Monsoon Updates

Oct, 03, 2019

National Monsoon Mission


News

  • The new monsoon model, called the Coupled Forecast Model (CFS), deployed by the IMD under the National Monsoon Mission (NMM) has failed to forecast the excess rainfall received during Aug-Sept 2019.

National Monsoon Mission (NMM)

  • Ministry of Earth Sciences (MoES) had launched NMM in 2012 with a vision to develop a state-of-the-art dynamical prediction system for monsoon rainfall on different time scales.
  • The responsibility of execution and coordination of this mission is vested to the Indian Institute of Tropical Meteorology (IITM), Pune.
  • Climate Forecast System (CFS) of USA has been identified as the basic modelling system for the above purpose, as it is one of the best among the currently available coupled models.

Objective

To build an ocean atmospheric model for –

  • improved prediction of monsoon rainfall on extended range to seasonal time scale (16 days to one season) and
  • improved prediction of temperature, rainfall and extreme weather events on short to medium range time scale (up to 15 days).

About Coupled Forecast Model (CFS)

  • The American model called “Climate Forecast System” (CFS) is developed by National Centres for Environmental Prediction (NCEP), USA.
  • CFS is a coupled ocean-atmosphere modeling system that combines data from ocean, atmosphere and land for providing long range forecasting (seasonal prediction of Indian Monsoon).
Jun, 17, 2019

[op-ed snap] If the rains fail

CONTEXT

Low retail food inflation, ample stocks of pulses and cereals give government leeway to plan for the exigencies of a poor monsoon.

Monsoon Data

  • The first half of this month has seen the country receive 43 per cent below-normal rainfall, on top of a 25 per cent deficiency in the pre-monsoon season (March-May).
  • Moreover, Gujarat, Maharashtra, northern Karnataka, coastal Andhra Pradesh and large areas in the Northeast have been experiencing an extended dry spell since the last post-monsoon period (October-December).
  • If current conditions persist — the US Climate Prediction Center has forecast an 81 per cent chance of El Nino, the abnormal warming of the equatorial eastern Pacific Ocean waters known to adversely impact rainfall in India, continuing till July and 66 per cent up to August — kharif crop production will take a hit.
  • The agriculture ministry’s data already shows a 9 per cent fall in plantings so far this kharif season compared with last year’s corresponding acreage, with even sharper declines for pulses (51 per cent) and coarse cereals (26 per cent).

Given the delayed onset of monsoon and likely rainfall deficit, farmers should be advised to sow short-duration pulses (moong and urad), soyabean, groundnut, sesame, guar and fodder crops, apart from maize and cotton that need less water than paddy or sugarcane.

More important, however, is to think beyond the immediate.

    • That would mean freeing up agricultural markets by totally abolishing stocking, Movement and export restrictions on produce;
    • Giving farmers the freedom to sell their crop to anybody and anywhere;
    • And replacing all input and output subsidies with per-acre direct benefit transfers.

Conclusion

The farm sector must no longer be viewed as a source of wage-goods for meeting industrialisation or inflation-targeting goals, but a potent instrument for raising rural incomes and reducing poverty.

Jun, 01, 2019

[op-ed snap] Getting drought ready

CONTEXT

More than 40% of India faces drought this year—with half of this area set to experience severe to exceptional drought—as per a Business Standard analysis of the IIT Gandhinagar’s Drought Early Warning System.

Precarious Situation

  • The pre-monsoon rains have fallen short of usual by 23%—the worst deficit in six years. As of May 25, nearly 6% of India’s land area was in the exceptionally dry category, seven times the area that was classified as such the same time last year.
  • A little over 16% of the country’s area was in the extremely and exceptionally dry categories, nearly four times that last year. India’s future in the face of the unfolding climate crisis, as a 2013 World Bank study shows, is quite precarious.
  • Since the 1950s, there has been a decline in monsoon rainfall, while the frequency of heavy rainfall events has also increased.
  • Against such a backdrop, it is alarming that 60% of India’s districts are not drought-ready, as per a 2018 paper by researchers at two IITs, Indore and Gandhinagar—only 241 of India’s 634 districts are drought-resilient. Inter- and intra-state water disparity is a powder keg waiting to be lit as access to water dwindles in the coming years.

Factors affecting water security

  • The factors that affect India’s water-security are numerous, thus, there are multiple prescriptions for developing drought readiness.
  • To start with, the country needs to urgently add reservoir capacity—while it receives an annual precipitation of about 4,000 billion cubic metre (bcm), the country makes a heavy discount for evaporation, of 2,131 bcm. Of the remaining 1,869 bcm, the water eventually available for utilisation is 1,123 bcm—the government says “various constraints” don’t allow full usage.
  • Some of the constraints might be topographical or otherwise insurmountable, but surely India could do a lot better here.
  • Just 34% of India’s cultivated area has access to irrigation; this means the rain-fed majority is highly dependent on groundwater.
  • But, there too, vulnerability is increasing because of the rapid depletion of groundwater—even without climate change, 15% of India’s groundwater resources are over-exploited.
  • Part of the problem is the large subsidies given by states to the farm sector for power—which enables indiscriminate groundwater pumping—and fertiliser, the excessive application of which changes the soil’s water requirement.
  • Thankfully, states like Punjab are beginning to wean farmers away from this.
  • But, at the crux of this is farmers sowing crops ill-suited to a region’s soil type and water availability—a water-deficient Maharashtra dedicating two-thirds of its irrigation water to sugarcane, grown on just 4% of the state’s cultivated area, or a Punjab growing most of India’s rice for exports when West Bengal has an economic water productivity for the crop that is 2.5 times higher.

Conclusion

India’s water-stressed future looks much worse if it does nothing resolve these issues.

May, 21, 2019

[op-ed snap] Eye on the monsoon

CONTEXT

As India awaits the arrival of the annual summer monsoon, hopes are particularly high for normal rainfall that is so vital for agriculture, the health of forests, rivers and wetlands. The India Meteorological Department has forecast normal rainfall of 96% of the long period average of 89 cm rain, with an onset date in the first week of June in Kerala. It has also signalled a significant possibility of a deficit.

Monsoon’s Importance

The monsoon bounty is crucial for the 60% of gross cropped area in farming that is rain-fed, and represents, in the assessment of the National Commission on Farmers, 45% of agricultural output.

Given the erratic patterns of rainfall witnessed over the past few decades and their possible connection to atmospheric changes caused by a variety of pollutants, the distribution of monsoon 2019 will add to the insights.

The southwest monsoon is a determinant of India’s overall prosperity, and sustained efforts to make the best use of rainfall are absolutely important for farms, cities and industry.

Areas of Concern

Decline in groundwater

Considering that there has been a 52% decline in groundwater levels based on tests conducted last year over the previous decadal average, State governments should have pursued the setting up of new recharging wells and made improvements to existing ones on a war footing.

Delay in building infrastructure

They also have lagged in building structures to harvest surface water and helping farmers raise the efficiency of irrigation.

Ineffective Support

The approach to the farming sector, however, has been influenced more by the imperatives of an election year, and the Centre’s biggest intervention was to announce a cash handout to specified categories of small farmers.

Effects of Industrial Pollution

  • A normal summer monsoon over the subcontinent brings widespread prosperity, but does not guarantee a uniform spread.
  • This, as scientists point out, may be due to the effect of particulates released through various industrial and agricultural processes.
  • Some of these aerosols suppress the rainfall and disperse it across the land, causing long breaks in precipitation, while others absorb heat and lead to a convection phenomenon that increases rainfall in some places.

Work on Industrial Pollution

Such evidence points to the need for India to clean up its act on rising industrial emissions, and burning of fossil fuels and biomass in order to improve the stability of the monsoon.

Freshwater availability

An equally key area of concern is freshwater availability for households, which, NITI Aayog says, account for 4% of available supplies, besides 12% used by industry.

Conclusion

Urbanization trends and the severe water stress that residents experience underscore the need for mandatory rainwater harvesting policies and augmented efforts by States to preserve surface water by building new reservoirs. Yet, governments are adopting a commodity approach to the vital resource, displaying deplorable indifference to the pollution and loss of rivers, wetlands and lakes that hold precious waters. This is no way to treat a life-giving resource.

May, 06, 2019

Pacific Decadal Oscillation (PDO)

News

Low monsoon rainfall in NE

  • Northeast India, one of the wettest places on the Earth has been experiencing rapid drying, especially in the last 30 years.
  • Some places which used to get as high as 3,000 mm of rain during the monsoon season have seen a drop of about 25-30%.
  • This decreasing monsoon rainfall is associated with natural changes in the subtropical Pacific Ocean.
  • The team used observed rainfall and sea surface temperature data for the period 1901-2014 for the study.
  • The results show out that the reduction in rainfall during a major part of the last 114 years may be associated with global man-made factors, while the trend during the last 36 years is associated with natural phenomena.
  • Only about 7% of the rainfall in this region is associated with local moisture recycling, which means that anthropogenic activities can affect only this small percentage.
  • So the rapid drying is a part of inter-decadal variability of monsoonal rainfall which is strongly associated with the PDO.

Pacific decadal oscillation (PDO)

  • PDO is a long-lived El Niño-like pattern of Pacific climate variability.
  • Both PDO and ENSO have similar spatial climate fingerprints yet the major difference is that PDO persists for 20-30 years while the typical ENSO persists for 6 to 18 months.
  • The PDO, like ENSO, consists of a warm and cool phase which alters upper level atmospheric winds.
  • During a “warm”, or “positive”, phase, the west Pacific becomes cooler and part of the eastern ocean warms; during a “cool” or “negative” phase, the opposite pattern occurs.
  • Shifts in the PDO phase can intensify or diminish the impacts of ENSO according to its phase.
  • If both ENSO and the PDO are in the same phase, it is believed that El Niño/La Nina impacts may be magnified.
  • This in turn affects the northeast Indian summer monsoon during its negative phase.
  • Conversely, if ENSO and the PDO are out of phase, it has been proposed that they may offset one another, preventing “true” ENSO impacts from occurring.
Apr, 16, 2019

Long Period Average: The IMD yardstick for determining rainfall

News

  • While releasing its monsoon forecast, the IMD expressed the projected rainfall in terms of Long Period Average (LPA), saying that it was expected to be 96% of LPA.

What is LPA of Monsoon

  • The LPA for the season is calculated on the basis of the mean rainfall during the four-month monsoon season over the 50-year period from 1951-2010.
  • It works out to an average of 89 cm for the country as a whole.
  • This is the average rainfall recorded during the months from June to September, calculated during the 50-year period.
  • It is kept as a benchmark while forecasting the quantitative rainfall for the monsoon season every year.
  • When IMD forecasts the category of rainfall, be it for country, region or month, the forecast is based on these standardised figures calculated for a period of 50 years.
  • As per the outputs obtained from the weather models, the rainfall is categorised as normal, below normal, or above normal.

Five Rainfall Distribution categories

  1. Normal or Near Normal: When per cent departure of actual rainfall is +/-10% of LPA, that is, between 96-104% of LPA
  2. Below normal: When departure of actual rainfall is less than 10% of LPA, that is 90-96% of LPA
  3. Above normal: When actual rainfall is 104-110% of LPA
  4. Deficient: When departure of actual rainfall is less than 90% of LPA
  5. Excess: When departure of actual rainfall is more than 110% of LPA

Region-wise LPA

  • 83 cm for East and Northeast India,
  • 55 cm for Central India,
  • 61 cm for South Peninsular India, and
  • 50 for Northwest India, which put together, bring the all-India figure to 88.75 cm.
Apr, 08, 2019

[op-ed snap]The heat is on

CONTEXT

A forecast of a below average monsoon in 2019, after last year’s erratic rainfall that flooded Kerala and crippled agriculture in eastern and western States, is a cause for worry.

Forecast and predictions regarding Monsoon

  • If the assessment from one agency, Skymet, is any indication, there is a prospect of an El Niño, often associated with drought conditions, taking hold.
  • If the assessment from one agency, Skymet, is any indication, there is a prospect of an El Niño, often associated with drought conditions, taking hold.
  • Should the monsoon, which normally sets in between June 1 and July 15 across the country, turn out to be deficient, it will add to the pressures on rural employment and the economy as a whole.
  • Things may become clearer when the India Meteorological Department also issues its forecast, although error margins and the erratic nature of rainfall in different regions render the exercise fraught with uncertainty.
  • Last year, for instance, the realisation of rainfall was 91% of the long-term average, while the prediction was for 97%.

Preparations to handle an extreme situation

  • It is the responsibility of State administrations to prepare for the likelihood of a heat spike, particularly during April and May, to prevent loss of life and extreme distress to communities.
  • Official agencies and NGOs should start adopting the drill on this, using the template drawn up by the National Disaster Management Authority.

Steps to be taken

  • Small Precautions-The key elements of protection in a heat wave are avoiding exposure during the hottest part of the day around noon, especially in the case of senior citizens, staying adequately hydrated, wearing suitable clothing including headgear, and creating shade in public places.
  • Information technology-These messages and weather alerts can be disseminated through television, mobile phone messaging and social media platforms.
  • Local Bodies-Urban local bodies in particular have a responsibility to care for the large number of vulnerable city dwellers.

Challenges

  • During the current year, there is apprehension that the focus of administrators will mainly be on the conduct of the elections, relegating the public health risk of heat waves to the backburner.
  • With the availability of advance weather alerts, there is no reason why local bodies cannot institute remedial measures.
  • Mitigating the effect of heat waves is vital to ensuring a high turnout in the elections by making it safe for voters.

Conclusion

  • India is looking at another uncertain monsoon, bringing into sharp relief the neglected potential of decentralised water-harvesting.
  • It is more than a decade since the National Commission on Farmers suggested the wider adoption of both rainwater harvesting and aquifer recharge, in order to provide irrigation for small farmers.
  • It is time to take measures that will help communities achieve resilience.
Mar, 26, 2019

Explained: How rocks in Meghalaya cave connect Northeast monsoon to El Niño

Note4students

Mains Paper 1: Geography | Salient features of World’s Physical Geography

From UPSC perspective, the following things are important:

Prelims level: El Nino, Karst Topography

Mains level: Impact of El-Nino


News

A new study led by researchers from a US university, on the rock formations in a cave near Cherrapunji in Meghalaya, has found new evidence to suggest that India’s winter rainfall are influenced by the state of the ocean waters in the faraway Pacific.

El Niño & monsoons

  • India’s summer monsoon which brings in about 70% of annual rainfall in the country, is already known to be heavily influenced by the variability in sea-surface temperatures of Pacific Ocean.
  • This is a condition referred to as El Niño Southern Oscillation (ENSO).
  • A warmer than usual Pacific Ocean, off the coast of South America, is known to suppress the monsoon rainfall in India.

Connection with retreating Monsoon

  • This relationship is not so strongly established with the winter monsoon, also called as the northeastern monsoon, which occurs during the months of October, November and December.
  • It is vital for several regions in the Northeast and India’s eastern coast.
  • More than 50% of the annual rains in coastal Andhra Pradesh, Rayalaseema, Tamil Nadu, south interior Karnataka, and Kerala comes during these winter months.
  • ENSO is known to have an impact on the winter monsoon as well but is weaker and opposite.
  • The warming of sea-surface waters, for example, is seen to help winter rainfall rather than suppressing it.
  • The impact varies in time and space. The influence is weaker in October and stronger in November and December.

Deducing monsoon variations from stalagmites

  • The latest study claims to have found new evidence to suggest that the state of Pacific Ocean do indeed impact the winter rains.
  • Their findings are based on more than three years of research on stalagmites (mineral deposits, mainly limestone, in caves) of the Mawmluh Cave, near Cherrapunji, in the East Khasi Hills district.
  • These solid stalagmite structures, or mineral deposits, are the result of slow but steady water dripping in the caves, and contain several thin layers of different kinds of minerals that get picked up while the water is flowing.
  • From a careful study of the composition of these stalagmites, scientists can deduce the amount of rainfall that could have happened over the caves in the past, or even whether the water was a result of local rainfall, or had flown in from a different place.
  • Using such techniques, the researchers in this case were able to estimate local variations in rainfall in the past, and then correlate it with old ocean records of the Pacific Ocean.

Stalagmites revives drought history

  • The stalagmites indicate the recurrence of intense, multi-year droughts in India over the last several thousand years.
  • Stalagmite records from monsoon regions, including India, are vital to understanding past variability in the global climate system and the underlying reasons for this variability.

Back2Basics

Karst Topography

  • Karst is a landscape which is underlain by limestone which has been eroded by dissolution, producing towers, fissures, sinkholes, etc.
  • Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum.
  • It is characterized by underground drainage systems with sinkholes, caves etc.

Stalactite and Stalagmite

  • The water containing limestone in solution, seeps through the roof in the form of a continuous chain of drops.
  • A portion of the roof hangs on the roof and on evaporation of water, a small deposit of limestone is left behind contributing to the formation of a stalactite, growing downwards from the roof.
  • The remaining portion of the drop falls to the floor. This also evaporates, leaving behind a small deposit of limestone aiding the formation of a stalagmite, thicker and flatter, rising upwards from the floor.
  • Sometimes, stalactite and stalagmite join together to form a complete pillar known as the column.
Nov, 29, 2018

India may face an intense and increased water deficit in 2019

Note4students

Mains Paper 1: Geography | Important Geophysical phenomena

From UPSC perspective, the following things are important:

Prelims level: Monsoon dynamics in India, Global Water Monitor & Forecast Watch List

Mains level: Impact of deficit monsoon


News

  • Water deficits will increase and intensify in India in 2019, says the latest edition of Global Water Monitor & Forecast Watch List.

About WSIM

  1. The report is presented by IScience (US based LLC) states the findings from the latest Water Security Indicator Model (WSIM).
  2. ISciences Water Security Indicator Model (WSIM) monitors and forecasts water anomalies on a near global basis.
  3. WSIM includes algorithms to assess the impacts of water anomalies on people, agriculture and electricity generation.
  4. WSIM has been run continuously since April 2011 and has been validated against subsequent monitoring based on observed data.

Details of the Forecast

  1. The forecast predicts severe to exceptional surplus water for regions including Jammu and Kashmir, Himachal Pradesh, Uttar Pradesh and Mizoram.
  2. Moderate to severe deficits were forecast for Bihar.
  3. From February through April, deficits in India are expected to moderate overall and some regions in the country’s eastern third will normalize.
  4. However, intense deficits will persist throughout Gujarat and Madhya Pradesh and along the Tungabhadra River through Karnataka.
  5. The forecast for the final months — May through July (2019) — indicates primarily moderate deficits in India and pockets throughout the region.
  6. The 12-month forecast through July 2019 indicates exceptional (greater than 40 years) water deficits in Maharashtra, Telangana, Andhra Pradesh, Karnataka, and Madhya Pradesh.

Expected El-Nino Impact

  1. Though this September’s extreme heat was unrelated to El Niño which usually introduces warm dry conditions.
  2. El Niño is being blamed for low rainfall during the June-to-September monsoon season.
  3. The monsoon rain deficits have caused drought-like conditions in almost a third of Indian districts, and added stress for the farmers.

Coffee production to decline

  1. India’s coffee production is expected to fall to its lowest in five years due to flood damage to plantations in southern states such as Kerala and Karnataka.
  2. India exports about three quarters of the coffee it produces, and flood damage has been reported in all key producing areas of the country.
Oct, 03, 2018

For the first time, India gets its soil moisture map

Note4students

Mains Paper 3: Agriculture| Major crops cropping patterns in various parts of the country, different types of irrigation and irrigation systems

From UPSC perspective, the following things are important:

Prelims level:  Rabi and Kharif Season, Variable Infiltration Capacity Model

Mains level: Utility of Moisture Mapping


News

Moisture Mapping

  1. With the Rabi season around the corner, a countrywide forecast is prepared at the end of the monsoon season.
  2. This forecast, following a joint exercise by IIT Gandhinagar and the India Meteorological Department (IMD), for the first time, provides a country-wide soil moisture forecast at seven and 30-day lead times.
  3. Soil moisture is crucial for agriculture since it directly affects crop growth and how much irrigation is required for the area.
  4. It suggests deficit soil moisture conditions are likely in Gujarat, Bihar, Jharkhand, Tamil Nadu and southern Andhra Pradesh.

Variable Infiltration Capacity Model

  1. The experts used the ‘Variable Infiltration Capacity’ model to provide the soil moisture prediction.
  2. The product, termed ‘Experimental Forecasts Land Surface Products’, is available on the IMD website.
  3. It has been developed using the hydrological model that takes into consideration soil, vegetation, land use and land cover among other parameters.
  4. The team has been working on high-resolution soil database that is essential for soil parameters used in the modelling.
  5. However, the database is not available for the entire country currently.

Why need Moisture Map?

  1. Crucial information needed for agriculture is not revealed only through rainfall data.
  2. Even if there’s a normal rainfall, if the temperature is abnormally high, it can rapidly deplete the soil moisture.
  3. So essentially soil moisture gives us more information on what is needed for crop growth in different parts of the country.
  4. Forecasting of soil moisture holds significance for the rabi season.
  5. As per official data, the total area sown under rabi crops is around 625 lakh hectares of which wheat takes up 300 lakh hectares.
  6. Timely soil moisture forecasts will help target interventions, in terms of seed varieties for better planning in agriculture.

Leap over Kharif uncertainties

  1. In Bundelkhand, most farmers keep their land fallow or just grow some fodder crop during the kharif season since the rains are unpredictable and there could be extended dry spells after sowing.
  2. They then mainly cultivate the rabi crop using the soil moisture left behind by the monsoon rains.
  3. It is a similar trend in Bihar, in low lying areas of Seemanchal and Kosi belt, where no crop is grown during Kharif because of inundated lands.
  4. This means that if there is not enough rainfall in one or two months, these are regions which will demand heavy irrigation whether that comes from groundwater or surface water storage (reservoirs).
  5. Based on observed conditions at present, Gujarat, parts of Maharashtra, Chhattisgarh, Jharkhand, Tamil Nadu and parts of Andhra Pradesh are deficient in terms of soil moisture right now.
Jun, 30, 2018

Monsoon covers country fortnight early

Note4students

Mains Paper 1: Geography | Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.

From UPSC perspective, the following things are important:

Prelims level: Monsoon dynamics, westerly winds, western disturbances

Mains level: Role played by the monsoon in Indian economy


News

Early monsoon arrival

  1. The Southwest monsoon has now covered the entire country, a fortnight ahead of its normal schedule of mid-July
  2. This has happened for the first time since 2015

Monsoon advance in India

  1. The monsoon trough will lie over the Himalayan foothills in the first week of July
  2. There was strong interaction between monsoon currents and dry westerly winds, which brought thundershowers and revived monsoon
  3. This was also supported by strong western disturbances, making the advance quicker
Jun, 12, 2018

What caused the Dec. 1, 2015 Chennai downpour?

Note4students

Mains Paper 1: Important Geophysical phenomena, geographical features and their location- changes in critical geographical features

From UPSC perspective, the following things are important:

Prelims level: Cold Pool Theory

Mains level: This sought to be a better explanation for the floods in some unexpected regions.


News

IISc researcher answers this by linking the Eastern Ghats and rain-bearing clouds

  1. In December 2015 Chennai and its surrounding regions experienced an unprecedented, heavy rainfall.
  2. In a region where the average rainfall during the season is expected to be 8-10 mm per day, one of the rain gauges in the city recorded an abnormally high, 494 mm rainfall in over 24 hours that day.
  3. This led to death of nearly 250 people, and Chennai was declared a ‘disaster zone’.

Cold Pool Theory

  1. When clouds give out water droplets, the droplets evaporate mid-air, as they fall down. This cools the surrounding air, forming a cold pool of air which sinks down and flows horizontally
  2. The gusty cold wind that heralds an approaching thunderstorm is nothing but a cold pool, which plays a pivotal role in cloud dynamics.
  3. Unlike the Western Ghats, which run close to the west coast of India, the Eastern Ghats are nearly 200 km away from the coast.
  4. Therefore, the link between the mountains orography and the rainfall over the region is crucial.
  5. The cold pool was obstructed by the Eastern Ghats from flowing downward; hence it piled up and remained stationary over the Chennai region.
  6. The reason for the clouds remaining stationary was that there was a balance between the piling of cold pool along the mountain and the winds from the bay.

Dust storms: Aandhis in North India are too caused by ‘Cold Pool’

  1. Cold pools are known to play an important role in the dust storms (Aandhi) that form in northern India.
  2. They form by the evaporation of raindrops.
  3. This process is more efficient in the drier and warmer environment as there is lot of scope of evaporation.
  4. So, the cold pools that form in these conditions, are deeper and more vigorous.
  5. As pre-monsoon conditions in north India are very dry and warm, cold pools that accompany the pre-monsoon thunderstorms there are far more destructive, causing widespread damages.

The Way Forward

  1. For the first time, this study links cold pools and the mountain structure to explain rainfall over south India.
  2. Though the primary aim of the study is to explain the anomalous rainfall over Chennai on December 1, 2015, the understanding gained from this analysis can be useful for improving the general weather forecast over this region.
May, 17, 2018

Scientists develop new model to determine monsoon variations across India

Note4students

Mains Paper 3: Science & Technology | Developments and their applications and effects in everyday life

From UPSC perspective, the following things are important:

Prelims level: Agencies Involved, MLR, El Nino, Indian Ocean Dipole, Equatorial Indian Ocean Oscillation (EQUINOO)

Mains level: Factors affecting Indian Monsoon and Utility of this weather model in studying them.


News

New model for estimating variability and trends in rainfall

  1. Scientists have developed a new model for estimating variability and trends in rainfall over different climate regions of the country
  2. The new statistical model based on multiple linear regression (MLR)
  3. It has been developed by scientists from the Centre for Oceans, Rivers, Atmosphere and Land Sciences (CORAL), IIT Kharagpur, the Indian Institute of Tropical Meteorology (IITM), Pune, and the Indian National Centre for Ocean Information Services (INCOIS), Hyderabad

Complexities in Predicting Monsoon Variability

  1. Indian monsoon, both southwest and northeast is complex
  2. It depends on various climatic forcings (conditions) like El Nino, Indian Ocean Dipole, which affect rainfall in different regions, in different ways
  3. Researchers highlight that current dynamic models used for monsoon forecast face two major problems
  4. First, they respond a little too much to El Nino Southern Oscillation (ENSO)
  5. Second, the relationship between Equatorial Indian Ocean Oscillation (EQUINOO) and summer monsoon in models has been found to be opposite to actual observation
  6. If we can improve our understanding of EQUINOO’s impact on monsoon, then we can make corrections in the dynamic model and improve our teleconnections. This will help us get an accurate monsoon forecast

Importance of this weather model

  1. The research is one of the first to have analyzed the variability of the Indian monsoon because of these factors together
  2. It confirmed with statistical analysis, that ENSO and EQUINOO are two major drivers for Indian monsoon and explain around 50% variability in monsoon
  3. Such studies would help scientists to better tune their models for accurate weather prediction
  4. The research assumes significance as the monsoon decides the livelihood of more than a billion people and influences the agrarian economy which is largely dependent on its accurate forecast
Apr, 18, 2018

[op-ed snap] Chasing the monsoon: Agriculture

Note4students

Mains Paper 3: Agriculture | Different types of irrigation and irrigation systems storage

From UPSC perspective, the following things are important:

Prelims level: Particulars of the IMD, El Nino, La Nino, etc.

Mains level: What should be done by the Indian Government to increase the benefit of good monsoon?


News

Good news from the India Meteorological Department(IMD)

  1.  For farmers, the IMD’s estimate that rainfall during the summer, between June and September, will be 97% of the 50-year average of 89 cm, is bound to raise fresh expectations
  2. The forecast of a normal monsoon has brought relief all around
  3. The IMD’s decision to provide a more fine-grained forecast on the monsoon’s progress, particularly in the central and northern regions, will meet a long-felt need and can potentially guide farmers better

High crop output

  1. The normal monsoon is the third year in a row and farmers can look forward to a high output for a variety of crops
  2. What is well known is that a good monsoon raises agriculture’s contribution to GDP growth, while a drought year depresses it

Some positive steps taken by the government

  1. he Centre has been supportive of higher returns through the Minimum Support Price mechanism and additional bonuses have been announced by States such as Madhya Pradesh for procurement

What should be done by the government?

  1. Now that another year of good cropping is expected, and unremunerative prices will depress public sentiment,
  2. it is vital for the Centre to arrive at a policy that gives constructive advice to farmers on the ideal cropping mix and help them get the cost-plus-50% margin that it has promised them
  3. The long-term challenge is to make the most of the rainfall that India gets, ranging from a few hundred millimetres or less in the northwest to more than a few thousand millimetres elsewhere
  4. The Master Plan for Artificial Recharge to Ground Water drawn up by the Centre should be pursued scientifically, to help States with the most water-stressed blocks get adequate funds to build artificial recharge structures
  5. Moreover, for those farmers who choose to continue with wheat and rice, transfer of expertise and provision of equipment that enables efficient utilisation of water is vital

One of the main reasons of water stress in India

  1. An estimate of water used to grow rice and wheat, measured in cubic metres per tonne, shows that India uses more than what, say, China does
  2. In the case of cotton, the figures present an even more staggering contrast: 8,264 cubic metres for India, against 1,419 for China
  3. Combined with distortions in procurement subsidies, water stress due to such use is inevitable

The way forward

  1. Clearly, governments need to invest consistently to harvest the monsoon, both on the surface and underground, with community participation

Back2basics

India Meteorological Department

  1. The India Meteorological Department (IMD), also referred to as the Met Department, is an agency of the Ministry of Earth Sciences of the Government of India
  2. It is the principal agency responsible for meteorological observations, weather forecasting and seismology. IMD is headquartered in Delhi and operates hundreds of observation stations across India and Antarctica.Regional office are at Mumbai, Kolkata, Nagpur and Pune.
  3. IMD is also one of the six Regional Specialised Meteorological Centres of the World Meteorological Organization. It has the responsibility for forecasting, naming and distribution of warnings for tropical cyclones in the Northern Indian Ocean region, including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf
Oct, 09, 2017

Mapping the not-so-normal monsoon

Image source

Note4students

Mains Paper 1: Geography | changes in critical geographical features (including waterbodies & ice-caps) & in flora & fauna & the effects of such changes.

From UPSC perspective, the following things are important:

Prelims level: Monsoon and its types, spatial and temporal distribution of rains, Kharif and Rabi seasons

Mains level: Heavy dependence of Indian agriculture on monsoon, impact of this dependence and remedial measures


News

Monsoon normal in 2017

  1. South-west monsoon for 2017, has turned out to be normal for the second consecutive year
  2. IMD deems the season ‘normal’ if the all-India quantum of rain falls within a 10% range of its long-period average of 887.5 mm
  3. The 2017 monsoon fell short of the number only by 5%
  4. But there can be many shades of grey to an officially ‘normal’ monsoon

Another bumper year?

  1. In 2016-17, India harvested a record crop of cereals and managed a quantum jump in its output of both pulses and oilseeds
  2. This contributed to a significant bump-up in the agriculture leg of the GDP which grew 4.9% in FY17 compared with 0.7% in FY16
  3. But expecting an encore of that impressive performance just because this year’s monsoon has turned out ‘normal’, would be unrealistic
  4. More than the quantum of rainfall that is dumped on the sub-continent during the four critical months, it is the spatial and temporal distribution of rains that make or break crop prospects
  5. On this score, the 2017 monsoon has been quite whimsical

Patchy distribution

  1. For the purposes of measuring the spatial spread of rainfall, the IMD categorises India into 36 meteorological sub-divisions
  2. IMD’s wrap-up of the recent monsoon season tells us that 5 of India’s 36 sub-divisions received excess rains, 25 received normal rains and 6 witnessed deficient rains
  3. But the devil really lies in the details and the identity of the States that suffered deficient rains really matter to crop prospects
  4. This year’s monsoon has played truant in some key food-bowl States
  5. West Bengal, Uttar Pradesh and Punjab account for a lion’s share of kharif rice production. But this year’s monsoon has been 29% below normal in Uttar Pradesh and 22% short of normal in Punjab
  6. Madhya Pradesh, which is a critical growing region for the rabi wheat crop, has seen a deficiency of 20%. This will also impact pulses output.

Weak ending

  1. Rainfall in the last two months of the south-west monsoon dictate reservoir storage and soil moisture
  2. This sets the tone for the planting of the winter crops
  3. The rabi season accounts for the whole of India’s wheat and gram harvest, a fourth of the output for coarse cereals and chips in with over a third of the yearly harvest of urad and moong
  4. Oilseeds such as rapeseed and mustard, sunflower and safflower are also predominantly winter crops
  5. Therefore, dry spells in the latter half of this monsoon, taken with deficient rains in key rabi growing regions, can make for less than rosy rabi prospects
Jun, 07, 2017

El Nino is weaker than anticipated, says IMD

Note4students:

Mains Paper 1: Geography | Salient features of world’s physical geography

From UPSC perspective following things are important:

Prelims level: El Nino, La Nino and IOD concepts.

Mains level: These kind of phenomenons are important for the static part of the syllabus. Expect a direct question
if already not asked


News:

  1. What: The India Meteorological Department(IMD) is expecting better this year
  2. Why: Because El Nino would be much weaker than anticipated
  3. New monsoon forecast system: IMD has shifted to a new monsoon forecast system, called a dynamical model that works by supercomputers simulating the weather and extrapolating it(i.e. Deducing the weather by assuming that existing trends will continue)

What is El Nino?

  1. The El Nino is characterised by surface waters of the equatorial Pacific warming up by more than half a degree
  2. It is known to negativey affect monsoon rain every six out of 10 years
  3. A positive Indian Ocean Dipole (IOD) is said to buffer the impact of El Nino and contribute to better rains
  4. The Indian Ocean Dipole (IOD) is also known as the Indian Niño. IOD is an irregular oscillation of sea-surface
    temperatures in which the western Indian Ocean becomes alternately warmer and then colder than the
    eastern part of the ocean
  5. The IOD is a swing in surface temperatures that turns the western Indian Ocean alternately warmer and then
    colder than the eastern part of the ocean
Oct, 27, 2016

Northeast monsoon to set in by October 30: IMD

  1. Arrival of: The northeast monsoon, which brings the bulk of rainfall in Tamil Nadu and other southern States
  2. Date: It will commence by October 30, according to the India Meteorological Department
  3. Last year, the northeast monsoon wreaked havoc in Tamil Nadu, with a record downpour in December 2015
Oct, 03, 2016

India got 3% less rain than normal: IMD

  1. IMD: India has ended up with 3% less rain than normal during the monsoon months of June to September
  2. This is the first time since 2011 that the IMD was not able to forecast the overall ‘sign’ of the monsoon
  3. It expected heavy rain but ended up with less than normal
  4. In 2014 and 2015, it could not anticipate the severity of the droughts but had indicated that monsoon would be below normal
  5. In 2011, the IMD said India would get below normal (95% of the average) rain, but the country ended up with 2% more rain than normal
Sep, 20, 2016

Monsoon to be normal: IMD

  1. The India Meteorological Department (IMD) said the monsoon will be normal this year
  2. It has gone back on its earlier forecast of above normal monsoon
  3. Why? Due to delay in La Nina weather pattern
  4. Background: India has been hit by drought in the last two years, with the last monsoon being affected by El Nino
  5. However, it was expected that this year there would be a gradual transition to La Nina phenomenon, which would have boosted monsoon and given excess rain in September

Discuss: Discuss the significance of the normal monsoon rains on Indian economy. How good rains should be used to recharge groundwater through policy means?

May, 26, 2016

Australia signals end of El Nino

  1. Context: Australia’s current climate model suggest that La Nina will begin in second half of monsoon
  2. La Nina: Reverse condition of El Nino
  3. El Nino: A warm current replaces cold current in tropical pacific region and affect the Indian monsoon
  4. La Nina will bring heavy rains over India
  5. Effects: Good for Kharif crops, the area under crops is expected to increase
May, 19, 2016

Cyclonic storm over Bay of Bengal to intensify: IMD

  1. Context: Season’s first cyclone will be brought by cyclonic depression form in Bay of Bengal
  2. Effect: Will bring rain fall in Kerala, Chennai and Andhra Pradesh
  3. Conditions are favourable for advance southwest monsoon in some parts of Bay of Bengal, entire south Andaman Sea and Nicobar Islands
  4. The forecast of delayed monsoon in Kerala remains same
May, 16, 2016

Remnants of El Nino holding up monsoon- II

  1. Signs of Monsoon: Raining over Andman with Cyclones in month of May
  2. But raining over Andman is decreasing because they are not sufficiently fuelled by cross equatorial flows
  3. No cyclones have been seen seen yet
  4. Prediction: Lag in seasonal transition, pre monsoon rains over Tamil Nadu and Kerala around 1 June
  5. Earlier: IMD predicted that there would be rains early than usual and above normal level and 106 % of 89 cm
May, 16, 2016

Remnants of El Nino holding up monsoon

  1. Context: Monsoon may be delayed due to effects of El Nino
  2. El-Nino effect: This time the rain bearing winds doesn’t begin to draw across equator
  3. Therefore, Cross Equatorial flows haven’t developed
May, 11, 2016

What caused the monster El Nino in 2015?

  1. Context: New study gives the reason for EL Nino 2015
  2. Reason: Presence of warm water current due to effect of El Nino of previous year (2014)
  3. El Nino: A warm ocean current which replaces cold Peru Current into warm current
  4. It gives rise to heavy precipitation in Peru coast while drought and less rainfall in eastern pacific region & affects monsoon badly
Apr, 13, 2016

It’s official: India set for an ‘above normal’ monsoon

  1. News: India’s official weather forecasting agency too has said the monsoon is likely to be “above normal” and likely to be 106% of the average of 89 cm
  2. Reason: Waning El Nino and Positive Indian Ocean Dipole is also likely to form during the middle of the monsoon season
  3. Distribution: The monsoon will be fairly well distributed but southeast India will get slightly less rain
  4. Some regions would see floods and that the chances of drought were only 1% this year
  5. Observation: In the last century, 7 out of 10 years that followed an El Nino saw normal or above normal monsoon rains in India
  6. Fact: The years 2014 and 2015 were among the strongest El Nino years in meteorological history
Apr, 01, 2016

India to see a hotter-than-normal summer this year

  1. News: IMD has predicted that the above-normal heat wave conditions are very likely over central and northwest India during the summer
  2. The strong El Nino conditions in the Pacific are now on the decline
  3. For this season, IMD will provide extended range forecasts of heat wave conditions over the country every five days for the next 15 days
  4. Fact: 2015 was the third hottest year since 1901 and it was the third warmest year ever recorded since 1901
Mar, 19, 2016

Experts unsure if El Nino will fade away

  1. News: Meteorologists expect the monsoon in 2016 to be normal but are unclear if El Nino will completely fade away during the crucial monsoon months
  2. About: El Nino refers to an anomalous heating up of the waters in the central-eastern regions of the equatorial Pacific
  3. This implies a consistent, average rise in temperature of 0.5 degree Celsius above normal
  4. Relevance: Historically that translates to the monsoon drying up over India 6 in 10 years
  5. About La Nina: when waters in the same regions dip at least 0.5 degree Celsius and generally considered favourable for the monsoon, is only expected to set in after Sept
  6. Relevance: 2015 was only the fourth time in a 100-yr span that El Nino-like conditions raged on for 2 consecutive yrs
Feb, 20, 2016

El-Nino is receding

  1. Context: World Meteorological Organization (WMO) said El Niño has passed its peak and is in retreat
  2. Relief: Should bring relief for policy planners in India after two consecutive years of drought
  3. One of the most powerful: We have just witnessed one of the most powerful ever El Niño events
  4. Effects: Caused extreme weather in countries on all continents and helped fuel record global heat in 2015
  5. But not a time to celebrate: In meteorological terms El Niño is now in decline but we cannot lower our guard as it is still quite strong
  6. Future impact: in humanitarian and economic terms, its impacts will continue for many months to come
  7. Effect on India: A normal monsoon would help improve India’s macroeconomic prospects and boost rural demand
  8. Rural distress: A challenge for India is rural distress, triggered by a combination of consecutive droughts and a collapse of global commodity prices
Dec, 07, 2015

Freak weather whipped up a perfect storm

The highest daily rainfall in a century, a hottest-ever Indian Ocean, a strongest-ever El Niño.


  1. Freak weather conditions all came together on one single day to swamp Chennai with the heaviest rainfall in a century and it could all happen again.
  2. The World Meteorological Organisation(WMO) has been producing regular updates on the scale of this year’s El Niño.
  3. It’s expected, impact was a significant contributor to the India Meteorological Department’s forecast of a deficient south-west monsoon, a forecast that was spot on.
  4. El Niño affects whole season and is not responsible for individual episodes of intense rain.
Jun, 25, 2015

El Nino may have only a minor impact

  1. Contrary to an 8% average decline in agri output in previous El Nino years, this projected El Nino year will reduce output only by ~4.5%.
  2. Cotton will not be much impacted because of an increase in area under cultivation and long sowing periods.
  3. Majority of sugarcane is grown in irrigated areas which insulate it from El Nino effect.
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