ESAEducationHomeWeather and ClimateGlobal ChangeNatural Disasters
   
Weather
Foehn windInteractive MeteosatMeteosat images
Climate
African climateEl NiñoGulf StreamHimalayan climateExplore the world and its climate with JP ExplorerLake Chad
 
 
 
 
 
printer friendly page
Exercise 4: La Niña
 
La Niña
 
 
La Niña is characterised by colder than usual ocean temperatures in the Equatorial Pacific. It is caused by strong trade winds that make the warm pool shrink and cool the Tropical Pacific. The climate is drier and colder off the coast of both North and South America. The upwelling of cold water is stronger, and the phytoplankton concentration grows. The La Niña phenomenon usually takes places in the months following an El Niño event, and is part of the ENSO process.
 
Atmospheric convection is confined to the Western end of the basin. Rain is abundant over Indonesia.

We can also observe the effect of La Niña on sea level and surface temperatures. They are the opposite of the El Niño year. Usually SST anomalies show a more visible pattern than altimetry anomalies.  
 
LEOWorks exercise
 
It is possible to make some animations with the series of data we have.

Open the data files from 2007-2008. Compose animations with the altimetry and SST data for this period and study them.

In the LEOWorks image processing programme open Tools/Image Animation, which brings up the Select Files for Animation window. Choose the proper animation speed. You can see the number of the slide by activating the Active Slider.
 
 

1. Can you explain what effect La Niña has over the mean sea level and SST?

2. What are the differences with respect to El Niño?


 
 
 


El Niño
IntroductionBackground
Exercises
Exercise 1: Sea Level HeightExercise 2: Sea Surface TemperatureExercise 3: Ocean Colour
Eduspace - Software
LEOWorks 3
Eduspace - Download
Altimetry (2007-2008) (zip)SST (2007-2008) (zip)
Related links
Ocean Surface Topography from SpaceGHRSSTAVISO - ENSO maps
 
 
 
   Copyright 2000 - 2014 © European Space Agency. All rights reserved.