The Saint Louis “Ozone Garden”, An Education/Outreach Component of AQAST by Jack Fishman and Kelley Balina. The St. Louis Ozone Garden Project is a collaborative effort led by Saint Louis University’s Center for Environmental Sciences (CES), the Missouri Botanical Garden, and the Saint Louis Science Center.  It is intended to be the prototype garden for NASA’s Air Quality Applications Science Team that will serve as a display that demonstrates the impact of degraded air quality on the planet’s living biota.  In future years, it is envisioned that similar gardens will be planted at other locations around the country, with other members of the AQAST forming partnerships with their own local Science Centers and/or Botanical Gardens.  For more information, please see these updates: May 2012 | Apr 2012.

Air quality over the Canadian oil sands: A first assessment using satellite observations by Chris McLinden et al., Geophys. Res. Lett., 39, L04804, doi:10.1029/2011GL050273, 2012. [Download] This first analysis of pollution over the Canadian oil sands using satellite instruments (primarily OMI) revealed distinct enhancements in NO2 and SO2 over a region of intensive surface mining (roughly 30 km E-W by 50 km N-S). A pixel averaging technique was used to obtain high-resolution maps which showed the peak values of both species were directly over the mining locations. The trend in NO2 over this period was found to be +10.4%/year, a figure consistent with both in-situ NO2 monitors in the area and the rate of oil production. A quantitative estimate of how SO2 varied over this period could not be made. Figure at left: Time series of the mass of NO2 enhancement (above background) over the surface mining area based on seasonally-averaged (2005-2011) OMI data.  The linear trend derived from these data was 10.4±3.5 %/year.

Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations by Siwen Wang et al., Atmos. Chem. Phys. Discuss., 12, 45-91, 2012. [Download] This work continues efforts to apply satellite column retrievals to study NOx emissions from newly constructed coal-fired power plants in China, using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid, 3-D global chemical transport model (GEOS-Chem) over the period 2005-2009. The modeled, summer-average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82) with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. Figure at left: Relative changes of annual and summer-average OMI NO2 columns, biomass burning emissions, major anthropogenic activities, and absolute changes of annual and summer-average temperature, relative to 2007, in Northeast China.

Meteorological modes of variability for fine particulate matter (PM2.5) air quality in the United States: implications for PM2.5 sensitivity to climate change, by A.P.K. Tai, L.J. Mickley, D.J. Jacob, et al., Atmos. Chem. Phys. Discuss., 11, 31031–31066, 2011. [Download]. Model projections in the literature for the sensitivity of PM2.5 to 21st-century climate change show no consistency even in the sign of the effect. This work takes an observation-based approach by identifying the dominant meteorological modes affecting PM2.5 in different US regions and then examining the effect of climate change on these modes.  It concludes that 21st-century climate change will likely degrade PM2.5 air quality. Figure at left: 1999-2010 anomaly correlation of annual mean PM2.5 concentrations and cyclone period for the US Midwest.

Statistical Air Quality Forecast Support during DISCOVER-AQ, by Gregory G. Garner and Anne M. Thompson, in prep. Statistical models, using regression trees and extreme-value prediction theory, were provided to the Maryland Department of the Environment as supplemental forecast tools in predicting poor air quality days. Ensembles of these models objectively provide the probability and confidence in experiencing the various levels of air quality for a given day. Figure at left: Distribution of statistical predictions of maximum 8-hr average surface ozone at Howard University’s site in Beltsville, MD valid for July 2, 2011. Distribution is color-coded according to the Air Quality Index. Mean, mode, and 95% confidence interval around the mean are provided.

Improved estimate of the policy-relevant background ozone in the United States using the GEOS-Chem global model with 1/2° x 2/3° horizontal resolution over North America", by Zhang et al., Atmos. Environ., 6,769-6,776, 2011. [Download]. This work provides the foundation for the PRB ozone estimates used in the Integrated Science Assessment (ISA) for the ongoing review of the ozone NAAQS. Figure at left: Annual 4th highest PRB ozone simulated by GEOS-Chem for 2006-2008.

Transport of Asian pollution into surface air over the western United States in spring”, by Lin et al., submitted to J. Geophys. Res., 2011 [Download]. This work shows that Asian emissions can contribute 8-15 ppb ozone in western US surface air on days when total ozone exceeds 60 ppb. It introduces a proof-of-concept approach to forecast Asian pollution events in the western US using AIRS satellite CO observations with time lags of 1-2 days. Figure at left: Correlation of  Asian ozone pollution enhancement at Grand Canyon NP (white circle) in the GFDL AM3 global high-resolution (~50x50 km2) model with AIRS satellite CO observations 2 days prior.