دورية أكاديمية

Physicochemical characterization of free troposphere and marine boundary layer ice-nucleating particles collected by aircraft in the eastern North Atlantic

التفاصيل البيبلوغرافية
العنوان: Physicochemical characterization of free troposphere and marine boundary layer ice-nucleating particles collected by aircraft in the eastern North Atlantic
المؤلفون: D. A. Knopf, P. Wang, B. Wong, J. M. Tomlin, D. P. Veghte, N. N. Lata, S. China, A. Laskin, R. C. Moffet, J. Y. Aller, M. A. Marcus, J. Wang
المصدر: Atmospheric Chemistry and Physics, Vol 23, Pp 8659-8681 (2023)
بيانات النشر: Copernicus Publications, 2023.
سنة النشر: 2023
المجموعة: LCC:Physics
LCC:Chemistry
مصطلحات موضوعية: Physics, QC1-999, Chemistry, QD1-999
الوصف: Atmospheric ice nucleation impacts the hydrological cycle and climate by modifying the radiative properties of clouds. To improve our predictive understanding of ice formation, ambient ice-nucleating particles (INPs) need to be collected and characterized. Measurements of INPs at lower latitudes in a remote marine region are scarce. The Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign, in the region of the Azores islands, provided the opportunity to collect particles in the marine boundary layer (MBL) and free troposphere (FT) by aircraft during the campaign's summer and winter intensive operation period. The particle population in samples collected was examined by scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure spectroscopy. The identified INPs were analyzed by scanning electron microscopy with energy-dispersive X-ray analysis. We observed differences in the particle population characteristics in terms of particle diversity, mixing state, and organic volume fraction between seasons, mostly due to dry intrusion events during winter, as well as between the sampling locations of the MBL and FT. These differences are also reflected in the temperature and humidity conditions under which water uptake, immersion freezing (IMF), and deposition ice nucleation (DIN) proceed. Identified INPs reflect typical particle types within the particle population on the samples and include sea salt, sea salt with sulfates, and mineral dust, all associated with organic matter, as well as carbonaceous particles. IMF and DIN kinetics are analyzed with respect to heterogeneous ice nucleation rate coefficients, Jhet, and ice nucleation active site density, ns, as a function of the water criterion Δaw. DIN is also analyzed in terms of contact angles following classical nucleation theory. Derived MBL IMF kinetics agree with previous ACE-ENA ground-site INP measurements. FT particle samples show greater ice nucleation propensity compared to MBL particle samples. This study emphasizes that the types of INPs can vary seasonally and with altitude depending on sampling location, thereby showing different ice nucleation propensities, which is crucial information when representing mixed-phase cloud and cirrus cloud microphysics in models.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1680-7316
1680-7324
Relation: https://acp.copernicus.org/articles/23/8659/2023/acp-23-8659-2023.pdf; https://doaj.org/toc/1680-7316; https://doaj.org/toc/1680-7324
DOI: 10.5194/acp-23-8659-2023
URL الوصول: https://doaj.org/article/eed1f32144fe4b6180a81b1d3b40f691
رقم الأكسشن: edsdoj.1f32144fe4b6180a81b1d3b40f691
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:16807316
16807324
DOI:10.5194/acp-23-8659-2023