Dr. Robock (with ccs, and adding Dr. Seitz)
Thanks for early and full comments, with your (unexpected) already prepared
response to Dr.
Seitz' SRM proposal for "Bright Water". This is mainly to express hope that
Dr. Seitz has already been thinking of a response.
I put the albedo options into a different "box" than the stratospheric
options - and especially as relates to the urgency I see re the Arctic.
I also hope we can explore some possible benefits of Bright Water in the
CDR (Biochar) arena.
Ron
Sent from my iPad
On Apr 4, 2011, at 11:24 PM, Alan Robock <[email protected]> wrote:
> For guns, see:
>
> Robock, Alan, Allison B. Marquardt, Ben Kravitz, and Georgiy Stenchikov,
> 2009: The benefits, risks, and costs of stratospheric geoengineering.
> Geophys. Res. Lett., 36, L19703, doi:10.1029/2009GL039209.
> http://climate.envsci.rutgers.edu/pdf/2009GL039209.pdf
>
> For bubbles, see:
>
> Robock, Alan, 2011: Bubble, bubble, toil and trouble. An editorial comment.
> Climatic Change, doi:10.1007/s10584-010-0017-1.
> http://climate.envsci.rutgers.edu/pdf/Bubble.pdf
>
>
> Alan
>
> Alan Robock, Professor II (Distinguished Professor)
> Editor, Reviews of Geophysics
> Director, Meteorology Undergraduate Program
> Associate Director, Center for Environmental Prediction
> Department of Environmental Sciences Phone: +1-732-932-9800 x6222
> Rutgers University Fax: +1-732-932-8644
> 14 College Farm Road E-mail: [email protected]
> New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock
>
> On 4/4/2011 8:50 PM, [email protected] wrote:
>>
>> Andrew etal
>>
>> 1. I once looked at an all-electromagnetic (linear motor) launch approach
>> that might be a low cost alternative for what you want to do. Should be a
>> lot of literature on it.
>>
>> 2. Changing subject, I don't believe this list has had mention of an
>> alternative (bubbles - entirely ground-based) albedo-modifying approach..
>> Hopefully others can point out serious risks, if applied soon to the Arctic,
>> which application isn't specifically in the following Seitz draft article:
>>
>>
>> http://dash.harvard.edu/bitstream/handle/1/4737323/Seitz_BrightWater.pdf?sequence=1
>>
>> Ron
>>
>>
>> ----- Original Message -----
>> From: "Andrew Lockley" <[email protected]>
>> To: "geoengineering" <[email protected]>
>> Sent: Monday, April 4, 2011 5:43:40 PM
>> Subject: [geo] Another look at gunnery?
>>
>> Hi
>>
>> I've been going over some reports and notes recently, notably the Aurora
>> report http://people.ucalgary.ca/~keith/Misc/AuroraGeoReport.pdf
>>
>> The report makes it pretty clear that they've not done a huge amount to
>> expand on gunnery as a tool. Specifically, the report states that: " In the
>> 80-100 kft range, the relative simplicity of
>> the gun system begins to look attractive despite the high recuring cost of
>> shells, if the payload fraction can be increased"
>>
>> Back to basics here. Gunnery was developed by the military. Navies need
>> portable guns that aren't fired often - the exact opposite design criteria
>> that geoengineers need. Sailors therefore have short thick barrels with
>> massive overpressures, and robust shells to withstand the high g forces a
>> short barrel requires.. This is absolutely nothing like what we need for
>> geoengineering.
>>
>> We need long guns that work at low overpressure. Low overpressure means a
>> lightweight shell casing, a less tight barrel seal leading to lower friction
>> and hence lower wear and thus lower costs.
>>
>> I think we need to look at completely different gunnery technologies, as
>> well as just looking at gun redesign. My favorite is the ram launcher.
>> This works with a loose (sub calibre) shell as it doesn't rely on barrel
>> friction, so there's not the wear and cooling problem you get with a gun.
>> It doesn't require expensive propellants, as you can run it on a cheap
>> fuel/air mix. The acceleration is continuous, not declining like with a gun
>> - so it's much gentler. In fact, accelerations as low as 600g with a 1.2km
>> barrel are possible - and that still gives you 8kms/s launch speed - well
>> over what's needed for accessing the stratosphere. That's 1/10th the
>> acceleration in a conventional gun (although you do need to initiate the
>> projectile with a primary launcher - a ram accelerator can't self start).
>>
>> In case people need a reminder, the ram projectile works by firing a
>> loose-fitting projectile which relies on aerodynamic effects to ingnite fuel
>> behind it by compression ignition, like a ramjet. It travels through the
>> propellant, rather than being pushed in front of it.
>>
>> As a result of the loose fit and low launch stresses, the shells are likely
>> to be very much thinner, cheaper and less well-engineered than conventional
>> shells, and it may even be possible to make the shells reusable or at least
>> recyclable.
>>
>> What do other people think of this?
>>
>> For more info on the technology, check the following links:
>> http://www.tbfg.org/papers/Ram%20Accelerator%20Technical%20Risks%20ISDC07.pdf
>> and for an improved version, check
>> http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF
>>
>> A
>>
>>
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