Global systems Sections 1.1 and 2.2

Climate

the average weather conditions in a region measured over a period of several years

Weather

refers to specific atmospheric conditions at a particular location at a specific instant of time

What is climate determined by

Temperature and precipitation

The biosphere contains …

Atmosphere (air)

Hydrosphere(water)

Lithosphere(earth)

What is the source of all energy on earth

Sun

Insolation - Climate term

The amount of the sun’s energy that is actually received on the the Earth’s surface.

The higher latitudes receive slanting rays and more

at lower latitudes the sun rays are

the suns rays arrive

diffuse energy

more concentrated

parallel to the earth

Angle of incidence- Climate terms

The angle between the ray and a line that is drawn perpendicular to the Earth’s surface

How does insolation at the equator compare to the poles?

• More insolation at the equator due to direct sunlight and less atmospheric filtering.

• Less insolation at the poles due to low-angle sunlight and more atmosphere to pass through.

How would this impact climate and weather in those areas?

• Equator: Hot, wet, stormy → tropical climates and frequent rain.

• Poles: Cold, dry, calm → icy deserts with little precipitation.

• These differences drive global climate zones, wind patterns, and weather systems that affect the entire planet.

what impacts the angle of incidence and insolation

Earth

Angle of inclination-Climate terms

The earth’s axis of rotation is tilted at an angle of 23.5 from a line drawn perpendicular from its orbital plane.

The only reason why we have seasons is because of this

angle of inclination. The earths tilt changes the insolation at different prats of the earth at different times of the year

Solstice-climate term

one of two points in earths orbit when the poles are most tiltes towards or away from the sun

June 22 summer solstice and winter solstice december 22

Equinox - climate term

When the number of daylight hours is exactly equal to the number of hours of might

Autumnal equinox september 23, vernal equinox is march 21

Absorption and reflection of solar radiation

When solar radiation (sunlight) reaches Earth, it is either absorbed or reflected by the atmosphere, clouds, and Earth's surface. Here's a breakdown:

In the lithmosphere and hydrosphere

The albedo of a surface is the percent of solar radiation that it relfects. THe average albedo of the Earth’s surface is about 30%

Are there ways we as humans could increase albedo?

Decrease albedo?

Can you think of an issue with decreasing albedo in terms of climate change?

Increase: painting roofs with with or reflective colors, creating reflective surfaces

Decreasing: Deforestation, urbanization, melting ice due to global warming, and agriculture changes

In terms of climate change: ice and snow are melting due to global warming

The types and amounts of radiation absorbed or reflects is affected by

1. The gases in the atmosphere: different layers contain different types and amounts of gases

2. Cloud cover and atmospheric dust

The natural greenhouse effect

When solar energy is absorbed by the Earth’s surface, some of it is re-emitted into the atmosphere in the form of radiation

Greenhouse gases such as carbon dioxide, nitrous oxide,

Methane and water vapour prevent some of this longwave

radiation from leaving the atmosphere.

Without this natural greenhouse effect, our average atmospheric temperature would be below 0ºC.

Enhanced greenhouse effect

Human activities led to the build-up of extra greenhouse gases in the atmosphere, As a result, average surface temperatures are rising. Some of these examples are burning fossile fuels, deforestation, and landfills

Earths net radiation buget

• Earth stays at a stable temperature (about 15°C) when the energy it receives from the Sun is equal to the energy it radiates back into space.

• This balance is called radiative equilibrium.

• The equation for Earth’s net radiation budget is:

  Incoming Radiation – Outgoing Radiation = 0

• As long as greenhouse gas levels stay constant and the Sun’s energy stays steady, this balance is maintained.

Affected by the enhanced greenhouse

Thermal energy

According to the second law of thermodynamics, thermal energy always moves from an area of high temperature to an area of low temperature

Radiation

is the emission of energy as particles or waves.

This energy, when absorbed by an object, will increase the kinetic energy and

Therefore, the temperature of the particles that make up the object

example earth taking in energy from the sun

Conduction

Heat moves from one particle to another within a solid. This happens when fast moving particles(hot particles) bump into slower (coolr) particles transferring energy

Convection

Heat travels through the movement of fluids such as liquids or gases. War fluids rise because its less dense and cooler fluids sink, creating a circular flow known as the CONVECTION CURRENT

wind

movement of air from areas of high pressure to low

pressure

Coriolis Effect-

bending of moving currents in response to

Earth’s rotation. The Coriolis effect causes winds in the two

hemispheres to move in opposite directions.

Jet streams

a narrow fast flowing "river" of air in the stratosphere. Changes

in Jet streams are important in predicting severe weather.