Strong Ocean/Sea-Ice Contrasts Observed in Satellite-Derived Ice Crystal Number Concentrations in Arctic Ice Boundary-Layer Clouds

• Published in: Geophysical Research Letters
• Main Authors: Papakonstantinou-Presvelou, Iris, Sourdeval, Odran, Quaas, Johannes
• Other Authors: Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: aerosol-cloud interactions; DARDAR-Nice; low-level clouds; ice microphysics; Arctic Amplification; [SDU]Sciences of the Universe [physics]; Arctic; Sea ice
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03779807; https://hal-insu.archives-ouvertes.fr/insu-03779807/document; https://hal-insu.archives-ouvertes.fr/insu-03779807/file/Geophysical%20Research%20Letters%20-%202022%20-%20Papakonstantinou%25u2010Presvelou%20-%20Strong%20Ocean%20Sea%25u2010Ice%20Contrasts%20Observed%20in.pdf; https://doi.org/10.1029/2022GL098207

International audience The Arctic climate changes at a faster rate than the rest of the globe. Boundary-layer clouds may play an important role in this change. At temperatures below 0°C, mixed-phase clouds exist and their phase and longevity is influenced by the abundance of ice crystals, which in turn is a function of aerosols serving as ice nucleating particles (INPs). Previous in situ studies suggested a local source of INPs due to biological activity over open ocean. Here we investigate ice crystal concentrations in clouds below 2 km at a large scale, by exploiting a newly developed data set—DARDAR-Nice—retrieved from active satellite remote sensing. The data set spans from 2006 to 2016. Contrary to previous expectation, we find that at a given latitude and temperature, there are more ice crystals over sea ice than over open ocean. This enhancement is particularly found in clouds south of 70°N, and also at temperatures between 0°C and −10°C.