Mineralogy Sensitive Immersion Freezing Parameterization in DREAM

• Published in: Journal of geophysical research. Atmospheres 2022-03, Vol.127 (5), p.n/a
• Main Authors: Ilić, Luka, Jovanović, Aleksandar, Kuzmanoski, Maja, Lazić, Lazar, Madonna, Fabio, Rosoldi, Marco, Mytilinaios, Michail, Marinou, Eleni, Ničković, Slobodan
• Format: Article
• Language: English
• Subjects: aerosol lidar; Atmosphere; atmospheric modeling; Atmospheric models; Atmospheric particulates; Atmospheric transport; Clouds; Crystals; DREAM; Droplets; Dust; dust modeling; Dust particles; Dust plumes; Dust storms; Feldspars; Freezing; Geophysics; High temperature; Horizontal distribution; Ice; Ice crystals; Ice formation; ice nuclation; Ice nuclei; Immersion; Lidar; Lidar measurements; Mathematical models; Mineral composition; mineral dust; Mineralogy; Minerals; Modelling; Nucleation; Parameterization; Particle concentration; Plumes; Probability theory; Quartz; Radar; Remote sensing; Satellite observation; Satellites; Submerging; Supercooled water; Temperature; Transport; Vertical profiles; Water droplets; Water drops; Work platforms
• ISSN: 2169-897X; 2169-8996
• DOI: 10.1029/2021JD035093

Dust aerosols are abundant in the atmosphere and are very efficient ice nucleating particles at temperatures below −15°C. Depending on temperature, dust particles containing certain minerals (i.e., feldspar and quartz) are the most active as ice nuclei. A mineralogy‐sensitive immersion freezing parameterization for ice nucleating particle concentration (INPC) is implemented in Dust Regional Atmospheric Model (DREAM) for the first time. Additionally, four mineralogy‐indifferent parameterizations are implemented, two for immersion freezing and two for deposition nucleation. Dust concentration and its feldspar and quartz fractions are forecasted by DREAM for a dust episode in the Mediterranean in April 2016. DREAM results are compared with vertical profiles of cloud‐relevant dust concentrations and INPC from ground‐based lidar measurements in Potenza, Italy and Nicosia, Cyprus. INPC predictions are also compared with vertical profiles of ice crystal number concentration (ICNC) from satellite observations for two overpasses over the dust plume. The model successfully simulates the evolution and vertical extent of the dust plume. Mineralogy‐sensitive and mineralogy‐indifferent INPC parameterization results generally differ by about an order of magnitude. Forecasted INPC and observed ICNC values differ by an order of magnitude for all parameterizations. Feldspar fraction increase within a dust plume during transport can increase INPC by around 6% at −35°C, and up to 17% at −25°C, but sedimentation can reduce this effect. Over the Atlantic, mineralogy‐sensitive parameterization predicts horizontal distribution of clouds with higher probability of success, while in the Mediterranean; the results for different parameterizations show lower variability. Plain Language Summary Supercooled water droplets in clouds can freeze at temperatures around −37°C. Dust particles immersed in water droplets can enhance formation of ice crystals at higher temperatures. The efficiency of dust particles in ice initiation has been attributed to the presence of ice‐active minerals, such as feldspar and quartz. In this work, we use a computer model (DREAM) to calculate how mineral dust particles from Sahara and Middle East are lifted and transported by the atmospheric flow. The model, includes equations that predict ice initiation depending on dust concentration and mineral composition, temperature and humidity. Atmospheric remote sensing observations from lidar and radar ground‐based a