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.