2023 Program Topics

Program Topics

The 2023 conference program focused on the following topics:

Program Overview

Review the session descriptions and speaker list below then take a look at the schedule overview here or review presentation details and recordings here!

PDF of Print Program

Keynote: Perturbed parameter ensembles as a way to understand system behavior and improve models

Keynote Speaker: Ken Carslaw, University of Leeds, Professor

The complexity of aerosol and cloud models makes it very challenging to understand system behaviour and to reduce the persistent large uncertainty in the outputs. For example, in terms of system behaviour, cloud behaviour depends on numerous covarying environmental factors whose effects can be difficult to disentangle. In terms of uncertainty, the magnitude of aerosol-cloud interaction (ACI) radiative forcing has remained stubbornly uncertain in models despite many advances in model realism. In this presentation I will show several examples of how perturbed parameter ensembles (PPEs) have helped us to make progress with these related problems. I will show how PPEs of a large eddy simulator can be used to visualise how the transition from stratocumulus to cumulus clouds depends on aerosol in combination with five environmental conditions. The results highlight the limitations of trying to understand this system using smalls sets of simulations. For the model uncertainty question, I will show a PPE of 37 uncertain parameters in a global climate model. I will show that is possible to calibrate the model parameters to obtain good model-observation agreement and thereby robustly reduce uncertainty in ACI forcing. I will also show preliminary work using the PPE in combination with multiple observations to expose the model’s structural deficiencies, which could provide a new way to prioritize model developments.

Keynote: Representing the evolution of biomass burning aerosols in models

Keynote Speaker: Jeffrey Pierce, Colorado State University, Professor

Open biomass burning, such as wild and prescribed fires, is a significant source of aerosols to the atmosphere, greatly influencing both climate and human health. These biomass burning particles evolve in both size and composition within the smoke plumes, affecting the particles’ abilities to act as cloud condensation nuclei, interact with radiation, and impact climate. However, this particle evolution differs between fires, being strongly influenced by aerosol mass concentrations in the plumes. Aerosol mass concentrations in a plume of a small fire (think agricultural field) will dilute to <1 µg/m^3 in seconds or minutes due to the short dilution length scale. On the other hand, the PM in large wildfires may remain >100 µg/m^3 or even >1000 µg/m^3 for hours or days. These concentration differences greatly impact the evolution of aerosol size and composition. However, smoke plumes are often too small to be resolved in 3D models, creating challenges in capturing the roll of concentration in smoke aging. In this talk, I will discuss how field work and high-resolution modelling has elucidated the roll of plume concentrations on smoke aging, describe methods to represent sub-grid plume processes in regional and global models, and show how accounting for in-plume aging affects smoke radiative forcing estimates.

Fundamental aerosol processes from nano- to microscale

Co-Chairs: Tinja Olenius and Dan Westervelt
The atmosphere is a complex dynamic entity whose composition of gas-phase molecules and aerosol particles varies considerably in space and time. Large-scale atmospheric modeling of the constituents and their effects critically depends on understanding and representing the chemical and physical properties and processes occurring from nano- to microscale. This session highlights fundamental research on aerosol properties and microphysics, including molecular-level modeling of gas, aerosol and surface phases, assessment of process rates related to, for example, particle formation and growth, and methods for their optimal representation in box and large-scale model frameworks.

Session Speakers:

Siddharth Iyer, Tampere University (Invited Session Speaker)
Kari Lehtinen, University of Eastern Finland (Invited Session Speaker)
Laura Fierce, Pacific Northwest National Laboratory (Invited Session Speaker)
Noora Hyttinen, University of Jyväskylä

Advances in regional and global scale aerosol modeling

Co-Chairs: Daven Henze and Knut von Salzen
Simulating the formation and physico-chemical properties of particles in the atmosphere at regional and global scales remains a significant challenge. In addition to computationally efficient algorithms to represent complex aerosol processes, detailed model evaluation is needed with respect to multiple features and properties of particles (e.g., vertical profiles, size, composition, optical properties) that affect their impacts on climate and health. Here we invite recent advances in regional and global-scale modeling of particles relevant to climate and human health, developments of computationally efficient algorithms to represent these processes in models, and their evaluation with laboratory and field measurements. We particularly encourage contributions highlighting aerosol model intercomparisons for air quality and climate, regional to global aerosol data assimilation and forecast systems, and constraints on aerosol models from current and future remote sensing instruments.

Session Speakers:

Simone Tilmes, NCAR (Invited Session Speaker)
Jun Wang, University of Iowa (Invited Session Speaker)
Maegan DeLessio, Columbia University/NASA GISS
Samuel Frederick, University of Illinois Urbana-Champaign
Jiachen Liu, Drexel University
Pietro Vannucci, University of California, Berkeley
Duncan Watson-Parris, University of California, San Diego
Li (Kate) Zhang, CIRES University of Colorado Boulder & NOAA GSL
Julia Bruckert, KIT Karlsruhe

Process and Box Models of Aerosol Chemistry and Physics

Co-Chairs: Nicole Riemer and Thomas Berkemeier
Process-level models in the atmospheric sciences connect the fundamental physical and chemical properties of gases and aerosols with treatments of mass transport and detailed chemical mechanisms. These models enable atmospheric scientists to utilize results from quantum mechanical calculations, interpret laboratory experiments, and provide a process understanding that can be used in larger scale models such as chemical transport models. This session highlights work using detailed chemical, thermodynamic, and kinetic models on the reactor or box model scale in applications including, for example, gas, particle, and multiphase chemistry or gas-particle partitioning.

Session Speakers:

Mary Barth, NCAR (Invited Session Speaker)
Shantanu Jathar, Colorado State University (Invited Session Speaker)
Adam Milsom, University of Birmingham (Invited Session Speaker)
Zachary D'Aquino, University of Illinois Urbana-Champaign
Eugene Mikhailov, Saint-Petersburg state university
Ryan Schmedding, McGill University, Department of Atmospheric and Oceanic Sciences
Xiaotian Xu, University of Illinois Urbana-Champaign

Development, Application, and Reduction of Gas- and/or Particle-Phase Chemical Mechanisms for Aerosol Predictions

Co-Chairs: Karine Sartelet and Kelley Barsanti
Secondary aerosol formation proceeds by reactions of volatile compounds in the gas- and/or particle-phases. These reactions are described in models by chemical reaction mechanisms of varying complexity. This session highlights the development, application, and/or reduction of gas- and/or particle-phase chemical mechanisms relevant for aerosol predictions. We welcome abstraction submissions on relevant topics including, but not limited to: mechanisms for unrepresented precursors in SOA models, multi-phase mechanisms, reduction of detailed mechanisms for chemical transport modeling, and adaptation of mechanisms for multi-compartment modeling (e.g., health impacts).

Session Speakers:

Alma Hodzic, NCAR (Invited Session Speaker)
Zhizhao Wang, ENPC France (Invited Session Speaker)
Haofei Zhang, UC Riverside (Invited Session Speaker)
Yicen Liu, University of Illinois Urbana-Champaign
Nanna Myllys, University of Helsinki

Air Quality Modeling for Health and Regulatory Assessments

Co-Chairs: Havala Pye and James Kelly
The primary goal of this session is to connect fundamental modeling developments and insights discussed in other sessions to applied regulatory and health assessments. The session also aims to illustrate how scientific advances are being used by regulators and the health science community to better understand the impact of pollution management efforts. Discussions in this session are also expected to highlight the emerging challenges in regulatory and health applications that may be met with advanced aerosol model algorithms.

Session Speakers:

Minghui Diao, San Jose State University (Invited Session Speaker)
Manabu Shiraiwa, UC Irvine (Invited Session Speaker)
Sultan Abdillah, Chung Yuan Christian University
Xue Meng (Sue) Chen, California Air Resources Board
Sarika Kulkarni, California Air Resources Board
Benjamin Murphy, U.S. EPA
Mbiake Robert, University of Douala
Maninder Thind, California Energy Commission/ Formerly University of Washington, Seattle

Machine Learning and Data Science

Co-Chairs: Christopher Tessum and Sam Silva
This session provides a forum to discuss modern machine learning and data science techniques as they are applied to open research questions in aerosol science. Our motivation is to foster discussion that can enhance the predictability and understanding of aerosol processes and abundances. We particularly encourage unconventional or early-stage approaches with the potential to transform the practice of aerosol science. We welcome submissions from any subfield, including process-based modeling, data-driven modeling, or multi-source data fusion techniques.

Session Speakers:

Andrew Giess, PNNL (Invited Session Speaker)
Paula Harder, Fraunhofer Institute for Industrial Mathematics (ITWM) (Invited Session Speaker)
David Topping, University of Manchester (Invited Session Speaker)
Jakub Kubecka, Aarhus University
Hilda Sandström, Aalto University
Kostas Tsigaridis, Columbia University and NASA GISS