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India’s 50-year dry spell reversed with strengthening monsoons over past 15 years: Study

August 19, 2017

By Paul Homewood

 

 

The climate mafia often claim that global warming leads to worse droughts.

A new study has found that the reverse is the case as far as India is concerned:

 

 

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New Delhi: The arrival of the monsoon season is a sign of respite from the dry spells in India and the past 15 years have witnessed the rains getting stronger.

 

A study carried out by MIT has found that Indian summer monsoons have strengthened over the course of the last 15 years, thus reversing a 50-year dry period, with northern and central India receiving relatively little rainfall.

The Indian monsoon season falls between the months of June and September every year.

According to researchers, the dry spell began to fade away from 2002, when the rains paved the way for a much wetter pattern, with stronger monsoons supplying much-needed rain, along with powerful, damaging floods, to the populous north central region of India.

A shift in India’s land and sea temperatures may partially explain this increase in monsoon rainfall, according to the study published in the journal Nature Climate Change.

Researchers note that starting in 2002, nearly the entire Indian subcontinent has experienced very strong warming, reaching between 0.1 and 1 degree Celsius per year. Meanwhile, a rise in temperatures over the Indian Ocean has slowed significantly.

According to Chien Wang, a senior research scientist at Massachusetts Institute of Technology (MIT) in the US, this sharp gradient in temperatures – high over land, and low over surrounding waters – is a perfect recipe for whipping up stronger monsoons.

“Climatologically, India went through a sudden, drastic warming, while the Indian Ocean, which used to be warm, all of a sudden slowed its warming,” Wang said.

“This may have been from a combination of natural variability and anthropogenic influences, and we are still trying to get to the bottom of the physical processes that caused this reversal,” he said.

The Indian monsoon phenomenon is the longest recorded monsoon system in meteorology, researchers said.

From yearly measurements, scientists had observed that, since the 1950s, the monsoons were bringing less rain to north central India – a drying period that did not seem to let up, compared to a similar monsoon system over Africa and East Asia, which appeared to reverse its drying trend in the 1980s.

However, researchers found that India has already begun to reverse its dry spell.

The team tracked India’s average daily monsoon rainfall from 1950 to the present day, using six global precipitation datasets, each of which aggregate measurements from the thousands of rain gauges in India, as well as measurements of rainfall and temperature from satellites monitoring land and sea surfaces.

Between 1950 and 2002, they found that north central India experienced a decrease in daily rainfall average, of 0.18 millimetres per decade, during the monsoon season.

To their surprise, they discovered that since 2002, precipitation in the region has revived, increasing daily rainfall average by 1.34 millimetres per decade.

“The Indian monsoon is considered a textbook, clearly defined phenomenon, and we think we know a lot about it, but we do not,” Wang said.

“Here, we identify a phenomenon that was mostly overlooked,” said Wang who collaborated with Qinjian Jin from MIT for the study.

The researchers did note a brief drying period during the 2015 monsoon season that caused widespread droughts throughout the subcontinent.

They attribute this blip in the trend to a severe El Nino season, where ocean temperatures temporarily rise, causing a shift in atmospheric circulation, leading to decreased rainfall in India and elsewhere.

“But even counting that dry year, the long-term (wetting) trend is still pretty steady,” Wang added.

http://zeenews.india.com/environment/indias-50-year-dry-spell-reversed-with-strengthening-monsoons-over-past-15-years-study-2026767.html

 

There should be no surprise at all about this. HH Lamb recorded back in the 1970s how the Indian monsoon became wetter and more reliable when the Earth was warming between around 1925 to 1960. When the world’s climate went into a cooling phase for the next twenty years droughts there increased.

Concerning the post 1940s cooling, this is what he wrote in “Climate: Present, Past & Future”. (The book was published in 1977).

Air temperatures prevailing over most of the globe reached their maximum about the early 1940’s, and their subsequent fall to the levels maintained from 1965-75, or after, seems likely to be their longest continued downward trend since 1700.

Examples of the consequences of these features include a number of serious items besides the extremes of cold and warmth, drought and flood associated with the occurrences of blocking in middle latitudes.

The greater yield of equatorial rains since 1961 over the equator led to abrupt rises of the levels of the great lakes there, drowning harbours and much land.

But  far more serious were the droughts in the zones to the North and South. In the Sahel between 200,000 and 400,000 died in the drought of 1972-73.

In those parts of N and NW India, near the limit reached by the summer monsoon, Bryson (1973) has noted a corresponding effect, scarcely less threatening to the inhabitants than the 6 year drought from 1968-73 in the West African Sahel.

In the first quarter of the century, there was a severe drought in N and NW India every 3rd or 4th year. Then, as the Earth warmed up and the circumpolar vortex contracted, the monsoon rains penetrated regularly into Northern India, and drought frequency declined to 2 in 36 years, from 1925-60. But since 1960, with the cooling of the Earth and the southern movement of the subtropical high pressure areas, drought frequency has been increasing again and the probability may be now more than once a decade.

Bryson adds that if a drought frequency like that which prevailed at the start of the century were to occur now, with India’s population having increased by a factor of 4, the human and political consequences would be enormous.

https://notalotofpeopleknowthat.wordpress.com/2014/05/14/hh-lambs-climate-history-the-modern-world-in-review-part-ii/

 

The phenomena he describes has been well known for some time.

For instance, scientists have found evidence of a mega drought in West Africa between 1400 and 1750. At the time, Lake Bosumtwi in Ghana dropped so low for so long that a forest sprouted on the crater’s edges. Those trees now stand in 15 to 20 metres of water.

The submerged trees on Lake Bosumtwi, Ghana, stand in 15 to 20 metres of water (Image: Timothy Shanahan)

The submerged trees on Lake Bosumtwi, Ghana, stand in 15 to 20 metres of water

7 Comments
  1. Joe Public permalink
    August 19, 2017 6:26 pm

    Another tangible benefit of climate changing:

    “(Indian) Govt revises foodgrain output to record 275.68 million tonnes”

    http://timesofindia.indiatimes.com/india/govt-revises-foodgrain-output-to-record-275-68-million-tonnes/articleshow/60090001.cms

  2. John Ellyssen permalink
    August 19, 2017 7:15 pm

    “a combination of natural variability and anthropogenic influences”. Now how is it possible for man to cool off the indian ocean?

  3. August 19, 2017 7:23 pm

    Reblogged this on WeatherAction News.

  4. Climate Otter permalink
    August 20, 2017 12:27 am

    I recall looking up the 1990 IPCC report, and the fact that it claimed Monsoons would shift and various regions would become dryer. Another prophecy gone wrong.

  5. Ben Vorlich permalink
    August 20, 2017 7:21 am

    I saw on the News (BBC) yesterday that Bangladesh was having its worst floods for many years, the worst some people could remember.

  6. August 20, 2017 8:37 am

    “This may have been from a combination of natural variability and anthropogenic influences, and we are still trying to get to the bottom of the physical processes that caused this reversal,” he said.
    – – –
    That’s the whole climate issue in a nutshell. It’s been decreed that there are ‘anthropogenic influences’ on ‘the climate’ and scientists are supposed to be able to find the evidence. But the definition of any such evidence is somewhat flexible to say the least.

    Instead of the null hypothesis they assume ‘anthropogenic influences’ and get into all sorts of logical contortions to try and justify their assertions.

  7. August 20, 2017 11:31 am

    Have been watching geology videos on YouTube. There was a fascinating one on the creation of Mt. Everest and the sampling of different rock strata from 3 levels including the summit.

    According the the latest thinking, it was the smacking of India into Asia and the resulting Himalayan orogeny which led to the weather patterns creating the monsoon phenomena.

    The Himalaya are still rising as India is still pushing into the Asian plate.

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