El Nino Current Affairs - 2019

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Scientists discover reasons behind 2015 Chennai Floods

A study conducted by the University of Hyderabad and the Indian Institute of Technology – Bombay has found out that the extreme El Nino conditions and warming of the Bay of Bengal had resulted in unprecedented heavy rainfall in Chennai for three days between November 30th to December 2nd in 2015.

Salient Findings

El Nino usually causes less than normal rainfall in the case of south-west monsoon. However, it does the reverse in the case of the northeast monsoon. It causes above-normal rainfall during the northeast monsoon. This is due to the difference in seasonal wind patterns between the two monsoons.

The researchers had carried out a simple linear correlation analysis that points out that the sea surface temperature at the Bay of Bengal is positively correlated with northeast monsoon rainfall. It has been found out that the magnitude of correlations of northeast monsoon rainfall with El Nino conditions and the Bay of Bengal warming to be almost same.

Based on several experiments, the scientists have attributed around 21% of the intensity of the extreme Chennai rainfall to the extreme El Nino condition

The consistent warming of the Bay of Bengal off the coast of Tamil Nadu and Andhra Pradesh is also considered as an important factor for the floods by the scientists.

However, scientists are yet to ascertain whether the contribution from the tropical Pacific to extreme rainfall during the northeast monsoon occurs only at the time of extreme El Nino or whether normal El Ninos too are capable of causing them.

El-Nino

El-Nino is a weather phenomenon, during which temperature at sea surface is warmer than normal sea-surface temperatures. El Nino is a warming of the Pacific Ocean between South America and the Date Line, centred directly on the Equator, and typically extending several degrees of latitude to either side of the equator. It accompanies high air surface pressure in the western Pacific. El Niño occurs when tropical Pacific Ocean trade winds die out and ocean temperatures become unusually warm

Month: Categories: Environment & Biodiversity

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CO2 level reaches record high in 2016: WMO

According to the World Meteorological Organization’s (WMO) annual Greenhouse Gas Bulletin level of carbon dioxide (CO2) emissions in the atmosphere has reached a record high.

The globally averaged concentration of CO2 in the atmosphere reached to 400 parts per million (ppm) for the first time in 2015. It is expected to surge again to new records in 2016 on the back of the very powerful El Niño event.

Key Facts

  • This is for the first time CO2 levels have reached the 400 ppm barrier on a global average basis for the entire year.
  • Besides, longest-established GHGs monitoring station at Mauna Loa, Hawaii predicts that CO2 concentrations will stay above 400 ppm for whole of 2016 and not dip below that level for many generations.
  • There was a 37% increase in radiative forcing (the warming effect on our climate) because of long-lived GHGs such as CO2, methane and nitrous oxide (N2O) released from industrial, agricultural and domestic activities between 1990 and 2015.

What is relation between CO2 emissions and El Niño event?

  • According to WMO, the growth spurt in CO2 was fuelled by the El Niño event, which started in 2015 and had a strong impact well into 2016.
  • The El Niño event had triggered droughts in tropical regions and reduced the capacity of “sinks” like forests, vegetation and the oceans to absorb CO2.
  • These sinks currently absorb about half of CO2 emissions but now there is a risk that they may become saturated.
  • Once these sinks become saturated it will increase the fraction of emitted CO2 which stays in the atmosphere.

About World Meteorological Organization (WMO)

  • WMO is an intergovernmental organization and specialised agency of the UN for meteorology (weather and climate), operational hydrology and related geophysical sciences. It is a member of the United Nations Development Group.
  • Established: It had originated from the International Meteorological Organization (IMO), which was founded in 1873.
  • Membership: 191 Member States and Territories.
  • Headquarters: Geneva, Switzerland.

Month: Categories: Environment & BiodiversityInternational

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