Factors that Influence Climate

Factors that Influence Climate• Unequal heating of Earth’s surface by the Sun.

• Angle of insolation, albedo, proximity to water. • Rain Shadow Effect • Atmospheric Convection Currents

Shape of the Earth

The light is more intense when it hits the Earth’s surface at higher angle.

Earth’s Tilt and Orbit Around the Sun• There are three ingredients that create the seasons

on Earth. – Earth revolves around the sun. – Earth’s axis is tilted. – Earth’s axis always points in the same direction.

• Because of this, the angle of insolation changes in a given location, which changes the: – Intensity of the insolation. – Temperature of the area.

Other Factors To Consider...• Albedo

– Some areas reflect the sun’s light better than others. • Use albedo to quantify how well it reflects.

Changes In Albedo• The concern with global warming is the melting of the

polar ice caps, glaciers, and sea ice.

Urban Heat Island Effect• The increase in

temperature of a man-made area in comparison to the area’s natural landscape.

– The annual mean air temperature of a city with 1 million people or more can be 1-3°C warmer than its surroundings.

– In the evening the difference can be as high as 12°C. • More pronounced at night because of the slow release of heat from urban

infrastructure.

Urban Heat Island Effect• The increase in temperature of a man-made area in comparison

to the area’s natural landscape. – Built surfaces replace vegetation and moisture-trapping soils.

• Reduces the amount of insolation used for evapotranspiration, which keeps the air cooler.

– Built surfaces have a lower albedo and therefore absorb the insolation.

• Narrow building arrangements create urban canyons that inhibit the escape of reflected radiation.

– Air conditioners, refrigerators, and industrial processes create heat that is released into the atmosphere.

Conventional paving materials can reach peak summertime temperatures of 48–67°C, transferring excess heat to the air

above them and heating stormwater.

Consequences• Increased urban

temperatures leads to… – Increased energy demands – Elevated Air Pollution

Emissions – Elevated Greenhouse Gas

Emissions – Compromised human

health and comfort – Impaired Water Quality

Solutions• Change the albedo by…

– Cool paving materials – Increasing tree and vegetative cover – Installing cool - mainly reflective - roofs – Creating green roofs

Proximity To Water• Water has a high heat capacity, which means…

…water heats up and cools down slowly • Coastal areas heat up and cool down slower than

inland. • Less variation in temperature than inland.

• Coastal areas heat up and cool down slower than inland. • Less variation in

temperature than inland.

What Can We Learn From Israel?

Cool and Dry

Hot and DryHot and Humid

It’s All About the Mountains!

• Mountains – Air rises up the mountains,

the warm, moist air expands and cools to form clouds and rain.

– Air coming down the mountain is dry and contracts so clouds can’t form.

• Elevation – Because we live in the troposphere, the temperature

decrease with altitude. – Mountain tops are cooler than sea level.

It’s All About the Mountains!

On the windward side there is rainy weather.

On the leeward side there is dry, desert conditions.