Modelling artificial sea salt emission in large eddy simulations

Area of Science:

• Atmospheric Science
• Cloud Physics
• Aerosol Science

Background:

• Designing effective marine cloud brightening emission sources requires understanding aerosol processes.
• Previous studies lacked explicit treatment of aerosol water's impact on particle dispersion and buoyancy.

Purpose of the Study:

• To investigate sea salt particle dispersion from artificial sea spray injections at a cloud-resolving scale.
• To quantify the effects of aerosol water condensation and evaporation on particle dispersion and ambient temperature.

Main Methods:

• Utilized a cloud-resolving scale model with explicit treatment of aerosol water.
• Incorporated condensation, evaporation, and their impact on ambient temperature.
• Employed higher model resolution to capture near-source aerosol loss via coagulation.

Main Results:

• Evaporation-induced cooling (up to 1.4 K) delayed particle dispersion by 10-20 minutes for a seawater flux of 15 kg s⁻¹.
• Aerosol water increased particle scavenging by a factor of 1.14 compared to simulations without it.
• Cooling and dispersion were resolution-dependent, with maximum scavenging of 20% at 50m resolution within 5 hours.

Conclusions:

• Aerosol water significantly influences sea salt particle dispersion and scavenging in marine cloud brightening.
• High-resolution modeling is crucial for accurately simulating these processes and designing effective emission strategies.
• Further regional, high-resolution studies modeling extended injection periods are recommended.