Unit 4

Question 1

The role of the Sun in defining the Earth’s climate system

Answer 1

• main driver of the climate system.
• emits solar radiation which heats the Earth and sets in motion the circulation patterns of the atmosphere and ocean that influence the development of weather systems.
• the amount of solar radiation received by the Earth is modulated by aspects of the Earths orbit around the sun

Question 2

The role of the Oceans in defining the Earth’s climate system

Answer 2

• covers about 70 percent of the Earth’s surface
• oceans heat and cool more slowly than air, moderating the climate of coastal areas
• ocean currents help to distribute heat around the globe by moving warm tropical water toward the poles, and then at depth, returning coolerwater back toward the equator

Question 3

The role of Water in defining the Earth’s climate system

Answer 3

• the average amount of precipitation an area receives (as rain or snow) is an important part of its climate
• water also helps to cool the surface (through evaporation), reflects the sun’s energy (as clouds or ice caps), and helps to keep the earth wam (as water vapour)

Question 4

The role of the Atmosphere in defining the Earth’s climate system

Answer 4

• acts like a protective blanket, keeping Earth warm and screening out many of the sun’s harmful ultraviolet rays
• made up of distinct layers, the atmosphere acts as a storehouse for various gases and particles
• both the composition of the atmosphere and air circulation patterns have a major effect on climate and weather systems

Question 5

The role of Land in defining the Earth’s climate system

Answer 5

• Land masses and their features - such as forests, deserts, glaciers and mountains - can influence both global and regional climate in a number of ways
• land heats and cools more quickly than water, affecting the flow of air currents and the formation of weather systems
• the type of land surface affects the amount of the sun’s energy that is reflected or absorbed by the earth
• bright areas such us snowpack and sea ice are very reflective
• darker areas such as those with forest cover absorb more heat
• vegetation and soils also play an important role in the hydrological cycle and in the flux of greenhouse gases into and out of the atmosphere

Question 6

Albedo

Answer 6

• the reflectivity of a surface, the fraction of sunlight that is reflected by a surface rather than absabed
• higher albedo (more reflection) leads to cooler temperatures because less sunlight is absorbed
• lower albedo (more absorption) leads to warmer temperatures because more sunlight is absorbed
• heat island - urban areas experience higher temperatures than surrounding rural areas due to human activities

Question 7

Earths energy budget

Answer 7

• the Sun is the primary source of energy for earth (solar radiation)
• 30% reflected back into space
  -70% absorbed by earths surface

Question 8

Outgoing energy (Earths radiation)

Answer 8

• the earths surface and atmosphere radiate heat back into space primarily as longwave infrared radiation
• not all outgoing radiation escapes into space, a portion is absorbed and re-radiated by gases in the atmosphere which trap heat in the greenhouse effect

Question 9

Energy balance

Answer 9

• ideally, the amount of incoming energy from the Sun equals the amount of outgoing energy from the earth
• if more energy is retained than is radiated out, the planet warms
• if more energy is radiated out than is received, the planet cools

Question 10

Atmosphere

Answer 10

• made up of layers of gases, distributing heat around the earth because of convection, conduction, and radiation
• convection - the earths surface absorbs heat from the sun, warming the air directly above it
• radiation - the atmosphere plays a role in heat distribution by trapping some of the outgoing infrared radiation from earths surface

Question 11

Atmosphere layers

Answer 11

Troposphere - layer closest to the earths surface
Stratosphere - commercial jets fly here
Mesosphere - meteors burn up from friction with air molecules in the mesosphere
Thermosphere - reflects outgoing radio waves back to earth without the use of satellites, auroras occur here

Question 12

Oceans

Answer 12

• heat distribution due to its ability to absorb, store, and release heat
• thermohaline gradient - ocean conveyer belt, driven by temperature and salinity differences