Geography & History Notes | KCSE, NECTA, ZIMSEC & GCSE

  Lapse rate refers to the natural fall in temperatures with an increase in altitude OR a rise in temperatures with a decrease in altitude. As warm air rises, it expands and cools leading to a fall in temperatures. The increase in temperature or heat is caused by the compression of the air as altitude falls. Types of Lapse Rate: The lapse rate is described in three (3) ways: Environmental lapse rate It is the rate at which temperatures change with an increase or a decrease in altitude. It is the vertical distribution of the temperature of a given geographical location at a particular period Dry adiabatic lapse rate It is the rate at which dry air cools as it rises without affecting the temperature of the surrounding atmosphere. Dry air cools at a faster rate of 1-degree centigrade per 100 metres of ascent Saturated (Wet) adiabatic lapse rate this refers to the rate at which air saturated with water vapour cools as it rises to greater heights (higher levels) of the atmosphere . Sa...

  Solar radiation refers to the energy transmitted from the sun to the earth through the atmosphere . It passes in the atmosphere in form of a beam of short wave rays (solar shortwave radiation) Solar radiation is received in a place during the day in a form of light and it is converted into heat at the earth’s surface The amount of solar radiation received in a place also varies from time to time. The air, clouds , and the ozone in the atmosphere absorb some of this energy while dust particles and clouds reflect and scatter the energy into the space. The earth, therefore, absorbs only a fraction of the energy emitted by the sun. The nature of the earth’s surface (Albedo) is used to express the ability of a surface to reflect insolation Conditions Influencing the In-coming Solar Radiation In an area: Latitude The angular distance of a place from the equator partly determines the distance from the sun to the earth’s surface. This further determines the angle of incidence at which th...

  Some of the most significant consequences of temperature inversions are the extreme weather conditions they can sometimes create. One example of this is freezing rain. This phenomenon develops with a temperature inversion in a cold area because snow melts as it moves through the warm inversion layer. The precipitation then continues to fall and passes through the cold layer of air near the ground. When it moves through this final cold air mass it becomes "super-cooled" (cooled below freezing without becoming solid). The super-cooled drops then become ice when they land on items like cars and trees and the result is freezing rain or an ice storm. Intense thunderstorms and tornadoes are also associated with inversions because of the intense energy that is released after an inversion blocks an area’s normal convection patterns. Smog Although freezing rain, thunderstorms, and tornadoes are significant weather events, one of the most important things impacted by an inversion la...

  We have two types of climatic classifications, that is the Greek System of climatic classification and Köppen's scheme. Both have their functions according to how they are used, we are going to look at this classification of climates one by one and also discuss how the Greek System and Köppen's scheme work together. The Greek System climate classification The Greeks were among the first set of people in the world to classify climates. Their scheme divided the world into the following three climatic zones based on temperature : 1. Torrid or Hot: Areas within the Tropics that experience intense heat. 2. Frigid or Very Cold: Areas of excessive cold in the Arctic and Antarctic regions. 3. Temperate or Mild: Areas lying between the torrid and frigid zones which are neither too hot nor too cold. The Greek scheme is inadequate because: 1. It is simplistic. 2. It ignores such vital climatic factors as latitude , altitude, prevailing winds, vegetative cover, and ocean currents ....