Splash-Plate Atomization as a Candidate Spraying Technique for Marine Cloud Brightening

MARYAM SHAHRASEBI, Steven Rogak, University of British Columbia

     Abstract Number: 609
     Working Group: Aerosols, Clouds and Climate

Abstract
Marine Cloud Brightening (MCB) has been proposed as a technique to produce local or regional cooling over remote oceans. The underlying principle of MCB is to artificially enhance the reflectivity and longevity of the maritime stratocumulus clouds by injecting seawater aerosols at low elevations. However, the presence of giant (1-10 microns) cloud condensation nuclei within the seeded size spectrum expedites precipitation, which may break up the cloud layer. This emphasizes the importance of the energy-efficient injection of the right-sized particles (median of 30-100 nm).

Splash-plate atomization (SPA) uses jet impingement on an inclined plate to develop a thin liquid sheet that subsequently breaks into droplets of a size comparable to the sheet thickness rather than the orifice diameter. We measure the energy consumed by SPA from liquid flow and pressure, and with the size distribution (Scanning Mobility Particle Spectrometer and Electrical Low-pressure Impactor), we estimate the energy required for a particle of the correct size. SPA requires in the order of 10^-9 J/particle, comparable to current state-of-the-art effervescent atomizers being field tested for MCB. Plate angle, orifice diameter, and jet velocity influence the efficiency of SPA.