel to it, they also help in the fast propagation of monsoon current Northwards.”

While scientists refuse to pin down the reason behind the change in the rainfall patterns, they admit to recording changes annually and seasonally too. “The variability has increased in the recent years,” added Abhilash. “For example, Kerala has witnessed occurrences of intense droughts (2015 and 2016) and floods (2018 and 2019) in the last 10 years. Even in intensity, extreme rain events have increased. Heavy rain days are increasing and light to moderate rainy days are decreasing. For example, a large rainfall deficit of 30 per cent is compensated in one or two intense heavy spells.”

While climate change is being pointed to as an indicator of these trends, scientists have been saying that changes in land use have contributed to the disruptions in natural systems. These land use changes become catastrophic in areas that are susceptible to natural hazards like landslides and floods.

“Kerala, which sees tropical monsoonal climate, and is sandwiched between the towering Western Ghats and the Arabian Sea, has three physiographic stretches viz, the coastal plains, the midlands and the highlands. Midlands, being a huge potential area for cash crops like rubber, population pressure, increased toward mountainous regions and coastal plains,” said Sajin Kumar K.S, adjunct assistant professor, department of Geological & Mining Engineering & Sciences, Michigan technological university. “These two physiographic regions are susceptible to landslides and floods, respectively. Hence any shifts in the natural vegetation in these regions will see catastrophic natural hazards similar to what occurred in 2018.”

The first alert comes almost ten days before the actual onset, when the clouds swelled with rain makes its presence felt in the Andaman sea According to him, a correlation of the land use of the Western Ghats part of Kerala, between 1973 and 2020, reveals that there is a shift in land use patterns, showing mainly a decrease in dense forest whereas increase in built-up areas. “Built-up area have shown a steep growth of approximately 300 per cent, and this could be at the expense of mixed vegetation, a common type of land use pattern seen in and around the households of Kerala,” he said.

Research also shows a threefold rise in heavy rains over the west coast and central/north India. “Climate change projections indicate that the number and intensity of heavy rains will continue to increase as manmade emissions continue unabated,” said Roxy Mathew Koll. “We need to utilise our monitoring and early warning systems efficiently so that we can take advance precautions and mitigate their impacts.”

[edit] History

[edit]  ‘Indian monsoon system 27 million years old’

Rohan Dua, February 20, 2021: The Times of India

For decades, the evolution of the Indian monsoon has not been entirely understood. Nor have scientists decoded how it intensified and how it has varied with time. By analysing sediment from the Bay of Bengal, researchers have found that the present Indian monsoon system goes back at least 27 million years.

“Previous studies only went as far back as 12 million years. They used wind and vegetation data, but that would not paint a clear picture of monsoon intensity,” corresponding author Sajid Ali from the Birbal Sahni Institute of Palaeontology in Lucknow told TOI. “We analysed sediment from the Bay of Bengal. Change in sediment is directly linked to change in monsoon … The presence of minerals depends on the intensity of monsoon. Different minerals are formed when the monsoon is strong and others when it is weak.”

For the study, to be published in Wiley journal ‘Paleoceanography and Paleoclimatology’, they collected 38 sediment samples under Japan’s International Ocean Discovery Program.

When they studied nano fossils (plankton which are one thousand millionth of a metre) from the bottom of the sediment deposits, “those were found to be 27 million years old,” Ali explained.

[edit] Storms and monsoons

[edit] 1955-2014

Sudha Nambudiri, May 17, 2021: The Times of India

4 cyclones made landfall over the Indian coast in 2020
From: Sudha Nambudiri, May 17, 2021: The Times of India

How Arabian Sea is becoming a hotbed for cyclones
From: Sudha Nambudiri, May 17, 2021: The Times of India

Infographics and lead by Sajeev Kumarapuram

“Cyclones draw their energy from the warm ocean waters below. Now with rapid ocean warming, the Arabian Sea has also become fertile like the Bay of Bengal, supporting intense cyclone formation,” said Roxy Mathew Koll, senior scientist, centre for climate change research (CCCR), Indian institute of tropical meteorology-Pune. “These cyclones interact with the monsoon system, based on where they form and what track they follow. In 2020, Cyclone Amphan formed prior to the onset of monsoon and moved towards the north Bay of Bengal. This took away the moisture and rains that should have reached peninsular India, delaying the progress of the monsoon. Cyclone Amphan was followed by Cyclone Nisarga, which moved towards the Maharashtra coast. This pulled the monsoon also inland, and most of the regions north of peninsular India got an early monsoon onset.”

A study by researchers of the Cochin university of science and technology (CUSAT), covering 60 years from 1955 to 2014, shows that the number of cyclones in the Bay of Bengal has been decreasing every 20 years. The team divided the entire study period into three sets, or “epochs” as they like to call it – the early (1955−74), middle (1975−94) and recent (1995−2014) epochs. Over the Arabian Sea, however, there is a decrease in the early epoch, before then reaching a minimum in the middle epoch, followed by an increase in the recent epoch, indicating a clear variation in the pattern.

“In the last five years, we have had a couple of instances of cyclones affecting monsoon progress. In 2015, cyclone Ashobha arrived between June 8-11, and that year, the monsoon propagated fast. In 2018, there were two cyclones, Sagar and Mekunu, in May,” said S Abhilash, associate professor, Advanced Centre for Atmospheric Radar Research (ACAAR), Cochin university. “Though the monsoon had arrived, further progression was halted for a week. The next year, in 2019, cyclones Vayu from June 10-13 took away the moisture, which affected monsoon progression negatively. All these are Arabian Sea systems. However, most Bay of Bengal systems which formed in May have helped the monsoon for normal onset and further progress.”

[edit] Factors that influence the monsoons

[edit] Air pollution

Neha Madaan, April 28, 2023: The Times of India

Pune: Air pollution and a rise in west Pacific tropical cyclones have played their parts in weakening the Indian monsoon the past few decades, according to a study by researchers from Indian Institute of Tropical Meteorology in Pune.


The researchers held that greenhouse gas emissions and other human activities can significantly alter the pattern of monsoon flow over the tropical Indo-Pacific Oceans and lead to an increase in tropical cyclones over the west Pacific. Higher frequency of tropical Pacific cyclones can cause a weakening of the monsoon, as it is associated with moisture depletion over India. “Monsoon in India depends on low-level moisture transport from the Indian Ocean towards the Indian landmass. This flow tends to weaken due to human-induced pollution as per our model simulations,” said Dr TP Sabin, a senior IITM scientist. The study was led by Dr R Krishnan, director of the institute.

“Human-induced climate drivers, particularly greenhouse gases and aerosols, can impact precipitation patterns over the Asian monsoon region. While the increase in greenhouse gases can intensify rainfall, aerosol emissions (minute suspended pollutant particles) exert the opposite influence,” Sabin said. The scientist explained that high levels of aerosol in the atmosphere can deflect the sun’s heat back into space rather than warming the earth’s surface. “This leads to a decrease in temperatures on the earth’s surface and reduces rainfall,” he said. The study found that aerosol emissions in the northern hemisphere have contributed to a decline in monsoon rainover India.

[edit] Dust, soot from West Asia affect monsoon in India

[edit] Summary

Dust & soot from West Asia affect monsoon in India, November 16, 2018: The Times of India

Dust and soot transported from the deserts of the Middle East settle on the snow cover of the Himalaya mountain range and affect the intensity of the summer monsoon in India, a study has found.

Using a powerful Nasadeveloped atmospheric model, researchers from University of Maryland in the US found that large quantities of dark aerosols — airborne particles such as dust and soot that absorb sunlight — settle on top of the Tibetan Plateau’s snowpack in spring before the monsoons begin.

These dark aerosols cause the snow to absorb more sunlight and melt more quickly. The findings suggest that, among these dark aerosols, windblown dust from the Middle East has the most powerful snow-darkening effect.

In years with heavy springtime dust deposition, the end result is reduced snow cover across the Tibetan Plateau, which leads to warmer temperatures on the ground and in the air above it.

Hundreds of studies have supported this relationship since British meteorologist Henry Blanford noted a connection between springtime Himalaya snow cover and the intensity of Indian monsoons. However, they have struggled to explain the reason for the same.

Researchers used the Goddard Earth Observing System Model to simulate 100 years’ worth of springtime snow cover and its influence on the yearly summer monsoon cycle. To test the effect of dust blown in from the Middle East, the researchers ran the same simulations again, with an added software package that incorporates the snowdarkening effects of dark aerosols deposited atop the Tibetan Plateau.

Adding dark aerosol deposition to the model substantially increased the amount of sunlight absorbed by the snow, accelerating the rate of melting. This is because when snow melts, it begins to expose the darker ground underneath, which absorbs even more sunlight and intensifies the rate of melting.

Researchers also found that the strongest effect in cycles when a large amount of dust settled on the snowpack in April, May and June.

[edit] Details

November 14, 2018: Science Daily

Source: University of Maryland

Middle Eastern desert dust on the Tibetan plateau could affect the Indian summer monsoon: New atmospheric modeling study could explain the mechanism behind a century-old hypothesis

New research led by William Lau, a research scientist at the University of Maryland's Earth System Science Interdisciplinary Center (ESSIC), provides a plausible mechanism to explain Blanford's observations. Surprisingly, the explanation involves dust transported from the deserts of the Middle East, more than a thousand miles away.

Using a powerful NASA-developed atmospheric model, Lau found that large quantities of dark aerosols -- airborne particles such as dust and soot that absorb sunlight -- settle on top of the Tibetan Plateau's snowpack in spring before the monsoons begin. These dark aerosols cause the snow to absorb more sunlight and melt more quickly. The model findings suggest that, among these dark aerosols, windblown dust from the Middle East has the most powerful snow-darkening effect.

In years with heavy springtime dust deposition, the end result is reduced snow cover across the Tibetan Plateau, which leads to warmer temperatures on the ground and in the air above it. This in turn sets off a series of interconnected feedback loops that intensify India's summer monsoon. A paper describing the research, co-authored by Kyu-Myung Kim of NASA's Goddard Space Flight Center, was published online November 12, 2018 in the journal Atmosphere.

"Blanford knew that snow cover on the Tibetan Plateau wasn't the only phenomenon that influenced the monsoon, but he knew it was important," Lau said. "The relationship between snow cover and the monsoon is useful enough that the India Meteorological Department still uses it to develop its annual summer monsoon forecast. By adding knowledge of the physical mechanism responsible for this relationship, our study may help to develop more accurate monsoon forecasts."

Lau and Kim used the Goddard Earth Observing System Model, Version 5 (GEOS-5) to simulate 100 years' worth of springtime snow cover and its influence on the yearly summer monsoon cycle. To test the effect of dust blown in from the Middle East, the researchers ran the same simulations again, with an added software package that incorporates the snow-darkening effects of dust, soot and other dark aerosols deposited atop the Tibetan Plateau.

Adding dark aerosol deposition to the model substantially increased the amount of sunlight absorbed by the snow, accelerating the rate of melting. This is because when snow melts, it begins to expose the darker ground underneath, which absorbs even more sunlight and intensifies the rate of melting.

In addition to darkening the snow early in the season, the dust also strongly enhanced atmospheric warming of the Tibetan Plateau, leading to changes in wind patterns that intensify the peak monsoon. Notably, this series of feedbacks also strengthened the same winds that transport dust from the Middle Eastern deserts, bringing more dust and further enhancing the feedback loop.

According to Lau, many researchers contend that heavy monsoon rains should wash any airborne dust particles from the air, canceling out the dust's atmospheric heating effects and shutting down the feedback loop. But Lau and Kim's results suggest that enhanced winds transport enough dust to overwhelm this washout effect, leading to a net accumulation of dust on the Tibetan Plateau.

The timing of the dust's arrival was also important. Lau and Kim found the strongest effect in cycles when a large amount of dust settled on the snowpack in April, May and June.

"Every year was different in the model results. When dust arrived early in the season, it set up the initial conditions needed to change the monsoon dynamics," Lau said. "But in some years, late-season snowstorms at high altitudes covered the dust and shut down the feedback loop. It's very clear that there is a relationship between snow darkening by aerosols -- particularly Middle Eastern desert dust -- and the Indian monsoon season."

Lau and Kim acknowledge the need to move beyond modeling and investigate the connections between dark aerosols, heating and the monsoon cycle using other methods and new observations. But they are confident that their results -- which used real-world data to seed the GEOS-5 model -- could help inform monsoon prediction efforts now.

"This could be extremely important for agriculture. Farmers have to plan around the monsoon season to decide when to plant and when to harvest," Lau said. "In order to understand how human influences like climate change and land use affect the monsoon, we have to understand the basics -- including the effects of light-absorbing aerosols in darkening the snow on the Tibetan Plateau and in modulating the Asian summer monsoon. Such effects are so important that in the end, we may have to rewrite the curriculum for 'Monsoon 101.'"

Materials provided by University of Maryland. Note: Content may be edited for style and length.

[edit] Criteria used in deciding whether monsoon has arrived

i) The criteria that IMD adopts to decide whether monsoon has arrived or not.
ii)The dates on which the monsoon normally reaches various parts of India. From The Times of India

See graphic, ' i) The criteria that IMD adopts to decide whether monsoon has arrived or not.
ii)The dates on which the monsoon normally reaches various parts of India. ',

[edit] The amount of rainfall

[edit] 1901-2013: Monsoons that crossed the 100% mark

Years of excessive rain and most deficient rain in monsoon season, 1901-1945; Graphic courtesy: The Times of India, May 30 2015

Years of excessive rain and most deficient rain in monsoon season, 1946-2013; Graphic courtesy: The Times of India, May 30 2015

See graphics, '| Years of excessive rain and most deficient rain in monsoon season, 1901-2013 '

Since 1901, there have been 59 years when the monsoon has crossed 100% of the LPA. Since 2000, there have been only four years when monsoon crossed the 100% mark. These are 2003, 2007, 2010 and 2011. The projection is welcome news for the government as a stuttering monsoon can cast a long shadow on its political fortunes with growth slipping below 5% and high food inflation — prices for consumers rose 11.84% in June — proving a sizeable thorn in the side for UPA-2.

The government hopes the farm sector significantly improves on 2012’s 1.8% growth with R Rangarajan, chairman of the PM’s economic advisory council, saying a normal monsoon could even yield a 3.4% growth.

[edit] India: Back-to-back, ‘above normal’ monsoon after 1958-59

After 61 yrs, India gets back-to-back ‘above normal’ monsoon seasons, October 2, 2020: The Times of India

Salient features of Monsoon 2020
From: After 61 yrs, India gets back-to-back ‘above normal’ monsoon seasons, October 2, 2020: The Times of India

For the first time in 61 years, India recorded back-to-back “above normal” monsoon years, with this year’s season ending with countrywide rainfall at 9% above the long period average (LPA). Monsoon rains this year were also the second highest in 26 years after 2019, when rainfall across the country was 10% above the LPA. The last time India had two consecutive years of above normal monsoon was in 1958 (110% of LPA) and 1959 (114% of LPA). This year, an average of 95.8cm of rain was recorded in the country as against the LPA of 88cm.

Surplus rains in June, Aug & Sept

However, the distribution of seasonal rainfall during the June-September period was not uniform. The country recorded the highest 127% of LPA rainfall in August while July was a deficit month with 90% of LPA. The monsoon rainfall has to be between 96%-104% of LPA to be considered “normal” and between 104-110% of the LPA to be described as “above normal”. Anything more is termed “excess” rainfall.

In its first stage forecast for the seasonal rainfall issued in April, the IMD had predicted rains to be 100% of LPA (normal) with a model error of ± 5%. The forecast was upgraded to 102% of LPA, with a model error of ± 4%, in IMD’s update in May end. IMD also predicted a probability of 65% of monsoon rainfall to be “normal” to “above normal”. The actual seasonal rainfall for the country as a whole was 109% of LPA, which is more than the predicted value and thus turned out to be positive for the kharif (summer) crops.

Though India had recorded deficit rainfall in July, the surplus rains in June, August and September helped in the country recording an all-time high acreage. Based on it, the agriculture ministry has set a record target of 301 million tonnes of foodgrains for the 2020-21 crop year. The monsoon started retreating from western parts of north-west India on September 28 against the normal withdrawal date of September 17. As on Thursday, the south-west monsoon had withdrawn from Punjab, western Himalayan region, Haryana, Chandigarh, Delhi and parts of Rajasthan and some parts of Uttar Pradesh.

[edit] Driest, wettest cities of India: Jun-Aug

The driest and wettest cities of India during the monsoons ; Graphic courtesy: The Times of India

See graphic, ' The driest and wettest cities of India during the monsoons '

[edit] Dates when monsoons reach different regions

[edit] In typical years

The dates on which the monsoon normally reaches various parts of India.

See graphic, ' The dates on which the monsoon normally reaches various parts of India. '

[edit] Years in which the monsoon arrived early

[edit] 2011-2014

Years in which the monsoon arrived early: 2011-2014; Graphic courtesy: The Times of India

See graphic, ' Years in which the monsoon arrived early: 2011-2014'

[edit] Years in which the monsoon arrived late

[edit] 2000-23

Years when the monsoon arrived late over the Indian mainland, 2000- 2023
From: June 9, 2023: The Times of India

See graphic:

Years when the monsoon arrived late over the Indian mainland, 2000- 2023

[edit] All of India: Date of Monsoon covering entire country

[edit] 2012-21

Monsoon covers India 12 days in advance, fastest since 2013, June 27, 2020: The Times of India

Date of Monsoon covering entire country, 2012-20
From: Monsoon covers India 12 days in advance, fastest since 2013, June 27, 2020: The Times of IndiaIn 2021 the date was 13 July

22% Rain Surplus In June, Good Sign For Sowing

Pune/New Delhi:

In a swift and smooth advance through the country, the monsoon covered the whole of India, 12 days before the normal date of July 8, the India Meteorological Department (IMD) said.

Along with 2015, when the monsoon had raced through the country on the same date, this was the fastest progression of the rain-bearing system since 2013.

In the past 13 years, the monsoon has covered the entire country before June 26 only once — in 2013, when a freak convergence of several weather systems had caused the catastrophic Kedarnath deluge while advancing the monsoon by an all-time record date of June 16.

IMD said the monsoon marched into the remaining parts of Punjab, Haryana and Rajasthan to cover the entire country, 26 days after hitting the Kerala coast. This sets the stage for timely sowing of kharif crops across the country.

“This was one of the smoothest advances of the monsoon in recent years. Usually the monsoon progresses in fits and starts, but this year it did not stall for long at any stage,” said D Sivananda Pai, IMD’s lead monsoon forecaster.

[edit] 2013-2022

The date by which the Monsoon covered all of India, 2013-2022
From: Vishwa Mohan, July 3, 2022: The Times of India

See graphic:

The date by which the Monsoon covered all of India, 2013-2022

[edit] Kerala, 2005-2017: actual dates

i) The date when the monsoon arrived in Kerala, 2005-2017: and the date when forecasters had said it would
ii) Actual rainfall vis-à-vis official forecasts, 1990-2015;
iii) The dates on which the monsoon normally reaches various parts of India. The Times of India, May 17, 2017

[edit] Delhi

[edit] 1960-21

Monsoon advancement in Delhi, 1960-21
From: Priyangi.Agarwal, June 29, 2022: The Times of India

See graphic:

Monsoon advancement in Delhi, 1960-21

[edit] 2007-12

The arrival of the monsoon in Delhi: 2007-12

See accompanying chart for Delhi The arrival of the monsoon in Delhi: 2007-12

[edit] Kerala: 2008-15, onset vs performance

Date of onset of Monsoons in Kerala, 2008-15, vis-à-vis its all- India performance. There is no correlation between early or late arrival in Kerala and good or bad all- India performance
Graphic courtesy: The Times of India

See graphic, ' Date of onset of Monsoons in Kerala, 2008-15, vis-à-vis its all- India performance. There is no correlation between early or late arrival in Kerala and good or bad all- India performance'

[edit] Mumbai

Dates of arrival

June 9: 2021

June 11: 2022 [the normal date of arrival]

June 14: 2020

June 25: 2019.

[edit] Mumbai and Delhi together

2023: The monsoon on 23 June advanced over both Delhi and Mumbai together for the first time since June 21, 1961, the IMD said.

[edit] 2011-15: actual and forecast dates

Onset date for Monsoons, actual and forecast, 2011-15, year-wise; Graphic courtesy: The Times of India, May 16, 2016

See graphic, ' Onset date for Monsoons, actual and forecast, 2011-15, year-wise '

[edit] 2020: 2 weeks early

Monsoon covers entire country nearly two weeks early: IMD, June 26, 2020: The Times of India

NEW DELHI: The Southwest Monsoon has covered the entire country nearly two weeks ahead of its schedule, the India Meteorological Department said.

The monsoon usually sets over Kerala on June 1 and it takes 45 days to reach Sriganganagar in west Rajasthan, its last outpost in the country.

From this year however, the IMD has advanced the onset date over Sriganganagar by a week and the new normal date for monsoon to cover the entire country is July 8.

"The Southwest Monsoon has further advanced into the remaining parts of Rajasthan, Haryana and Punjab and thus it has covered the entire country today, June 26," the IMD said.

A low-pressure area over the Bay of Bengal, which moved west-northwestwards, and another cyclonic circulation over central India helped in advance of the monsoon.

In 2013, the monsoon had covered the entire country on June 16. This had also coincided with the deadly Uttarakhand flash floods.

"After 2013, monsoon has covered the country so rapidly this year," IMD Director General Mrutunjay Mohapatra said.

[edit] 2020: progress across India

Progress of Southwest Monsoon 2020- Advance (See above) and Withdrawal (See below)
From: Sudha Nambudiri, May 18, 2021: The Times of India

See graphic:

Progress of Southwest Monsoon 2020- Advance (See above) and Withdrawal (See below)

[edit] Monsoon cycle

The Times of India , Jun 02 2015

Monsoon cycle: India; Graphic courtesy: The Times of India

If after May 10, 60% of 14 stations -Minicoy, Amini, Thiruvananthapuram, Punalur, Kollam, Allapuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kannur, Kudulu and Mangalore -report rainfall of 2.5 mm or more for two consecutive days, the onset of the monsoon is declared on the second day. Normally, the monsoon sets in over Kerala around June 1 and then advances northwards. By June 5, it goes past half of Karnataka and Andhra Pradesh and crosses Maharashtra by the 10th.It covers significant portions of Gujarat, Madhya Pradesh and Uttar Pradesh by June 15 and the entire country by June-end.

[edit] The El Niño effect

[edit] 1951-2017: El Niño Vs. IOD

Impact of the El-Nino on Indian monsoons, 1951-2017; The Times of India, April 20, 2017

See graphic:

Impact of the El-Nino on Indian monsoons, 1951-2017

[edit] 1970-2015

Amit Bhattacharya, Does IMD forecast signal monsoon acing El Nino in ’19?, April 17, 2019: The Times of India

How monsoon rains have fared during El Nino years, 1987-2015.
From: Amit Bhattacharya, Does IMD forecast signal monsoon acing El Nino in ’19?, April 17, 2019: The Times of India

IMD has forecast a “near normal” monsoon this year while also indicating that a weak El Nino is likely to persist through the rainy season. If both forecasts hold true, it would be only the second time in nearly 50 years that India will have a normal monsoon in an El Nino year.

There have been nine El Nino years since 1970, and only once has the Indian summer monsoon remained unscathed from its influence. That was in 1997, when despite one of the strongest El Ninos, the monsoon ended 2% above normal.

In the other eight instances, the June-September rains in India were hit irrespective of El Nino’s strength — weak, moderate or strong — indicating a strong link between the weather anomaly in the Pacific and monsoon’s performance in India.

El Nino is an abnormal warming of ocean waters in east and central equatorial Pacific that drives changes in wind currents which, in turn, have weather impact around the world.

Apart from 1997, other instances of good monsoons during El Nino years are all from the 1950s and 60s. “There are two years when the monsoon was normal or above normal during a weak El Nino, 1953 and 1969. This year’s El Nino is also predicted to be weak,” said D Sivananda Pai, IMD’s lead monsoon forcaster. The monsoon also defied El Nino in 1957 and 1963, IMD records show.

However, the link between El Nino and poor monsoon appears to have strengthened in recent decades. All four El Ninos since year 2000 have adversely impacted rainfall in India. This includes a weak episode in 2004, which led to a drought year with the monsoon ending at 14% below normal.

In recent years, just a warming in the Pacific, which didn’t result in an El Nino, is believed to have impacted the monsoon in 2012 and 2014. However, every El Nino is unique with its own peculiarities. How it plays out, and whether large-scale features that depress the monsoon actually develop, remains to be seen.

[edit] How the monsoons control our destiny

[edit] 1950-2010: India’s growth rate in drought years

Growth rate in drought years in India and monsoon departure from normal: 1950-2010
Graphic courtesy: The Times of India

See graphic ‘Growth rate in drought years in India and monsoon departure from normal’

[edit] Why Monsoon Matters Beyond The Farm

[edit] 1965-2010

June 11, 2018: The Times of India

Monsoon rain departure from normal;
GDP growth rate;
Change from previous year's growth rate'
1965-2010
From: June 11, 2018: The Times of India

Growth of Kharif and Rabi crop during monsoon and winter- 2003-16, year-wise;
annual rainfall, state-wise
From: June 11, 2018: The Times of India

Amid hopes that the projected 97% monsoon will fuel growth, here’s a look at monsoon’s role in India’s economy

How does the monsoon affect India’s economy?

The monsoon’s failure is often linked to the economy’s overall performance. It is not the agricultural sector alone that is affected by a bad monsoon — industry too suffers as lower farm output decreases demand from this sector, which employs half the country’s workforce. Contrasting GDP growth rates with drought years since 1951-52 reveals growth is sluggish in drought years. In recent years this correlation has become weaker, which may be linked to the fact that agriculture’s share in GDP has also fallen. But it continues to employ half of India’s workforce.

Is there a major difference between agricultural output in Kharif and Rabi seasons?

Over the past decade, the share of Kharif (monsoon) crops in the national output have fallen, while Rabi (winter) crops are on the rise. Crops like rice and maize, which grow in monsoon and winter, have seen a marked decline in Kharif output, while the share of their Rabi output has risen. Exclusively Rabi crops, such as wheat, remain unaffected by monsoons.

What is the Indian monsoon?

The southwest monsoon is a summertime reversal in wind direction that provides nearly 70% of the Indian subcontinent’s annual rainfall. Monsoon winds originate from the southern Indian Ocean. They get deflected southwestwards towards India after crossing the equator. These winds are driven by air pressure differences caused by the more rapid heating up of the land in summers compared to the ocean. The land heats up the air over it, causing it to rise and create a low-pressure zone, which attracts winds from the highpressure regions over the ocean. In south Asia, the effect is enhanced by the Tibetan plateau, which heats up more than the atmosphere would at its height. Monsoon has a set pattern of advance and withdrawal. It arrives in southern India in May or June, and advances northwards and westwards, reaching Pakistan by July. It retreats from Pakistan by September, finally withdrawing from southern India by December. The season doesn’t see a continuous deluge, but has alternate wet and dry phases, the timing and duration of which account for much of the year-to-year variation in monsoon rains.

What are the country’s wettest and driest states?

Mawsynram, a village in Meghalaya is the world’s wettest place. Meghalaya receives the country’s highest rainfall followed by Goa and Sikkim. The national capital on the other hand was among the driest states in 2016.

[edit] 2008-19

April 6, 2019: The Times of India

How monsoon affects our lives in India, 2008-19
From: April 5, 2019: The Times of India

See graphic:

How monsoon affects our lives in India, 2008-19

Skymet, a private weather forecaster, has predicted the likelihood of below-normal rains this year, particularly in the central and eastern regions. The forecaster pegged rainfall in the country during the 2019 monsoon (June-September) at 93% of the long-period average (LPA) of 887 mm. LPA is defined as the average annual rainfall over a 50-year period. There is a a 55% probability that the total rainfall will be below normal and a 15% probability of drought. What is a normal monsoon

India defines average, or normal rainfall as between 96-104% of a 50-year average of 89 cm for the entire four-month season beginning June until September. Anything less than 90% is a 'deficient' monsoon, while 90-96% is considered 'below normal'. An average between 104-110% is 'above normal' and anything above 110% is 'excess'. Indian Meteorological Department (IMD), the country's official weather forecaster, will issue its monsoon outlook later this month. A good monsoon which waters more than half of the country's farmland is essential to boost consumption and economy. Even though farming output makes up just less than 14% of India's economy, the sector employs more than half of the country's 1.3 billion population. Here's a look at how the adequacy of monsoons has affected key indicators of the economy in the past 10 years.

1. RAINFALL

IMD forecast as % of LPA; Actual rainfall as % of LPA, 2009-18
From: April 6, 2019: The Times of India

The country narrowly escaped a drought in 2018, following two successive years of normal rains. Skymet's forecast of a below normal monsoon in 2019 is on account of a developing El Nino phenomenon, when warm waters in the Pacific Ocean impact summer rains in India. "The Pacific Ocean has become strongly warmer than average. This means, it is going to be a devolving El Nino year," said Jatin Singh, Skymet's managing director. "But even if it is a mild El Nino, it will have its impact on rainfall," added GP Sharma, Skymet's president of meteorology.

2. AGRICULTURE PRODUCTION

YoY % change in foodgrain production, 2008-19
From: April 6, 2019: The Times of India

The monsoon delivers about 70% of India's annual rainfall and is key to the success of the agriculture sector, There is a 75% probability of below normal rainfall this June, which could decrease to 55% in July, the two months when rains are critical for the sowing of kharif (summer) crops. The monsoon is then likely to pick up pace in August and September, during which El Nino will begin to decay. Every year of below-normal monsoon badly affects foodgrain output. Farm output suffers majorly in a drought year, when rainfall is more than 10% below normal, like in 2014-15 and 2015-16. Both years -- the first two of PM Narendra Modi's tenure -- saw negative growth in farm production, but recovered substantially in the 2016-17.

3. AGRICULTURE GDP

YoY % change in GVA of agriculture, forestry, fishing, 2008-19
From: April 6, 2019: The Times of India

Thanks to price support, the Gross Value Added (GVA) of agriculture output is less adversely affected by poor rainfall than farm output is.

4. FOOD INFLATION

% change in consumer price index of food, 2011-19
From: April 6, 2019: The Times of India

Food prices are less affected by monsoon due to buffer stocks and import. Other factors that drive food inflation in India -- rural wages, minimum support prices (MSP), agriculture input costs and global food prices.

First, rural wages are important because human labour accounts for 25-20% of the total cost of cultivation of crops such as rice and wheat. Second, MSP directly feeds into food inflation by forming a floor for wholesale food prices. Third, agriculture input costs such as electricity, diesel, pesticides and machinery also impact food inflation. Fourth, global food prices are important because of their influence on products that India imports and because international prices are one of the factors used to determine the MSPs of crops.

5. RURAL WAGES

YoY % change in rural wage for men, 2008-18
From: April 6, 2019: The Times of India

Since food inflation and rural wages are correlated, with a fall in inflation, rural wage growth too has slowed down.

6. GDP

YoY % change in GDP at constant prices, 2008-19
From: April 6, 2019: The Times of India

Largely due to the shrinking share (about 17-18%) of agriculture in India's GDP, the monsoon's direct impact on the GDP has weakened over the years.

[edit] Monsoon and agriculture

[edit] 1986-2015

Monsoons in India: Geographical spread, monsoon and foodgrains, monsoon and vegetables, monsoon and fruits, monsoon and food prices and monsoon and farm GDP: 1986-2015
Graphic courtesy: The Times of India, April 18, 2016

See graphic, ' Monsoons in India: Geographical spread, monsoon and foodgrains, monsoon and vegetables, monsoon and fruits, monsoon and food prices and monsoon and farm GDP: 1986-2015'

[edit] 2004-09

Rain and grain: 2004-09; The Times of India , Jun 02 2015

See graphic, ' Rain and grain: 2004-09 '

[edit] 2006-16

See the graphic 'How monsoon affects farming, 2006-16'

How monsoon affects farming, 2006-16; The Times of India, April 19, 2017

[edit] Monsoon break

[edit] Definition

A monsoon break — a period when rain activity comes to a stop in most of central India, the region where the monsoon trough is formed — is a common occurrence during the season. “The monsoon has been active without a break since mid-June. This does not happen often and is a reason why the rains were higher than the predicted 101% of LPA for July,” said D Sivananda Pai, IMD’s lead monsoon forecaster. (By Amit Bhattacharya)

[edit] Monsoons without a break

[edit] 2003-2010

Non-stop monsoon marches on

Amit Bhattacharya TNN

Monsoons without a break, 2003-2010

The Times of India 2013/08/16

One or two periods of a break in monsoon — defined as three straight days of very low rain activity across central India — are common during the rainy season. Since 2000, there have only been three years when there was no monsoon break. And all three years coincided with plentiful rains.

“Two months of monsoon activity without a break is rather rare. It’s an indication of agood monsoon,” said M Rajeevan, senior weather scientist at the earth sciences ministry.

At least four factors have worked in favour of the monsoon in 2013. The first good sign was an absence of El Nino — an anomalous rise in ocean surface temperatures in the east Pacific that is linked to monsoon failure in India.

Currently, weak La Nina conditions exist in the Pacific, which is the opposite of El Nino and is known to help the monsoon here.

“Then, typhoons breaking out over the south Pacific this season have also helped because these have generally moved in a direction that reinforces the Indian monsoon. This is consistent with the weak La Nina conditions,” said Rajeevan.

More importantly, what has helped sustain the rains — and distribute it more or less evenly across the region — has been a series of low pressure formations over the Bay of Bengal that have travelled westwards at regular intervals.

“There have been an unusually high number of low pressure systems, along with cyclonic circulation over land. These have nurtured the monsoon this year, especially in the interior regions of south and central India,” said Pai.

Lastly, Pai said a strong Arabian Sea branch of the monsoon first helped accelerate the rain coverage over the country, and also brought good rains over the west coast.

[edit] Monsoons in Chennai

[edit] 2007-2018

Rain Chennai got from the Southwest monsoon, 2007-2018
From: U Tejonmayam, July 27, 2019: The Times of India

See graphic:

Rain Chennai got from the Southwest monsoon, 2007-2018

[edit] Monsoons in Delhi

[edit] 2010-20: a backgrounder

Jasjeev Gandhiok, June 4, 2021: The Times of India

Monsoons in Delhi, 2010-20
From: Jasjeev Gandhiok, June 4, 2021: The Times of India

Above normal’ monsoon in Delhi only thrice since 2010

Predicted To Be Slightly Below Normal To Normal This Year

Jasjeev.Gandhiok@timesgroup.com

Delhi has received above normal rainfall in the monsoons only three times in the last 11 years, according to data from 2010 till 2020. This year, too

While the normal mark for the June-September period is 648.9mm of rain, the city received 576.6mm in 2020 and only 404.3mm in 2019.

In 2020, the monsoon arrived two days early on June 25.

June 29 had historically been the normal monsoon onset date for Delhi, but this was revised in 2020 to June 27.

In the decade between 2010 and 2020, Delhi recorded the highest seasonal rainfall in 2010, 1031.5mm of rain poured over the city. The lowest during this period was 370.8mm in 2014. On average, Delhi receives only around 65.5mm of rainfall in June, largely because of premonsoon showers. In July, the normal average for precipitation is 210.6mm and in August, 247.7mm.

[edit] Monsoons in Punjab, Haryana

[edit] 1980- 2010

Monsoons in Punjab, Haryana: 1980- 2010

See graphic, ' Monsoons in Punjab, Haryana: 1980- 2010 '

[edit] 1999-2014

Monsoons in Punjab, Haryana: 1999-2014

See graphic, ' Monsoons in Punjab, Haryana: 1999-2014 '

16-year trend of poor monsoon in Punjab, Haryana

Amit Bhattacharya New Delhi The Times of India Sep 22 2014

India's bread basket states of Punjab and Haryana received just around half the normal rainfall this monsoon season. But more worryingly , this year's rain deficit is not an isolated event. The two key agricultural states have been getting below par rainfall for the past 16 years.

Met department figures reveal Punjab has seen above normal monsoon rainfall in just two years since 1999. The last time that happened was seven monsoons ago, in 2008.The stats are similar for Haryana, where rains have been above normal in just four of the last 16 monsoons.

Experts are divided over why rains have been consistently failing in the region but the trend has dire implications for agriculture, which relies heavily on groundwater. The two states are among the most exploited regions in the world for groundwater.

Deficient rains add another dimension to the crisis.Groundwater mainly de pends on rainfall for recharge. So, less rain means less groundwater availability .A failed monsoon also means farmers draw more ground water to irrigate their crops, particularly paddy , accelerating the fall of the water table.

At TOI's request, Prof Krishna AchutaRao from IIT Delhi's Centre for Atmospheric Sciences plotted the annual and seasonal rainfall in the two states since 1980.The rain stats were obtained from the India Meteorological Department. A linear graph reveals a disturbing trend of decreasing rains in the bread basket of India. It shows average annual rainfall in Punjab falling during this period from just over 800mm in 1980 to less than 600mm in 2014 — a drop of roughly 200mm. Haryana’s annual average shows a similar drop, from around 780mm in 1980 to less than 580mm at present.

For monsoon season rainfall, Punjab has seen a drop of nearly 120mm, from an average of around 600mm in 1980 to roughly 480mm this year.

In Haryana, it’s down from more than 600mm to around 470mm during the same 35year period.

“The long term decrease in rainfall is apparent from the graph,” says AchutaRao, “although the rain statistics for the 1980s show very high variation.” But what’s not so apparent is the cause of the decline.

D Sivananda Pai, head of long range forecasting at IMD Pune, believes the drop is part of natural variability which will get reversed in time.

“Indian monsoon is passing through a low rainfall epoch since the 1990s. The drop in rainfall in this region could be part of that phenom enon,“ says Pai.

The story may not be that straightforward, says AchutaRao, who is coordinating multi-agency research into the Indian monsoon.

[edit] Monsoon/ water cycle

Let’s respect the water cycle

Amit Bhattacharya | TNN 2010

Think of water and chances are you wouldn’t picture a farmer digging a tubewell. Most urban Indians can’t think beyond their own water woes — dry taps; waking up at odd hours to tank up for the day. Yet, 80% of all the water India uses goes into agriculture. But even so, 60% of our farmlands remain dependent on the rains. Just as water evaporates, it seems, so do the resources that go into water management in the countryside.

The scale of this ‘evaporation’ is so massive it is surprising the issue hasn’t generated more public debate. Nothing illustrates this better than the money spent on canals. In the 15 year-period from 1991-92 to 2006-07, the government spent Rs 1.3 lakh crore on major and medium irrigation projects without achieving any net increase in the irrigated area!

If anything, India’s total canalirrigated area has decreased from 17,791,000 hectares in 1991-91, to 16,531,000 hectares in 2007-08, according to provisional figures released by the agriculture ministry. The story behind this dubious feat encapsulates almost everything that’s wrong with water planning and use in agriculture.

Himanshu Thakkar, coordinator for South Asia Network on Dams, Rivers and People, should know. Last year, he co-authored a paper that contained exactly those startling statistics. He says it’s not about too few new canals but about “many old ones have stopped functioning, at least partially, due to siltation, lack of maintenance and faulty assumptions of water use. Then there are water management and sharing issues. Often there’s intensive water use in upstream areas which leaves no water at the tail-ends.”

Thakkar says it boils down to bad investment decisions. “The government keeps pushing for big irrigation projects without taking care of the existing ones, which in itself is a huge task. According to a 2005 World Bank report, the annual maintenance bill for India’s canal network comes to around Rs 17,000 crore. Less than 10% of that money is available,” he says.

Experts lament that new irrigation projects often fail to take into account the larger hydrological processes they would affect. They also pay little attention to water-use patterns. This has led to river basins such as the Krishna becoming over-irrigated.

Planning Commission member Mihir Shah calls such policy practices “hydroschizophrenia (or) a schizophrenic view of an indivisible resource like water, failing to recognize the unity and integrity of the hydrologic cycle.”

Shah elaborates: “It’s a strange situation. Water management in villages comes under two ministries — rural development ministry and ministry of water resources. Often the left hand doesn’t know what the right hand is doing.”

Both Shah and Thakkar say the first step in dealing with the crisis is accepting ground realities. “While huge amounts are spent on canal systems, groundwater has emerged as the dominant method of irrigation,” says Thakkar. The latest official figures show that more than 60% of India’s 62 million irrigated hectares is fed by groundwater.

With no regulation, this has obvious perils. In August, two independent studies used satellite data from GRACE or the Gravity Recovery and Climate Experiment to show that northern India was losing more groundwater than anywhere else in the world except for the Arctic ice sheets. One of the studies put the annual net groundwater loss in Punjab, Haryana and Rajasthan at 109 cubic km, which is roughly equivalent to 109 billion tonnes. The water table has dropped dramatically in many areas and this is one of main problems Indian agriculture faces today.

Thakkar identifies four urgent policy measures: “Ensure that our old water recharge systems are sustained and enhanced, develop new recharge systems and harvest water where it falls, regulate groundwater use and, lastly, massively promote conservation methods like drip irrigation and rice intensification.”

Shah, who has been asked by the Prime Minister to write a paper for the National Development Council on a holistic water policy, says it's possible for agriculture to grow even as water use falls. “In Australia, water consumption in agriculture has reduced by 30% in the past 20 years. If they can do it, so can we,” he says.

But for that to happen, water policy has to become participatory. “The irrigation department, which is managed by civil engineers, needs to recruit people managers who understand local needs and sentiments,” concludes Shah.

It will make all the difference to a thirsty nation and parched fields.

TOTAL AREA IRRIGATED BY CANALS 1991-92: 17.8 mn hectares 2006-07: 16.8 mn hectares Amount spent on irrigation projects from 1991-92 to 2006-07: Rs 1.3 lakh crore

INFLATION IN IRRIGATION Nagarjunasagar project (AP) Original cost (pre-fifth Plan):

Rs 91.12cr Latest estimates*: Rs 1,184cr Increase: 1299%

Western Kosi canal (Bihar) Original cost: Rs 13.49cr Latest estimates: Rs 904cr Increase: 6701%

Barnar (Bihar) Original cost (in seventh Plan): Rs 8.03cr Latest estimates*: Rs 216.23cr Increase: 2689%

• All ‘latest estimates’ as on 2003, according to Planning Commission document

[edit] Monsoon: floods

Every monsoon means flood of bad news