Current Affairs Question - 16 April 2019

Explanation :

Xinjiang Province of People’s Republic of China is bordered by eight countries namely Mongolia, Russia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan and India.

Explanation :

EI-Nino is merely an extension of the warm equatorial current which gets replaced temporarily by cold Peruvian Current or Humboldt Current. This current increases the temperature of water on the Peruvian coast by 10°C. Hence, statement 1 is correct.

The process of upwelling along the coast of South America in eastern pacific takes place during a normal year and not during an El-Nino. Statement 2 is therefore incorrect. Upwelling occurs where water from the deeper parts of the ocean is allowed to travel upwards to the surface. In Upwelling deep ocean water is generally very cold and nutrient rich. Therefore, in areas of upwelling we often find very productive waters.

This nutrient rich water transport into the surface waters where sunlight, also required for phytoplankton growth (photic zone), is present, results in rapid growth of phytoplankton populations.

Since phytoplankton form the base of marine food webs, the world’s most productive fisheries are located in areas of coastal upwelling that bring cold nutrient rich waters to the surface.

Explanation :

The shifting of the warm water current towards the Peruvian Coast creates a low pressure area over the South American coast and a high pressure area around the indo pacific region. It leads to dry conditions in the Indo pacific region and wet conditions on the Peruvian coast thereby affecting the equatorial atmospheric circulation. Statement 1 is therefore correct.

During a normal year there is more evaporation at the Australian Coast as compared to the Peruvian Coast due to the presence of a warm water current near the Australian Coast. All of this is reversed and this causes irregularities in the evaporation of sea water. Hence, statement 2 is also correct.

Since the process of upwelling is weak during an El Nino, the nutrient rich water is unable to come to the surface and bring nutrients leading to reduction in the amount of planktons and thereby the number of fish.

Explanation :

Indian Ocean Dipole (IOD) is an event which the western Indian Ocean becomes alternately warmer and then colder than the eastern part of the Indian Ocean. Hence, statement 1 is incorrect.

A positive IOD leads to greater monsoon rainfall and more active (above normal rainfall) monsoon days while negative IOD leads to less rainfall and more monsoon break days (no rainfall). So yes, IOD can influence El Nino’s impact on Monsoon. Hence, the second statement is correct.

Explanation :

The atmospheric carbon dioxide concentration is rising year-on-year due to human emissions, but now it is getting an extra boost due to the recent El Nino event. El Nino warms and dries tropical ecosystems, reduces their uptake of carbon as well as exacerbates forest fires.

Also, generally warm El Niño events are characterized by more tropical storms and hurricanes in the eastern Pacific and a decrease in the Atlantic, Gulf of Mexico and the Caribbean Sea. In El Niño years, the wind patterns are aligned in such a way that the vertical wind shear is increased over the Caribbean and Atlantic. The increased wind shear helps to prevent tropical disturbances from developing into hurricanes. In the eastern Pacific, the wind patterns are altered in such a way to reduce the wind shear in the atmosphere, contributing to more storms.