15th Symposium on Aerosol–Cloud–Climate Interactions

Abstract Information

Abstracts are closed! The deadline was 31 August 2022 at 11:59 PM EDT.

Abstract Fee and Author Instructions
All presenters must also register for the meeting.

The 15th Symposium on Aerosol–Cloud–Climate Interactions is sponsored by the American Meteorological Society and organized by the AMS Committee on Atmospheric Chemistry.

Call for Papers

Papers for the 15th Symposium on Aerosol–Cloud–Climate Interactions are solicited on the following:

  • Advances in observational and modeling studies of mineral dust in the Earth system;

Dust aerosols play important roles in the Earth system by degrading air quality, influencing weather systems, perturbing radiation budget, modulating biogeochemical cycles, and affecting the climate. Assessing these impacts requires realistic and accurate characterization of dust particle properties, emissions, transport, and deposition. This session invites presentations that report the latest advances in modeling and observational characterization of dust and its impacts on various components of the Earth system, including but not limited to: (1) properties and distributions of dust assessed from in situ and remote sensing measurements; (2) dust emission and transport quantified using observations and models; (3) dust variability in association with climate variability and anthropogenic activities on various time scales; (4) effects of dust aerosols on radiation budget and cloud microphysics (i.e., direct, indirect, and semi-direct effects); (5) interactions of dust with precipitation, circulation, and regional climate (e.g., African easterly jet–African easterly wave system, African and Indian monsoons, tropical cyclones, mesoscale convective complexes, and springtime cyclones over Southern Europe and Asia); (6) interactions with global biogeochemical cycle; (7) dust impacts on air quality and public health; and (8) novel use of observations to constrain dust modeling.

Session Chairs: Bing Pu (bpu@ku.edu), Shu-Hua Chen (Shachen@ucdavis.edu), Hongbin Yu (hongbin.yu@nasa.gov), and Terrence R. Nathan (trnathan@ucdavis.edu).

  • Aerosol-Cloud Interactions in Deep Convective Clouds;

Deep convective clouds (DCCs) play an important role in the global energy balance through vertical transport and a redistribution of water, energy, particulates, and trace gases through the depth of the troposphere. The representation of DCCs and their feedback on the global circulation and cloudiness represents one of the largest uncertainties in Earth system models. In particular, the aerosol impacts on DCC properties remain poorly understood, with the importance of the aerosol influences a continuing topic of debate within the scientific literature. Quantifying the magnitude and importance of aerosol impacts on DCC properties is an important step towards improved predictability of the climate and water cycle. This session invites theoretical, observational, and modeling studies aiming at advancing process-level understanding of two-way aerosol-DCC interactions, including but not limited to, the following topics: (1) fundamental DCC processes and their interactions and feedbacks with the environment; (2) aerosol impacts on DCC microphysics, kinematics, thermodynamics, radiative properties, macrophysics, and/or precipitation processes; (3) influence of environmental conditions, such as wind shear, humidity, and instability, on DCC processes and two-way aerosol–DCC interactions; (4) climatic influence of aerosol–DCC interactions and their future climate prediction; (5) DCC transport of aerosol particles and subsequent influence on the aerosol and cloud condensation nuclei size distributions; (6) novel measurements such as laboratory, in situ, and remote sensing, advanced machine learning methods, and modeling techniques from large eddy simulation to global scale to quantify aerosol–DCC interactions and their impacts.

Session Chairs: Dié Wang (diewang@bnl.gov), Michael P. Jensen (mjensen@bnl.gov), and Zachary J. Lebo (zlebo@uwyo.edu).

  • Aerosol-Cloud-Interactions in Warm Clouds;

Many shallow cloud systems are sensitive to changes in aerosol properties, which act as cloud condensation nuclei, modulate cloud microphysical properties, and can influence precipitation formation and cloud-scale dynamics. Ultimately, these controls may alter low-cloud radiative properties and climate. Aerosol particles, in turn, are impacted by shallow-cloud processes. Together, these interactions result in an aerosol–cloud system whose coupling strength is highly variable and is poorly understood in terms of basic process understanding. Correctly representing this coupling in large-scale models has proven challenging. In this session we invite presentations on all topics related to aerosol–cloud interactions in shallow clouds, including those addressing basic physical aerosol-cloud processes, the quantification of aerosol indirect effects, cloud and precipitation effects on aerosols, and the coupling between microphysical processes and boundary layer turbulence or mesoscale cloud dynamics. Contributions from recent field campaigns, such as ATOMIC – Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign and ACTIVATE – Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment, are encouraged.

Session Chairs: Emily de Jong (edejong@caltech.edu), Peng Wu (peng.wu@pnnl.gov), and Youtong Zheng (youtong.zheng@noaa.gov).

  • Aerosol-Cloud interactions over the North Atlantic Ocean: insights from recent field campaigns;

The North Atlantic (NA) ocean is one of the most cloudy regions over the globe and influenced by various types of both natural and anthropogenic aerosols. Previous studies suggest that global climate models have the largest uncertainties in terms of aerosol-cloud interaction simulations in the NA region. Therefore, NA is an interesting and important region for aerosol-cloud interactions studies, which inspires several field campaigns such as the Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) and Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA), and North Atlantic Aerosols and Marine Ecosystems Study (NAAMES), and Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE). This session seeks contributions from the research, operational, and user communities that utilize the observations from these recent field campaigns to study the aerosol-cloud interactions in the NA region. 

Session Chairs: Jean-Francois Lamarque (lamar@ucar.edu) and Yu Gu (gu@atmos.ucla.edu).

  • Aerosol-climate interactions from regional to global scale;

Atmospheric aerosols from natural or anthropogenic sources have profound impacts on Earth's radiation budget, hydrological cycle, as well as regional and global climate. Currently, the radiative forcing of aerosols in the climate system remains highly uncertain, representing the largest uncertainty in climate predictions. For the direct effect, aerosols scatter and absorb solar radiation. Light scattering by aerosols changes the radiative fluxes at the top-of-atmosphere (TOA), at the surface, and within the atmospheric column, while aerosol absorption modifies the atmospheric temperature structure, decreases the solar radiation at the surface, and lowers surface sensible and latent fluxes, suppressing convection and reducing cloud fraction. Also, aerosols indirectly impact climate by altering cloud development, lifetime, albedo, and precipitation efficiency. On the other hand, climate variabilities also affect aerosol cycle and lifetime by altering aerosol removal processes. Current treatments of aerosol-cloud-radiation interactions remain crude in climate models. This session aims to review the state of current understanding on aerosol-climate interaction, so we invite any paper on the related subjects.

Session Chairs: Jean-Francois Lamarque (lamar@ucar.edu) and Yu Gu (gu@atmos.ucla.edu).

  • Aerosol-cloud interactions in mixed-phase clouds;

Mixed-phase clouds composed of a mixture of supercooled liquid droplets and ice crystals are found across the globe. They are the dominant cloud type during the colder three-quarters of the year in the Arctic while at lower latitudes, mixed-phase clouds occur are associated with deep convection, synoptic-scale midlatitude weather systems, and orographic clouds. Aerosols by serving both cloud condensation nuclei and ice nuclei can alter mixed-phase cloud properties, and consequently modulate the regional hydrological cycle. This session invites papers on any of the following or related subjects: (1) characterization of mixed-phase clouds using observations and modeling; (2) process-level understanding of CCN/IN impacts on mixed-phase clouds; (3) assessment of the climatic influence of aerosol–cloud interaction in mixed-phase clouds, especially over the Arctic; (4) evaluation and improvement of mixed-phase clouds in numerical models. Contributions from recent field campaigns such as MOSAiC (Multidisciplinary Drifting Observatory for the Study of Arctic Climate) are encouraged.

Session Chairs: Chuanfeng Zhao (czhao@neu.edu.cn) and Susannah M. Burrows (susannah.burrows@nasa.gov). 

  • Aerosol-radiation interactions;

Aerosol interacts with radiation in both solar and thermal infrared spectrum through scattering, absorption, and emission, which in turn influences the radiative energy distribution and thermodynamical structure of the Earth-atmosphere system. This session seeks recent research advancing process-level understanding of the aerosol-radiation interactions (ARI), including but not limited to, the following topics: 1) how ARI influences the energy balance and thermodynamical structure of the Earth-atmosphere system 2) how the direct and semidirect radiative effects of aerosols influence mesoscale and synoptic-scale weather systems and climate, including, but are not limited to, wave systems, monsoons, tropical cyclones, and mesoscale convective complexes; 3) understanding of how environmental factors, such as underlying and surrounding clouds (e.g., “twilight zone”), surface brightness and meteorological conditions influence the radiative effects of aerosols. 4) novel measurement (e.g., laboratory, in situ, and remote sensing) and modeling (e.g., from LES to global scale) techniques to quantify aerosol–radiation interactions and their impacts. 5) ARI in past climate change and future climate prediction; vi) ARI influences on the atmospheric boundary layer and feedback on air quality; and 6) how ageing and chemical interactions impacts ARI. 

Session Chairs: Qianqian Song (cd11735@umbc.edu), Ian Chang (ian.change@ou.edu), Osinachi Ajoku (osi.ajoku88@gmail.com), and Ryan Kramer (ryan.j.kramer@nasa.gov).

  • Atmospheric ice-nucleating particles and ice formation processes in clouds;

Our proposed session on “Atmospheric ice-nucleating particles (INPs) and ice formation processes in clouds” will be part of the Symposium on Aerosol–Cloud–Climate Interactions. We are looking forward to scientific contributions across all aspects of laboratory and field based INP research, including long-term monitoring of INPs, intensive field INP observations at the ground and using vertical profiling, and studies investigating secondary ice formation processes. We are also inviting contributions bridging the gaps between experimental work and modeling, e.g., through the development of new parameterizations for INPs in the atmosphere and dedicated aerosol closure studies, as well as atmospheric ice formation modeling across scales.

Session Chairs: Ottmar Moehler (ottmar.moehler@kit.edu), Isabelle Steinke (isabelle.steinke@pnnl.gov), and Naruki Hiranuma (nhiranuma@wtamu.edu). 

  • Challenges and progress in understanding, simulating and forecasting fog;

The prediction of the timing of the onset, progression and dispersal of fog has been a long-standing challenge in the numerical weather prediction community, despite its immediate societal impacts through visibility conditions and broad impacts on aviation, coastal ecology, agriculture, energy and public health. The simulation of fog by current numerical weather prediction models suffers from significant biases not only in its broad lifecycle features but also its microphysical characteristics (like cloud droplet number concentration, liquid water content) that directly impact visibility metrics. These deficiencies are associated with complex interactions of myriad physical processes involved in fog formation and evolution by different pathways like stratus lowering and radiation fog in different types of marine, coastal and continental fog. The involved processes include aerosol emissions, aerosol and cloud microphysics, radiation processes, boundary layer mixing processes, large scale dynamical environmental forcings, varied topography and land-atmosphere interactions. Recent works suggest that improvements in the model representation of these processes enhance different attributes of fog simulation and prediction. Further, the impact of climate change in driving long term trends in fog formation and its lifecycle over different regions remains an open research question.

We invite submissions relevant to all these broad-ranging aspects of fog simulation including intensive observational studies, field experiments, and satellite and lidar detection methods. We also welcome discussion of varied numerical formulations and parameterization schemes of processes involved, new mathematical or computational techniques such as machine learning, multi-scale numerical model simulations (DNS to mesoscale to high resolution global models) that exploit modern hybrid computer architecture, model validation metrics and societal impacts. Recent field experiments relating to fog such as C-FOG, SOFOG and WIFEX have emphasized the importance of aerosols in influencing fog thickness and development. The effects of aerosol absorption and radiative cooling on fog are attracting particular interest. We welcome presentations that address these issues. We hope to assemble the current state of understanding on fog simulation and prediction. Our goal is to help identify and scope out future research directions to attain more accurate fog predictions across different regions of the globe.

Session Chairs: Hamish Gordon (gordon@cmu.edu), Salil Mahajan (salil_mahajan@hotmail.com), Wei Zhang (zhangw3@ornl.gov), Min Xu (xum1@ornl.gov), and Hyun Kang (kangh@ornl.gov). 

  • Measurement and modeling of atmospheric cloud condensation nuclei and related chemistry;

A large fraction of atmospheric aerosols acts as cloud condensation nuclei, but the atmospheric chemical and physical processes to form cloud condensation nuclei (CCN) remain uncertain. We welcome all studies that present new knowledge of atmospheric chemistry and physics in CCN formation and transformation using measurements and/or modeling tools. Relevant topics include aerosol chemical and physical processes that affect new particle formation and growth, heterogeneous/multiphase chemistry, chemical aging, mixing state/phase state variations, cloud condensation activities, as well as cloud processing of aerosols, such as cloud chemistry, wet scavenging, and resuspension.

Session Chairs: Mingyi Wang (mingyiw@caltech.edu) and Xu-Cheng He (xucheng.he@helsinki.fi). 

  • Mesoscale cloud organization and transition: the role of meteorology and aerosols;

Mesoscale organization of shallow and deep convection is a ubiquitous feature of cloud systems with climatic importance for modulating cloud water, precipitation, and top-of-atmosphere and surface radiation. However, our fundamental understanding of what drives pattern formation in clouds and its impact on the strength of cloud feedback and therefore climate sensitivity remains limited. This uncertainty is exacerbated by the potential effects of anthropogenic atmospheric aerosols on modulating cloud organization in conjunction with other meteorological drivers. This session invites observational, theoretical, and numerical modeling studies that expand our understanding of the interactions between cloud organization, meteorology, and aerosol, and their implications for climate. All topics related to shallow cloud organization, deep convective organization (including convective self-aggregation studies), Lagrangian and climatological transitions between shallow cloud organizational structures, and extreme events that are tied to mesoscale convective organization are welcome. New insights into the control and responses of aerosols on cloud organization and their implications on cloud radiative properties and cloud feedback are especially welcome. We encourage thought-provoking contributions and novel ideas based on satellite observations, large eddy and cloud resolving model simulations, conceptual modeling, theoretical approaches, and recent field campaigns (e.g. ACE-ENA, ACTIVATE, CAMP2Ex, CAP-MBL, COMBLE, CSET, EUREC4A/ATOMIC, MAGIC, ORACLES/CLARIFY, OTREC, RELAMPAGO-CACTI, TRACER).

Session Chairs: Xiaoli Zhou (xiaoli.zhou@noaa.gov), Michael S. Diamond (michael.diamond@noaa.gov), Isabel L. McCoy (imccoy@ucar.edu), and Kathleen Schiro (kschiro@virginia.edu). 

  • Probabilistic Particle-Based Methods in Aerosol-Cloud Microphysics Modeling.

Particle-based microphysics models differ significantly from the conventional computational fluid dynamics approaches of representing aerosol, cloud and precipitation particle populations as separate categories of trace constituents modeled with continuous density fields (so-called bulk or bin models). The particle-based microphysics modeling techniques are also termed super-particle or super-droplet methods, because the simulation particles represent a significant multiplicity of simulated aerosol/cloud/precipitation particles. The super-particles constitute a coarse-grained view of the aerosol particles, droplets and hydrometeors in both real and attribute space. The probabilistic aspects of the particle-based techniques are multifaceted and, depending on the model formulation, refer to randomly populating the phase space with super-particles and/or Monte-Carlo type representation of stochastic-in-nature processes such as coagulation, nucleation or small-scale motions. The aim of this session is to spin-up interactions among, on the one hand, research groups working on the development of particle-based aerosol/cloud simulation tools and, on the other hand, wider modeling community as well as experimentalists performing measurements relevant to model formulation and validation. We thus welcome contributions highlighting applications of the particle-based methodology in both aerosol-cloud interactions research and neighboring domains, as well as pitches for tackling open problems with particle-based methods. Session topics include (but are not limited to): (i) applications of particle-based microphysics models; (ii) comparisons with bulk and bin simulations; (iii) performance and scaling analyses including CPU/GPU usage strategies; (iv) flow-particle coupling aspects including subgrid scale motions; (v) phase-space sampling strategies; (vi) Monte-Carlo algorithms for particle-resolved models; (vii) coupling radiative-transfer models with particle-based microphysics; (viii) aerosol mixing state and biochemical properties in cloud simulations; (ix) mixed-phase particle-based models; (x) model validation against ambient and laboratory measurements.

Session Chairs: Sylwester Arabas (sylwester.arabas@uj.edu.pl), Anna Jaruga (ajaruga@caltech.edu), Jon M. Reisner (reisner@lanl.gov), Nicole Riemer (nriemer@illinois.edu), Shin-Ichiro Shima (s_shima@sim.u-hyogo.ac.jp, and Simon Unterstrasser (simon.unterstrasser@dlr.de). 

Student Award Opportunities

The Symposium Organizing Committee will host a student paper competition with award certificates and cash prizes for exemplary undergraduate and graduate student poster and oral presentations. Students must be the first author and presenting their own, original work. Students who wish to be considered for this prize must indicate their eligibility when submitting their abstract.

Conference Contacts

For additional information, please contact the program chairs: Yuan Wang (yuan.wang@caltech.edu), Adeyemi Adebiyi (aaadebiyi@ucmerced.edu), Zhibo Zhang (zzbatmos@umbc.edu), and Nicole Riemer (nriemer@illinois.edu).