2525 Space Research Building (North Campus) Climate Change: An Inter-disciplinary Approach to Problem Solving (AOSS 480 // NRE 480) Richard B. Rood Cell: 301-526-8572 2525 Space Research Building (North Campus) rbrood@umich.edu http://aoss.engin.umich.edu/people/rbrood 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.

Class Information and News Ctools site: CLIMATE_480_001_W16 Record of course Rood’s Class MediaWiki Site http://climateknowledge.org/classes/index.php/Climate_Change:_The_Move_to_Action A tumbler site to help me remember http://openclimate.tumblr.com/ Remember to finish blizzard assignment

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.

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.

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

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

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.

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

Earth’s aerosols

Earth’s Aerosols http://www-das. uwyo

Dust and fires in Mediterranean

Forest Fires in US

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

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

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

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

Aerosol: South & East Asia http://earthobservatory.nasa.gov/Newsroom/NasaNews/2001/200108135050.html

Reflection of Radiation due to Aerosol http://earthobservatory.nasa.gov/Newsroom/NasaNews/2001/200108135050.html

Atmospheric Warming: South & East Asia WARMING IN ATMOSPHERE, ABSORPTION, DUE TO SOOT (BLACK CARBON) http://earthobservatory.nasa.gov/Newsroom/NasaNews/2001/200108135050.html

Surface Cooling Under the Aerosol http://earthobservatory.nasa.gov/Newsroom/NasaNews/2001/200108135050.html

Aerosol relation to clouds

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

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

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

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

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, 1086-1103, 1995. Alan Robock Department of Environmental Sciences

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

Models and Little Ice Age

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”

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 ))

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

Earth-system Summary

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

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

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

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

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

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

Changes in Radiative Forcing

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

Radiative Forcing Changes Excellent article on history of this figure http://www.realclimate.org/index.php/archives/2013/10/the-evolution-of-radiative-forcing-bar-charts/ Interesting History of This Plot at RealClimate

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.

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.

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.