[ad_1]

EL NINO AND INDIAN MONSOON

WHY IN NEWS?

  • Recently, India Meteorological Department predicted a hotter summer this year, with above-normal temperatures and an above-normal number of heatwave days.

WHAT IS EL NINO SOUTHERN OSCILLATION (ENSO) ?

  • It is an interaction of ocean and atmospheric conditions.
  • The ‘southern oscillation’ component in ENSO refers to a specific atmospheric condition that is a measure of the difference in sea-level air pressure over western and eastern side of the Pacific Ocean.
  • Other atmospheric condition that plays a key role in ENSO is the strength and direction of winds.
  • Merely abnormal warming or cooling of surface waters in Pacific Ocean doesn’t ensure an El Nino or La Nina event. The other associated atmospheric conditions also have to be in sync.

ABOUT EL-NINO:

  • It refers to the abnormal warming of sea surface waters in the equatorial Pacific Ocean.
  • This phenomenon occurs naturally during autumn-summer in the northern hemisphere, typically once every 2-7 years.
  • El nino peaks during winter (October-February) before weakening in the subsequent summer, making it a phenomenon that typically lasts for between 9 and 12 months.

  • The episodes of El Nino affect the global weather patterns, leading to an increase in temperatures and large-scale dryness and droughts, and disrupt normal rainfall patterns globally.
  • Due to El Niño conditions, large parts of East Africa have experienced multiple failed rainy seasons in recent years.

IMPACT OF EL-NINO & HEAT FORECAST FOR INDIA:

  • As per IMD,“El Niño conditions will push temperatures above normal in most of the country during March, April, and May”.
  • Occurence of heat waves over Central and Northern Peninsular India during March to June, when day temperatures rise 4.5 degree Celsius above normal.
  • Due to prevailing El Niño conditions, IMD has also warned of longer and harsher heat waves this summer.
  • Above normal maximum temperatures are likely to be experienced over Ladakh, Himachal Pradesh, Rajasthan, Uttar Pradesh, Jharkhand, Odisha, Maharashtra, coastal Gujarat, Karnataka, Kerala, Tamil Nadu, Lakshadweep and the Andaman and Nicobar islands.
  • Except some regions in Eastern India, nights too shall remain warmer than usual over almost the entire country.

IMPACT ON INDIAN MONSOON 2024:

  • According to multiple global climate models, “ENSO neutral conditions will emerge during the April-June period”.
  • India’s Monsoon Mission Climate Forecast System (MMCFS) model has predicted ENSO neutral conditions to be established along the equatorial Pacific Ocean by May.
  • Then the transition from El Niño to ENSO neutral will take some time after that.
  • If such conditions are realised, the desired establishment of favourable oceanic conditions could take place ahead of the onset phase of the southwest monsoon over the country.
  • As the southwest monsoon arrives over the Andaman and Nicobar Islands around mid-May and then it progresses and enters the mainland through the gateway in Kerala around June 1 and by mid-July, it covers the entire country.
  • The prediction about the development of ENSO neutral conditions suggests that the southwest monsoon may not be directly impacted by the ongoing El Niño episode.
  • There are good chances of normal monsoon rainfall — provided other ocean-atmosphere parameters, wind conditions, formation of low-pressure systems, etc remain favourable — this year.

ENSO AND CLIMATE CHANGE:

  • As in general, El Nino has a warming effect on the planet, while La Nina tends to cool it down.
  • Dubbed as Godzilla El Nino, the warmest-ever year on record is 2016. It was part of one of the longest and strongest El Nino episodes ever.
  • El Nino or La Nina years do not alter the overall heat in the system, but they influence how much of it gets sunk in the ocean.
  • During the La Nina phase, a larger than normal amount of warm surface water of Pacific Ocean is pushed towards the Indonesian coast.
  • On the other side of the Pacific Ocean, relatively colder water from the deep emerges on the top.
  • A large area over the eastern Pacific Ocean thus contains colder water.
  • This has the ability to absorb some of the heat from the atmosphere, making the atmosphere slightly cooler.
  • This is how La Nina produces a cooling effect.

The post EL NINO AND INDIAN MONSOON appeared first on Vajirao IAS.

[ad_2]

Source link

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *