Air Pollutants and GHGs: Field Observations

Miyun Atmospheric Station

The China Project's atmospheric research is committed to building observationally validated, fundamental research on the physical and chemical dimensions of China’s atmospheric environment and the emissions that influence it, at local, regional, and global scales. In addition to the observational research described below, it includes modeling research described here and bottom-up emissions research described here.

In November 2004, a team led by J. William Munger (Harvard School of Engineering and Applied Sciences, SEAS), Michael McElroy (SEAS and Harvard Department of Earth and Planetary Sciences), and HAO Jiming (Tsinghua University School of Environment) deployed a permanent observational station for use in atmospheric research, including the China Project's GEOS-CHEM modeling activities. Since that time, the station has made continuous observations of key trace gases and local meteorological conditions. The station is sited in Miyun, a rural area north of Beijing, to distance it from the influence of individual sources and to measure a variety of conditions as local meteorology shifts, from relatively clean background air to polluted urban plumes. In 2008, WANG Yuxuan (Tsinghua Center for Earth System Science) took over lead responsibilities on the Tsinghua side of the partnership, joined by WANG Shuxiao (School of Environment, Tsinghua University) in 2013. As of 2016, Harvard-Tsinghua measurements at the Miyun station are sponsored by the Harvard Global Institute, and a methane analyzer is in the process of being added. 

A 2008 paper in Atmospheric Chemistry and Physics (ACP) (Wang et al. 2008) used station data and GEOS-Chem to investigate variations of ozone and carbon monoxide in summertime in the Beijing area, contrasting the impacts of monsoonal meteorology in early versus late summer on photochemistry and ozone formation. Wang et al. (2009), in ACP, uses the data record to differentiate how much of reduced ozone levels observed at the station during the Beijing Olympics can be attributed to policy-driven restrictions of emissions, and how much to natural meteorological conditions. Wang et al. (2010a), in Tellus B, examines seasonal variations of CO and O3 over 2005-2007.

A number of subsequent papers analyze the observational records of other important species observed at Miyun.

A study led by Wang and Munger (Wang et al. 2010b) in ACP analyzes the rising observed CO2:CO ratio at Miyun, indicating increasing combustion efficiency in China over time that is consistent with the energy efficiency policies of the 11th Five Year Plan. Given the policy relevance, a summary for non-scientists is available at this link hosted by the ChinaFAQs initiative of the World Resources Institute in Washington, DC. 

Following addition of an analyzer of black carbon (BC) with support of Yutaka Kondo of the University of Tokyo, a 2011 paper in the Journal for Geophysical Research (JGR) led by Wang and Kondo (Wang et al. 2011) takes a first look at the record of BC observations at Miyun, comparing it to bottom-up emission estimates of this critical short-lived climate forcing agent, and identifying possible inventory refinements. Another paper in JGR makes top-down estimates of BC using surface observations, and evaluates the sensitivity to observation representativeness and transport model error (Wang et al. 2013)

A paper in Atmospheric Chemistry and Physics examines the change of sulfate-nitrate-ammonium (SNA) aerosols over China due to anthropogenic emission changes of their precursors (SO2, NOX and NH3) from 2000 to 2015 (Wang et al. 2013).

Acknowledgment: Some of the material summarized here is based on work supported in part by the National Science Foundation under Grants No. ATM-1019134 or ATM-0635548 (indicated by acknowledgments in the papers). Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.