NSF Facilities User WorkshopAir Pollution Breakout Group
9/25/07
“Each breakout session will define outstanding science questions and key
hypotheses, what observational facilities are needed to address them, and what new technologies would make a difference.”
Key Questions
• Urban air quality, health effects and climate change
• Biomass burning and effects of climate change• Air quality, human health, and global impact
in/of megacities• Long range transport
Air Quality in meduim sized urban areas - Testbed
• Air Quality Testbed idea in Denver/Boulder area? – case study for other medium sized urban areas
• Increasing number of medium-sized urban areas in non-attainment
• Models are used to make policy decisions but underlying science (met., boundary conditions, local transport) are often not well represented
• Model “cases” often constrained to a few days of observations made during intensive field campaigns
• Model uncertainties: 1. emissions (local: oil/gas drilling) 2. met. 3. chemistry
• However there are significant chemistry uncertainties !
• Aerosols poorly represented. Secondary Chemistry important for aerosol formation/growth.
• Coupling chemistry/meteorology• Nonlinearities• Evolution of mixing layer – transition of daily
fully mixed layer to nighttime stable conditions (implications for tightly compacted relic mixing layers and nocturnal jet)
Air Quality in meduim sized urban areas - Testbed
• Climate/chemistry• Using Heat waves to project into future • Increased stability of atmosphere• Increased moisture• Accelerated chemistry• Higher stress on humans – higher sensitivity to pollutants• Trends in urban areas – measurements needed in real time to
characterize this trend – sufficient precision• Needed: low-speed devices which can do lagrangian studies on an
urban/regional scale• Human health impacts – societal issue• Hybrids and other new transportation technology will change
emission patterns in cities in the future• Mercury emissions from energy efficient CF light bulbs – direct
emissions in urban areas
Air Quality in meduim sized urban areas - Testbed
Air Quality in meduim sized urban areas - Testbed
• “Suburban forests”- interaction of urban emissions with biogenic emissions
• Carbon budget• Identity of carbon forming SOA• Intermediate volatility compounds largely
unidentified• EPA enforcement system is flawed (cutting
transportation funding after 8-hour ozone exceedances (often caused by regional background) in an urban area
Air Quality in meduim sized urban areas - Testbed
• Most networks are ground based measurements and they do not characterize the vertical structure of the BL
• Advantage of ground based measurements is temporal space. Remote sensing methods can help characterize the boundary layer structure
• Use satellite data to extrapolate from a local study to other urban areas
Air Quality Testbed Study• Complications for Denver area– Low Humidity– High altitude– Oil exploration– Mountain range
• Advantage for Denver area– logistics– Aircraft emissions– Population
• Other possible sites – Phoenix, San Antonio, Kansa city, Indianapolis, Austin TX
Air Quality Testbed Study• Observation Network
– Access for satellite measurements– Regional radar networks
• Zeppelin– Dedicated at testbed site; storage issue for severe wx– Real time data downlink – enabling scientists on the ground to direct
flight– Duration - few weeks?– Chemistry species: CO, CO2, NOx, O3, Hg, NO, NO2, H2O , VOCs, grab
samples, PAN, radicals – Aerosols: size, composition (AMS), scattering, absorption– Measurement Suites – Pre-package instrument suites depending on
needs for flight day– Dedicated measurement packages
• Small aircraft: G1, Cessna, Hyperlight• C130, others• New OFAP proposal paradigm: long term request for repeat
measurement campaigns over several years
Set Up for Testbed Study• Meteorological Observation Network
– Domain 200 km x 200 km– Resolution for measurement sites (variable)– Rapid response paradigm– Techniques : wind profilers, sondes, aerosol lidars, chemistry sensors,
Max DOAS, existing air quality monitoring networks • NSF Facilities – zepellin, radar network, research aircraft (small
aircraft, slow aircraft)• Possible Partners/ sponsors – Private industry (auto, power
industry, Vaisala, others), Homeland Security, EPA, DEQ, NOAA, DOE
• Sustainability of study – how long does it need to be? Commitment of access to resources of instruments, people, access to aircraft
Set Up for Testbed StudySite selection depends on projection of changing
climate; nature of environmental change needs to be characterized (range of variability –daily/seasonal, precision needed)
Models – input data needed matches what is measured? WRF, CMAQ, CMAX, RAQMS; othersNeed models that forecasts change
Emissions inventory Measurement Techniques :precision must match
processes being measured
Set Up for Testbed Study
Epidemiology – Need to get air quality and public health groups together
Air Quality connection to Public HealthJonathan Patz – aware of epidemiology and air
quality
Science QuestionsBiomass Burning
• Biomass burning – climate change• Drought length increase leads to higher incidence of fire• Wildfires vs ecosystem change• Heating/burning another issue• Two different issues:
– Increase of wildfires due to climate change – Landscape change leads to climate change
• Issue in developing countries and boreal zone• Peat:
– If wet, CH4; if dry, more complex emissions– Peat fires smoulder, are long-lived & more extensive
• Heavy fuel loads existing in forests-> higher risk for more intense and extensive fires
• Savanna/grasslands/chapparral: faster moving fires, prone to drought
Science QuestionsBiomass Burning
• Facilities: mobile van• Ongoing field campaigns and airborne investigations, combined with
satellite data and models, provide the opportunity for additional data • Pyro-cumulus form most intense fires reach UTLS; agricultural fires
emissions tend to stay in lower atmosphere; power plant plumes emit different chemicals so completely different issue
• Plumes: volatile species, pyro-convective, composition difficult to predict (depends on fuel, environmental conditions, location, nature of forest)
• Need better characterization of plume (meteorology, chemistry, dynamics); satellite data (extent, chemistry, evolution, dynamics)
• OCO Validation: include chemistry (CO, O3, others)• HIPPO (CO CO2 CH4 others)• We have the facilities to address this but they may have not be used very
efficiently in a sense of forming a global picture
Air Quality in developing Megacities• Biofuels – public health• Developing countries need assistance in monitoring,
measurements, air quality guidance• Emissions????• Observations needed to verify emission estimates• Need easy to operate instrument package that can
measure lower atmosphere composition • Need to measure HCs, CO, particles, NOy, grab samples
(weekly), in large developing cities (tropical, desert, mid-latitudes, high latitudes); develop instrument package/sampling system for urban emissions
• Build ~10 for pilot study and then more• Needs to be international community effort
Air Quality in developing Megacities• Same connections with epidemiology / public
health than for US urban areas
Impact of long-range transport of pollution
• Bill’s talk – “it matters where it comes down”• How to address this with aircraft? Ground-based
studies?• Good example for value of long-term
measurements is UW station, Pico (Azores)• Remote sensing techniques (aerosols) and small
aircraft could be on station to measure vertical profiles during times of predicted transport events and when transport is absent.