1. 2525 Space Research Building (North Campus)
Climate Change: An Inter-disciplinary Approach to Problem Solving (AOSS 480 // NRE 480)
Richard B. Rood
Cell:
2525 Space Research Building (North Campus)
Winter 2016
January 28, 2016
Particles in the Atmosphere, Aerosols: The role of particulate matter (aerosols) in the atmosphere: heating, cooling; Air quality and climate change; Changes in the Earth’s energy balance changes since the Industrial Revolution.

2. Class Information and News
Ctools site: CLIMATE_480_001_W16
Record of course
Rood’s Class MediaWiki Site
A tumbler site to help me remember
Remember to finish blizzard assignment

3. Resources and Recommended Reading
NASA Resources
Aerosols: What and Why Important
NASA/EO: Smoke and Clouds
NASA/EO: Dust and Desertification
NASA/EO: Volcanoes and Climate Change
NASA/EO: Big Effects of Aerosols
Aerosols: Open Source Systems, Science, Solution
NASA
Realclimate
Aerosols Wikipedia
Miller et al. Onset of Little Ice Age
Particles in the Atmosphere, Aerosols: The role of particulate matter (aerosols) in the atmosphere: heating, cooling; Air quality and climate change; Changes in the Earth’s energy balance changes since the Industrial Revolution.

4. South and East Asian brown cloud Aerosol relation to clouds
Outline: Class 6, Winter 2016
Basics of aerosols
South and East Asian brown cloud
Aerosol relation to clouds
Volcanoes and climate
Models and Little Ice Age
Earth system summary
Changes in radiative balance
Particles in the Atmosphere, Aerosols: The role of particulate matter (aerosols) in the atmosphere: heating, cooling; Air quality and climate change; Changes in the Earth’s energy balance changes since the Industrial Revolution.

5. So what matters? Changes in the sun THIS IS WHAT WE ARE DOING
Things that change reflection
Things that change absorption
When we think of mitigation of climate change, managing or controlling warming, we really only have two things to think about, things that change absorption and things that change reflection.
Accumulation, transport and storage of energy in ocean, ice, land

6. Following Energy through the Atmosphere
We have been concerned about, almost exclusively, greenhouse gases.
Need to introduce aerosols
Continuing to think about
Things that absorb
Things that reflect

7. Aerosols
Aerosols are fine, airborne particles consisting, at least in part, of solid material
They impact the radiative budget.
Absorb
Reflect
They influence cloud formation and growth.

8. Particles in the Atmosphere
Clouds and Aerosols: Particles in the atmosphere.
Water (and other) droplets and ice particles – (CLOUDS)
“Pure” water
Sulfuric acid
Nitric acid
Smog …
Dust
Soot / Black Carbon
Salt
Organic hazes
AEROSOLS CAN:
REFLECT RADIATION
ABSORB RADIATION
CHANGE CLOUD DROPLETS

9. Earth’s aerosols

10. Earth’s Aerosols http://www-das. uwyo

11. Dust and fires in Mediterranean

12. Forest Fires in US

13. The Earth System: Clouds
Clouds are difficult to predict or to figure out the sign of their impact
Warmer  more water  more clouds
More clouds mean more reflection of solar  cooler
More clouds mean more infrared to surface  warmer
More or less clouds?
Does this stabilize?
Water in all three phases essential to “stable” climate
Top of Atmosphere / Edge of Space
CLOUD
ATMOSPHERE
(infrared)
SURFACE

14. The Earth System: Aerosols
Aerosols directly impact radiative balance
Aerosols can mean more reflection of solar  cooler
Aerosols can absorb more solar radiation in the atmosphere  heat the atmosphere
In very polluted air they almost act like a “second” surface. They warm the atmosphere, cool the earth’s surface.
Top of Atmosphere / Edge of Space
ATMOSPHERE
AEROSOLS ?
(infrared)
SURFACE
Composition of aerosols matters.
This figure is simplified.
Infrared effects are not well quantified

15. South & East Asia “Brown Cloud”
But don’t forget
Europe and the US in the 1950s and 1960s
Change from coal to oil economy

16. Asian Brown Cloud (But don’t forget history.)
Coal emits sulfur and smoke particulates
“Great London smog” of 1952 led to thousands of casualties.
Caused by cold inversion layer
 pollutants didn’t disperse + Londoners burned large amounts of coal for heating
Demonstrated impact of pollutants and played role in passage of “Clean Air Acts” in the US and Western Europe

17. Aerosol: South & East Asia

18. Reflection of Radiation due to Aerosol

19. Atmospheric Warming: South & East Asia
WARMING IN ATMOSPHERE, ABSORPTION, DUE TO SOOT (BLACK CARBON)

20. Surface Cooling Under the Aerosol

22. Aerosol relation to clouds

23. The Earth System Aerosols and Clouds Interactions
Aerosols impact clouds and hence indirectly impact radiative budget through clouds
Change their height
Change their reflectivity
Change their ability to rain
Change the size of the droplets
Top of Atmosphere / Edge of Space
CLOUD
ATMOSPHERE
(infrared)
SURFACE

24. Aerosols and Clouds and Rain
Less
Error on original viewgraph for clean cloud. More to less

25. Alan Robock: Volcanoes and Climate Change (36 MB)
Department of Environmental Sciences

26. Department of Environmental Sciences
Explosive
backscatter
absorption (near IR)
Solar Heating
More Reflected
Solar Flux
absorption (IR) IR
Heating
emission
IR Cooling
More
Downward
IR Flux
Less
Upward
Stratospheric aerosols
(Lifetime » 1-3 years)
H2S
SO2
® H2SO4
NET HEATING
Heterogeneous ® Less
O3 depletion Solar Heating
CO2
H2O
forward scatter
Enhanced
Diffuse
Flux
Reduced
Direct
Less Total
Solar Flux
Ash
Effects
on cirrus
clouds
Tropospheric aerosols
(Lifetime » 1-3 weeks)
This diagram shows the main components of non-explosive and explosive volcanic eruptions, and their effects on shortwave and longwave radiation.
Quiescent
Indirect Effects on Clouds
SO2 ® H2SO4
NET COOLING
Alan Robock
Department of Environmental Sciences

27. Superposed epoch analysis of six largest eruptions of past 120 years
Year of eruption
Superposed epoch analysis of six largest eruptions of past 120 years
Significant cooling follows sun for two years
Robock and Mao (1995)
Robock and Mao (1995) removed the ENSO signal, and averaged the temperature change for the six largest recent eruptions, showing the anomaly from the preceding 5-year period. The cooling follows the sun for two years after the eruptions, but is displaced north of the Equator because there is more land in the Northern Hemisphere, so the cooling is larger there. The volcanic aerosol clouds were fairly evenly distributed in latitude.
Robock, A. and J. Mao, The volcanic signal in surface temperature observations, J. Climate, 8, , 1995.
Alan Robock
Department of Environmental Sciences

28. Some important things to know about aerosols
They can directly impact radiative budget through both reflection and absorption.
They can indirectly impact radiative budget through their effects on clouds  both reflection and absorption.
They have many different compositions, and the composition matters to what they do.
They have many different, often episodic sources.
They generally fall out or rainout of the atmosphere; they don’t stay there very long compared with greenhouse gases.
They often have large regional effects.
They are an indicator of dirty air, which brings its own set of problems.
They are often at the core of discussions of geo-engineering

29. Models and Little Ice Age

30. Temperature and CO2: The last 1000 years
Surface temperature and CO2 data from the past 1000 years. Temperature is a northern hemisphere average. Temperature from several types of measurements are consistent in temporal behavior.
Medieval warm period
“Little ice age”

31. Schematic of a model experiment.
Observations or “truth”
Model prediction with
forcing and source of
internal variability T
Model prediction with
forcing
Start model prediction
Model prediction without
forcing T
Eat+Dt = Eat + Dt((Pa – LaEa) + (Traoil + Ma ))

32. Miller et al. Onset of Little Ice Age
Numerical Experiment based on observational evidence of decades long period of high volcanic activity
50 years 4 major eruptions
Sea-ice/ocean feedbacks
No requirement of large changes solar energy

33. Earth-system Summary

34. The Earth System SUN ATMOSPHERE ICE OCEAN (cryosphere) LAND
CLOUD-WORLD
ATMOSPHERE
OCEAN
ICE
(cryosphere)
LAND

35. Where absorption is important
The Earth System
SUN
CLOUD-WORLD
Where absorption is important
ATMOSPHERE
OCEAN
ICE
(cryosphere)
LAND

36. Where reflection is important
The Earth System
SUN
Where reflection is important
CLOUD-WORLD
ATMOSPHERE
OCEAN
ICE
(cryosphere)
LAND

37. The Earth System SUN Solar Variability ATMOSPHERE ICE OCEAN
CLOUD-WORLD
ATMOSPHERE
OCEAN
ICE
(cryosphere)
LAND

38. Storage and transport of energy. Influences surface air temperature
The Earth System
SUN
CLOUD-WORLD
ATMOSPHERE
OCEAN
ICE
(cryosphere)
LAND
Storage and transport of energy. Influences surface air temperature

39. The Earth System
SUN
Increase greenhouse gases reduces cooling rate  Warming
Changes in land use change absorption and reflection
Solar
variability
Cloud feedback?
Aerosols cool?
Cloud feedback?
ATMOSPHERE
LAND
OCEAN
ICE
Water vapor feedback accelerates warming
Ice-albedo feedback accelerates warming

40. Changes in Radiative Forcing

41. Radiative forcing: Changes to absorption and reflection
Earth's most abundant greenhouse gases
water vapor (H2O)
carbon dioxide (CO2)
methane (CH4)
nitrous oxide (N2O), commonly known as "laughing gas"
ozone (O3)
chlorofluorocarbons (CFCs)
Long-lived, well mixed
Short-lived, regional variability
Aerosols, short-lived and regional

42. Radiative Forcing Changes
Excellent article on history of this figure
Interesting History of This Plot at RealClimate

43. Asian brown cloud demonstrate aerosol effects
Summary: Class 6, Winter 2016
Aerosols
Absorb
Reflect
Human and natural
Regional
Short lived
Asian brown cloud demonstrate aerosol effects
Likely “masking” warming
Particles in the Atmosphere, Aerosols: The role of particulate matter (aerosols) in the atmosphere: heating, cooling; Air quality and climate change; Changes in the Earth’s energy balance changes since the Industrial Revolution.

44. Summary: Class 6, Winter 2016 Aerosols change clouds Volcanoes
Precipitation
Characteristics of absorption and reflection
Volcanoes
Important natural drivers of climate variability
Provide one of our best “controlled” experiments
Considering all source of radiative forcing
Warming from greenhouse gases
Aerosols in net cooling  black carbon management
Cloud-aerosol effects are cooling
Particles in the Atmosphere, Aerosols: The role of particulate matter (aerosols) in the atmosphere: heating, cooling; Air quality and climate change; Changes in the Earth’s energy balance changes since the Industrial Revolution.

45. South and East Asian brown cloud Aerosol relation to clouds Volcanoes
Outline: Class 6, Winter 2016
Basics of aerosols
South and East Asian brown cloud
Aerosol relation to clouds
Volcanoes
Models and Little Ice Age
Earth system summary
Changes in radiative balance
Particles in the Atmosphere, Aerosols: The role of particulate matter (aerosols) in the atmosphere: heating, cooling; Air quality and climate change; Changes in the Earth’s energy balance changes since the Industrial Revolution.