Understanding ENSO: An Ocean-Atmospheric Process
The El Nino Southern Oscillation (ENSO) is a significant climate pattern found across the equatorial Pacific Ocean.
ENSO is fundamentally an ocean-atmospheric process. This means it involves the continuous interaction and feedback between the ocean's surface conditions and the overlying atmosphere.
- Oceanic Component: ENSO is marked by changes in sea surface temperatures (SSTs). Specifically, the waters in the central and eastern equatorial Pacific periodically warm up (El Niño) or cool down (La Niña) compared to average.
- Atmospheric Component: These ocean temperature changes directly impact atmospheric circulation. They affect wind patterns, air pressure, and rainfall distribution across the Pacific and often globally.
The key is the *coupling* between the ocean and atmosphere. Changes in the ocean influence the atmosphere, and atmospheric patterns, like trade winds, can in turn modify ocean conditions. This interconnected system defines ENSO.
While ENSO events have widespread effects on land weather patterns, the core phenomenon driving these effects is the interaction occurring between the ocean and the atmosphere.
Important Questions from Enso and Ocean-Atmosphere
- Which of the following is NOT a dominantly interannual phenomenon?
- How does El Nino influence atmospheric $\text{CO}_2$ levels?
- Which one of the following has a positive correlation with the NINO3 INDEX, which represents ENSO variability?
Given:
a) The Eastern Indian Ocean is warmer than the Western Indian Ocean
b) The Eastern Indian Ocean is colder than the Western Indian Ocean
c) Excess anomalous rainfall in the East Africa
d) The westerly wind anomaly is in the Eastern Indian Ocean
Which of the above conditions co-occur with the positive Indian Ocean Dipole?
- Which one of the following anomalous features is NOT associated with the El Nino?
