1. Climate Theory Introduction
Document Reference: RTC-PRE_Climate_Theory_ Date of last revision: 20 Feb 2018

2. Definition of climate
The statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years.
“Average weather”
The classical period is 30 years, as defined by the WMO
Temperature, precipitation, wind, etc
Biomes

3. Factors influencing Climate
Latitude (its influence on the amount of solar radiation received) ***
Air mass influences ***
Location of global high and low pressure areas (pressure belts) ***
Heat exchange from ocean currents
Distribution of mountain barriers
Pattern of prevailing winds
Location of land to the sea
Altitude
*** => Macro Level

4. Different Scales of Climate
Regional climates
Variety of different scales of climatic investigations
macroclimate- largest area of study, area extends for 4 x 108 m2, up to 6000 m vertically
(continental in scale)
mesoclimate- 103 m2 up to 4 x 108 m2 in area
(sub continental in scale)
Local climate - a group of microclimates that characterize a specific region; 103 to 108 m2 in size
Microclimate - the smallest category 1 to 104 m2 in area
An individual field or park

5. Köppen climate classification system
Annual and monthly averages of temperature and precipitation that generally coincided with world patterns of vegetation and soils.
A - Tropical Moist Climates, where all months have average temperatures above 18°C
B - Dry Climates, with deficient precipitation during most of the year.
C - Moist Mid-latitude Climates with Mild Winters.
D - Moist Mid-Latitude Climates with Cold Winters.
E - Polar Climates, with extremely cold winters and summers.

6. Factors influencing climate

7. Latitude and its influence on the amount of solar radiation received.

8. Latitudinal Influence
location of the overhead Sun at solar noon
Inter-tropical convergence zone (ITCZ) – Uplift->clouds->Precip.
Subtropical high pressure zone _ clear skies.
Polar Front Uplift->clouds->Precip.
Polar vortex _clear skies.
Tropical/subtropical and polar air masses (Fronts).
These respond to the seasonal movements of the Sun.

9. Air mass influences

10. Location of global high and low pressure areas
Pattern of prevailing winds

11. Heat exchange with ocean currents

12. Distribution of mountain barriers
Altitude

13. Location of land relative to the sea

14. Wet Dry Warm Cold Köppen climate classification system Grp I Grp II
Tropical wet
Tropical wet and dry
Tropical dry (desert)
Grp I
mid latitude wet
Mid latitude summer or winter dry
mid latitude dry (desert)
Grp II
Polar wet
Polar wet and dry
Polar dry (desert)
III