The Cold-Air Outbreaks in the Marine Boundary Layer Experiment model-observation intercomparison project (COMBLE-MIP) – Part 1: Model specification, observational constraints, and preliminary findings

@article{juliano2026coldair,
  title = {{The Cold-Air Outbreaks in the Marine Boundary Layer Experiment model-observation intercomparison project (COMBLE-MIP) – Part 1: Model specification, observational constraints, and preliminary findings}},
  author = {Timothy W. Juliano and Florian Tornow and Ann M. Fridlind and Andrew S. Ackerman and Gregory S. Elsaesser and Bart Geerts and Christian Philipp Lackner and David Painemal and Israel Silber and Mikhail Ovchinnikov and Gunilla Svensson and Michael Tjernström and Peng Wu and Alejandro Baró Pérez and Peter Bogenschutz and Dmitry Chechin and Kamal Kant Chandrakar and Jan Chylik and Andrey V. Debolskiy and Rostislav Yu. Fadeev and Anu Gupta and Luisa Ickes and Michail Karalis and Martin Köhler and Branko Kosović and Peter Kuma and Weiwei Li and Evgeny V. Mortikov and Hugh Morrison and Roel Neggers and Anna Possner and Tomi Raatikainen and Lea Raillard and Sami Romakkaniemi and Niklas Schnierstein and Shin‐ichiro Shima and Nikita Silin and Mikhail Tolstykh and Étienne Vignon and Lulin Xue and Meng Zhang and Xue Zheng},
  journal = {Atmospheric Chemistry and Physics},
  year = {2026},
  month = sep,
  doi = {10.5194/acp-26-13267-2026},
  url = {https://hal.science/hal-05829768v1},
  note = {CC BY 4.0},
}

TY  - JOUR
TI  - The Cold-Air Outbreaks in the Marine Boundary Layer Experiment model-observation intercomparison project (COMBLE-MIP) – Part 1: Model specification, observational constraints, and preliminary findings
AU  - Timothy W. Juliano
AU  - Florian Tornow
AU  - Ann M. Fridlind
AU  - Andrew S. Ackerman
AU  - Gregory S. Elsaesser
AU  - Bart Geerts
AU  - Christian Philipp Lackner
AU  - David Painemal
AU  - Israel Silber
AU  - Mikhail Ovchinnikov
AU  - Gunilla Svensson
AU  - Michael Tjernström
AU  - Peng Wu
AU  - Alejandro Baró Pérez
AU  - Peter Bogenschutz
AU  - Dmitry Chechin
AU  - Kamal Kant Chandrakar
AU  - Jan Chylik
AU  - Andrey V. Debolskiy
AU  - Rostislav Yu. Fadeev
AU  - Anu Gupta
AU  - Luisa Ickes
AU  - Michail Karalis
AU  - Martin Köhler
AU  - Branko Kosović
AU  - Peter Kuma
AU  - Weiwei Li
AU  - Evgeny V. Mortikov
AU  - Hugh Morrison
AU  - Roel Neggers
AU  - Anna Possner
AU  - Tomi Raatikainen
AU  - Lea Raillard
AU  - Sami Romakkaniemi
AU  - Niklas Schnierstein
AU  - Shin‐ichiro Shima
AU  - Nikita Silin
AU  - Mikhail Tolstykh
AU  - Étienne Vignon
AU  - Lulin Xue
AU  - Meng Zhang
AU  - Xue Zheng
PY  - 2026
DA  - 2026/09/22
JO  - Atmospheric Chemistry and Physics
DO  - 10.5194/acp-26-13267-2026
UR  - https://hal.science/hal-05829768v1
AB  - Models struggle to represent the coupled microphysical, turbulent and radiative processes within widespread, long-lived marine cold-air outbreak (CAO) cloud fields, contributing to forecast and climate biases. Here we combine ground-based and satellite measurements to initialize and constrain large-eddy simulations (LES) of cloud field evolution with distance downwind from the marginal ice zone during a strong, highly supercooled and convective CAO observed during the Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE). LES results are compared with large-scale models run in single-column model (SCM) mode, providing an observation-constrained framework for large-scale model evaluation and future improvements. All models reproduce rapid cloud formation off the ice edge, and a monotonic ascent of downwind cloud-top heights, closely linked with time-integrated surface heat fluxes. LES generally reproduce domain-mean observational targets using a modest test domain (25×25 km 2 ), and a larger domain (125×125 km 2 ) enables better reproducing the observed growth of convective cell sizes. In realistic mixed-phase LES compared with liquid-only simulations, ice processes lead to thinner, broken cloud decks and substantially reduced cloud radiative effects on top-of-atmosphere longwave fluxes. By contrast, mixed-phase SCM simulations generally underpredict the radiative impact of ice, primarily owing to insufficient reduction of cloud cover. Results indicate that cellular cloud structure is qualitatively captured by LES, and thus LES could provide guidance to improvement of large-scale model physics schemes. Follow-on work will extend these results to larger domains, apply objective analysis of mesoscale structure, and include prognostic aerosol properties for droplet and heterogeneous ice formation.
SN  - 1680-7316
SN  - 1680-7324
ER  -