Cloud Tops Dropping Closer to Earth, NASA Satellite Finds

reply to post by Aloysius the Gaul

Really? Where is the evidence for that? ditto - what is the mechanism by which "natural" cirrus is "supplanted"?? how is that?? clearly their inception is different - but what is the evidence that the behaviour after that is any different? In what way are they different? I have never seen any reason being given for deliberate formation of cirrus aviaticus at all - where did yuo get this from? so what are the references for this conclusion? Destroying all clouds?? Really? so no rain? How will that cool the planet? Again - where are the references?

The strange questions and bizarre statements just go on and on. Failure to observe and failure to read links has not served you well.

So what else where the rockets were not too visible?

This one on SRM I'm going to address because it hasn't really been covered at all as far as how jet emissions affect the stratosphere and affecting the stratosphere affect everything else.

So SRM...solar radiation management...the deliberate act of trying to reflect sunlight away from earth...in order to combat global warming...is also deliberately or ignorantly or as a side-effect, practised through jet emissions.

www.ipcc.ch...

The stratosphere is also much drier than the troposphere, and clouds rarely form at this level.

Subsonic aircraft fly in the troposphere and lower stratosphere, whereas supersonic aircraft fly in the stratosphere 80-85% of the time, with cruise altitudes several kilometers above those of subsonic aircraft.

Comparisons of aircraft cruise altitudes with mean tropopause heights has led to estimates for stratospheric release of 20-40% of total emissions (Hoinka et al., 1993; Baughcum, 1996; Schumann, 1997; Gettleman and Baughcum, 1999).

In the future, aircraft with more fuel-efficient engines will produce lower exhaust temperatures for the same concentration of emitted water vapor, hence will tend to cause contrails at higher ambient temperatures and over a larger altitude range

Aircraft generate far less aerosol than that emitted and produced at the Earth's surface or by strong volcanic eruptions. Aircraft emissions injected directly at 9- to 12-km altitudes are more important than similar surface emissions because of longer atmospheric residence times in the upper troposphere.

Regions of ice-supersaturation vary with time and location and are estimated to cover an average of 10 to 20% of the Earth's surface at mid-latitudes. Ice-supersaturation in these regions is often too small to allow cirrus to form naturally, so aircraft act as a trigger to form cirrus clouds

So in the case of the stratosphere and whether or not it is being affected, the proof would be: see plane; see plane fly. And if these parameters are present then the stratosphere is impacted.

reply to post by luxordelphi


Radiative Forcing from jet emissions is a very small part of total man-made radiative forcing.

Originally posted by Uncinus
reply to post by luxordelphi

 

Radiative Forcing from jet emissions is a very small part of total man-made radiative forcing.

Thank you.

reply to post by luxordelphi

Yes, and, in forming, prevent the formation of natural clouds.

I guess that means that with conditions under which natural clouds would have formed contrails form instead because they form sooner.

But when natural cirrus already exist contrails do not somehow suck the moisture out of the ice crystals and cause the natural clouds to evaporate.

Contrail cirrus exist alongside and interact with natural clouds and, depending on their overlap with natural clouds, can increase overall cloud coverage

www.nature.com...
It does not say contrail cirrus destroys natural clouds. I suppose the contrails may inhibit further growth of natural clouds but the natural clouds don't go away, they merge with the contrails.

I'm not a chemist but that's what I get from reading the material even though it never gets specifically stated all in one paper.

It's not so much a matter of chemistry but I understand what you mean about that second part. It's sort of like how it's not specifically stated anywhere that chaff and SRM are not really complementary.

Since the discussion has been about your statement that contrail cirrus can lead to drought conditions because, unlike natural cirrus, they for some unstated purpose do not produce ice crystals which precipitate to lower levels. This study would seem to indicate otherwise:

Mixing of moist environmental air and vapor depleted contrail air produced localized regions of supersaturation along the contrail periphery, where crystals grew to several hundred microns at about 0.1 µm s−1 These particles could then fall from the contrail into the vapor rich, undepleted, supersaturated environment below. As heavier crystals left the contrail, others moved into the regions of ice supersaturation. Precipitation trails developed as this process continued over time.

www.agu.org...

Another article:

The main cluster of Fig.1 could thus be attributed to "aged" contrails, dominated by ice crystals that were larger than a few microns. This interpretation was supported by the presence in the time-height-backscatter plots of virgas or diffuse structures around the core of the majority of these contrails

lidarmax.altervista.org...
Virga is precipitation.

The development of virga falling from contrails is a manifestation of a favorable environment for growth and the development of contrail cirrus (T1, T4, and T10). With a sustained ice-supersaturated environment, some contrail microphysical properties become similar to those of natural cirrus, for example, concentrations of ice crystals larger than 100 μm in diameter are of the order of 10–100 l−1, and the habits are bullet rosettes (T5).

eprints.whiterose.ac.uk...

As far as precipitation goes, contrail cirrus seems to behave in the same manner as natural cirrus (as I suspected). The ice crystals grow to large enough sizes to precipitate. I still don't see why you think contrails can lead to droughts.

reply to post by luxordelphi

So SRM...solar radiation management...the deliberate act of trying to reflect sunlight away from earth...in order to combat global warming...is also deliberately or ignorantly or as a side-effect, practised through jet emissions.

But the article you've been talking about says the opposite. It says that aviation increases forcing. That it has warming effect. Not, as you claim, a cooling effect.

Aviation makes a significant contribution to anthropogenic climate forcing. The impacts arise from emissions of greenhouse gases, aerosols and nitrogen oxides, and from changes in cloudiness in the upper troposphere.

www.nature.com...

So does this one:

Aviation contributes to climate change by increasing atmospheric radiative forcing through the emission of gases and aerosols and changing cloud abundance.

airquality.ucdavis.edu...

Another:

Aviation emissions contribute to the radiative forcing (RF) of climate. Of importance are emissions of carbon dioxide (CO2), nitrogen oxides (NOx), aerosols and their precursors (soot and sulphate), and increased cloudiness in the form of persistent linear contrails and induced-cirrus cloudiness.

www.tiaca.org...

And if these parameters are present then the stratosphere is impacted.

Well, yes. Just as pretty much the entire environment is affected to one degree or another by a whole lot of things that humans do. Unfortunately (or not, depending on your point of view), it's what we do.

Originally posted by Uncinus
reply to post by luxordelphi

 

Radiative Forcing from jet emissions is a very small part of total man-made radiative forcing.

I don't think the jury is back yet.

www.nature.com...#/implications-for-evaluating-the-impact-of-aviation

Besides the uncertainty due to the treatment of contrail cirrus, our radiative-forcing estimates are also affected particularly by uncertainties related to the model’s representation of upper-tropospheric humidity and clouds. Clouds are influenced by small-scale processes that cannot be resolved by a large-scale climate model and which therefore need to be parametrized. The representation of clouds is a major source of uncertainty in climate simulations. The same problems also affect the representation of contrail cirrus.

The uncertainty of the radiative-forcing estimates should be evaluated from independent studies based on different models and contrail-cirrus parameterizations. Reducing the uncertainty in the evaluation of contrail-cirrus radiative forcing requires more and better observational data sets.

And, oh king of trivialization, did you not read previous entries on the differences between ground based emissions and emissions injected directly into the troposphere, tropopause and stratosphere? This would actually be observable because you will not see a car or motorcycle creating cirrus aviaticus. This would be the first clue.

After considering this, we might consider the previous gross underestimates of the impact of aviation. I think one of them said that effects had been underestimated by 5000 times. That seems like a little bit more than a blip on the radar.

Then we might continue in our considerations and move on to the inability to distinguish by satellite cirrus aviaticus from natural cirrus and at that point we might, justifiably, wonder just how much is what.

A factor of 5000 would be rather significant. Do you have a quote for that?

Holy crap. Been gone for months after tiring of the same people, posting the same thing, being shown that what they post is just flat wrong, with no rebuttal. Like the "Local News reports chemtrails..." p.o.s. on the first page. SSDD.
Really, before posting crap, especially recycled ad nauseum crap like that "news" report, you should be required to show it is correct. It's refuted all the time, and I have yet to see any of the questioned posters explain how the mistakes so clearly visible still make that video valid......they just twaddle on, and insert it in the next thread.

Geesh. Luckily, I am multi-skilled and enjoy knitting.
TTFN.......Believers, try actually learning something. Anything....please.

Originally posted by luxordelphi
reply to post by Aloysius the Gaul

 

Really? Where is the evidence for that? ditto - what is the mechanism by which "natural" cirrus is "supplanted"?? how is that?? clearly their inception is different - but what is the evidence that the behaviour after that is any different? In what way are they different? I have never seen any reason being given for deliberate formation of cirrus aviaticus at all - where did yuo get this from? so what are the references for this conclusion? Destroying all clouds?? Really? so no rain? How will that cool the planet? Again - where are the references?

The strange questions and bizarre statements just go on and on. Failure to observe and failure to read links has not served you well.

Your continual failure to answer the questions serves me perfectly.

So what else where the rockets were not too visible?

This one on SRM I'm going to address because it hasn't really been covered at all as far as how jet emissions affect the stratosphere and affecting the stratosphere affect everything else.

So SRM...solar radiation management...the deliberate act of trying to reflect sunlight away from earth...in order to combat global warming...is also deliberately or ignorantly or as a side-effect, practised through jet emissions.

www.ipcc.ch...

The stratosphere is also much drier than the troposphere, and clouds rarely form at this level.

Subsonic aircraft fly in the troposphere and lower stratosphere, whereas supersonic aircraft fly in the stratosphere 80-85% of the time, with cruise altitudes several kilometers above those of subsonic aircraft.

Comparisons of aircraft cruise altitudes with mean tropopause heights has led to estimates for stratospheric release of 20-40% of total emissions (Hoinka et al., 1993; Baughcum, 1996; Schumann, 1997; Gettleman and Baughcum, 1999).

In the future, aircraft with more fuel-efficient engines will produce lower exhaust temperatures for the same concentration of emitted water vapor, hence will tend to cause contrails at higher ambient temperatures and over a larger altitude range

Aircraft generate far less aerosol than that emitted and produced at the Earth's surface or by strong volcanic eruptions. Aircraft emissions injected directly at 9- to 12-km altitudes are more important than similar surface emissions because of longer atmospheric residence times in the upper troposphere.

Regions of ice-supersaturation vary with time and location and are estimated to cover an average of 10 to 20% of the Earth's surface at mid-latitudes. Ice-supersaturation in these regions is often too small to allow cirrus to form naturally, so aircraft act as a trigger to form cirrus clouds

So in the case of the stratosphere and whether or not it is being affected, the proof would be: see plane; see plane fly. And if these parameters are present then the stratosphere is impacted.

And not one single question of mine actually answered - as I expected

Congratulations - you have identified that:

Aircraft make clouds, also known as contrails
Aircraft emit pollutants
Aircraft created/emitted clouds and pollutants have some effects on the atmosphere

Are you actually going anywhere with this, or is mindless repetition of readily available info your only goal??

reply to post by stars15k


Well I will say one thing to you....

Welcome back and enjoy the chemtrail fun.

reply to post by Phage

I guess that means that with conditions under which natural clouds would have formed contrails form instead because they form sooner.

The atmosphere is like a primordial soup - full of potential. Then contrail cirrus come along and steal some of the ingredients. Once they get going, their spread is exponential. Because of them, what could have been is no longer possible because contrail cirrus by the very nature of their beginning will never herald weather systems. So in a Zen kind of a way, the beginning is the end and without a right beginning there can be no right ending.

But when natural cirrus already exist contrails do not somehow suck the moisture out of the ice crystals and cause the natural clouds to evaporate.

This is not crystal from the literature. In fact, some of the literature seems to indicate that 'that was the plan, man,' Naigin, mayor of New Orleans, talking about the response to Katrina.

www.nature.com...#/reduction-of-natural-cirrus-coverage-and-optical-depth

Therefore, contrail cirrus have the potential to modulate the optical properties of natural clouds, delaying their onset and replacing them, which may partly offset the direct climate impact of contrail cirrus.

www.ipcc.ch...

This potential for heterogeneous nuclei to cause ice formation at ice supersaturations that are relatively low compared to those needed to freeze sulfate particles leads to concern about the role of aircraft exhaust in modifying ambient clouds (Jensen and Toon, 1997).

www.intechopen.com...

Thus, cirrus clouds have a net warming effect on the earth's climate (Hartmann et al, 1992; Chen et al, 2000). It follows then that the most effective way to increase OLR may be to reduce the cloud cover of the highest, coldest cirrus clouds.

One method for how this goal might be accomplished is described in MF2009. They suggested "seeding" cirrus clouds with efficient ice nuclei that would out-compete the natural ice nuclei for water vapor.

And the last excerpt is ironically exactly what is happening with cirrus aviaticus. In order to make a case for this being deliberate, we might start by looking at the dates of the studies and admonishing that this was known prior to the explosion of cirrus aviaticus.

The excerpt from the study that you continue to quote as proof of essentially benign effects:

www.nature.com...#/reduction-of-natural-cirrus-coverage-and-optical-depth

Contrail cirrus exist alongside and interact with natural clouds and, depending on their overlap with natural clouds, can increase overall cloud coverage.

also says this in the same paper:

Only part of the contrail/contrail-cirrus coverage leads to an increase in overall cloud coverage.

The change in cirrus coverage, calculated by vertically overlapping all ice clouds in a column, confirms that the natural-cirrus coverage is decreased owing to the presence of contrail cirrus.

Furthermore, in the main contrail-cirrus areas of North America and Europe, the optical depth of natural clouds is significantly (at the 95% significance level) reduced by up to 10% owing to the presence of contrail cirrus.

I think that's pretty clear and also we discussed this previously in saying that contrail cirrus add themselves to cloud coverage and that is how they increase cloud coverage. That too is pretty clear. As far as contrail cirrus merging with anything - this is not a marriage but a clear question of dominance by virtue of water confiscation.

(...to be continued...)

reply to post by Phage

It's sort of like how it's not specifically stated anywhere that chaff and SRM are not really complementary.

Boy...talk about a side-step. When you talk about the military, you have to talk in their terms. The military understands obfuscation and obscurants. The military also understands the enemy. What's chaff? It's an obscurant used for obfuscation to keep an enemy from 'seeing' something. What's the most visible result of SRM? In military terms it's obfuscation. Obscurants are an evolving field. Obscurants have evolved on into nano size. Nano is a size that straddles two realms. Not really this and not really that. So its' reactions are often unusual - not necessarily following the reactions of bulk of the same substance. Aluminum, as nano, is basically - 'a little bit will do you' - because the enormous surface area of the tiny particle is completely out of proportion to what a bulk size particle would exhibit. In a world of 'let's try this and see what happens' chaff and SRM are the handmaidens of geoengineers. Technology is developing faster now than in the previous 3600 or so years since the Exodus, the last cataclysm to hit planet earth. Why would the expense of mirrors in space be needed when aluminum nano in the stratosphere will do more and cheaper?

Since the discussion has been about your statement that contrail cirrus can lead to drought conditions because, unlike natural cirrus, they for some unstated purpose do not produce ice crystals which precipitate to lower levels. This study would seem to indicate otherwise:

You go on to talk about virga and this is the new plan. Get it to fall out thus preventing the formation of natural cirrus with its' net warming effect. In either case...drought is a side-effect. As is clear from the same study (sorry - too many studies in the air - so if it's not the same one, remain calm.)

www.intechopen.com...

Thus, cirrus clouds have a net warming effect on the earth's climate (Hartmann et al, 1992; Chen et al, 2000). It follows then that the most effective way to increase OLR may be to reduce the cloud cover of the highest, coldest cirrus clouds.

One method for how this goal might be accomplished is described in MF2009. They suggested "seeding" cirrus clouds with efficient ice nuclei that would out-compete the natural ice nuclei for water vapor.

As noted above, higher fall speeds will result in shorter cloud lifetimes, less cloud coverage, lower ice water paths and lower cloud optical depths.

2.2 Reducing cloud cover for the coldest cirrus clouds...Cirrus clouds might be modified by seeding aerosol at any temperature, provided the natural ice nuclei, whether heterogeneous or homogenous, activates at a RH, well above the RH, threshold of the seeding aerosol.

and the old method and thought before the net warming of cirrus hit home:

www.geology.iastate.edu...

If the amount of water available for condensation in the cloud is not changed, this means that there will be more smaller drops, which are less likely to grow to sufficient size to fall out as precipitation and making clouds last longer, again contributing to cooling.

For two reasons, therefore, - cooling of the surface because of increased reflection of solar energy, and reduced efficiency of clouds to produce rain ? increases in aerosol will weaken the hydrological cycle.

but already then, drought was known.

As far as precipitation goes, contrail cirrus seems to behave in the same manner as natural cirrus (as I suspected). The ice crystals grow to large enough sizes to precipitate. I still don't see why you think contrails can lead to droughts.

There are two methods here - kind of like the changing of the guard. The old one was to increase cirrus coverage. That produced drought conditions. It also had a net warming effect which became a no no so a new method was put into play. The object of this new method is no clouds at all. It's hard to say which 'let's do this and see what happens' has created current conditions requiring even more modification. With many and tiny ice crystals that fall out before clouds can form, drought is the result. Either case means no rain.

Observationally, the new clouds, the ones with virga, produce, at times some huge, heavy drops - like one or two and then they too are dust in the wind.

Originally posted by luxordelphi
reply to post by Phage

 

[

There are two methods here - kind of like the changing of the guard. The old one was to increase cirrus coverage. That produced drought conditions.

Source?

It also had a net warming effect which became a no no so a new method was put into play. The object of this new method is no clouds at all.

Source that this is actually an "object" of making contrails?

Observationally, the new clouds, the ones with virga, produce, at times some huge, heavy drops - like one or two and then they too are dust in the wind.

Virga means the rain doesn't actually reach the ground in the first place - that is the definition of Virga

reply to post by Phage

But the article you've been talking about says the opposite. It says that aviation increases forcing. That it has warming effect. Not, as you claim, a cooling effect.

Sure and that's all true...but wait a minute...what about 9/11?...what about the spike in temperature when aviation stopped?...what about how that was supposed to be attributed to jet emissions and the clouds they cause not being there, cooling us. And remember global warming - first it was on, then it was off and now it's just confused.

So it depends on what you read and when. In the two recent studies I've been quoting, aviation is the bad guy. Is this by device? - the new whipping boy? or is it because you can't get all the climate scientists to publish the party line and some slip through the cracks? Or is it because aviation is pretty much a government subsidized activity these days? So they do what they're told.

Or is it because too many lies have been told and some of them are starting to put the lie to each other? But you're getting into motive here and there are plenty of studies that showed little or no climate impact from aviation but this is a brand new day and today we're finding that these things were underestimated in some cases by gross amounts.

And more, we're finding that they're still not properly estimated because satellite can't tell cirrus aviaticus from natural cirrus.

And last, jet emissions were supposed to be a sunscreen - saving us. Now they're not. Now we need something else. The new, short-lived, cirrus aviaticus - the lower clouds that this thread was about. The thinner ones, the ones without rain.

There are so many papers that call for testing, research and development of these techniques. There is almost no doubt IMO, that there is now a competition for the best methods to use. I would not be surprised if different airline companies were conducting or participating in these tests all within the guidelines set up for scientists to research SRM.

Who ever can prove that they have the best method for delivery and deployment of these Aerosol SRM techniques will certainly make a lot of money. Just as there scientists researching the best type and size aerosol particles to use. There are also research into how to inject these aerosols into our atmosphere most effectively and efficiently.

Here's just a few articles discussing the need for SRM aerosol field research and testing

2010 Research on Global "sun block" needed now

"Solar-radiation management may be the only human response that can fend off rapid and high-consequence climate change impacts. The risks of not doing research outweigh the risks of doing it," says Keith, director of the Institute for Sustainable Energy, Environment and Economy's energy and environmental systems group and a professor in the Schulich School of Engineering.

Solar-radiation management (SRM) would involve releasing megatonnes of light-scattering aerosol particles in the upper atmosphere to reduce Earth's absorption of solar energy, thereby cooling the planet. Another technique would be to release particles of sea salt to make low-altitude clouds reflect more solar energy back into space.

Field tests of SRM are the only way to identify the best technologies and potential risks, Keith says. He and the American scientists propose carefully controlled testing that would involve releasing tonnes – not megatonnes – of aerosols in the stratosphere and low-altitude clouds.

"If SRM proves to be unworkable or poses unacceptable risks, the sooner we know the less moral hazard it poses; if it is effective, we gain a useful additional tool to limit climate damages.".

www.sciencedaily.com...

Still, it will take decades to develop air capture and algal bioenergy systems, scale up prototypes, prepare underground carbon repositories and deploy such systems on a global scale.
"In an ideal case, we could have full deployment on a global scale by 2050," said Greene.

To buy time, another geoengineering strategy that many scientists are exploring involves altering the Earth's radiation budget by injecting sulfate aerosols into the atmosphere and blocking the sun's rays, mimicking what happens after a volcanic eruption, says the paper. Other strategies involve injecting seawater droplets into clouds and deploying shades or mirrors in space, all to block the sun's rays from reaching Earth's surface.

Such solar radiation management strategies "can be done quickly, but should only be considered as a last resort to buy ourselves some time" since they simply "cover up the problem without doing anything about the CO2," said Greene.

www.sciencedaily.com...

This new study looked at the impacts of different strengths of geoengineering, from full strength (sufficient to return global average temperatures back to normal), through to no geoengineering.


Their analysis revealed that with increasing geoengineering strength, most regions become drier while others buck the trend and become increasingly wet. For example, the USA became drier with increasing geoengineering, and returned to normal conditions under half-strength geoengineering, whereas Australia became wetter, returning to normal conditions only for full strength geoengineering

www.srmgi.org...

event.arc.nasa.gov...

reply to post by Uncinus

A factor of 5000 would be rather significant. Do you have a quote for that?

Here's the quote from this link:

www.ipcc.ch...

A single aircraft operating in conditions favorable for persistent contrail formation appears to exert a contrail-induced radiative forcing some 5000 times greater (in W m?2km?1) than recent estimates of the average persistent contrail radiative forcing from the entire civil aviation fleet.

There was another source too that said the same thing but that was more like a news story and this is like some kind of a manual.

reply to post by Aloysius the Gaul

Are you actually going anywhere with this, or is mindless repetition of readily available info your only goal??

You said:

So what else where the rockets were not too visible?

So I told you about what else where the rockets were not too visible because that's the only part of your post that wasn't repetitious. The repetition is eating me alive.

The stratosphere is impacted by jet emissions. The tropopause is impacted by jet emissions. The troposphere is impacted by jet emissions. The hydrological cycle is impacted by jet emissions. Net warming is impacted by jet emissions. SRM: a bloody nightmare.

Originally posted by luxordelphi
SRM: a bloody nightmare.

Which is why nobody has done it yet, and everyone recommends extensive research before any future deployment, and avoiding that deployment if at all possible

Originally posted by luxordelphi
reply to post by Aloysius the Gaul

 

Are you actually going anywhere with this, or is mindless repetition of readily available info your only goal??

You said:

So what else where the rockets were not too visible?

So I told you about what else where the rockets were not too visible because that's the only part of your post that wasn't repetitious. The repetition is eating me alive.

Try answering some questions or making a point then, instead of posting all sorts of info with no obvious link or reason.

The stratosphere is impacted by jet emissions. The tropopause is impacted by jet emissions. The troposphere is impacted by jet emissions. The hydrological cycle is impacted by jet emissions. Net warming is impacted by jet emissions.

Yep - well spotted....yawn..and you complain about me being repetitious??

Also all those things are impacted by industrial emissions, vehicle emissions, deforestation.

WTF IS YOUR POINT?????

SRM: a bloody nightmare.

there you go again implying that SRM is solely spraying stuff in the atmosphere.

What is a nightmare about reforestation? Or cool roofs? Or grasslands management? Or space mirrors?

Spraying sulphates has enormous problems - which is why no-one is ding it and pretty much everyone who has contemplated it says "let's not do it unless we REALLY have to"

"Spraying" aluminium and barium micro particles would probably have fewer problems - at least it wouldn't involve acid rain.

Trying to say all forms of SRM are the same and are all "nightmares" simply shows your ignorance about SRM.

Originally posted by luxordelphi
reply to post by Uncinus

 

A factor of 5000 would be rather significant. Do you have a quote for that?

Here's the quote from this link:

www.ipcc.ch...

A single aircraft operating in conditions favorable for persistent contrail formation appears to exert a contrail-induced radiative forcing some 5000 times greater (in W m?2km?1) than recent estimates of the average persistent contrail radiative forcing from the entire civil aviation fleet.

That quote is not at that link.