What is climatology?  How does it differ from weather?  Describe the Koppen 
Climate Classification and its purpose.


	Climatology is one of the several branches of  physical geography, but it differs 

from weather in several ways.  The term climate implies an average, or long term record 

of weather conditions at a certain region.  It conveys a generalization of all the recorded 

weather observations in a given area.  Weather conditions are recorded in specifics for 

any given moment  in time:  the temperature, percentage of rainfall, and percentage of 

humidity.  Climate on the other hand, is described in more general terms.  Humid 

Equatorial climates, Dry climates, and Cold Polar climates are marked by certain 

prevailing characteristics that can be mapped such as continuous snow or deserts.

	One of the most popular classification systems is the Koppen Climate 

Classification system, which gives different climates three letters that describe that 

climate.  The Koppen Climate Classification system is comparatively simple

and is based on a triad of letter symbols.  The first (capital) letter is the critical one;  the

A climates are humid and tropical;  the B climates are very dry;  the C climates are 

humid and mild;  the D climates reflect increasing cold;  and the E climates mark the 

polar areas.  The first letter is followed by two more letters that further define the climate

of that region.  The second letter represents and explains the dry season:  whether there is 

or isn't a dry season, whether it is a short or long dry season, and what season it comes in
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either a dry winter or a dry summer.  The third letter defines the temperature of different

seasons either a hot or cool summer or a cold or warm winter.

	The purpose of the Koppen Climate Classification  system is to assist in the 
											
realization of the importance of generalization, allowing you to concentrate on the big 

picture unaffected by less important complexities such as trade winds and jet streams.  

This methodology persists as a leading model in contemporary geography.  In fact in 

recent years, geography has expanded the search for theoretical principles through the 

use of laboratory-like abstractions called spatial models.  These spatial models are a 

modern approach to generalization in both physical and human regional geography.