Geography SL
10
Chapters
152
Notes
Option A - Freshwater – Drainage basins
Option B - Oceans & coastal margins
Option C - Extreme Environments
Option D - Geophysical Hazards
Option E - Leisure, Tourism And Sport
Option F - The Geography Of Food & Health
Option G - Urban Environments
Unit 1 - Changing Population
Unit 2 - Global Climate - Vulnerability & Resilience
Unit 3 - Global Resource Consumption & Security
Geography SL
Option B - Oceans & coastal margins
Understanding El Niño & La Niña Their Impact On Global Climate
674 words
4 mins read
Last edited on 5th Nov 2024
Table of content
Introduction
- El Niño: Warms up the eastern Pacific approximately every 2-10 years and lasts up to two years. It started as a Peruvian warm current but is now identified as a larger system.
- La Niña: An intermittent cold current flowing from the east across the equatorial Pacific Ocean. It pushes cold upwelling water off the coast of South America into the western Pacific.
Normal pacific conditions
- The Walker Circulation is an east-west wind circulation in lower latitudes. Winds blow offshore near South America, causing cold waters to upwell. Warm surface water is pushed into the western Pacific.
- The Sea Surface Temperatures (SSTs) in the western Pacific are normally over 28°C, creating low pressure and heavy rainfall. In contrast, the SSTs near South America are lower, resulting in high pressure and dry conditions.
- Real World Example: Imagine you're sitting by a campfire (the warm western Pacific). The heat from the fire (or the wind) pushes the smoke away (warm water and rainfall), while behind you (South America), it's colder and clear (dry conditions).
El niño conditions
- El Niño Southern Oscillation (ENSO): During these events, the usual pattern reverses. Warm water flows into the eastern Pacific, increasing SSTs and causing low pressure and heavy rainfall in South America. In contrast, the western Pacific and Indonesia experience warm, dry conditions.
- The effects can be severe. The 1997-98 El Niño event led to over 21,000 deaths and an estimated $36 billion in damages.
- Real World Example: Remember the campfire? Now imagine someone (El Niño) suddenly throws water on it. There's steam (rain) where the fire was (South America) and the smoke (warm, dry conditions) now moves where it was clear before (western Pacific and Indonesia).
Unlock the Full Content! 
Dive deeper and gain exclusive access to premium files of Geography SL. Subscribe now and get closer to that 45 🌟
Geography SL
Option B - Oceans & coastal margins
Understanding El Niño & La Niña Their Impact On Global Climate
674 words
4 mins read
Last edited on 5th Nov 2024
Table of content
Introduction
- El Niño: Warms up the eastern Pacific approximately every 2-10 years and lasts up to two years. It started as a Peruvian warm current but is now identified as a larger system.
- La Niña: An intermittent cold current flowing from the east across the equatorial Pacific Ocean. It pushes cold upwelling water off the coast of South America into the western Pacific.
Normal pacific conditions
- The Walker Circulation is an east-west wind circulation in lower latitudes. Winds blow offshore near South America, causing cold waters to upwell. Warm surface water is pushed into the western Pacific.
- The Sea Surface Temperatures (SSTs) in the western Pacific are normally over 28°C, creating low pressure and heavy rainfall. In contrast, the SSTs near South America are lower, resulting in high pressure and dry conditions.
- Real World Example: Imagine you're sitting by a campfire (the warm western Pacific). The heat from the fire (or the wind) pushes the smoke away (warm water and rainfall), while behind you (South America), it's colder and clear (dry conditions).
El niño conditions
- El Niño Southern Oscillation (ENSO): During these events, the usual pattern reverses. Warm water flows into the eastern Pacific, increasing SSTs and causing low pressure and heavy rainfall in South America. In contrast, the western Pacific and Indonesia experience warm, dry conditions.
- The effects can be severe. The 1997-98 El Niño event led to over 21,000 deaths and an estimated $36 billion in damages.
- Real World Example: Remember the campfire? Now imagine someone (El Niño) suddenly throws water on it. There's steam (rain) where the fire was (South America) and the smoke (warm, dry conditions) now moves where it was clear before (western Pacific and Indonesia).
Unlock the Full Content!
Dive deeper and gain exclusive access to premium files of Geography SL. Subscribe now and get closer to that 45 🌟