CERTAINTY-ACI @certainty-aci.bsky.social · 08/09/2026The new 2026 Air Quality and Climate Bulletin is out! | 📖 Have a look at the bulletin, and in particular at the article on aerosol–cloud interactions by Jennie Thomas, Harri Kokkola and Paolo Laj. 001
CERTAINTY-ACI @certainty-aci.bsky.social · 01/09/2026Can rime splintering explain ice production in Arctic mixed-phase clouds? ➡️ Read the publication: acp.copernicus.org/articles/26/... ➡️ Learn more about CERTAINTY's recent results: certainty-aci.eu/news/acp.copernicus.orgCan rime splintering explain the ice production in Arctic mixed-phase clouds?Abstract. Secondary ice production (SIP) can increase ice crystal number concentration (ICNC) by several orders of magnitude, particularly in clean clouds with low concentrations of ice-nucleating par... 000
CERTAINTY-ACI @certainty-aci.bsky.social · 27/08/2026Marine gases influence the Arctic climate through aerosols and clouds Summary: certainty-aci.eu/news-marine-... Publication: agupubs.onlinelibrary.wiley.com/doi/10.1029/... 000
CERTAINTY-ACI @certainty-aci.bsky.social · 25/08/2026ORCESTRA is an international field campaign dedicated to advancing our understanding of tropical deep convection (the towering clouds and thunderstorms that transport heat, moisture & energy through the tropical atmosphere) and its role in Earth’s climate system 🔍 certainty-aci.eu/news-orcestr... 000
CERTAINTY-ACI @certainty-aci.bsky.social · 24/07/2026⏯️ The recording of our webinar "New aerosol and surface reflectance products from novel satellite observations and their synergies" is now available online: www.youtube.com/watch?v=RuWX... 🙏 A big thank you to Oleg Dubovik for sharing his expertise and insights, and to Anna Gialitaki for moderatingyoutube.comNew aerosol and surface reflectance products from novel satellite observations and their synergiesYouTube video by CERTAINTY-ACI 000
CERTAINTY-ACI @certainty-aci.bsky.social · 11/06/2026📢 One Week to Go! certainty-aci.eu/events/ ⬇️ 000
CERTAINTY-ACI @certainty-aci.bsky.social · 02/06/2026Have you ever wondered how ice forms in clouds? Watch Marios Chatziparaschos and @drgilbz.bsky.social to find out! ⏯️ www.youtube.com/watch?v=5FRL...youtube.comThese tiny particles control how clouds freezeYouTube video by CERTAINTY-ACI 041
CERTAINTY-ACI @certainty-aci.bsky.social · 27/05/2026📢 CERTAINTY & AIRSENSE WEBINAR New aerosol and surface reflectance products from novel satellite observations and their synergies 🌍 🛰️ 🎤 Oleg Dubovik (CNRS, Université de Lille) Moderator: Anna Gialitaki (National Observatory of Athens) 🗓️ Thursday, June 18 🕐 14:00 CEST 💻 Zoom: lnkd.in/eGrqEqjp 020
CERTAINTY-ACI @certainty-aci.bsky.social · 21/05/2026☁️ 🌏 How do clouds and aerosols influence our climate? In this interview conducted by @drgilbz.bsky.social, Georgios Dekoutsidis from the CERTAINTY project explains how he studies complex atmospheric processes using data collected during the PERCUSION campaign. www.youtube.com/watch?v=AYCF...youtube.comWhat scientists can learn by flying through cloudsYouTube video by CERTAINTY-ACI 152
CERTAINTY-ACI @certainty-aci.bsky.social · 11/05/2026Despite their tiny size and small number, ice nucleating particules have a huge impact on global weather and climate through their influence on clouds. @drgilbz.bsky.social & Marios Chatziparaschos ▶️ www.youtube.com/watch?v=5FRL...youtube.comThese tiny particles control how clouds freezeYouTube video by CERTAINTY-ACI 031
CERTAINTY-ACI @certainty-aci.bsky.social · 07/05/2026A recent publication in the @tellusjournal.bsky.social by Bjorn Stevens et al. provides an overview of the ORCHESTRA field campaign 📄 tellusjournal.org/articles/10.... 052
CERTAINTY-ACI @certainty-aci.bsky.social · 04/05/2026We’re looking forward to sharing our latest results at EGU 2026. Come see sessions organized by CERTAINTY & the presentations from team members at these sessions: certainty-aci.eu/egu26/ 000
CERTAINTY-ACI @certainty-aci.bsky.social · 29/04/2026[New publication] 🌍 Desert dust exerts twice the longwave radiative heating estimated by climate models Jasper F. Kok, Ashok Gupta, Amato Evan, Carlos Pérez García-Pando, et al. www.nature.com/articles/s41...nature.comDesert dust exerts twice the longwave radiative heating estimated by climate models - Nature CommunicationsThis study shows that atmospheric desert dust keeps about twice as much infrared heat from escaping to space as climate models predict, highlighting that improving dust in models could sharpen weather... 000
Reposted by CERTAINTY-ACIDr Ella Gilbert @drgilbz.bsky.social · 28/04/2026Clouds can impact climate massively - and it turns out, their impact changes between day and night. 🌜🌞 Great to chat with Geoff Pugsley and Ed Gryspeerdt about their recent work on nighttime cloud impacts. 0254
CERTAINTY-ACI @certainty-aci.bsky.social · 28/04/2026⏰ Human activity is changing clouds… at one particular time of day What time is it? Watch the video with @drgilbz.bsky.social Geoffrey Pugsley & Edward Gryspeerdt to find out! ▶️ www.youtube.com/watch?v=HK9h...youtube.comHuman activity is changing clouds… at one particular time of dayYouTube video by CERTAINTY-ACI 020
CERTAINTY-ACI @certainty-aci.bsky.social · 22/04/2026Why aerosols matter 🌥️ What happens to our climate if the ingredients of clouds change? That question is asked in a recent paper written by CERTAINTY scientists. 🎤 @drgilbz.bsky.social & @annelev.bsky.social ▶️ www.youtube.com/watch?v=0B6S...youtube.comOur climate is surprisingly sensitive to these tiny particlesYouTube video by CERTAINTY-ACI 032
Reposted by CERTAINTY-ACIDr Ella Gilbert @drgilbz.bsky.social · 21/04/2026Made some videos with @certainty-aci.bsky.social about the climate impact of clouds and aerosols. And you can check out the first one here 👇youtube.comOur climate is surprisingly sensitive to these tiny particlesYouTube video by CERTAINTY-ACI 43512
CERTAINTY-ACI @certainty-aci.bsky.social · 16/04/2026The EC–ESA Aerosol Cloud Cluster brings together over 220 researchers across 40 institutions, uniting projects like CleanCloud, CERTAINTY, and AIRSENSE to improve climate predictions and support more effective climate action. More info: certainty-aci.eu/ec-esa-aeros... 010
CERTAINTY-ACI @certainty-aci.bsky.social · 14/04/2026[New publication] ☁️ 🌳 Beyond cloud cover: Low- and high-altitude clouds have distinct impacts on tree sap flow and transpiration ✍️Talvinen, S., Salmon, Y., Guttierez Lopez, J., et al. www.sciencedirect.com/science/arti...sciencedirect.comBeyond cloud cover: Low- and high-altitude clouds have distinct impacts on tree sap flow and transpirationTranspiration drives up to 40 % of terrestrial precipitation, with forests playing a critical role. This study combines long-term sap flow measurement… 010
CERTAINTY-ACI @certainty-aci.bsky.social · 03/04/2026From Canada to India: the far-reaching impact of 2023’s wildfire smoke 🔥 ✒️ Rosu Iulian-Alin et al. ➡️ Read the publication: www.nature.com/articles/s44... ➡️ Find out more on the climate effects of the Canadian wildfires: certainty-aci.eu/news-climate...nature.comSevere rapid indian monsoon weakening due to emissions from extreme Canadian wildfires - npj Natural Hazardsnpj Natural Hazards - Severe rapid indian monsoon weakening due to emissions from extreme Canadian wildfires 020
CERTAINTY-ACI @certainty-aci.bsky.social · 03/04/2026[New publication] 📄 Implementation of primary and secondary ice production in EC-Earth3-AerChem: global impacts and insights ✒️ Montse Costa Surós et al. ➡️ Read the paper: acp.copernicus.org/articles/26/... ➡️ Discover all EC-ESA Aerosol Cloud Cluster publications: certainty-aci.eu/ec-esa-aeros...acp.copernicus.orgImplementation of primary and secondary ice production in EC-Earth3-AerChem: global impacts and insightsAbstract. Clouds and aerosol–cloud interactions remain major sources of uncertainty in climate projections. Here, we improve the representation of mixed-phase clouds (MPCs) in the EC-Earth3-AerChem Ea... 000
CERTAINTY-ACI @certainty-aci.bsky.social · 18/03/2026Two recent studies co-authored by CERTAINTY members are improving our understanding of how the polar oceans, sea ice, and the associated atmospheric particles form and behave in polar regions and influence clouds. ➡️ certainty-aci.eu/contribution... 133
CERTAINTY-ACI @certainty-aci.bsky.social · 17/03/2026Great to come together with such a fantastic team at our Annual Meeting as we reflect on our progress and set the course for Year 3 and beyond! @ilmatieteenlaitos.fi 040
CERTAINTY-ACI @certainty-aci.bsky.social · 13/03/2026🌍 Better weather and climate projections mean smarter, safer, and more resilient decisions, for Europe and beyond ▶️ www.youtube.com/watch?v=ji3z...youtube.comAerosol–Cloud Interactions Are Key to Climate ResilienceYouTube video by CleanCloudProject 011
CERTAINTY-ACI @certainty-aci.bsky.social · 12/03/2026Explore how clouds form, the crucial role aerosols play in weather and climate, and why understanding these tiny particles remains one of society’s biggest scientific challenges. ▶️ www.youtube.com/watch?v=RehM...youtube.comAerosol Cloud InteractionsYouTube video by CleanCloudProject 021
CERTAINTY-ACI @certainty-aci.bsky.social · 10/03/2026Do we really know by how much ellipsoidal shapes enhance the extinction of solar radiation by dust? By Obiso et al. 🔍 doi.org/10.5281/zeno...doi.org 000
CERTAINTY-ACI @certainty-aci.bsky.social · 09/03/2026The EC-ESA Aerosol Cloud Cluster addresses the biggest uncertainty in regional climate prediction: aerosol-cloud interactions. It unites +220 researchers linking EU projects CleanCloud & CERTAINTY with ESA’s AIRSENSE to advance climate modeling & mitigation 🔗 www.youtube.com/watch?v=CPHt...youtube.comWhat is the EC ESA Aerosol Cloud Cluster?YouTube video by CleanCloudProject 010
Reposted by CERTAINTY-ACIUlas Im @ulasim77.bsky.social · 27/02/2026Our perspective paper on aerosol cloud interactions is featured in Eos.com as editor ‘s highlight 👇 @cleancloud-he.bsky.social @certainty-aci.bsky.social Understanding Aerosol-Cloud Interactions is Pivotal for Improving Climate Predictions eos.org/editor-highl...eos.orgUnderstanding Aerosol-Cloud Interactions is Pivotal for Improving Climate Predictions - EosGlobal cooperation and knowledge sharing are essential to improve our understanding of cloud formation and evolution through aerosol-cloud interaction. 062
CERTAINTY-ACI @certainty-aci.bsky.social · 23/02/2026[EC–ESA Aerosol Cloud Cluster Activity] ⁉️Uncertainty in how air pollution interacts with clouds is the largest source of uncertainty in near-term climate projections 🔍New policy brief explains why reducing the uncertainty is essential for effective climate policy certainty-aci.eu/policy-brief... 021
Reposted by CERTAINTY-ACIUlas Im @ulasim77.bsky.social · 22/02/2026Excited to announce our new publication on #aerosol #cloud #interactions 👇 Proud to lead this perspective with great experts from the field @cleancloud-he.bsky.social @certainty-aci.bsky.social #ESA-AIRSENSE agupubs.onlinelibrary.wiley.com/doi/full/10....agupubs.onlinelibrary.wiley.comAerosol‐Cloud Interactions: Overcoming a Barrier to Projecting Near‐Term Climate Evolution and RiskAerosol-cloud interactions (ACI) remain a barrier to provide precise and actionable advice to policy makers at global and regional levels We recommend improving satellite retrievals, expanding gr... 032
CERTAINTY-ACI @certainty-aci.bsky.social · 11/02/2026[New EC-ESA Aerosol Cloud Cluster publication] Aerosol-Cloud Interactions: Overcoming a Barrier to Projecting Near-Term Climate Evolution and Risk By Im et al. ➡️ agupubs.onlinelibrary.wiley.com/doi/10.1029/... @cleancloud-he.bsky.socialagupubs.onlinelibrary.wiley.comAerosol‐Cloud Interactions: Overcoming a Barrier to Projecting Near‐Term Climate Evolution and RiskAerosol-cloud interactions (ACI) remain a barrier to provide precise and actionable advice to policy makers at global and regional levels We recommend improving satellite retrievals, expanding gr... 020
CERTAINTY-ACI @certainty-aci.bsky.social · 22/01/2026📄🔥 Diverse aerosol effects revealed during wildfire and dust storm events in Ukraine in April 2020 ✍️ Savenets, M., Mahura, A., Nuterman, R., Kulmala, M., Petäjä, T. Atmospheric Pollution Research, 2026, 102906, ISSN 1309-1042 www.sciencedirect.com/science/arti...sciencedirect.comDiverse aerosol effects revealed during wildfire and dust storm events in Ukraine in April 2020Aerosol particles are significant drivers of meteorological phenomena, especially during high concentration events such as wildfires and dust storms. … 020
CERTAINTY-ACI @certainty-aci.bsky.social · 05/01/2026📄New publication: Regional climate imprints of recent historical changes in anthropogenic Near Term Climate Forcers ✍️ Santos-Espeso, A. et al. ➡️ esd.copernicus.org/articles/16/... ➡️ all CERTAINTY papers: certainty-aci.eu/publications/esd.copernicus.orgRegional climate imprints of recent historical changes in anthropogenic Near Term Climate ForcersAbstract. Near-Term Climate Forcers (NTCFs) play a crucial role in shaping Earth's climate, yet their effects are often overshadowed by long-lived greenhouse gases (GHGs) when addressing climate varia... 020
CERTAINTY-ACI @certainty-aci.bsky.social · 04/12/2025[Continuing collaboration with @cleancloud-he.bsky.social] ❄️ Efficient ice multiplication from freezing raindrop fragmentation 🖊️ Nils Pfeifer, Bernd Mom, Dmitri Moisseev, Susan Hartmann, Julian Meusel, Corinna Hoose & Maximilian Maahn 🔎 Read the publication: www.nature.com/articles/s43...nature.comEfficient ice multiplication from freezing raindrop fragmentation - Communications Earth & EnvironmentDrop fragmentation upon freezing is an efficient secondary ice process, contributing to cloud ice formation even at relatively high temperatures, according to quantitative analyses of ice crystals via... 041
CERTAINTY-ACI @certainty-aci.bsky.social · 26/11/2025🌗☁️Aerosols have an uncertain climate impact because they interact with clouds in complex ways, especially stratocumulus. These clouds behave differently by day and night, yet a new analysis by Pugsley et al. shows that the key processes actually occur at night: certainty-aci.eu/news-the-nig... 020
CERTAINTY-ACI @certainty-aci.bsky.social · 17/11/2025🇪🇺 🌎 Building Europe’s most ambitious joint effort to address one of the main knowledge gaps in climate science by advancing fundamental understanding of cloud–aerosol interactions Last week CERTAINTY, @cleancloud-he.bsky.social & @esa.int funded projects including AIRSENSE joined forces in Lausanne 040
CERTAINTY-ACI @certainty-aci.bsky.social · 07/11/2025[New publication] 📃 Secondary ice formation in cumulus congestus clouds: insights from observations and aerosol-aware large-eddy simulations ✒️ @silviamcalderon.bsky.social et al. ➡️ Paper: acp.copernicus.org/articles/25/... ➡️ All CERTAINTY publications: certainty-aci.eu/publications/acp.copernicus.orgSecondary ice formation in cumulus congestus clouds: insights from observations and aerosol-aware large-eddy simulationsAbstract. Secondary ice production (SIP) was investigated in a cumulus congestus system observed during the Secondary Production of Ice in Cumulus Experiment (SPICULE) campaign. Large-eddy simulations... 010
CERTAINTY-ACI @certainty-aci.bsky.social · 21/10/2025Assessing the global contribution of marine aerosols, terrestrial bioaerosols, and desert dust to ice-nucleating particle concentrations ✍️ Marios Chatziparaschos et al. 🔍 acp.copernicus.org/articles/25/...acp.copernicus.orgAssessing the global contribution of marine aerosols, terrestrial bioaerosols, and desert dust to ice-nucleating particle concentrationsAbstract. Aerosol–cloud interactions, particularly ice processes in mixed-phase clouds (MPCs), remain a key source of uncertainty in climate change assessments. This study introduces state-of-the-art ... 010
Reposted by CERTAINTY-ACICleanCloud Project @cleancloud-he.bsky.social · 16/10/2025Don’t miss Prof. Trude Storelvmo’s talk on Arctic mixed-phase #clouds, connecting insights from small-scale processses to large-scale #climate impacts. 🌍☁️ 📆 Wednesday 29 Oct at 1pm (CET) on Zoom! epfl.zoom.us/j/6156668523... 075
CERTAINTY-ACI @certainty-aci.bsky.social · 02/10/2025☁️ 🌲 Cumulus clouds amplify boreal forest photosynthesis A recent study by Ezhova et al., based on long-term observations in Finland, shows that, in boreal forests, organic aerosols enhance photosynthesis under cumulus clouds. 🔍 www.nature.com/articles/s43... 🔍 certainty-aci.eu/news/nature.comOrganic aerosol enhances boreal forest photosynthesis under cumulus clouds - Communications Earth & EnvironmentNatural aerosols under cumulus clouds enhance diffuse radiation and therefore photosynthesis in boreal forests, increasing carbon uptake, according to analysis of atmospheric data from a forest site in southern Finland. 020
CERTAINTY-ACI @certainty-aci.bsky.social · 29/09/2025🌎🔥Roșu et al. found that the 2023 Canadian wildfires emissions caused widespread increases in aerosol concentrations across the Northern Hemisphere, leading to a measurable cooling of surface air temperatures 🔍 certainty-aci.eu/news-climate... 🔍 www.nature.com/articles/s44...nature.comLarge-scale impacts of the 2023 Canadian wildfires on the Northern Hemisphere atmosphere - npj Clean Airnpj Clean Air - Large-scale impacts of the 2023 Canadian wildfires on the Northern Hemisphere atmosphere 010
CERTAINTY-ACI @certainty-aci.bsky.social · 23/09/2025Missed the great fireside chat with Gavin Pretor-Pinney & Edward Gryspeerdt on clouds? 🌥️ No worries, you can catch the replay here: ⬇️⬇️⬇️ 030
CERTAINTY-ACI @certainty-aci.bsky.social · 23/09/2025🛳️ 🌎 Impacts of shipping fuel regulations on global warming 👉 Read the paper: www.nature.com/articles/s43... (Jianhao Zhang, Yao-Sheng Chen, Edward Gryspeerdt, Takanobu Yamaguchi & Graham Feingold) 👉 Discover more CERTAINTY web stories: certainty-aci.eu/news/ 000
CERTAINTY-ACI @certainty-aci.bsky.social · 19/09/2025A recent study by Hermant, Huusko and Mauritsen shows that the direct radiative effect of aerosols has continued to strengthen, even as emissions declined, whereas the indirect effect has weakened in line with emissions. 🔍 Read a summary here: certainty-aci.eu/news-aerosol... 000
CERTAINTY-ACI @certainty-aci.bsky.social · 17/09/2025🚀 Coming up on 19 September 2025: a fireside chat on clouds and climate with Gavin Pretor-Pinney and Edward Gryspeerdt 🔗 Register now: luma.com/3wtgxi06luma.comClouds & Climate: A Fireside Chat with Gavin Pretor-Pinney & Dr Ed Gryspeerdt · LumaAsterisk Labs and the Cloud Appreciation Society are delighted to invite you to an online 'fireside chat' between Gavin Pretor-Pinney and Dr Ed… 020
CERTAINTY-ACI @certainty-aci.bsky.social · 12/09/2025☁️ Clouds & Climate: A Fireside Chat with Gavin Pretor-Pinney & Ed Gryspeerdt 🗓️ 19 Sept. 🕔 17:00–18:00 (GMT+2) 📍 Online luma.com/3wtgxi06 A special online fireside chat exploring the wonder of clouds & their vital role in the Earth’s climate system, bridging science, beauty & public engagement 020
CERTAINTY-ACI @certainty-aci.bsky.social · 04/09/2025[ 📣 New publication] Weak influence of anthropogenic emissions on aerosol, cloud, and rain in the wet season of the Amazon rainforest ✒️ Wang, X., Carslaw, K. S., Grosvenor, D. P., and Gordon, H. 🔗 acp.copernicus.org/articles/25/... 🔎 All CERTAINTY papers: certainty-aci.eu/publications/acp.copernicus.orgWeak influence of anthropogenic emissions on aerosol, cloud, and rain in the wet season of the Amazon rainforestAbstract. Anthropogenic emissions have been shown to affect new particle formation, aerosol concentrations, and clouds. Such effects vary with region, environmental conditions, and cloud types. In the... 030
CERTAINTY-ACI @certainty-aci.bsky.social · 03/09/2025📣 A new study examines the effects of the extreme 2023 Canadian wildfires using an Earth system model, comparing modelled atmospheric conditions with and without wildfire emissions. ✒️ Roșu et al. 🔎 www.nature.com/articles/s44... 🔎 All CERTAINTY publications: certainty-aci.eu/publications/nature.comLarge-scale impacts of the 2023 Canadian wildfires on the Northern Hemisphere atmosphere - npj Clean Airnpj Clean Air - Large-scale impacts of the 2023 Canadian wildfires on the Northern Hemisphere atmosphere 010
CERTAINTY-ACI @certainty-aci.bsky.social · 01/09/2025[ 📣 Summer 2025 - Publication] Organic aerosol enhances boreal forest photosynthesis under cumulus clouds ☁️ ✒️ by Ekaterina Ezhova et al. 🔗 Read the paper here: www.nature.com/articles/s43...nature.comOrganic aerosol enhances boreal forest photosynthesis under cumulus clouds - Communications Earth & EnvironmentNatural aerosols under cumulus clouds enhance diffuse radiation and therefore photosynthesis in boreal forests, increasing carbon uptake, according to analysis of atmospheric data from a forest site i... 010
CERTAINTY-ACI @certainty-aci.bsky.social · 26/08/2025⏰ Join us tomorrow ⏰ 📢 WEBINAR Distinguishing aerosol-cloud interactions amidst cloud variability 🗨️ @harrikokkola.bsky.social 🗓️ Wednesday, Aug 27 🕐 13:00 CEST | 📍 Zoom: epfl.zoom.us/j/6156668523... @cleancloud-he.bsky.social 000