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This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. ; We present observations of terminator CO2 ice clouds events in three groups: Equatorial dawn, Equatorial dusk (both between 20°S and 20°N) and Southern midlatitudes at dawn (45°S and 55°S east of Hellas Basin) with ESA ExoMars Trace Gas Orbiter's Nadir and Occultation for MArs Discovery instrument. CO2 ice abundance is retrieved simultaneously with water ice, dust, and particle sizes, and rotational temperature and CO2 column profiles in 16 of 26 cases. Small particles (<0.5 μm) prevail at dusk, while water ice likely provides most source nuclei at dawn. Clouds east of Hellas are found to be dominantly nucleated on surface-lifted dust. CO2 ice is sometimes detected in unsaturated air together with dust nuclei at dawn, suggesting ongoing sublimation. Depending on latitude and local time, the interplay between particle precipitation and the lifetime of temperature minima (i.e., cold pockets) determines CO2 ice properties. © 2021. The Authors. ; ExoMars is a space mission of the European Space Agency (ESA) and Roscosmos. The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (IASB-BIRA), assisted by Co-PI teams from Spain (IAA-CSIC), Italy (INAF-IAPS), and the United Kingdom (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), with the financial and contractual coordination by the ESA Prodex Office (PEA 4000103401, 4000121493), by the Spanish MICINN through its Plan Nacional and by European funds under grants PGC2018-101836-B-I00 and ESP2017-87143-R (MINECO/FEDER), as well as by UK Space Agency through grants ST/V002295/1, ST/V005332/1, ST/R001405/1 and ST/S00145X/1 and Italian Space Agency through grant 2018-2-HH.0. The IAA/CSIC team acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This work was supported by NASA's Mars Program Office under WBS 604796, "Participation in the TGO/NOMAD Investigation of Trace Gases on Mars" and by NASA's SEEC initiative under Grant Number NNX17AH81A, "Remote sensing of Planetary Atmospheres in the Solar System and Beyond". This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 101004052. U.S. investigators were supported by the National Aeronautics and Space Administration. ; Peer reviewed