Grantee Research Project Results

2011 Progress Report: Constraining ammonia emissions and PM2.5 control efficiencies with a new combination of satellite data, surface observations and adjoint modeling techniques

EPA Grant Number: R834559
Title: Constraining ammonia emissions and PM2.5 control efficiencies with a new combination of satellite data, surface observations and adjoint modeling techniques
Investigators: Henze, Daven K
Institution: University of Colorado at Boulder
EPA Project Officer: Chung, Serena
Project Period: May 1, 2010 through April 30, 2013 (Extended to April 30, 2014)
Project Period Covered by this Report: May 1, 2011 through April 30,2012
Project Amount: $249,942
RFA: Novel Approaches to Improving Air Pollution Emissions Information (2009) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air

Objective:

The project goal is to reduce existing uncertainties in current estimates of NH₃ emissions in order to better characterize and control distributions of fine particulate matter (PM_2.5) and reactive nitrogen. The specific research objectives are to:

quantify the magnitude and variability, both geographical and seasonal, of U.S. NH₃ emissions at a high spatial resolution; and
provide detailed estimates of PM_2.5 control efficiencies and how they will evolve owing to regulations that alter key balances among inorganic particulate species.

Progress Summary:

The main goal of the second year of this project was to constrain NH₃ emissions through assimilation of remote sensing observations from TES. Assimilation of TES NH₃ retrievals into the GEOS-Chem model has been performed for April, July, and October over North America, using observations from the years 2006-2009 and model simulations for the year 2008 run at 2^oby 2.5^o resolution. The NH₃ simulations after emissions optimization were compared to surface observations from several sources: the AMoN network of NH₃ monitoring, NTN wet deposition data, and IMPROVE aerosol measurements. These evaluations are included in Zhu et al. (2012), to be submitted shortly following final approval from the co-authors. This manuscript also includes inverse modeling tests using pseudo observations performed during year 1, and draws from experience gained in evaluating the TES NH₃ product in year 1 (Shephard et al., 2011; Pinder et al., 2011). A challenge during the assimilation has been the fine spatial resolution (5 km 8 km) and sparsity of the TES observations compared to the GEOS-Chem model grid. The nested grid GEOS-Chem adjoint has now been developed, and thus subsequent analysis will be performed at the 0.5^o to 0.666^o resolution over the United States.

Additional efforts have begun to focus on NH₃ deposition. The adjoint of GEOS-Chem was extended to allow for calculation of the sensitivity of reactive nitrogen deposition to emissions. This is the first such tool that has been used to evaluate source contributions to deposition (as opposed to concentrations). A manuscript has been submitted focusing on the role of various sources of reactive nitrogen worldwide (Paulot et al., 2012). This work includes evaluations of the relative importance of NO_x vs NH₃ in controlling deposition of reactive nitrogen to ecosystems, and how these factors are likely to evolve in the coming decades following estimated emissions projections from the RCP4.5 scenario prepared for the next IPCC report.

Lastly, with additional support from a complementary project (NASA ACMAP NNX10AG63G), the impacts of the bidirectional exchange of NH₃ are being explored. Initial evaluations in CMAQ have compared the NH₃ simulations with the standard emissions inventory to a process-based bidirectional exchange model. TES observations, in additional to many in situ surface measurements, are used to evaluate these simulations. These efforts may help us to interpret the changes to the emissions resulting from the inverse modeling.

Future Activities:

The remaining efforts will focus on non-attainment modeling and evaluation of emissions control efficiencies. For this purpose, the nested GEOS-Chem adjoint model will be used for sensitivity analysis over the United States. We will consider both present day and future emissions scenarios. In addition, we also will complete a study using deposition observations as an alternative means of constraining the NH₃ inverse model.

Journal Articles on this Report : 4 Displayed | Download in RIS Format

Publications Views
Other project views:	All 49 publications	10 publications in selected types	All 10 journal articles

Publications
Type	Citation	Project	Document Sources
Journal Article	Paulot F, Jacob DJ, Henze DK. Sources and processes contributing to nitrogen deposition: an adjoint model analysis applied to biodiversity hotspots worldwide. Environmental Science & Technology 2013;47(7):3226-3233.	R834559 (2011) R834559 (2012) R834559 (Final)	Abstract from PubMed Full-text: ES&T-Full Text HTML Exit Abstract: ES&T-Abstract Exit Other: ES&T-Full Text PDF Exit
Journal Article	Pinder RW, Walker JT, Bash JO, Cady-Pereira KE, Henze DK, Luo M, Osterman GB, Shephard MW. Quantifying spatial and seasonal variability in atmospheric ammonia with in situ and space-based observations. Geophysical Research Letters 2011;38(4):L04802 (5 pp.).	R834559 (2010) R834559 (2011) R834559 (2012) R834559 (Final)	Full-text: Wiley-Full Text HTML Exit Abstract: Wiley-Abstract Exit Other: Wiley-Full Text PDF Exit
Journal Article	Shephard MW, Cady-Pereira KE, Luo M, Henze DK, Pinder RW, Walker JT, Rinsland CP, Bash JO, Zhu L, Payne VH, Clarisse L. TES ammonia retrieval strategy and global observations of the spatial and seasonal variabiity of ammonia. Atmospheric Chemistry and Physics 2011;11(20):10743-10763.	R834559 (2010) R834559 (2011) R834559 (2012) R834559 (Final)	Full-text: ACP-Full Text PDF Exit Abstract: ACP-Abstract Exit
Journal Article	Zhu L, Henze DK, Cady-Pereira KE, Shephard MW, Luo M, Pinder RW, Bash JO, Jeong G-R. Constraining U.S. ammonia emissions using TES remote sensing observations and the GEOS-Chem adjoint model. Journal of Geophysical Research–Atmospheres 2013;118(8):3355-3368.	R834559 (2011) R834559 (2012) R834559 (Final)	Full-text: Wiley-Full Text PDF Exit Abstract: Wiley-Abstract Exit

Supplemental Keywords:

ammonia, emissions, inverse modeling, adjoint sensitivity, environmental policy, air quality regulations, fine particulate matter, aerosols, remote sensing, data assimilation, 4D-Var, public health, eutrophication

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.