Climate Lecture 1- The Climate System

Question 1

What is climate?

Answer 1

What you expect

Question 2

What is weather?

Answer 2

What you get

Question 3

What is a system?

Answer 3

A set of interacting objects

Question 4

What are the three elements of a system?

Answer 4

Components
Flows of energy
Feedbacks

Question 5

What is an open system?

Answer 5

Allows energy and mass to pass across the system boundary

Question 6

What is a closed system?

Answer 6

Allows energy but not mass across its boundary system.

Question 7

What are the 5 spheres?

Answer 7

Atmosphere
Hydrosphere
Cryosphere
Biosphere
Lithosphere

Question 8

Give an example of sea ice albedo feedback.

Answer 8

Increased temp, Arctic sea ice melts, darker surfaces revealed, albedo reduced, increased absorption of solar radiation.
Positive feedback

Question 9

What is the atmosphere?

Answer 9

Envelope of air held to the earth’s surface by gravity.

Question 10

What is the structure of the armosphere?

Answer 10

Troposphere (11km - tropopause)
Stratosphere (50km - stratopause)
Mesosphere (80km- mesopause)
Thermosphere

Question 11

What is the ABL?

Answer 11

Atmospheric boundary layer/planetary boundary layer
Troposphere
Around 2km then there is a capping inversion.

Question 12

What is the most abundant gas in the atmosphere?

Answer 12

N (78.08%)

Question 13

How much Oxygen in atmosphere?

Answer 13

20.95%

Question 14

How much water in atmosphere?

Answer 14

0 to 4%

Question 15

How much carbon dioxide in the atmosphere?

Answer 15

0.0360%

Question 16

How much methane in the atmosphere?

Answer 16

0.00017%

Question 17

Name a location where co2 is monitored?

Answer 17

Mauna Loa

Question 18

What was the August 2024 Co2 ppm?

Answer 18

422.99

Question 19

What was the August 2023 Co2 ppm?

Answer 19

419.68

Question 20

Discuss the greenhouse effect?

Answer 20

Infrared raditation is emitted by earth to space.
Radiation aborbed by Earth
Earth surface reflects radiation to atmosphere
Infrared radiation is reemitted back to earth.

Question 21

Discuss the distribution of air across Earth’s surface.

Answer 21

Either side of equator high pressure.
Poles typically have lower pressure but this is more noticable in the Southern Hemisphere.

Question 22

What does global cloud amount reflect?

Answer 22

Distibution of atmospheric moisture.

Question 23

Discuss global cloud cover.

Answer 23

Mid latitudes it decreases around (30 degrees)
Highest seen at around -60 degrees (SH)

Question 24

What is the hydrosphere?

Answer 24

Oceans, surface and subsurface water

Question 25

Discuss global ocean circulation patterns.

Answer 25

Cold water at the pole which heats up at the equator.

Question 26

What is the cryosphere?

Answer 26

Mountain glaciers, ice sheets, snow, sea ice, permafrost and frozen ground.

Question 27

Discuss seasonal variation in sea ice.

Answer 27

NH- high in Feb and low in Sept SH- low in Feb and higher in Sept

Question 28

Is global glacier mass balance decreasing?

Answer 28

Yes, -30 in terms of mass balance.

Question 29

What is the biosphere?

Answer 29

Flora and fauna

Question 30

Where is PET highest?

Answer 30

Hotter areas such as near the equator.

Question 31

What does the carbon cycle consist of?

Answer 31

Fluxes and storage

Question 32

What is the lithosphere?

Answer 32

Land surface and subsurface

Question 33

What is orographic rainfall?

Answer 33

Prevailing winds and moist warm air = moisture condenses as the air cools due to change in topography , relative humidity increases. Rainy windward slope. Dry leeward slope (rain shadow) as coop air depleted of moisture sinks and warms and so relative humdity decreases.

Question 34

How do volcanic eruptions influence global temperatures?

Answer 34

Partiulate matter and aerosols. E.g. Mount Pinatubo (1991) In 1992 and 1993 average temp in NH reduce 0.5-0.6 degrees and entire planet cooled by 0.4 to 0.5.

Question 35

Discuss chemical weathering feedback.

Answer 35

Negative - Initial change, warmer climate, increased temp and precipt and vegetation, increased chemical weather, increased co2 removal by weathering and so reduction of initial warming. Negative - Initial change, colder climate, decreased temp and precip and vegetation, decreased chemical weatherinf, decreased co2 removal by weather and so reduction of initial cooling.