climatic variation

Climatic VariationWhy climate is different in different locations

Latitude

Why does latitude make a difference?The same amount of solar energy is spread

across a greater area as you move away from the equator

Seasonal differences

* The angle of incidence changes as the seasons change•Summer = more direct sunlight (closer to 90°) + longer sunlight hours = more heating• A lower angle of incidence also means the suns rays pass through more atmosphere before they reach the earth = more diffusion = less heat

The surface of the earthDifferent

types of surfaces reflect or absorb sunlight

The amount of reflectivity is known as ‘albedo’

Land vs SeaLand heats and cools twice as much as water- to raise the temp 1°C water needs twice as

much heat as land!The transparency of water allows it to

distribute heat more readilyLand controlled climate (e.g. Russia) has

wide ranges of temp.Water (maritime) controlled climate (e.g. NZ)

has a smaller temp. range

Land vs Sea IINote the

amount reflected from ice vs water.

Think – why does melting ice caps matter…?

The moisture systemThis system is powered by the sun. The more

solar energy – the more the capacity to hold water vapour in the atmosphere.

Humidity = amount of water vapour in the air; 100 = saturated, 10% = dry

Air rises » As it rises it cools 0.6°C per 100m » it condenses into droplets and forms clouds » As clouds rise droplets increase and rain falls

There are three types of rainfall…

Convection rainfall

Frontal (cyclonic) rainfall

So how about the Waitakere Ranges?Summer – high incidence angle (72-75°),

wind predominantly from the West/North-West bringing hot moist air from the Tasman Sea. Occasionally large fronts of warm air come south and meet cooler air over North Island. Average temp =