Obrigado pela sua resposta. Eu reconheço que os modelos de mudança climática não são totalmente responsáveis por nuvens, mas você não acredita que os modelos climáticos fazer?

I recognize that clouds are not suitably accounted for in climate change models, but I think that we do a good job at measuring the insolation associated with varying clouds. With this, we could estimate a range of possible flux differences for a given set of conditions.

I understand your concern due to the complexities of albedo and transmittance. It is well explained in Barker et al.: http://onlinelibrary.wiley.com/doi/10.1002/qj.49712454811/abstract

You also ask a good question about the need to know the differences of cloud albedo according to region. I am familiar with some studies that give some insight into the effects globally, even if incomplete: http://www.atmos.uah.edu/atmos/HAN/publication/relationships.pdf

And even though that variability might impact the efficacy of cloud modification for a particular region, do you not think that we can estimate it for a better known region? Since there the corridor for transcontinental flights is relatively limited and since those areas are also the ones where clouds are better studied, could we not calculate the flux for a given series of days?

The radiation balance on clear days and cloudy days is well studied:

http://amsu.cira.colostate.edu/kidder/2001GL014041.pdf

http://www.google.com/url?sa=t&rct=j&q=albedo%20studies%20on%20cirus%20clouds&source=web&cd=4&ved=0CDkQFjAD&url=http%3A%2F%2Fwww.eumetsat.int%2Fidcplg%3FIdcService%3DGET_FILE%26dDocName%3DPDF_CONF_P46_S6_03_HUENERBEI_V%26RevisionSelectionMethod%3DLatestReleased&ei=UXk2UOiaDYWa9QT4zICwBw&usg=AFQjCNGkwQzq0J3dTPLkwfqnquaZdoMGbw

Kaisch and Make (2012) calculated the radiative budget related to clouds over the Atlantic:

http://www.atmos-meas-tech-discuss.net/5/2011/2012/amtd-5-2011-2012.html

Zib et al 2012 made observations over the Arctic: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00147.1?journalCode=clim

Using these observations for varying conditions along with an estimate of reduced half-life of cirrus clouds due to the addition of ice nuclei, could we not calculate a range of possible daily flux changes, say over the Atlantic?

Thank you

I feel very sad to see that you did not even made the effort to go to Wikipedia for this. There you find for instance a reference to the well-known publication by Nobel-price winner dr Paul Crutzen.

Thank You. This also has good info. As does:

Mitchell, D.L. and Finnegan, W., 2009. Modification of cirrus clouds to reduce global warming. Environmental Research Letters, 4: 045102.

I apreciate the primer.

I only looked at the abstract of the Mitchell paper (I have noaccess to the journal). And what strikes me is that it talks about trapping of (LW) radiation while your question is entitled coud refelctivity?

What I make up of the abstract is that by removing the cirrus layer you enhance the outgoing heat

Please let us know what you are after then

I am satisfied wth the information given. I am a novice on the topic. Thanks

The cloud cooling is already being done with powdered aluminum in the

Jet exhaust. It is making changes to the environment of the Pacific North West

where aluminum is being concentrated in the soil, lakes and fish.

The concept is or was to create more tiny particles to begin the crystallization of

water into snow flakes, or tiny water droplets so it would rain and snow more.

This all started in the 1960's when the American Military experimented with

cloud seeding using Iodide crystals to create more rain and snow. They found that the results were unpredictable, and it often snowed thousands of miles

down stream from the intended target area.

If you are going to cloud seed, it should be done with good old Saharan Dust, as the environmental effects are far less damaging in that nature has been seeding the

Atmosphere with dust for centuries, but expect some unintended consequences

like super snow storms, because every dust particle is a potential nucleation

point for a snow flake.

The more intense Volcanoes like Krakatoa, and Pinatubo put lots of dust in the

upper atmosphere that cooled the planet for years, and produced some

very snowy winters.

Man can not compete with Volcanoes in their ability to seed the atmosphere

with dust particles., but Volcanoes are not very useful in that they are unpredictable

and excessive in their seeding approach.

A more intelligent approach is to move away from generating power via

burning anything, and to remodel our transportation system to not

use individual combustion engines to create propulsion. We need to use the

excess CO2 to enhance growth in green houses. We need to reduce the volume of the atmosphere by using more natural, and man made solutions , utilize the

CO2 and produce O2.

Any scheme that reflects sunlight is at best a stop gap measure. We need to go back to not changing the atmosphere by not burning and releasing more CO2.

Michael

Climate engineering is NOT the cloud seeding you describe. In cloud engineering particles are genearated to enhnance the number of cloud droplets. A clous with more smaller droplets reflect more more sunlight; this is climate cooling. Inj addition, clouds with smaller droplets exist for a longer time, because it is more difficult to form rain droplets.

This is accomplished by artificailly generating seasalt aerosol particles;

also, this seeding is done in the low (stratus) clouds. The cloud seeding you discuss occurs with solid particles in high level clouds

Over very long periods of time, will the salt become an environmental

problem like the aluminum powder in the Pacific Northwest ?

no because natural seasalt is used form the sea itself and that will than rain back out to the sea. I termed it artifical seasalt becasue large generatiors will produce it from seawater

Michael Clark: "will the salt become an environmental problem like the aluminum powder in the Pacific Northwest ?"

in which way became Al powder a problem there?

The Aluminum powder is showing up in higher concentrations in the soil,

water and fish.