S. Twomey Created 2026-10-20 Updated 2026-11-05
S. Twomey analysed how changing the number of cloud particles can alter shortwave reflection. At fixed liquid-water amount, distributing the water among more, smaller droplets can increase cloud optical depth and albedo.[ref]
The fixed-water assumption separates this optical mechanism from changes in cloud lifetime, water content and atmospheric precipitation. It therefore identifies one contribution to a cloud's radiative response, rather than a universal numerical relation between aerosol abundance and total climate feedback.