Download to read offline
ENSO ppt.pdf , it is about ENSO phenomena
- 1.
- 2. DEFINITION OF ENSO ElNino– Southern Oscillation (ENSO) is a global climate phenomenon that emerges from variation in winds and sea surface temperatures over the tropical Pacific Ocean. The warming phase of the sea surface temperature is known as "El Nino" and the cooling phase as "La Nina". The Southern Oscillation is the accompanying atmospheric oscillation, which is coupled with the sea temperature change. Source:https://www.google.com/search
- 3. • El NinoSouthern Oscillation (ENSO) is a recurring oceano-atmospheric condition in the Southern equatorial pacific due to change in the sea surface temperature. This alternating warming and cooling pattern, also known as the ENSO cycle, has a direct impact on rainfall distribution in the tropics and may have a significant impact on weather across the Indian subcontinent and other parts of the world. So this combination of El Nino, La Nina, and the neutral state between the two opposite effects is called the El Nino Southern Oscillation (ENSO). DIFFERENT PHASES OF EL NINO-SOUTHERN OSCILLATION (ENSO): The El Nino– Southern Oscillation is a single climate phenomenon that periodically fluctuates between three phases: Neutral La Nina El Nino La Nina and El Nino are opposite phases in the oscillation which are deemed to occur when specific ocean and atmospheric conditions are reached or exceeded.
- 4. EL NINO El Ninois associated with higher than normal air sea level pressure over Indonesia, Australia and across the Indian Ocean to the Atlantic. Source:https://www.google.com/search El Nino is the warming of sea waters in the Central-east Equatorial Pacific that occurs every few years ( Warm phase off the coast of Peru ). During El Nino, surface temperatures in the equatorial Pacific rise which weakens the trade winds — east-west winds that blow near the Equator. Due to El Nino, warm western pacific mound created in normal years start receding back because of which warm water gets accumulated near eastern pacific ocean due to el nino current. It thus brings warm water from the western Pacific towards America.
- 5. CHARACTERISTICS OF ELNINO : • Associated with weak monsoons and drought-like conditions in India • Sea surface temperature in the equatorial Pacific Ocean rises above normal levels • Changes in the atmospheric circulation patterns • Shift in the location of the jet stream, affecting the strength and direction of the monsoon winds • Results in reduced rainfall, dry spells, and heatwaves, leading to crop failures and water scarcity Source : https:// www.google.com/search
- 6. LA NINA La Ninahas roughly the reverse pattern: high pressure over the central and eastern Pacific and lower pressure through much of the rest of the tropics and subtropics. Source :https://www.google.com/search • La Nina is just the opposite of El Nino. • It is the positive extreme of the walker cell. • It sees cooler than average sea surface temperatures in the eastern equatorial Pacific region. Trade winds are stronger than usual, pushing warmer water towards Asia.
- 7. CHARACTERISTICS OF LANINA : • Associated with above-normal rainfall and floods in India • Sea surface temperature in the equatorial Pacific Ocean drops below normal levels • Changes in the atmospheric circulation patterns • Increase in the strength of the monsoon winds, bringing more moisture and rainfall to India • Excessive rainfall can also lead to floods and landslides, causing damage to crops and infrastructure
- 8. NEUTRAL (WALKER CELL): • Neither El Nino nor La Nina situation . • The Walker circulation (walker cell) is caused by the pressure gradient force that results from a high pressure system over the eastern Pacific ocean, and a low pressure system over Indonesia and nearby regions. Source: https://en.wikipedia.org/wiki/Walker_circulation
- 9. THREE PHASES OFENSO Source:https://www.climate.gov/media/16090
- 10. EL NINO ANDINDIAN MONSOON The El Nino-Southern Oscillation (ENSO) significantly influences the Indian summer monsoon. • El Nino and its impact on Indian monsoon: El Nino refers to abnormal warming of surface waters in the equatorial Pacific Ocean, which tends to suppress monsoon rainfall in India. • Phases of El Nino Southern Oscillation (ENSO): ENSO consists of three phases in the Pacific Ocean: El Nino, La Nina (abnormal cooling), and a neutral phase with sea surface temperatures close to long-term averages. • Ocean and atmospheric conditions: ENSO involves not only temperature abnormalities of sea surface waters but also atmospheric conditions, including differences in sea-level air pressure and wind strength and direction. • Southern oscillation and the role of winds: Southern Oscillation Index measures the difference in sea-level air pressure over the western and eastern sides of the Pacific Ocean, while wind patterns play a crucial role in ENSO.
- 11. HOW ENSO IMPACTSMONSOON AND AGRICULTURE IN INDIA : Monsoon: • ENSO has a profound impact on summer monsoonal rainfall across India, as most major droughts occur during El Nino events. • During La Nina events, above average rainfall is witnessed in the Indian sub-continent. Agricultural productivity: • El Nino has a direct impact on India's agricultural sector since it tends to reduce the production of summer crops. • For example, affected crops include rice, sugarcane, cotton, and oilseeds. • Rainfall during La Nina events might result in farmers losing their standing Kharif crops. • For example, while Kharif crop harvesting happens in September-end or early October, any rain immediately before that would be damaging to the standing crops.
- 12. OTHER IMPACTS ININDIA • Temperature Extremes: ENSO can also influence temperature extremes in India. During El Nino, parts of India may experience higher temperatures, exacerbating heatwaves and affecting crops, livestock, and human health. • Water Resources: El Niño-induced droughts can deplete water reservoirs and groundwater levels, affecting irrigation and water availability for agricultural purposes. • Pest Outbreaks: Changes in temperature and moisture conditions during ENSO events can influence the prevalence of pests and diseases, affecting crop health and yields. • Livelihood and Food Security: The variability in monsoon rainfall due to ENSO can impact rural livelihoods, especially for farmers who heavily rely on rainfed agriculture. Fluctuations in agricultural productivity can also affect food security in the country.
- 13. ENSO is oneof the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation, which in turn influences temperature and precipitation across the globe. Because of ENSO, we can often predict the arrival of many seasons in advance of its strongest impacts on weather and climate.
- 14.