Aerosole und Klima Composition Air quality Climate inTeractions Initiative (CACTI): Emissions to Response
Goals
The overall goal of CACTI is to quantify and advance the scientific understanding of the global and regional forcing, climate and air quality responses, and Earth System feedbacks due to atmospheric composition and SLCF emission changes. Specifically, our research contributes to any of the three specific CACTI goals to:
- Characterize ERFs and assess adjustments from historical and future changes in atmospheric composition and SLCFs emissions in global models
- Quantify the climate and air quality responses to global and regional changes in SLCF emissions
- Understand the Earth System feedbacks through chemistry and aerosols in response to anthropogenic climate change
CACTI addresses several cross-cutting topics relevant to the specific goals. In particular, to enhance scientific understanding, CACTI endeavors to explore and characterize uncertainty and inter-model diversity in the model responses. This initiative will also evaluate the performance of models against a suite of observations to build confidence in their fitness for the purpose of the specific goals. Additionally, CACTI will respond to the need for policy-relevant information related to the mitigation of SLCF emissions.
Contact
All announcements about CACTI activities will be made through our mailing list. If you are interested, please subscribe by sending an email to cacti-join(at)geomar.de.
You can contact the CACTI committee by sending an email to cacti-committee(at)geomar.de.
Committee
Members of the CACTI committee (in alphabetical order):
- R. Allen (University of California Riverside, USA)
- B. Collins (University of Reading, UK)
- S. Fiedler (GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany)
- P. Griffiths (National Centre for Atmospheric, Cambridge University, UK)
- M. Kasoar (Leverhulme Centre for Wildfires, Environment and Society, Imperial College London, UK)
- V. Naik (NOAA Geophysical Fluid Dynamics Laboratory, US)
- F. O’Connor (Met Office Hadley Centre, Exeter, UK & Dept. of Mathematics & Statistics, University of Exeter, UK)
- M. Schulz (Norwegian Meteorological Institute, Norway)
- C. Smith (University of Leeds, UK)
- T. Takemura (Kyushu University, Japan)
- S. Turnock (Met Office Hadley Centre, Exeter, UK)
- D. Watson-Parris (University of California San Diego, USA)
- D. Westervelt (Columbia University, USA)
- L. Wilcox (National Centre for Atmospheric Science, University of Reading, UK)
You can contact the CACTI committee by sending an email to cacti-committee(at)geomar.de.
Collaboration and Coordination
Legacy
CACTI brings together the active and collaborative communities of RFMIP, AerChemMIP, and PDRMIP under a new initiative called CACTI (Composition Air quality Climate inTeractions Initiative: Emissions to Response). Previously, these communities came together as TriMIP. CACTI aims to follow on from the success of TriMIP. RFMIP aimed to characterize and assess ERF in CMIP6 models and determine errors when approximating accurate line-by-line radiative transfer with fast parameterizations used in climate models (Pincus et al., 2016). The main goals of AerChemMIP were to quantify the climate and air quality responses to aerosols and chemically reactive gases (Collins et al., 2017). The objective of PDRMIP was to understand global and regional responses of precipitation statistics to different forcing agents, and irradiance (Myhre et al., 2017). The three MIPs held joint meetings that were useful to inspire each other for scientific advancement of the field.
References:
- Wilcox, L. J., Allen, R. J., Samset, B. H., Bollasina, M. A., Griffiths, P. T., Keeble, J. M., Lund, M. T., Makkonen, R., Merikanto, J., O'Donnell, D., Paynter, D. J., Persad, G. G., Rumbold, S. T., Takemura, T., Tsigaridis, K., Undorf, S., and Westervelt, D. M.: The Regional Aerosol Model Intercomparison Project (RAMIP), Geosci. Model Dev. Discuss. [preprint], in review, 2022.
- Collins, W. J., Lamarque, J.-F., Schulz, M., Boucher, O., Eyring, V., Hegglin, M. I., Maycock, A., Myhre, G., Prather, M., Shindell, D., and Smith, S. J.: AerChemMIP: quantifying the effects of chemistry and aerosols in CMIP6, Geosci. Model Dev., 10, 585–607, 2017.
- Myhre, G., Forster, P. M., Samset, B. H., Hodnebrog, Ø., Sillmann, J., Aalbergsjø, S. G., Andrews, T., Boucher, O., Faluvegi, G., Fläschner, D., Iversen, T., Kasoar, M., Kharin, V., Kirkevåg, A., Lamarque, J.-F., Olivié, D., Richardson, T. B., Shindell, D., Shine, K. P., Stjern, C. W., Takemura, T., Voulgarakis, A., & Zwiers, F.: PDRMIP: A Precipitation Driver and Response Model Intercomparison Project—Protocol and Preliminary Results, 98(6), 1185-1198, Bulletin of the American Meteorological Society, 2017.
- Pincus, R., Forster, P. M., and Stevens, B.: The Radiative Forcing Model Intercomparison Project (RFMIP): experimental protocol for CMIP6, Geosci. Model Dev., 9, 3447–3460, 2016.
New Collaborations
RAMIP joins the CACTI initiative. The first new MIP, RAMIP, from the former TriMIP community is already running. The aim of RAMIP is to quantify robust regional climate and air quality responses to regional emissions of anthropogenic aerosols (Wilcox et al., 2022). The experiments are designed to explore sensitivities to aerosol type and location using realistic, time-varying emission perturbations.
Values
Our initiative adheres to scientific integrity, equal opportunities, and democratic leadership. Our values are for instance reflected by diversity in the scientific committee of CACTI, open email lists to inquire information on our activities and getting involved, hybrid meetings to allow participation from anywhere in the world, and open scientific discussions at our meetings for information transparency and the possibility for debates.
Tri-MIP-athlon meetings
Tri-MIP-athlon 2018, Reading, UK
Tri-MIP-athlon 2019, Princeton, USA
Tri-MIP-athlon 2021, online everywhere
Tri-MIP-athlon 2018, Reading, UK
Tri-MIP-athlon 2019, Princeton, USA
Tri-MIP-athlon 2021, online everywhere
CACTI workshop 2023, Kiel, Germany
CACTI workshop 2024, San Diego, USA
CACTI workshop 2025, Reading, UK