Comparison of Atomizers Intended for Marine Cloud Brightening

MARYAM SHAHRASEBI, Steven Rogak, University of British Columbia

     Abstract Number: 668
     Working Group: Aerosols, Clouds and Climate

Abstract
Geoengineering has been proposed to mitigate the impacts of climate change while decarbonization efforts are in progress. Geoengineering can be implemented using a solar radiation management technique called Marine Cloud Brightening (MCB). The underlying principle of MCB is to artificially enhance the reflectivity and longevity of the maritime stratocumulus clouds by injecting seawater aerosols into them. As a result, the imposed negative radiative forcing would cool the planet. 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 (sub-micrometer particles with median of 30-100 nm) into the targeted clouds.

To identify promising atomizers, we calculated the energy consumed per generated sub-micrometer particle for the atomizers described in the literature. Furthermore, using a Scanning Mobility Particle Spectrometer (SMPS), we evaluated candidate atomizers: Ultrasonic nebulizer (Sonair MedPro), TSI 3076 atomizer, Bubble-gas jet atomizer (proposed by Mezhericher et al. 2017), and effervescent atomizer. In addition, the influence of geometry on bubble-gas jet atomization has been studied. Preliminary results demonstrated the energy consumption of both the Ultrasonic nebulizer and TSI 3076 being in the order of 10^-9 J/particle, while the Bubble-gas jet atomizer appeared to be more energy-intensive by an order of magnitude. However, none of them falls within the range of energy-efficiency needed for MCB which is in the order of 10^-12 J/particle. Additional results of the effervescent atomizer would be presented.