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PMEL Atmospheric Chemistry Climate Air Quality. The Scientists History Highlights of results Near future plans.
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PMELAtmospheric ChemistryClimateAir Quality • The Scientists • History • Highlights of results • Near future plans
NOAA PMELTim Bates, Scientist, UW affiliate faculty Trish Quinn, Scientist Jim Johnson, Scientist Derek Coffman, Research TechnicianKristin Schulz, Research TechnicianDrew Hamilton, Research TechnicianUniversity of WashingtonDavid Covert, Research FacultyTad Anderson, Research FacultySarah Doherty, Research Scientist, IGAC executive officerYonghua Wu, Research associate Berko Sierau, Research associate Rob Elleman, PhD candidateRobert Charlson, ProfessorNOAA CMDL & Aeronomy, Boulder
JISAO/PMEL hosts the IGAC International Project Office Dr. Sarah Doherty, JISAO Scientist, IGAC Executive Officer www.igac.noaa.gov In Cooperation with the IAMAS Commission on Atmospheric Chemistry and Global Pollution (CACGP) A Core Project of the International Geosphere-Biosphere Programme (IGBP)
Aerosols, Climate, Air Quality • Direct effect - scattering (absorbtion) of solar radiation with a net cooling effect on the Earth’s surface. • Indirect effect – alter cloud reflectivity, lifetime, extent, precipitation. • Transport and transformation of gas and condensed phase from sources to downwind regions.
HistoryCharlson,Lovelock,Andreae,Warren.1987 1987 – Charlson et al.
PMEL/JISAO Atmospheric Chemistry - Aerosol Field Projects (1992-2004)
Atmospheric Aerosols Brighten CloudsDurkee et al., 2001 Ship tracks off the west coast of the US. Higher particle concentrations at a fixed liquid water content result in more reflective clouds.
Atmospheric Aerosols Brighten CloudsSchwartz et al., 2002 Sulfate particle number concentration Blue-high Red- medium Green-Low
Sea salt dominates total and submicron aerosol mass in remote marine regions (ACE-1). (Quinn and Bates, 2005)
Sea salt dominates total and submicron aerosol light extinction in remote marine regions (ACE-1). (Quinn and Bates, 2005)
The ocean is a minor source of CO, CH4, and OCS to the atmosphere. • The remote oceans are a small source of ammonia to the atmosphere. However, ammonia is still the dominant gas-phase basic species in the remote marine atmosphere. • The ocean is the major natural source of sulfur to the atmosphere. Air-sea exchange of DMS is only a minor sink in the seawater sulfur cycle. • There is no direct connection between DMS emissions and particle number concentration in the overlying atmosphere. • Sea salt dominates sub- and supermicron aerosol mass and light extinction in the remote marine atmosphere. PMELAtmospheric ChemistryClimateAir Quality
IPCC: In order to understand how the Earth’s climate is changing, it is critical to quantify each mechanism that changes the balance of radiation coming into and going out of the Earth-atmosphere system.
Aerosol chemical composition is needed to attribute aerosols to sources Quinn & Bates, 2005
Air pollutants are transported intercontinentally affecting air quality and climate in regions far downwind
The aerosol optical depth measured off the East Coast of the U.S. was comparable in magnitude to that measured off the coasts of Asia (ACE-Asia) and Indian (INDOEX). Quinn & Bates, 2005
A large fraction of the submicron aerosol mass over the oceans in not sulfate. • Absorbing aerosols have a complex impact on radiative forcing at the surface. • Asian dust is relatively non-absorbing. • The NE U.S. plume can be of comparable magnitude to the Indian and Asian plumes in terms of aerosol mass, surface extinction, and aerosol optical depth. PMELAtmospheric ChemistryClimateAir Quality
Mission Goal 2: Understand Climate Variability and Change to Enhance Society’s Ability to Plan and Respond • High-Level Outcome #2: Document and understand changes in climate forcings and feedbacks, thereby reducing uncertainty in climate projections • Mission Goal 3: Serve Society’s Needs for Weather and Water Information • High-Level Outcome #3: Establish National Air Quality Forecast Capability
Research Questions How do chemical transformation and physical transport processes affect the spatial distribution of aerosols in the marine boundary layer? What are the chemical, physical, and optical properties of atmospheric aerosol particles and how do these properties affect regional haze and aerosol direct and indirect radiative forcing of climate? How will the aerosol direct and indirect radiative forcing of climate change with changing regional air quality?
Improved chemical transport and radiative transfer models NASA, NCAR, NOAA, ONR, DOE Community Collaboration Strategy Satellite Observations Anderson, Charlson, Wu In-situ Measurements PMEL and UW
Obtaining a Global Aerosol Distribution Global satellite observations provide aerosol and geophysical data to refine and constrain chemical transport and radiative transfer models. MISR on Terra CALIPSO Aerosol Lidar in Space
2008 Pacific transport 2006 Gulf Coast
Single Scattering Albedo o = scat /ext = s /(s + a) The highest mass fractions of EC and lowest SSA were observed off the Indian subcontinent. Quinn and Bates, 2005
Single Scattering Albedo Mean SSA observed during ACE Asia in air masses containing pollution and dust was 0.94 ± 0.03. Quinn and Bates, 2005