Linking Radiative Forcing of Fine-Mode Aerosols and Tropospheric Ozone to Precursor Emissions

Related Research Areas
Atmospheric Composition
Project Description
Tropospheric ozone (O3) and fine-mode aerosols significantly impact climate through their direct radiative effects. Unlike carbon dioxide, the relationship between emissions of O3 and aerosol precursors and the ultimate consequence of these emissions on climate is highly variable, depending on the local chemical and physical environment. Anticipating climate change in the coming decades thus requires relating heterogenous, uncertain changes to global arrays of emission of O3 and aerosol precursors to changes in atmospheric composition and hence radiative forcing. Towards this goal, the following research steps will be taken in order to improve the overall accuracy of aerosol and ozone direct radiative forcing calculations and to relate these forcings to influences from specific types and locations of emissions. (1) The first step will rely on TES O3 products and MODIS reflectances to constrain concentrations and forcings through source estimation. These efforts will leverage several ongoing inverse modeling projects using additional remote sensing observations. (2) New observational constraints of the sensitivity of O3 radiative effects will be used to relate these effects to global O3 distributions. Similarly, MODIS reflectances will be used to further constrain the relationship between aerosol radiative effects and aerosol concentrations. (3) An adjoint model will be applied to calculate the sensitivity of the observationally constrained radiative effects with respect to changes in emissions, thus quantifying the radiative forcing of each precursor emission at the resolution of the modeled emissions inventories. (4) Lastly, this detailed information will be used to rapidly explore the radiative forcing consequences of numerous different emissions scenarios. The impacts of this plan will be to (a) increase scientific confidence in current estimates of radiative forcing of O3 and aerosol, which are still medium to medium to low, and (b) increase the value of radiative forcing estimates. By directly linking radiative forcing to emissions, we are better able to understand how changes in emissions will impact atmospheric composition and hence climate forcing. Exploring these relationships at a high level of spatial and source-specific detail will provide insight into the heterogenous influence of emissions of short-lived precursor species; quantifying these effects efficiently affords exploration of numerous possible future scenarios. Combined with larger efforts in my research program, such tools will ultimately provide a means of quantifying co-benefits of emissions strategies for both air quality and climate goals. Education and outreach components of this proposal address the challenges of reaching out to and training a diverse population, from undergraduate students to middle school teachers, on topics of air quality, remote sensing and climate. In each year, I will be involved with the Significant Opportunities in Atmospheric Research and Science (SOARS) program, through which minority undergraduate students gain a rich understanding of research practices, build the writing and communication skills necessary to pursue opportunities in STEM careers, and become integrated into the Boulder community of atmospheric research. My contribution each year will be in the role as a mentor, first as a community and computer mentor and later as a research project mentor. I will also contribute to educating middle and high school teachers via the Inspiring Climate Education Excellence (ICEE) program, a new NASA funded project at CIRES Education and Outreach by consulting on the design of online curriculum and participating as a speaker in the ICEE in-person workshops. Project PI: Daven Henze/University of Colorado at Boulder CU Mechanical Engineering Dept 1111 Engineering Drive ECME 114 Boulder, CO 80309 Phone: (303) 492-8716 Fax: (303) 492-3498 Email:
Project Administrator(s):
Cristina Milesi


Cristina Milesi