Source: The Hindu, Live Mint and Indian Express
THUNDERSTORMS AND TORNADOES
Context
- Rain, thunderstorm leave over 50 dead in Rajasthan, Madhya Pradesh, Gujarat and Maharashtra.
Essentials
Thunderstorms and Tornadoes
- These are examples of local storms.
- They occur for short durations, over a small area but are violent.
Thunderstorms
- A thunderstorm is a well-grown cumulonimbus (clouds with huge vertical development) cloud producing thunder and
- Thunderstorms are caused by intense convection on moist hot days.
- Convection: It is the upward movement of air after being heated by warmer ground and on account of being warmer than the surrounding air.
- When the clouds extend to heights where sub-zero temperature prevails, hails are formed and they come down as
- If there is insufficient moisture, a thunderstorm can generate dust-storms.
- A thunderstorm is characterised by intense updraft (an upward current of air) of rising warm air which causes precipitation.
Tornadoes
- From severe thunderstorms sometimes spiralling wind descends like a trunk of an elephant with great force, with very low pressure at the centre. Such a phenomenon is called a
- The sky usually turns green, yellow or black.
- The path of a tornado can be erratic and may suddenly change direction.
- Tornadoes typically snake erratically from southwest to northeast.
- A tornado can last just a few minutes or a few hours.
- A tornado moves over the ground at speeds between 20 and 90 km/h.
- Tornadoes generally occur in middle latitudes.
- The tornado over the sea is called water spouts.
What are Wall Clouds?
- A wall cloud is a portion of a thunderstorm cloud that appears to hang underneath the main cloud base.
- It is associated with the main updraft (upward moving warm air) of the storm.
- If the wall cloud persists for more than a few minutes and appears to rotate, it is a sign of a possible tornado, although only about 10-15% of rotating wall clouds generate tornadoes.
- Do tornadoes always come from a wall cloud? A wall cloud is not always present.
Scale to measure the intensity of Tornado?
- The Fujita scale (F0 to F5) is used to rate the severity of tornadoes after they occur by the extent of the damage they cause.
- F0 is the least intense; F5 the most intense.
DIRECTORATE GENERAL OF CIVIL AVIATION (DGCA) VS AIRPORTS AUTHORITY OF INDIA (AAI)
Context: The Directorate-General of Civil Aviation (DGCA) will conduct a special safety audit of the low-cost carrier IndiGo following concerns about the snag-ridden Pratt and Whitney (P&W) engines, which power the airline’s A320 Neo aircraft.
Essentials
Directorate General of Civil Aviation (DGCA)
- It is the regulatory body in the field of Civil Aviation, primarily dealing with safety issues.
- Functions:
- Registration of civil aircraft;
- Formulation of standards of airworthiness for civil aircraft registered in India and grant of certificates of airworthiness to such aircraft;
- Licensing of pilots, aircraft maintenance engineers and flight engineers, and conducting examinations and checks for that purpose;
- Granting of Air Operator’s Certificates to Indian carriers;
- Regulation of air transport services operating to/from/within/over India by Indian and foreign operators;
- Conducting investigation into accidents/incidents and taking accident prevention measures;
- Coordination at national level for flexi-use of air space by civil and military air traffic agencies;
- Interaction with the International Civil Aviation Organization(ICAO) for provision of more air routes for civil use through Indian air space;
- Keeping a check on aircraft noise and engine emissions and collaborating with the environmental authorities in this matter, if required;
- Promoting indigenous design and manufacture of aircraft and aircraft components by acting as a catalytic agent;
- Approving training programmes of operators for carriage of dangerous goods, issuing authorizations for carriage of dangerous goods, etc.
The Airports Authority of India (AAI)
- It was formed with a view to accelerate the integrated development, expansion, and modernization of the operational, terminal and cargo facilities at the airports in the country conforming to international standards.
- Major Functions:
- Design, Development, Operation and Maintenance of international and domestic airports and civil enclaves.
- Control and Management of the Indian airspace extending beyond the territorial limits of the country, as accepted by ICAO.
RISING CARBON DIOXIDE LEVELS AND THEIR EFFECTS ON CROPS/PLANTS
Context: Zinc deficiency rising in Indians due to rising CO2 levels in the atmosphere.
- Higher concentrations of atmospheric carbon dioxide affect crops in two important ways:
- they boost crop yields by increasing the rate of photosynthesis, which spurs growth, and
- they reduce the amount of water crops lose through transpiration.
- Plants transpire through their leaves, which contain tiny pores called stomata that open and collect carbon dioxide molecules for photosynthesis. During that process they release water vapour.
- As carbon dioxide concentrations increase, the pores don’t open as wide, resulting in lower levels of transpiration by plants and thus increased water-use efficiency.
- Trees and other plants help keep the planet cool through evapo-transpiration.
- Carbon dioxide decreases evaporative cooling by plants and that this decreased cooling adds to global warming.
- High carbon dioxide will increase the runoff from the land surface in most areas, because more water from precipitation bypasses the plant cooling system and flows directly to rivers and streams.
- Rising carbon dioxide levels can accelerate zinc deficiency in crops and thus in human consumption.
- The highest rate of inadequate zinc intake was concentrated mainly in the southern and northeastern States with rice-dominated diets: Kerala, Tamil Nadu, Andhra Pradesh, Manipur and Meghalaya.
- National grain fortification programmes, increased dietary diversity, bio-fortified crops, and reduced carbon dioxide emissions could all make a difference to slow or reverse the course.
- Inadequate zinc intake can have serious health consequences, particularly for young children, who are more susceptible to contracting malaria, diarrhoeal diseases and pneumonia, when suffering from zinc deficiency.
- The presence of zinc plays a critical role in human immune systems.
YEMEN CRISIS
- Context: President Donald Trump on Tuesday vetoed a resolution from Congress directing him to end U.S. support for the Saudi-led war in Yemen.
Essentials
- Yemen crisis: Who is fighting whom?
- Yemen, one of the Arab world’s poorest countries, has been devastated by a civil war.
- How did the war start?
- Failed political transition following an Arab Spring uprising that forced its longtime authoritarian president, Ali Abdullah Saleh, to hand over power to his deputy Abdrabbuh Mansour Hadi, in 2011.
- President Hadi struggled to deal with a variety of problems, including
- attacks by al-Qaeda,
- a separatist movement in the south,
- the continuing loyalty of many military officers to Mr Saleh, as well as
- corruption, unemployment and food insecurity.
- The Houthi movement (by Yemen’s Zaidi Shia Muslim minority) took advantage of the new president’s weakness by taking control of their northern heartland of Saada province and neighbouring areas and later forcing Mr Hadi to flee abroad.
- Disillusioned with the transition, many ordinary Yemenis – including Sunnis – supported the Houthis.
- Alarmed by the rise of Houthis – believed to be backed militarily by regional Shia power Iran, Saudi Arabia and other mostly Sunni Arab states (UAE, Bahrain, Kuwait, Qatar, Jordan, Sudan, Egypt) began an air campaign aimed at restoring Mr Hadi’s government.
- The coalition received logistical and intelligence support from the US, UK and France.
