[Flipside]

Well, I know for certain that our atmosphere isn't going through anywhere near the changes that Pluto's is.

Pluto's atmospheric pressure has tripled over the past 14 years, indicating a stark temperature rise, the researchers said. The change is likely a seasonal event, much as seasons on Earth change as the hemispheres alter their inclination to the Sun during the planet's annual orbit.

It could also be to do with where Charon is in orbit, I would suspect, something the size of Charon probably causes turmoil either tectonically or atmospherically to Pluto, not entirely dissimilar to the 'squeeze and stretch' effect that Jupiter has on Io.

[Ulala]

Bah, it's not like Pluto is actually a planet, so what's the fuss? 

[Bobboau]

yeah, so like I said, Pluto is getting warmer than it's been in 150 years! because now it's spring time there 

[aldo_14]

So it's possible to model what has already happened. When will this method allow us to do a reliable forecast?

Short term?  I'd imagine 'never'.  It's like, in layman terms (because I'm a layman ), forecasting the result of a coin-toss.  You can toss the coin a million times, and it'll give you a good idea of the frequency of heads vs tails (I'm assuming tiny imperfections in the coin make this a non-50/50 chance, incidentally, otherwise it's a daft analogy) over time.  But it won't give you a reliable indicator of the next toss.

How many ground stations are on Earth now?

Not sure.  A cursory check shows - for example - 62 automatic and 4 manned in Hong Kong, and 11,000 co-operative observers (I'm not sure exactly what this means; FYI each weather station has a 6-digit identifier, but I'm not sure if this applies internationally) in the US.  Greenland has 18.  I believe, though, it is a known problem that places like Africa have too few automatic weather stations (by about 200)

The recommended density of these stations is one every 3250 square miles (Africa is every 26000); they all get linked as part of the Global Climate Observing System.  This page gives a pretty neat indication of their spread.

Of course---it's further from the sun, but affected nonetheless.

But how affected?  I mean, what's the theoretical maximum?

I don't know, but if I google "Pluto warming" I find many articles which state otherwise.

Well, if I search for the converse what I find is that the surface is warming

On the self-reinforcing thing, I ask again, has such a thing ever been proved to happen before?

Modelled, yes; I believe things like the Permian extinction have been attributed to it (in that case volcanic emissions).  If what you're asking is whether it can be lab duplicated, you'd need a whole planet methinks before you could be definitive.  But they have done studies and AFAIK there is no dispute that the earth goes through cycles of positive-feedback climate change (warm-cool-warm-etc), the dispute is a) is it happening justnow and b) if so is it down to human activity.

Possible yes, but isn't plausible a strong term? Occam's razor and all that.

I'm not sure Occams razor applies unless it's the simplest possible solution, and I think to say the same factor was affecting every planet would not be the simplest solution given that you're talking about 4 disparate bodies, seperated by significant orbital distance (with other inbetween), with massively different geological (Mars might not even be molten core, and as for jupiter..) compositions, different orbits (Mars is apparently undergoing a periodical wobble), and different atmospheric conditions (for example, heavy CO2 in Mars). 

Apparently for Jupiter it isn't warming globally, anyways, but experiencing a 'migration' where the equator is becoming hotter and the poles cooler.

Also, it's particularly relevant for Pluto, because Pluto is one 'planet' definately affected by the sun simply because it's in such an elliptical orbit that its distance changes; insofar as I can see that's the simplest explanation and indeed the astronomers (etc) one, that the response of Pluto to this changing distance is simply a wee bit more complicated than anticipated.

(also, as Flip noted, Plutos inclination towards the sun changes, so this could be a seasonal affect)

Yes, but I don't know if the other satellites are being monitored or to what degree, so I can't say.

Well, how likely do you think it is?

I'm assuming you're referring to solar radiance here affecting 'all' (well, 4 planets, one of which is undergoing a Malinkovich cycle and the other of which isn't warming globally but regionally) the planets.  But the warming on earth isn't in tandem with solar radiance;



(source; http://www.mps.mpg.de/en/)

[Flipside]

One thought that also occured to me about Pluto, since the surface is frozen nitrogen, and the cooling effect is by the evaporation of that draining away heat, is it possible that, as Pluto orbits in such a strange way, that as it moves further away it passes beyond the temperature band of the melting point of Nitrogen, and therefore the 'warming' and 'pressure' recorded are really more of a return to the outer-orbit norm?

[aldo_14]

One thought that also occured to me about Pluto, since the surface is frozen nitrogen, and the cooling effect is by the evaporation of that draining away heat, is it possible that, as Pluto orbits in such a strange way, that as it moves further away it passes beyond the temperature band of the melting point of Nitrogen, and therefore the 'warming' and 'pressure' recorded are really more of a return to the outer-orbit norm?

I think that was one of the explanations I mentioned earlier, effectively a delayed reaction (due to the complexity of the interactions blah blah) to passing closer to the sun earlier.  to be honest, I can't help but think that comparing climate changes between Earth, Mars, Pluto, Jupiter, etc is a bit of an apples and oranges case.

[Wild Fragaria]

Be Nice

We all have BS detectors, problem is most people don't realise that it is self-tuned. For example, I consider sections of the Bible to trigger my 'BS Alert', but then, I am looking for things to trigger it. When it comes to science and religion, I think both sides could be accused on occasion of being so obsessed with minutae that they fail to see the bigger picture.

Yes, sir   *salut* (I did sound a bit mean)

[perihelion]

I kind of doubt that the nitrogen is sublimating just because Pluto gets closer to the sun.  I mean, yes, it does have a highly eccentric orbit that will vary incident solar radiation intensity, but I would suspect it has more to do with axial tilt.  Pluto's axis is tilted ~120 degrees from perpendicular to its orbital plane.  With a tilt like that, at some point in its orbit one pole is going to be almost constantly under the sun's glare.  Without day / night cycles to take in heat from the sun and release it at night (or a significant atmosphere to convect the heat away), the temperature will rise.  The nitrogen will sublimate, and then you'll start getting more significant convective cooling.

Only catch is I haven't been able to find mention anywhere of where Pluto's axis is pointing right now relative to its orbit, and I kind of need to get back to work.  Anyone want to check me on this?

[Bobboau]

that the south pole of Pluto came out of shadow for the first time in 120 years in 1987, and extra nitrogen sublimated from a polar cap. It will take decades for the excess nitrogen to condense out of the atmosphere.

[perihelion]

Well there you go, then.  I was looking more for an orbital chart, but that works just as well.

[Turambar]

has this been posted yet?

http://www.nytimes.com/2007/03/20/washington/20climate.html

just thought it was both interesting and relevant to this particular thread.

basic summary, a former white house expert, now an oil lobbyist, admitted to fudging figures in his speeches to various government groups, and might be taking some heat.


personally i think that people releasing a crapload of carbon into the atmosphere will change the climate for sure, but i dont feel like doing the kind of research needed to argue on your level.

have fun with this guys (come on deepspace9er, dont run away so easily)

[aldo_14]

I thought that was quite old news, actually, or perhaps I'm thinking of another scandal along the same lines.

[Huggybaby]

But the warming on earth isn't in tandem with solar radiance;

I don't think that graph makes your point very well. For 120 years there's a good correspondence, then for the last 25 it diverges but is now converging again. Unless you're saying that only the last 25 years counts. As a layman they look way more similar than dissimilar to me.

From http://strata-sphere.com/blog/index.php/archives/3434:

[aldo_14]

The lack of any correspondence in a period of exponential (EDIT; ok, not exponential but certain significant, and arguably exponential if we estimate the dimming effect of pollution etc upon global temperature) warming is surely enough?  Also, note the divergence from 1880-1910 in particular and 1860-1880.   

Without any source cited for the Antarctic / Greenland sunspot figures, I can only look at the Usoskin values.  THis article - http://www.realclimate.org/index.php/archives/2005/08/did-the-sun-hit-record-highs-over-the-last-few-decades/ - discusses it a bit, and notes that Usokins values (also IIRC garnered from ice cores) do not match the tree-ring records (perhaps this is pretty indicative, that the graph doesn't appear to mention the tree ring method of measuring solar activity, or Solanki who did a combination work for estimating solar activity using multiple sources AFAIK);

"However, regardless of these uncertainties the conclusions by Usoskin et al. (2003) and Solanki et al. (2004) cannot be confirmed by the analysis of the 14C records (Muscheler et al., 2005). The 14C tree ring records indicate that today’s solar activity is high but not exceptional during the last 1000 years."

This is a graph of tree ring records from that page;


and a paper - http://www.cgd.ucar.edu/ccr/raimund/publications/Muscheler_et_al_Nature2005.pdf

One important point I think the article makes is that sunspots are only a proxy for solar activity; see the end quote
"Regardless of any discussion about solar irradiance in past centuries, the sunspot record and neutron monitor data (which can be compared with radionuclide records) show that solar activity has not increased since the 1950s and is therefore unlikely to be able to explain the recent warming."

[perihelion]

FYI, the whole "Hummer has a smaller energy footprint than a Prius over vehicle lifetime" argument is getting shredded at /.

http://hardware.slashdot.org/hardware/07/03/20/1858204.shtml

Perhaps not a reputable source for accurate information, but I confess to some feelings of vindication anyway.  Especially seeing someone else (for once) espouse the idea that to get the true advantage a hybrid can offer, you need to completely decouple the combustion engine from the drive train.  I felt like jumping up and shouting, "FINALLY!  Someone else gets it!"  You run an internal combustion engine strictly as a generator, it only has to run at one speed.  The design can be optimized.  Better still, you aren't limited to a piston-cylinder engine either.  A turbine would be better still.

[/off topic(?)]