Andrew wrote On Sunday, April 23, 2017 at 9:40:00 PM UTC-4: I don't think hydrosols will behave like CNN, in terms of their radiative > properties. As I understand it, CCN act to brighten existing cloud cover. > They won't, therefore, work on cloudless days. Likely, relative efficacy > will depend on whether acute or chronic thermal stress is most important. > Furthermore, hydrosols will cause a lasting increase in diffuse radiation. > In terrestrial models, this has impacted NPP. > > I'm no expert on this niche - but that's my initial thoughts. > > Hope it helps > > > It will take field experiments and further modeling to quantify the Net Photosynthetic Product impact of surface water brightening , but Andrew should bear three things in mind
1. Backscattering light does not have the same effect as casting shade, because most plankton and algae can absorb light in all directions, 2. Hydrosols scatter the infalling light in all directions, - they change the geometry of the euphotic zone in a diffferent manner than extensive cloud cover. 3. Doubling surface brightess at high sun angles , from ~ 7% to 14% reduces the underwater light flux by about 7%, which while obviously significant, is a small reduction relative to full cloud cover, which often reduces surface light more than twice as much, as white clouds in the air can have an albedo of up to .55.- m It may l accordingly take as much NPP research to sort out the ecological meaning of the physically uncontroversial cloudy day analogy as that of CCN shading of overheated seas , both triopical and circumpolar. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
