March 4 th, 2019 Sample Current Affairs

Transcription

1 March 4 th, 2019 Sample Current Affairs

2 1. A weak El Niño is developing in the equatorial Pacific Ocean, which is expected to continue for a few months at least. What is El Nino? What causes El Nino? What are El Nino s effects? How frequently do El Niño events occur? Why there has been an increase in its frequency recent years? GS paper 1 (Salient features of world s physical geography) In this video, you can find detailed answers for all the above questions. The above article has been retrieved from: Amitabh Sinha. ( 2019, March, 4). El Niño rising: Will it affect the Indian monsoon?.indian Express. Retrieved from What is the context about? The National Oceanic and Atmospheric Administration (NOAA) of the United States recently announced the development of a weak El Niño in the equatorial Pacific Ocean that was expected to continue for a few months at least.

3 The status of El Niño at this time of the year is usually the first indication of the kind of rainfall that is to be expected during the monsoon season later in the year. What is El Nino? El Nino is a climatic cycle characterised by high air pressure in the Western Pacific and low air pressure in the eastern. In normal conditions, strong trade winds travel from east to west across the tropical Pacific, pushing the warm surface waters towards the western Pacific. The surface temperature could witness an increase of 8 degrees Celsius in Asian waters. At the same time, cooler waters rise up towards the surface in the eastern Pacific on the coasts of Ecuador, Peru, and Chile. This process called upwelling aids in the development of a rich ecosystem. What causes El Nino? El Nino sets in when there is anomaly in the pattern. The westward-blowing trade winds weaken along the Equator and due to changes in air pressure, the surface water moves eastwards to the coast of northern South America. The central and eastern Pacific regions warm up for over six months and result in an El Nino condition. The temperature of the water could rise up to 10 degrees Fahrenheit above normal.

4 Warmer surface waters increase precipitation and bring above-normal rainfall in South America, and droughts to Indonesia and Australia. What are El Nino s effects? El Nino affects global weather. It favours eastern Pacific hurricanes and tropical storms. Record and unusual rainfall in Peru, Chile and Ecuador are linked to the climate pattern. El Nino reduces upwelling of cold water, decreasing the uplift of nutrients from the bottom of the ocean. This affects marine life and sea birds. The fishing industry is also affected. Drought caused by El Nino can be widespread, affecting southern Africa, India, Southeast Asia, Australia, and the Pacific Islands. Countries dependent on agriculture are affected. Australia and Southeast Asia get hotter. A recent WHO report on the health consequences of El Nino forecasts a rise in vector-borne diseases, including those spread by mosquitoes, in Central and South America. Cycles of malaria in India are also linked to El Nino. The rise in sea surface temperature may be intensified by global warming. From the current study, we learn that El Nino can exacerbate global warming and hence the process could become a vicious circle.

5 How frequently do El Niño events occur? El Niño events repeat themselves in a two- to seven-year cycle, with a strong El Niño expected every years. However, since 2000, five El Niño events have already happened, and this year could witness a sixth one. Why there has been an increase in its frequency recent years? New scientific research is pointing to increased frequency of extreme El Niños due to climate change. A paper published in Nature Climate Change in July 2017 had suggested that such extreme events could happen twice as often as today if the average annual global temperatures reached 1.5 C above pre-industrial times.