Stratospheric Seeding - Hyde, Teller, Wood

[John Latham]

Hello All,

Re the interesting contributions made recently regarding
particles that might be used in the stratospheric seeding
SRM scheme, I'd like to make draw attention to a
seminal paper on this topic (1997, Hyde, Teller & Wood)
which I attach. In my view it constitutes by far the most
authoritatative and comprehensive examination of this
issue that I have seen.

Lowell (Wood) gave me permission to send this to you.

All Best, John. lat...@ucar.edu

John Latham
Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000
Email: lat...@ucar.edu or john.l...@manchester.ac.uk
Tel: (US-Work) 303-497-8182 or (US-Home) 303-444-2429
or (US-Cell) 303-882-0724 or (UK) 01928-730-002
http://www.mmm.ucar.edu/people/latham

[Michael Hayes]

Hi Folks,

In my reading of the Hyde et al. paper, the concept of using conductive sheets as a form of SRM stood out in my view as being a highly creative concept waiting for advancements in material science. Space based deployment was suggested over stratospheric placement due to oxidation shielding needs within the stratosphere. Here is the relative quote:

The constituent materials of  every efficient photoelectric absorber for solar-spectrum radiation 

inherently a r e  readily oxidizable, particularly in the highly (photoheactive upper atmosphere, so 

that only LEO deployment of  such systems appears feasible - unless 2two-fold mass penalties a r e  

paid for protective jacketing, e.g.,  Si02 ."

A recent MIT development along these lines may be appropriate to consider as a potential stratospheric alternative. Here is the media report:

How to grow nanowires and tiny plates

http://www.physorg.com/news/2011-07-nanowires-tiny-plates.html

The first key quote is:

“For nanostructures, there’s a coupling between the geometry and the electrical and optical properties,” explains Brian Chow, a postdoc at MIT and co-author of a paper describing the results that was published July 10 in the journal Nature Materials. “Being able to tune the geometry is very powerful,” he says. The system Chow and his colleagues developed can precisely control the aspect ratio (the ratio of length to width) of the nanowires to produce anything from flat plates to long thin wires."

I believe this development (particularly the TiO2 variant) may have potential to provide the fine tunning of SRM that Hyde et al. describe just prior to their conclusion:

"Indeed, scatterers of  sunlight could be deployed at some latitudes to decrement 

insolation, while  scatterers of  Earth-emitted long-wavelength infrared radiation 

(which effectively increment insolation) could be deployed at other latitudes.39 

Differential cooling and heating, respectively, of underlying land-and-ocean 

latitudinal bands could thereby be accomplished.  Furthermore, use of  scatterers 

of varying stratospheric residence times t o  simultaneously modulate insolation 

and LWlR radiative losses in a specified latitude band might be employed t o  fine- 

tune, e.g.,  diurnal or seasonal temperature variability.40".

The mass production potential indicated by Joo does seem to fall into line with the need for large yearly volumes needed for stratospheric SRM. 

Michael