Scientific Linkage of Air Pollution and Climate through Meteorological Mechanisms: A Summary of Find

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Scientific Linkage of Air Pollution and Climate
through Meteorological MechanismsA Summary of
Findings

• Daniel J. McNamara, S.J., Ph.D.
• Manila Observatory

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• The Manila Observatory is a private non-stock,
  non-profit, scientific research institution
  established in 1865 by the Jesuit mission in the
  Philippines.

PROGRAMS

Climate Change Assistance Center (klima)
Regional Climate Systems
- envisions itself as a vital partner in
critically global yet locally relevant concerns
in environment and development
Geomatics for Environment and Development
Urban Air Quality
Instrumentation and Technology Development
- through a science that must inform and guide
the shaping of a safe and sustainable future for
humankind.
Solid Earth Dynamics/Crustal Deformation
www.observatory.ph
www.klima.ph
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Objective

• To provide an overview of the physical mechanisms
  by which air pollution, particularly aerosols,
  affect climate and potential climate change.

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Aerosols a Form of Air Pollution

• Solid particles and liquid suspended in air.
• Ex. Elemental carbon/soot, organic carbon, HCs,
  VOCs, elemental sulfur, sulfate aerosols, traces
  of metals.
• Anthropogenic sources include internal combustion
  engines, industrial emissions, construction
  sites, fires/smoke.

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Effects of Aerosols

• Radiative Forcing
• Influence on Cloud Formation
• Shifting of Terrestrial Sinks/Sources

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Radiative Forcing
Absorption
LIGHT PARTICLES More reflection (high
albedo) DARK PARTICLES More absorption (low
albedo)
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Aerosol Radiative Forcing

• Forcing imposing changes on planetary energy
  balance by influencing incoming radiation
• Direct scattering/reflection or absorption by
  particles themselves
• Indirect influence of particles on optical
  properties and volumes of clouds

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Radiative Forcing

• Sulfates and Organic carbon light-scattering
• Black carbon and other dark aerosols large
  optical absorption cross-sections and low albedo
  which results in a dual effect
• Cooling effect absorption prevents shortwave
  radiation from reaching the earth.
• Warming effect heating in the atmosphere.

Source Carbonaceous Aerosols and Climate
Change How Researchers Proved Black Carbon is a
Significant Force in the Atmosphere, EETD, 2004.
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Radiative Forcing

• Influence of surfaces below
• Light-colored surface intensifies heating in the
  atmosphere by reflecting upwards radiation that
  was transmitted.

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Effects on Cloud Formation
Dark mixture of aerosols
Light-colored mixture of aerosols
Source NASA Explains Puzzling Impact of
Polluted Skies on Climate, Climate Science, July
19, 2006.
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Effects on Cloud Formation

• Particles can also serve as nuclei for
  condensation of cloud droplets and alter optical
  properties of the cloud.
• More surface area and potentially more
  reflectivity.
• Less chance of rain.
• Greater cooling power.

Source Improved Predictions of Cloud Formation
for Better Climate Modeling, Space Daily, Dec.
13, 2004.
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Significance of Clouds

• Cloud changes affect regional temperatures (by
  absorbing and reflecting solar radiation) and
  availability of fresh water.
• Tropical clouds act as hot towers,, a key
  element in convection currents that drive heat
  around the globe.

Source Experiment Probes Climate Riddle, BBC
News/ Science/Nature, January 18, 2006.
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Shifting of Terrestrial Sources/Sinks
Increase in level of aerosols
Changes in terrestrial carbon cycle

• Forest and croplands become carbon sinks.
• Grasslands become carbon sources.
• Lack of shade and higher temperatures slows
  photosynthesis to conserve water.
• Photosaturation easily reached.

Research conducted by North Carolina State
University, funded by NASA, NSF, Office of Naval
Research and NC State Faculty Research and
Professional Devt Award. Source Carbon Sink or
Carbon Source?, Space Daily, Dec. 9, 2004.
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Summary
Amount of Aerosols
Radiative Forcing/ Absorpion vs. Reflection
Cloud Formation

• Terrestrial Surface Properties
• lightness/darkness
• carbon sink/source

Amount of Global Warming
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Ongoing and Future Researchat the Manila
Observatory

• Application of geometric algebra to determine the
  index of refraction of aerosols and quantify
  scattering vs. absorption.
• Use of Light Detection and Ranging (LIDAR) to
  measure particulate matter and correlate with
  climatological parameters.

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Thank you!