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Subsidence Sinking (downward) motion in the atmosphere, usually over a broad area. Subsiding air usually leads to drier conditions. Convergence Convergence in a horizontal wind field indicates that more air is entering a given area than is leaving at that level. To compensate for the resulting “excess,” vertical motion may result: upward forcing if convergence… Read More »

The role of Oceans on Climate: 

4. El Niño and La Niña processes and their effects on Africa’s climate                                             El Niño and La Niña: Weather’s sibling rivalry – For Dummies Weekly Pacific sea temperatures Monthly Pacific sea temperatures Effects… Read More »

A synoptic weather map is a weather chart reflecting the state of the atmosphere over a large area at a given moment. Examples of synoptic charts can seen here. Today’s Synoptic Chart Today’s South African Weather Chart can be seen here. GRADE 10 RECAP: Weather elements: temperature, dew-point temperature, cloud cover, wind direction,wind speed and atmospheric pressure.… Read More »

The Earth’s Energy Balance 1. The unequal heating of the atmosphere 1.1. Latitudinal 1.2. Seasonal – Significance of Earth’s axis and revolution around the Sun 2. Transfer of energy and energy balance 2.1. Role of ocean currents   2.2. Role of winds SOURCE: http://montessorimuddle.org/2011/04/21/global-atmospheric-circulation-and-biomes/ The Northern Hemisphere’s Polar Jet Stream  

Africa’s Weather and Climate

Areas at risk: regional and local scales The global water crises Drought risk Map – source Compare the above map with the one below of Total Annual Rainfall – source   Source: http://www.eldoradocountyweather.com/ Causes of droughts  Drought from jmoncur Climate change is cause of Ethiopian drought El Niño as a cause of drought in… Read More »