within this range on which we could expect the normalor mean temperature to occur. This study could bebroken down further into hours of the day, etc., asrequired.REVIEW QUESTIONSQ6-6. If one adds all the daily high temperatures forthe week and divides by 7, whatclimatological parameter would bedetermined by this calculation?Q6-7.A temperature of 124 degrees Fahrenheit wasthe highest temperature ever recorded at aparticularstation.Whattypeofclimatological parameter was determined?Q6-8.What is a degree-day?CLASSIFICATION OF CLIMATELEARNINGOBJECTIVE: Recognizeclimatic zones and climatic types as they relateto the classification of climate.The climate of a given region or locality isdetermined by a combination of several meteorologicalelements and not by just one element. For example, tworegions may have similar temperature climates but verydifferentprecipitationclimates.Theirclimaticdifference, therefore, becomes apparent only if morethan one climatic factor is considered.Since the climate of a region is composed of all ofthe various climatic elements, such as dew, ice, rain,temperature, wind force, and wind direction, it isobvious that no two locations can have exactly the sameclimate. However, it is possible to group similar areasinto what is known as a climatic zone.CLIMATIC ZONESThe basic grouping of areas into climatic zonesconsists of classifying climates into five broad beltsbasedonastronomicalormathematicalfactors.Actually they are zones of sunshine or solar climate andinclude the torrid or tropical zone, the two temperatezones, and the two polar zones. The tropical zone islimited on the north by the Tropic of Cancer and on thesouth by the Tropic of Capricorn, which are located at23 1/2° north and south latitude, respectively. TheTemperate Zone of the Northern Hemisphere is limitedon the south by the Tropic of Cancer and on the north bythe Arctic Circle located at 66 1/2° north latitude. TheTemperate Zone of the Southern Hemisphere isbounded on the north by the Tropic of Capricorn and onthe south by the Antarctic Circle located at 66 1/2°south latitude. The two polar zones are the areas in thePolar Regions which have the Arctic and AntarcticCircles as their boundaries.Technically,climaticzonesarelimitedbyisotherms rather than by parallels of latitude (fig. 6-1).A glance at any chart depicting the isotherms over thesurface of the earth shows that the isotherms do notcoincide with latitude lines. In fact, at some places theisotherms parallel the longitude lines more closely thanthey parallel the latitude lines. The astronomical orlight zones therefore differ from the zones of heat.CLIMATIC TYPESAny classification of climate depends to a largeextent on the purpose of the classification. For instance,a classification for the purpose of establishing airstationswherefavorableflyingconditionsareimportant would differ considerably from one forestablishing the limits of areas that are favorable for thegrowing of crops. There are three classifications thatmerit particular attention. They are the classificationsof C. W. Thornthwaite, W. Köppen, and G. T.Trewartha.Thornthwaite’s classification of climates places agreat deal of emphasis on the effectiveness ofprecipitation. Effectiveness of precipitation refers tothe relationship between precipitation and evaporationat a certain locality. Thornthwaite classified climatesinto eight main climatic groups; five groups giveprimary emphasis to precipitation and the other threegroups are based on temperature.Köppen’s classification includes five main climatictypes. They are tropical rain, dry, warm temperaterainy, cool snow forest (boreal), and polar climates.These main types are further divided into climaticprovinces. The Köppen classification is based mainlyon temperature, precipitation amount, and season ofmaximum precipitation. Numerical values for theseelements constitute the boundaries of the above types,which were selected primarily according to their effecton plant growth. Figure 6-2, shows Köppen’s climatictypes.6-6
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business