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Flashcards in Aerosol forcing Deck (52)
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1

What is radiative forcing?

The change in net irradiance at the tropopause with surface and tropospheric temperatures held fixed (positive values imply a heating of the troposphere)

2

How will CO2 change in the future?

Considerable uncertainty, don't know how it will evolve in the future

3

What is an aerosol?

Suspension of tiny particles in the air, with a diameter between 0.01-10 micrometers

4

What makes up aerosols?

Sulfates, nitrates, organic compounds, metals, dust, sea salt ...

5

Where do aerosols come from?

-industry
-volcanoes (natural)
-fertilisers
-diesel fuel
-turpines

6

How many people does EU legislation on aerosols save per year?

800,000

7

How much soot is produced from biomass burning per year?

54 Tg

8

How much industrial dust is emitted every year?

100 Tg

9

How much anthropogenic sulphate is emitted each year?

200 Tg

10

How much biogenic volatile organic carbon (VOC) is emitted every year?

16-500 Tg

11

Where are aerosols generated?

-over industry
-natural: forest fires, dust etc.
-overall, anywhere outside of the poles, aerosol is being generated

12

Which two ways can be classify aerosols?

Primary and Secondary

13

What is a primary aerosol?

An aerosol that is directly emitted to the atmosphere e.g. sea salt

14

What is a secondary aerosol?

Originate from gases which then oxidise or nucleate to form the secondary aerosol (important for cloud formation)

15

What does volatile mean?

Easily evaporated (less volatile means something is more likely to condense)

16

What two ways are aerosols removed?

Dry and wet processes

17

How does lifetime of aerosols change if they reach the stratosphere?

Longer life time e.g. after volcanic eruptions, can remain for a few years

18

What is aerosol mass important for?

Light scattering

19

What is aerosol number important for?

Effect on clouds (CCN)

20

How does aerosol mass differ?

Bulk concentration near emission source

21

How does aerosol number differ?

Homogenised, reasonable spread (secondary aerosols are able to form further away from source)

22

What is the annual mean mass of PM2.5?

1-100 µg m-3

23

What is the annual mean surface particle number?

100-10,000 particles m-3

24

What model predicts annual mean surface particle number?

GLOMAP global aerosol model

25

What satellites predicts annual mean mass of PM2.5?

MODIS satellite

26

Where does anthropogenic sulphate originate from?

Burning fossil fuels, Volcanoes and Phytoplankton

27

How does burning fossil fuels generate sulphate aerosol?

SO2 and CO2 oxidises to Sulphuric acid (H2SO4) which nucleated and condenses to Sulfate aerosol

28

What is one direct aerosol effect?

Scattering and absorption of solar radiation

29

What is one indirect aerosol effect?

Changes in cloud properties

30

Which band of the EM spectrum does aerosol forcing mostly affect?

Short wave radiation