Tracey Holloway

Hi there - thanks for visiting my webpage. I am a Professor at the University of Wisconsin—Madison, jointly appointed in the Nelson Institue for Environmental Studies and the Department of Atmospheric and Ocean Sciences. I’ve been on the faculty of UW-Madison since 2003, when I was hired as part of an initiative to strengthen energy research and teaching. All of my work relates in some way to air quality or energy - from using satellites to study the chemistry of the atmosphere, to using computer models to understand how energy policies affect air pollution and public health.

I serve as the Team Leader for the NASA Health and Air Quality Applied Science Team (HAQAST), the President of the Earth Science Women’s Network (ESWN), and lead efforts in corporate and alumni engagement for the Energy Analysis and Policy (EAP) graduate certificate program in the Nelson Institute. I provide more detail on each of these projects below, as well as my research, teaching, and broader outreach initiatives.


Clouds and Power Plant

A photo I took in Seattle, 2017 - out on a morning walking before the NASA HAQAST meeting

My home base at UW-Madison is the Nelson Institute Center for Sustainability and the Global Environment, affectionately known as “SAGE." SAGE is an interdisicplinary research center connecting physical science methods with environmental policy issues. My work on air quality fits into SAGE, since air quality links meteorology, chemistry, computer science, and engineering with public policy, urban planning, and public health. In particular, my team uses computer models, ground-based measurements, and satellite data to understand links between regional air quality, energy, and climate. For a general overview of my work, I’d suggest a 2015 article online here.

Most of my work relates to computer models of atmospheric dynamics and chemistry, especially the Community Multiscale Air Quality (CMAQ) model and the Weather Research and Forecasting (WRF) model. We run these models over specific regions of the world, with most work focused on the U.S., but past studies looking at East Asia and India as well. These computer models allow us to understand how specific chemical reactions or meteorological processes affect air pollution, and they allow us to test out “what if?” scenarios related to energy policy, technology, urban planning, and climate change.

Over the past few years, I have become an active user of satellite data, and I have worked with the NASA Air Quality Applied Science Team (AQAST, 2011-2016) and the NASA Health and Air Quality Applied Science Team (HAQAST, 2016-2016), which both have the mission of connecting satellite data and other NASA science with decision-making and applications for health and air quality.


Tracey and Students at Climate Symposium

At the 2017 Climate Symposium - I’m in the middle - with undergraduate researchers Elise Penn and Stacy Montgomery (both left) and Peidong Wang and Maria Castillo (right)

In the Fall 2016 semester, I am teaching “Introduction to Air Quality” (ES401), a soup-to-nuts introduction to the science of air pollution, and “Energy for Modeling and Policy (ES900), a discussion-based seminar on energy modeling for graduate students, especially students in the Energy Analysis and Policy graduate certificate program. In the Spring 2017 semster, I will be teaching “Air, Energy, and Policy” (ES600) a capstone class for seniors, where we will work with a energy company or similar stakeholder to address a real-world problem related to air qualty and policy. Last year, this class worked with Alliant Energy in what was a fantastic partnership and learning opportunity. I will also be launching a new First-Year Interst Group (FIG) class on “Building a Clean Energy Future” (L&S 107), which will be paired with Chemistry 104 (students in the FIG will take both classes together, as a cohort).

I love engaging students in research, and I welcome inquiries from undergraduates (any year) who would like to get involved research related to air pollution. See details below.

Beyond the classroom and the lab, I am involved in programs to support career development and diversity in science, especially the Earth Science Women’s Network (ESWN), which I co-founded in 2002, and for which I current serve as President. I was honored as the first ever recipient of the MIT C3E (Clean Energy Education & Empowerment Awards) award in Education and Mentoring, and the 2012 Council on Undergraduate Research in the Geosciences (GeoCUR) Undergraduate Research Mentor Award. You can also check out my TEDxUWMadison talk on building more “on-ramps” to science in college.


Current Projects

Projects in my group range from new ideas…. to papers in review, from big-picture themes… to specific studies and outcomes. We submit final work to peer-reviewed journals for publication, so you can see past work under Publications (below).

1. Satellites, Health, and Air Quality

Much of my research works to connect NASA science with health and air quality applications through the NASA Health and Air Quality Applied Sciences Team (HAQAST). HAQAST is a 3-year projected funded by NASA Applied Sciences, which funds my work as a scientist and team member, as well as Team Lead. My work with HAQAST builds on past work with AQAST (2011-2016). Support from AQAST and HAQAST funds researchers in my group, including undergraduates, where we apply satellite data to new problems of relevance to decision-makers.

We have a couple of projects underway evaluating the sensitivity of ozone “smog” to its two main ingredients: NOx and VOCs. Past work in our group has used satellite data for this problem in China [Jin and Holloway, 2014], and reported on past work using this metric for decision-making in the state of Colorado [Witman et al., 2014]. Now, we are applying this metric across cities in the U.S., and find that the bigger the city, the more senstivity it is to VOC emissions. We are using this satellite data ratio to evaluate the skill of a widely used air quality model run by our collaborators at the Lake Michigan Air Director’s Consortium (LADCO). We are also investigating the way NO2 changes throughout the data across the U.S., comparing ground-based monitors with two different NO2 satellite retrievals (OMI and GOME-2).

2. Energy Strategies for Clean Air

We use computer models to evaluate the potential air quality benefits of energy system changes. Depending on the technology and policy, air emissions (of NOx, SO2, VOCs or other pollutants) may change in space and time. These emissions changes intereact with weather and atmospheric chemistry, affecting the spatial and temporal patterns of ozone and fine particulates. Although we have done work on both transportation and electricity system change, current projects focus primarily on electricity.

We work with energy system modelers to first calculate how changes to the power sector would affect generation and dispatch. We have one project with the National Renewable Energy Laboratory, where we evaluated the potential air quality benefits of increased solar power for electricity [Abel et al., in review at ERL]. We have another project with the MyPower model, where we assess the potential air quality outcomes of climate change on the electricity sector.

3. Supporting Diversity in Science

Most of my work advancing science diversity relates to my leadership in the Earth Science Women’s Network (ESWN), an organization I helped found in 2002 and now serve as President and Board Member. ESWN is an international peer-mentoring network of women in the Earth Sciences, many of whom are in the early stages of their careers. Our mission is to promote career development, build community, provide opportunities for informal mentoring and support and facilitate professional collaborations.

With over 3000 members working in over 50 different countries, ESWN is the largest organization serve women across the geosciences. Our approach depends on women-helping-women, scientists-helping-scientists. ESWN, work to support individual women building careers, provide free professional training to both men and women at large annual meetings, engage with professional societies to make science a more inclusive work environment, highlight our members as role models for the next generation, and extend our proven strategies to first-year college students. If you are a woman in the earth sciences, please join! It’s free - just click here. We are also working to connect with private and institutional supporters, both to help cover our basic expenses, and to help launch new initiatives like scholarships and workshops

Opportunities to Get Involved

UW-Madison undergraduate students - I welcome inquiries from undergraduates (any year) who would like to get involved research related to air pollution. All students start out learning a specialized software to make maps and analyze large data sets called NCL. Since there is a steep learning curve, work with my group is not a good fit for a 1-semester research project. Most students continue on for with research for 2 or more semesters, during which they enroll for 3-credits of independent study (ES 699, AOS 699 or CEE 699). If you are interested in learning more, please send me an email at

Prospective graduate students - Please see my letter to prospective graduate students here

Current or prospective students are also encouraged to consider enrolling in the Energy Analysis and Policy program, which provides an interdisciplinary graduate education in energy.

For members of the public who would like to connect, you are welcome to attend the weekly colloquium hosted by SAGE, the Weston Roundtable or follow me on Twitter @tracey_holloway.


Abel, D., T. Holloway, R. Kladar, P. Meier, D. Ahl, M. Harkey, J. Patz (2017), Response of Power Plant Emissions to Ambient Temperature in the Eastern United States, Environmental Science & Technology.

Jin X. and T. Holloway (2015), Spatial and Temporal Variability of Ozone Sensitivity over China Observed from the Ozone Monitoring Instrument, Journal of Geophysical Research - Atmospheres, Volume 120, Issue 14 27 July 2015, Pages 7229–7246, DOI: 10.1002/2015JD023250. (read)

Harkey, M., T. Holloway, J. Oberman, and E. Scotty (2015), An evaluation of CMAQ NO2 using observed chemistry-meteorology correlations, Journal of Geophysical Research-Atmospheres, 120(22), DOI: 10.1002/2015JD023316. (read)

Bickford, E., T. Holloway, A. Karambelas, M. Johnston, T. Adams, M. Janssen, and C. Moberg (2014), Emissions and Air Quality Impacts of Truck-to-Rail Freight Modal Shifts in the Midwestern United States, Environmental Science & Technology, 48 (1), pp. 446/454, DOI: 10.1021/es4016102. (read)

Patz, J.A., H. Frumkin, T. Holloway, D.J. Vimont, and A. Haines (2014), Climate Change Challenges and Opportunities for Global Health, JAMA, 312(15):1565-1580. doi:10.1001/jama.2014.13186. (read)

Plachinski, S., T. Holloway, P. Meier, G. Nemet, A. Rrushaj, J. Oberman, P. Duran, C. Voigt (2014), Quantifying the emissions and air quality co-benefits of lower-carbon electricity production, Atmospheric Environment, 94: 180 - 191. (read)

Witman, S., T. Holloway, and P.J. Reddy (2014), Integrating satellite data into air quality management: Experience from Colorado, Air and Waste Management Association, em NSAS AQAST Research, pp. 34-18. February 2014. (read)

Harkey, M. and T. Holloway (2013), Constrained dynamical downscaling for assessment of climate impacts, Journal of Geophysical Research-Atmospheres, 118(5): 2136-2148. DOI: 10.1002/jgrd.50223. (read)

Grabow, M.L., S.N. Spak, T.A. Holloway, B. Stone Jr., A.C. Mednick, and J.A. Patz (2012), Air quality and exercise-related health benefits from reduced car travel in the Midwestern United States, Environmental Health Perspectives, 120(1), 68-76. (read)

Holloway, T., C. Voigt, J. Morton, S.N. Spak, A.P. Rutter, and J.J. Schauer (2012), An assessment of atmospheric mercury in the Community Multiscale Air Quality (CMAQ) model at an urban site and a rural site in the Great Lakes Region of North America, Atmospheric Chemistry and Physics, 12, 7117-7133, doi: 10.5194/acp-12-7117-2012. (read)

Johnston, M., E. Bickford, T. Holloway, C. Dresser, and T.M. Adams (2012), Impacts of biodiesel blending on freight emissions in the Midwestern United States, Transportation Research Part D, 17D(1), 457-465. (read)

Holloway, T., and C. Littlefield (2011), Intercontinental air pollution transport: Links to environmental health, Encyclopedia of Environmental Health, Nriagu JO (ed.), volume 3, Chapter 29, pp. 266–272 Burlington: Elsevier.

Johnston, M., R. Licker, J. Foley, T. Holloway, N.D. Mueller, C. Barford and C. Kucharik (2011), Closing the gap: global potential for increasing biofuel production through agricultural intensification, Environmental Research Letters, 6 034026 (doi: 10.1088/1748-9326/6/3/034028). (read)

Rasmussen, D.M., Jr., T. Holloway, and G.F. Nemet (2011), Opportunities and challenges in assessing climate change impacts on wind energy – a critical comparison of wind speed projections in California, Environmental Research Letters, 6, 024008, doi: 10.1088/1748-9326/6/2/024008. (read)

Lin, J.-T., D.J. Wuebbles, H-C Huang, Z. Tao, M. Caughey, X-Z Liang, J-H Zhu,, and T. Holloway (2010), Potential effects of climate and emissions changes on surface ozone in the Chicago area, Journal of Great Lakes Research, 36, 59–64. (read)

Lin, M., T. Holloway, G.R. Carmichael, and A.M. Fiore (2010), Quantifying pollution inflow and outflow over East Asia through coupling regional and global models, Atmospheric Chemistry and Physics Discussions, 10, 4221–4239, 2010, doi:10.5194/acp-10-4221-2010. (read)

Nemet, G.F., T.A. Holloway, and P. Meier (2010), Implications of incorporating air-quality co-benefits into climate change policymaking, Environmental Research Letters, 5 (January-March 2010) 014007, doi:10.1088/1748-9326/5/1/014007. (read)

Johnston, M., J.A. Foley, T. Holloway, C. Kucharik, and C. Monfreda (2009), Resetting global expectations from agricultural biofuels, Environmental Research Letters, 4, 014004. (read)

Lin, M., T. Holloway, T. Oki, D.G. Streets, and A. Richter (2009), Multi-scale model analysis of boundary layer ozone over East Asia, Atmospheric Chemistry and Physics, 9, 3277-3301. (read)

Spak, S.N. and T. Holloway (2009), Seasonality of speciated aerosol transport over the Great Lakes region, Journal of Geophysical Research, 114, D08302, doi:10.1029/2008JD010598. (read)

Stone Jr., B., A.C. Mednick, T. Holloway, and S.N. Spak (2009), Mobile source CO2 mitigation through smart growth development and vehicle fleet hybridization, Environmental Science & Technology, 43 (6), 1704–1710, doi:10.1021/es8021655. (read)

Carmichael, G.R., T. Sakurai, D. Streets, Y. Hozumi, H. Ueda, S.U. Park, C. Fung, Z. Han, M. Kajino, M. Engardt, C. Bennet, H. Hayami, K. Sartelet, T. Holloway, Z. Wang, A. Kannari, J. Fu, K. Matsuda, N. Thongboonchoo, M. Amann (2008), MICS-Asia II: The model intercomparison study for Asia Phase II methodology and overview of findings, Atmospheric Environment, 42(15), MICS-ASIA II, May 2008, 3468-3490, doi:10.1016/j.atmosenv.2007.04.007. (read)

Gibbs, H.K., M. Johnston, J.A. Foley, T. Holloway, C. Monfreda, N. Ramankutty, and D. Zaks (2008), Carbon payback times for crop-based biofuel expansion in the tropics: the effects of changing yield and technology, Environmental Research Letters, 3 (July-September 2008) 034001 doi:10.1088/1748-9326/3/3/034001. (read)

Han, Z., T. Sakurai, H. Ueda, G.R. Carmichael, D. Streets, H. Hayami, Z. Wang, T. Holloway, M. Engardt, Y. Hozumi, S.U. Park, M. Kajino, K. Sartelet, C. Fung, C. Bennet, N. Thongboonchoo, Y. Tang, A. Chang, K. Matsuda, M. Amann (2008), MICS-Asia II: Model intercomparison and evaluation of ozone and relevant species, Atmospheric Environment, 42(15), , MICS-ASIA II, May 2008, 3491-3509, doi:10.1016/j.atmosenv.2007.07.031. (read)

Hayami, H., T. Sakurai, Z. Han, H. Ueda, G.R. Carmichael, D. Streets, T. Holloway, Z. Wang, N. Thongboonchoo, M. Engardt, C. Bennet, C. Fung, A. Chang, S.U. Park, M. Kajino, K. Sartelet, K. Matsuda, M. Amann (2008), MICS-Asia II: Model intercomparison and evaluation of particulate sulfate, nitrate and ammonium, Atmospheric Environment, 42 (15), MICS-ASIA II, May 2008, 3510-3527, doi:10.1016/j.atmosenv.2007.08.057. (read)

Holloway, T. and S. Spak (2008), Climate Change in Chicago, Projections and Potential Impacts. (read)

Holloway, T., S.N. Spak, D. Barker, M. Bretl, C. Moberg, K. Hayhoe, J. Van Dorn, and D. Wuebbles (2008), Change in ozone air pollution over Chicago associated with global climate change, Journal of Geophysical Research, 113, D22306, doi:10.1029/2007JD009775.(read)

Holloway, T., T. Sakurai, Z. Han, S. Ehlers, S.N. Spak, L.W. Horowitz, G.R. Carmichael, D.G. Streets, Y. Hozumi, H Ueda, S.U. Park, C. Fung, M. Kajino, N. Thongboonchoo, M. Engardt, C. Bennet, H. Hayami, K. Sartelet, Z. Wang, K. Matsuda, M. Amann (2008), MICS-Asia II: Impact of Global Emissions on Regional Air Quality in Asia, Atmospheric Environment, 42, 3543-3561. (read)

Lin, M., T. Holloway, T. Oki, D.G. Streets, and A. Richter (2008), Mechanisms controlling surface ozone over East Asia: a multiscale study coupling regional and global chemical transport models, Atmospheric Chemistry and Physics Discussions, 8, 20239-20281. (read)

Lin, M., T. Oki, T. Holloway, D.G. Streets, M. Bengtsson, S. Kanae (2008), Long-range transport of acidifying substances in East Asia – Part I: Model evaluation and sensitivity studies, Atmospheric Environment, 42 (24), 5939-5955, doi:10.1016/j.atmosenv.2 008.04.008. (read)

Lin, M., T. Oki, M. Bengtsson, S. Kanae, T. Holloway, D.G. Streets (2008), Long-range transport of acidifying substances in East Asia – Part II: source-receptor relationships, Atmospheric Environment, 42 (24), 5956-5967, doi:10.1016/j.atmosenv.2008.03.039. (read)

Snyder,D.C., T.R. Dallmann, J.J. Schauer, T. Holloway, M.J. Kleeman, M.D. Geller, and C. Sioutas (2008), Direct observation of the break-up of a nocturnal inversion layer using elemental mercury as a tracer, Geophysical Research Letters, 35, L17812, doi:10.1029/2008GL034840. (read)

Wang, Z., Fuying Xie, T. Sakurai, H. Ueda, Zhiwei Han, G.R. Carmichael, D. Streets, M. Engardt, T. Holloway, H. Hayami, M. Kajino, N. Thongboonchoo, C. Bennet, S.U. Park, C. Fung, A. Chang, K. Sartelet, M. Amann (2008), MICS-Asia II: Model inter-comparison and evaluation of acid deposition, Atmospheric Environment, 42(15), MICS-ASIA II, 3528-3542., doi:10.1016/j.atmosenv.2007.12.071. (read)

Johnston, M., and T. Holloway (2007), A global comparison of national biodiesel production potentials, Environ. Sci. Technol., 41 (23), 7967–7973 10.1021/es062459k. (read)

Spak, S., T. Holloway, B. Lynn, and R. Goldberg (2007), A comparison of statistical and dynamical downscaling for surface temperature, North America. J. Geophys. Res., 112, D08101, doi:10.1029/2005JD006712. (read)

Stone Jr., B., A.C. Mednick, T. Holloway and S.N. Spak (2007), Is compact growth good for air quality?, Journal of the American Planning Association, 73:4, 404 - 418. DOI: 10.1080/01944360708978521. (read)

Yamashita, K., F.Ito, K. Kameda, T. Holloway, and M.P. Johnston (2007), Cost-effectiveness analysis of reducing the emission of nitrogen oxides in Asia, Water Air Soil Pollut: Focus, 7, 357-369, DOI 10.1007/s11267-006-9097-3. (read)

Denholm, P. and T. Holloway (2005), Improved accounting of emissions from utility energy storage system operation, Environmental Science & Technology, 39(23), 9016-9022. (read)

Denholm, P., G.L. Kulcinski, and T. Holloway (2005), Emissions and energy efficiency assessment of baseload wind energy systems, Environmental Science & Technology, 39,1903-1911. (read)

Foley, J.A., R. DeFries, G.P. Asner, C. Barford, G. Bonan, S.R. Carpenter, F.S. Chapin, M.T. Coe, G.C. Daily, H.K. Gibbs, J.H. Helkowski, T. Holloway, E.A. Howard, C.J. Kucharik, C. Monfreda, J.A. Patz, I.C. Prentice, N. Ramankutty, and P.K. Snyder (2005), Global consequences of land use, Science, 309, 570-574. (read)

Holloway, T., P.L. Kinney, and A. Sauthoff (2005), Application of air quality models to public health analysis, Energy for Sustainable Development , IX(3), 49-57. (read)

Patz, J.A., D Campbell-Lendrum, T. Holloway, and J.A. Foley (2005), Impact of regional climate change on human health, Nature, 438, 310-317. (read)

Ezzati, M., R. Bailis, D.M. Kammen, T. Holloway, L. Price, L.A. Cifuentes, B. Barnes, A. Chaurey, K.N. Dhanapala (2004), Energy Management and Global Health, Annual Rev. Environ. Resources, 29, 383–419; doi: 10.1146/ (read)

Holloway, T., A. Fiore, M.G. Hastings (2004), Response to Comment on “Intercontinental Transport of Air Pollution:  Will Emerging Science Lead to a New Hemispheric Treaty?”, Environmental Science & Technology, 38, 1914. (read)

Fiore, A., T. Holloway, M. G. Hastings (2003), A global perspective on air quality: Intercontinental transport and linkages with climate, Environmental Management,13-22.(read)

Holloway, T.A., A. Fiore, and M.G. Hastings (2003), Intercontinental transport of air pollution: will emerging science lead to a new hemispheric treaty?, Environmental Science and Technology, 37, 4535-4542. (read)