UPDATE: Lead author Ben Laken responds in comments below.
I’ve reported several times at WUWT on the galactic cosmic ray theory proposed by Henrik Svensmark which suggests that changes in the sun’s magnetic field modulate the density of Galactic Cosmic Rays (GCRs) which in turn seed cloud formation on Earth, which changes the albedo/reflectivity to affect Earth’s energy balance and hence global climate.
A new paper published today in Atmospheric Chemistry and Physics suggests that the relationship has been established.
Figure 1 below shows a correlation, read it with the top and bottom graph combined vertically.
As the authors write in the abstract:
These results provide perhaps the most compelling evidence presented thus far of a GCR-climate relationship.
Dr. Roy Spencer has mentioned that it doesn’t take much in the way of cloud cover changes to add up to the “global warming signal” that has been observed. He writes in The Great Global Warming Blunder:
The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling.
Well, it seems that Laken, Kniveton, and Frogley have found just such a small effect. Here’s the abstract and select passages from the paper, along with a link to the full paper:
Atmos. Chem. Phys., 10, 10941-10948, 2010
doi:10.5194/acp-10-10941-2010
Cosmic rays linked to rapid mid-latitude cloud changes
B. A. Laken , D. R. Kniveton, and M. R. Frogley
Abstract. The effect of the Galactic Cosmic Ray (GCR) flux on Earth’s climate is highly uncertain. Using a novel sampling approach based around observing periods of significant cloud changes, a statistically robust relationship is identified between short-term GCR flux changes and the most rapid mid-latitude (60°–30° N/S) cloud decreases operating over daily timescales; this signal is verified in surface level air temperature (SLAT) reanalysis data. A General Circulation Model (GCM) experiment is used to test the causal relationship of the observed cloud changes to the detected SLAT anomalies. Results indicate that the anomalous cloud changes were responsible for producing the observed SLAT changes, implying that if there is a causal relationship between significant decreases in the rate of GCR flux (~0.79 GU, where GU denotes a change of 1% of the 11-year solar cycle amplitude in four days) and decreases in cloud cover (~1.9 CU, where CU denotes a change of 1% cloud cover in four days), an increase in SLAT (~0.05 KU, where KU denotes a temperature change of 1 K in four days) can be expected. The influence of GCRs is clearly distinguishable from changes in solar irradiance and the interplanetary magnetic field. However, the results of the GCM experiment are found to be somewhat limited by the ability of the model to successfully reproduce observed cloud cover. These results provide perhaps the most compelling evidence presented thus far of a GCR-climate relationship. From this analysis we conclude that a GCR-climate relationship is governed by both short-term GCR changes and internal atmospheric precursor conditions.
I found this portion interesting related to the figure above:
The composite sample shows a positive correlation between statistically significant cloud changes and variations in the short-term GCR flux (Fig. 1): increases in the GCR flux
occur around day −5 of the composite, and correspond to significant localised mid-latitude increases in cloud change. After this time, the GCR flux undergoes a statistically significant decrease (1.2 GU) centred on the key date of the composite; these changes correspond to widespread statistically significant decreases in cloud change (3.5 CU, 1.9 CU globallyaveraged) over mid-latitude regions.
and this…
The strong and statistically robust connection identified here between the most rapid cloud decreases over mid-latitude regions and short-term changes in the GCR flux is clearly distinguishable from the effects of solar irradiance and IMF variations. The observed anomalous changes show a strong latitudinal symmetry around the equator; alone, this pattern
gives a good indication of an external forcing agent, as
there is no known mode of internal climate variability at the
timescale of analysis, which could account for this distinctive
response. It is also important to note that these anomalous
changes are detected over regions where the quality of
satellite-based cloud retrievals is relatively robust; results of
past studies concerned with high-latitude anomalous cloud
changes have been subject to scrutiny due to a low confidence
in polar cloud retrievals (Laken and Kniveton, 2010;
Todd and Kniveton, 2001) but the same limitations do not
apply here.
Although mid-latitude cloud detections are more robust
than those over high latitudes, Sun and Bradley (2002) identified
a distinctive pattern of high significance between GCRs
and the ISCCP dataset over the Atlantic Ocean that corresponded
to the METEOSAT footprint. This bias does not
appear to influence the results presented in this work: Fig. 6 shows the rates of anomalous IR-detected cloud change occurring over Atlantic, Pacific and land regions of the midlatitudes during the composite period, and a comparable pattern of cloud change is observed over all regions, indicating no significant bias is present.
Conclusions
This work has demonstrated the presence of a small but statistically significant influence of GCRs on Earth’s atmosphere over mid-latitude regions. This effect is present in
both ISCCP satellite data and NCEP/NCAR reanalysis data for at least the last 20 years suggesting that small fluctuations in solar activity may be linked to changes in the Earth’s atmosphere via a relationship between the GCR flux and cloud cover; such a connection may amplify small changes in solar activity. In addition, a GCR – cloud relationship may also act in conjunction with other likely solar – terrestrial relationships concerning variations in solar UV (Haigh, 1996) and total solar irradiance (Meehl et al., 2009). The climatic forcings resulting from such solar – terrestrial links may have had a significant impact on climate prior to the onset of anthropogenic warming, accounting for the presence of solar cycle relationships detectable in palaeoclimatic records (e.g.,Bond et al., 2001; Neff et al., 2001; Mauas et al., 2008).
Further detailed investigation is required to better understand GCR – atmosphere relationships. Specifically, the use of both ground-based and satellite-based cloud/atmospheric monitoring over high-resolution timescales for extended periods of time is required. In addition, information regarding potentially important microphysical properties such as aerosols, cloud droplet size, and atmospheric electricity must also be considered. Through such monitoring efforts, in addition to both computational modelling (such as that of Zhou and Tinsley, 2010) and experimental efforts (such as that of Duplissy et al., 2010) we may hope to better understand the effects described here.
It seems they have found the signal. This is a compelling finding because it now opens a pathway and roadmap on where and how to look. Expect more to come.
The full paper is here: Final Revised Paper (PDF, 2.2 MB)
h/t to The Hockey Schtick
Thanks Ben,
That’s clearer now.
Dave Springer says:
November 26, 2010 at 2:07 am (Edit)
Steven Mosher says:
November 25, 2010 at 9:44 pm
“psst: no politician would talk about logical impossibility”
Impossibilities often mean practical impossibilities.
In this case what was meant is it is practically impossible to make reliable climate forecasts. The plethora of factors that determine climate are not all well understood, exceedingly complex, interdependent, subject to constant change, and for things like volcanic eruptions, comet impacts, and CMEs are quite unpredictable. Taken together that means it’s practically impossible to make long term forecasts.
##### that’s more like it, but still there are issues.
As I stated we can model the climate. the question is how reliable are the predictions?
Well the first problem we have is that we cannot run controlled experiments. we cannot hold independent variables constant and vary them in a factorial fashion.
Consequently we can only make conditional predictions:
1. Assuming no volcanic eruptions ( especially huge ones like Yellowstone caldera)
2. Assuming no comet impacts
3. Assuming no CMEs
4. Assuming the laws of physics dont change
5. Assuming no peak oil or peak coal
6. Assuming no mass extinctions via unknown viruses
7. assuming no breakthroughs in energy generation
8 assuming certain emmission pathways
9. assuming certain population changes
Lots of assumptions. So practically speaking we can make these predictions subject to these assumptions. Practically speaking we can. practically speaking we do.so it’s not practically impossible either. The issue is how much weight should we ascribe to these conditional predictions when making public policy. Should the assumptions hold the predictions could be very reliable ( say within .5c)
What you want to argue is this. We can and do model the climate. The predictions of those models are subject to various assumptions, assumptions that can dramatically change the results. Further, even if those assumptions hold, the predictions still have uncertainties. we cannot ascertain their reliability until after the fact.
Ben Laken says:
November 26, 2010 at 11:56 am
Finally, we then calculated the CR variation as a change that was relative to preceding days, by subtracting the average CR value (now in percent relative to solar cycle changes) from the average counts of a three day period beginning 5 days earlier.
Subtracting a percent value fro an average count doesn’t make sense, so
I hope this helps
It was of no help. what would be of help, would be pointing out where my little calculation goes wrong.
vukcevic says:
November 26, 2010 at 11:59 am
So by the time vapour has become cloud it is already charged and highly polarised.
Rubbing of ice crystals is a bit a doubtful physics.
You are still missing the essential point, that collisions [“rubbing”] lead to removal of some mass from the larger particle, fast growing ice surfaces charge positively and sublimating surfaces charge negatively. The impact of the collision [“rubbing”] melts a local volume on each particle, with the warmer particle supplying more mass than the colder one. The exchange of mass and charge during the collision results in the falling larger crystal becoming negatively charged.
I suggest: take two ice cubes from you drink glass and as an experiment rub them together. No starter.
This is just an example of your simplistic view of things, ignoring [or not knowing] what really goes on.
Ben Laken says:
November 26, 2010 at 11:56 am
Finally, we then calculated the CR variation as a change that was relative to preceding days, by subtracting the average CR value (now in percent relative to solar cycle changes) from the average counts of a three day period beginning 5 days earlier.
Subtracting a percent value from an average count doesn’t make sense, so
I hope this helps was of no help. What would be of help, would be pointing out where my little calculation goes wrong.
vukcevic says:
November 26, 2010 at 11:59 am
So by the time vapour has become cloud it is already charged and highly polarised.
Rubbing of ice crystals is a bit a doubtful physics.
You are still missing the essential point, that collisions [“rubbing”] lead to removal of some mass from the larger particle, fast growing ice surfaces charge positively and sublimating surfaces charge negatively. The impact of the collision [“rubbing”] melts a local volume on each particle, with the warmer particle supplying more mass than the colder one. The exchange of mass and charge during the collision results in the falling larger crystal becoming negatively charged. This is clearly explained in the link I gave.
I suggest: take two ice cubes from you drink glass and as an experiment rub them together. No starter.
This is just an example of your simplistic view of things, ignoring [or not knowing] what really goes on.
vukcevic says:
November 26, 2010 at 11:59 am
I suggest: take two ice cubes from you drink glass and as an experiment rub them together. No starter.
Perhaps you should just and watch your drink glass and let it all evaporate and see that how by then “it is already charged and highly polarised”.
Looks like you dug yourself into a hole.
Have you heard of lightning with no falling rain, cloud to cloud, have you heard ‘bolt from the blue’, sprites …
Read about Brownian motions, the first significant work by Albert Einstein.
…simplistic view ? Your rubbing ice crystals are not only simplistic view, but a bit of a joke. Just put couple of electrodes in the falling snow (ice crystals) and you got yourself a free electricity supply!
vukcevic says:
November 26, 2010 at 2:32 pm
Have you heard of lightning with no falling rain, cloud to cloud, have you heard ‘bolt from the blue’, sprites …
It would do you good to actually read Clive Saunders ‘Charge Separation Mechanisms in clouds” that I linked to: http://www.springerlink.com/content/w54350750g275214/
“The generally accepted concept for the development of the thunderstorm charge dipole is the physical separation of oppositely charged particles within the cloud. Larger cloud particles fall under gravity while smaller particles are transported in the updraught; if these particles carry negative and positive charges respectively then the normal charge dipole will result. […] Observations in thunderstorms have shown that strong electrification follows the development of ice particles. Most mechanisms considered today involve cloud ice in the charging process. […] Latham and Mason (1961), working in the laboratory, studied charge transfer during impacts of ice crystals on an ice sphere representing a falling graupel pellet. They noted that a temperature difference between the particles led to charge transfer, such that the warmer ice particle lost positive charge. […] Despite graupel usually being charged negatively in the lower charge region of thunderstorm dipoles, rainfall measured below cloud is often positively charged. Dinger and Gunn (1946) proposed a charge transfer process associated with melting. Drake (1968) noted that convection in a melting ice sphere produced negatively charged droplets ejected from bursting air bubbles at the surface. […] Ice splintering has had a long history of possible involvement in charging. Latham and Mason (1961) noted that ice splinters created during the freezing of supercooled droplets (riming) on a larger ice surface were charged. […] They did note that in the presence of liquid cloud, the ice crystals grew rapidly and when these larger crystals collided with a riming ice surface, then substantial charges were transferred […] Charge transfer associated with surface growth or sublimation has been noted by everyone who has worked in the area of collisional ice charging in clouds. […] In a series of multiple aircraft penetrations through thunderstorms in Montana, Dye et al. (1986) reported on simultaneous measurements of cloud parameters and electrical properties. They noted that increases in electric field strength occurred in regions containing a mix of liquid water and of ice particles. Ice crystals and graupel pellets were identified by airborne laser probes carried on aircraft flying in regions of strong electric field. They also reported that electrification appeared to be occurring at the interface between the updraught and downdraught regions of the clouds. These observations point strongly to a precipitation based charging process of thunderstorm electrification and they strengthened the growing conviction that ice crystals rebounding from riming graupel in the presence of supercooled liquid water is a requirement of the charge transfer process leading to electric field development and lightning. [..] A thunderstorm charging mechanism based on vapour deposition rate, first proposed by Baker et al. (1987), has been successful in helping to account for differences between the results from various laboratory studies. The concept follows on from the result described earlier that, during collisions leading to the removal of some surface mass from the larger particle, fast growing ice surfaces charge positively and conversely, sublimating surfaces charge negatively. Baker et al., suggested that an additional variable comes into play when two ice surfaces having different vapour diffusional growth rates come into brief contact, namely the surface state of the smaller particle in the collision process. They suggested that the relative diffusional growth rates of the interacting ice particle surfaces was the factor that controls the sign of charge transfer. The charge transfer follows the rule that the ice surface that grows faster by vapour diffusion charges positively during ice crystal/graupel rebounding collisions. This concept has stood the test of time, and has been shown to be consistent with the results obtained in various laboratories. […] Given that ice particles grow in supersaturated conditions, such as in cirrus clouds experiencing an updraught, charge transfer will occur during collisions between non-riming ice particles growing at different rates. The relative growth rate hypothesis predicts that the faster growing ice surface will charge positively. Laboratory measurements have confirmed substantial charge transfer in ice/ice collisions in the absence of supercooled droplets.”
Don’t forget that this is really my field [solar physics is just a sideshow].
Just put couple of electrodes in the falling snow (ice crystals) and you got yourself a free electricity supply!
Actually, putting a couple of electrodes in a thundercloud would give you a very nice free electricity supply.
Response to Leif post on November 26, 2010 at 1:42 pm
Apologies Leif, for the typo – that passage should have read “subtracting the average CR value (now in percentage relative to solar cycle changes) from the average percentage of a three day period beginning 5 days earlier.”
Back to your calculation of the change relative cosmic ray change; it would not be fractions of a count (you quote 0.013 counts). The neutron count variations experienced over the peak-to-peak changes of a solar cycle would surely be far larger than your quoted value of ~600 counts for Thule as you state. I do not have Thule data to hand, but for example, at Climax the average daily counts over the monitoring period are approximately 395,020 while the peak-to-peak solar cycle amplitude change is approximately 44,496 counts, which equates to a change in neutron counts of approximately 11 % of the total Cosmic Ray flux over the course an average 11-year solar cycle.
Best,
–Ben
Ben Laken says:
November 26, 2010 at 3:16 pm
Back to your calculation of the change relative cosmic ray change; it would not be fractions of a count (you quote 0.013 counts). The neutron count variations experienced over the peak-to-peak changes of a solar cycle would surely be far larger than your quoted value of ~600 counts for Thule as you state. I do not have Thule data to hand, but for example, at Climax the average daily counts over the monitoring period are approximately 395,020 while the peak-to-peak solar cycle amplitude change is approximately 44,496 counts, which equates to a change in neutron counts of approximately 11 % of the total Cosmic Ray flux over the course an average 11-year solar cycle.
As I said, my counts are per hour [yours are per day]. This makes no difference, of course, as everything just scales with a factor of 24. I.e. 600 out of 4300 is 14%. now you said 1% of the amplitude which [with my numbers] come to 6 counts [per hour]. It takes 5 years = 1825 days to go from min to max, so the rate per day is 6/1825. Now your state that you use the rate over four days, so 4*6/1825 = 0.013 counts would be 1 CU on your scale for one hour counts [since I do my superposed epoch with 1 hour resolution]. The daily variation has an amplitude 770 times larger, namely 10 counts.
One of the reasons I like this blog is that I get to see real scientists going back and forth. Compare and contrast that with Real Climate where everything is suppressed. Thanks to Svalgaard, Laken and moderators and Watts for the lively forum.
1DandyTroll says:
November 25, 2010 at 2:52 pm
Dude, he was correcting himself…
Sorry, I just woke up now. Am I correct in understanding that clouds do not get charged at all simply by their friction against air caused by differences in pressure?
That leaves my idea that the directional movement of these clouds may well be influenced by earth’s magnetic field, which in its turn may be influenced by that of the sun’s, improbable?
Leif Svalgaard says:
November 26, 2010 at 3:59 pm
As I said, my counts are per hour [yours are per day]. This makes no difference, of course, as everything just scales with a factor of 24.
It would help in clarity if there were errors accompanying these arguments. If one is using 24 hours and one is using 1 hour the error also scales by the square root of 24. Whether a measure is significant or not depends on the error accompanying it.
What is the conceptual difficulty in accumulating statistics to increase significance?
anna v says:
November 27, 2010 at 2:09 am
If one is using 24 hours and one is using 1 hour the error also scales by the square root of 24. Whether a measure is significant or not depends on the error accompanying it.
The cosmic ray intensity is a count and has no error. It is like counting the number of people entering a doorway during a given period. The error in a superposed epoch analysis scales with the square root of the number of key dates. In my case I have so many [1470] that the [statistical] error is negligible. But I would like to know how many key dates Ben et al. have. It is a defect of the paper not to give that number.
HenryP says:
November 26, 2010 at 10:18 pm
Am I correct in understanding that clouds do not get charged at all simply by their friction against air caused by differences in pressure?
I don’t think that is implicated in the charging process.
Four blind brothers sent to describe the elephant. One touches the trunk and tusks, the other the tail, the other the four legs,a nd the last brother touches the belly of the beast, they all get together and the four brothers argue for a good long time, and the “seeing” father has a good long laugh.
Leif Svalgaard says:
November 27, 2010 at 3:33 am
“anna v says:
November 27, 2010 at 2:09 am
If one is using 24 hours and one is using 1 hour the error also scales by the square root of 24. Whether a measure is significant or not depends on the error accompanying it.”
The cosmic ray intensity is a count and has no error. It is like counting the number of people entering a doorway during a given period.
The error would be the square root of the number of people coming through the door, and it reflects the statistics that is expected to hold with a random sample.
With all due respect Leif, in particle physics experiments, counts come with error the square root of the count ( plus a systematic if one exists). When we search for interactions and publish a cross section for the interaction, the error is the statistical error of the counts found (plus any systematic one). That is why we try to accumulate statistics.
HenryP says:
November 26, 2010 at 10:18 pm
That leaves my idea that the directional movement of these clouds may well be influenced by earth’s magnetic field, which in its turn may be influenced by that of the sun’s, improbable?
Not at all, I think there is lot of sense in what you are suggesting, but of course you should always read Dr.L.S (Dr. No).
Atmosphere contains positive charge in a way of space particles (free protons, etc). As the air heats up, updraft lifts water vapour to higher altitudes where these particles are more abundant. Positive particles by their presence initiate process of ionisation (‘charging’ of both polarities), but do not form compounds. From then on process is the self-sustaining one, depending on the amount of heat in the atmosphere. Warmer the air, more energy to Brownian motion, stronger the final polarisation.
This explains why thunderstorms are more frequent in the second part of the day than in the early morning (precipitations are not choosy), thunderstorms are more frequent in the summer than in winter.
Some meteorologists link thunderstorms to the velocity and intensity of the solar wind, which is a constant source of the charged particles in the upper atmosphere, initiating the ionisation process.
You could also look at this:
http://www.nasa.gov/centers/goddard/news/topstory/2006/space_weather_link.html
but if you wander about the magnetic field, you are right it should not be ignored, here is my take on it:
http://www.vukcevic.talktalk.net/LFC20.htm
anna v says:
November 26, 2010 at 12:00 pm
“The interest in the cosmic ray hypothesis rises from the desire to correlate the sun cycles to the weather/climate cycles. As the total energy variations coming from the sun output are very small….”
The massive changes in solar wind speed do correlate to large changes in surface temperatures, maybe its that changing the cloud cover and not the GCR`s.
@HenryP:
Static charge tends to concentrate at a point. Just before a raindrop breaks up due to air friction, free electrons migrate to the point of the teardrop which becomes the smaller droplet after breakup. The thunderstorm updraft carries the smaller droplets upward and the larger droplets fall as rain, yielding the charge separation which eventually results in lightning. This phenomena results in the “global electric circuit”, with the upper atmosphere negative with respect to ground. The authors of this paper refer to this as the GEC “Global Electric Circuit” and describe the means by which this phenomena might mediate the GCR – temperature connection. They say
“The GEC is made up of the ionosphere (which is maintained at a potential of 250 kV by upward current from thunderstorms and other electrified clouds) and the vertical current density, which flows downwards from the ionosphere to the Earth’s surface (at 1–6 pAm−2) over all fair-weather regions. The GCR flux maintains the atmosphere as a weakly conducting plasma, as a result variations in the GCR flux modulate the vertical current density.”
anna v says:
November 27, 2010 at 3:56 am
With all due respect Leif, in particle physics experiments, counts come with error the square root of the count ( plus a systematic if one exists).
This would be the case if there were an underlying single [constant] number that we were trying to measure [e.g. half-life], but is not the case when there is a variable number. Then the actual count is the number we are after, and it has no error [ignoring coincidence counting – two people trying to get through the door at the same time]. Same with sunspots. If I see four spots on the disk, four spots it is, not 4+/-2. If in an election [except in Florida, of course], there are 100 votes for candidate A and 91 for B, A wins.
vukcevic says:
November 27, 2010 at 4:50 am
You could also look at this:
http://www.nasa.gov/centers/goddard/news/topstory/2006/space_weather_link.html
Goes the other way: thunderstorms influence the ionosphere. You should really stop spreading misinformation.
Dave Springer says:
November 26, 2010 at 2:07 am
“In this case what was meant is it is practically impossible to make reliable climate forecasts. The plethora of factors that determine climate are not all well understood, exceedingly complex, interdependent, subject to constant change, and for things like volcanic eruptions, comet impacts, and CMEs are quite unpredictable. Taken together that means it’s practically impossible to make long term forecasts.”
An increase in volcanic activity predicted for Indonesia this Autumn
http://tallbloke.wordpress.com/2010/07/10/something-is-brewing/#comment-1095
A peak in flare activity predicted for around November 5th.
(WUWT)
Next stronger peak around 27th December 2010.
By using the appropriate look-back, we can see a series of cold to very cold N.H. winters from 2014 to the early 2020`s.
vukcevic says:
November 27, 2010 at 4:50 am
HenryP says:
Water molecules in clouds, obviously, are differently arranged than in liquid water, this is why when, after loosing its charge (lightning storms happen before raining, they fall down, only then subjected to “gravity”.
In clouds water it is as hydrogen hydroxide ( a solid metal hydroxide- hydrogen is a silvery colored metal close to zero degrees kelvin-).We all can reproduce a similar phenomenon in a glass or beaker, using instead a metal´s salt, as zinc or aluminum sulfate or chloride, and neutralizing it with an alkali solution: We will see how it appear “clouds” of the metal hydroxide (Al(OH)3 or Zn(OH)2).
This, BTW, explains how so many thousand tons of water hang over our heads, openly violating the “Holy Law of Gravitation”(while we do not even ask for it)
You see, the problem is, that, we humans like so much to give names and put tags (be it self-adhesive or not) and because of this we have divided science, “constants”, units, etc. in water tight compartments, where it is “forbidden” any communication among them:
http://www.scribd.com/doc/38598073/Unified-Field_1
http://www.scribd.com/doc/42482741/Unified-Field-Explained-9
Does anyone see a potential connection between variations in the solar wind / magnetic field / Global Electric Circuit and the downward NOx flux caused as a result of solar particles reacting with the highest levels of the atmosphere ?
The effect seems to be concentrated at the poles with ozone above about 45km being depleted (or not) at variable rates with a consequent effect on the vertical temperature profile and thus the various atmospheric heights (including the tropopause) with an influence on the size and intensity of the polar vortices.
Recent climate events lead me to think that the level of sensitivity to such variations within the climate system might be rather higher than I previously thought.
Stephen Wilde says:
November 27, 2010 at 6:29 am
The effect seems to be concentrated at the poles with ozone above about 45km being depleted (or not) at variable rates with a consequent effect on the vertical temperature profile and thus the various atmospheric heights (including the tropopause) with an influence on the size and intensity of the polar vortices.
The effects go the other way. It is the polar vortex that controls the downward flux of NOx.