Stratospheric clarity

[Gray-Wolf]

I noted from SpaceWeather that last weeks Lunar eclipse was up to 1,000 times brighter than a 'normal' dark eclipse. They tell us that at the moment the stratosphere is very clear (all the volcanic ash has fallen back to earth). We all know the impact of eruptions on global temps (nuclear winters) so is the converse true? could this 'clarity' be an extra mechanism in the record ice loss at the poles recently? could this clarity be a mechanism above and beyond that which is progged in the climate change models further accelerating the process?

Whad'ya think?

[Chris Knight]

I noted from SpaceWeather that last weeks Lunar eclipse was up to 1,000 times brighter than a 'normal' dark eclipse. They tell us that at the moment the stratosphere is very clear (all the volcanic ash has fallen back to earth). We all know the impact of eruptions on global temps (nuclear winters) so is the converse true? could this 'clarity' be an extra mechanism in the record ice loss at the poles recently? could this clarity be a mechanism above and beyond that which is progged in the climate change models further accelerating the process?

Whad'ya think?

Yet I also note that a day or two earlier, we had those remarkable sunsets and sunrises on the 18th and 19th February, (apparently PSCs?) possibly due to acid aerosols in the stratosphere:

http://spaceweather.com/archive.php?month=...8&view=view

We also have had an unusually large number of reports of Nacreous clouds this northern Winter (see spaceweather photo archive), and noctilucent clouds during the previous summer months. These are generally believed to be due to water vapour in the stratosphere, at very low temperatures. I wonder if the warming of earlier years has increased the levels of H₂O in the upper atmosphere?

I wonder if the Earth's upper atmosphere (backlit by the sun) was just more luminous than usual during the eclipse from the lunar point of view, due to these phenomena, which are almost certainly anthropogenic in nature, rather than volcanic. It would be interesting to see some views of the earth's limb from space showing the extent of the atmosphere and it's upper levels of haze.

[Chris Knight]

Yet I also note that a day or two earlier, we had those remarkable sunsets and sunrises on the 18th and 19th February, (apparently PSCs?) possibly due to acid aerosols in the stratosphere:

http://spaceweather.com/archive.php?month=...8&view=view

We also have had an unusually large number of reports of Nacreous clouds this northern Winter (see spaceweather photo archive), and noctilucent clouds during the previous summer months. These are generally believed to be due to water vapour in the stratosphere, at very low temperatures. I wonder if the warming of earlier years has increased the levels of H₂O in the upper atmosphere?

I wonder if the Earth's upper atmosphere (backlit by the sun) was just more luminous than usual during the eclipse from the lunar point of view, due to these phenomena, which are almost certainly anthropogenic in nature, rather than volcanic. It would be interesting to see some views of the earth's limb from space showing the extent of the atmosphere and it's upper levels of haze.

Another reason I doubt "clarity" of the stratosphere for this eclipse, was the moon's colour from the penumbra of the earth's shadow - very red, indicating a lot of light scattering in the atmosphere. A "clear" upper atmosphere would cause less red colouration, with a neutrally coloured, better defined penumbra and umbra. However it does indicate a clear troposphere, since for the really brilliant colours to appear, the sunlight has first to pass through the troposphere at the earth's limb to illuminate the stratospheric aerosols. The ash from volcanoes darkens the atmosphere by absorption of light at all wavelengths, but aerosols scatter the light effectively without absorbing the longer visible wavelengths. http://www.spc.noaa.gov/publications/corfidi/sunset/

The afterglow at Portsmouth on Feb 18 was still visible 50 minutes after sunset:

and similarly before dawn on the 19th:

whereas the sunset that evening (19th), due to low level haze, was hardly spectacular:

By the time the moon was in eclipse, the haze over W. Europe was well on the dark side of the earth, as well as the damn clouds that obscured my view!

It is such a pity that NASA has never left a permanent automatic "Earth observatory" on the moon - its images and data would be so useful and interesting.

#the clock on my Canon is an hour fast, still on summertime!

[PersianPaladin]

I noted from SpaceWeather that last weeks Lunar eclipse was up to 1,000 times brighter than a 'normal' dark eclipse. They tell us that at the moment the stratosphere is very clear (all the volcanic ash has fallen back to earth). We all know the impact of eruptions on global temps (nuclear winters) so is the converse true? could this 'clarity' be an extra mechanism in the record ice loss at the poles recently? could this clarity be a mechanism above and beyond that which is progged in the climate change models further accelerating the process?

Whad'ya think?

1,000 times brighter?

What a load of poppycock. We'd all be blind.

[Gray-Wolf]

1,000 times brighter?

What a load of poppycock. We'd all be blind.

Blinded by the light of an eclipse???? P.P. ,silly boy.

We also had the stunning sunsets (still on the camera....lazy boy) but we also had the fogs that followed! I think it was more to do with the water in the lower atmosphere than upper (at least here) for, as the termperatures fell, the fog precipitated out.

Edited February 27, 2008 by Gray-Wolf

[Osbourne One-Nil]

I suppose it's possible.

An average lunar eclipse has an umbral magnitude of about 1.2 (about the same as a fairly bright star like Betelguese). Because each magnitude is 2.5 times brighter than the previous one, 1000 tiumes brighter than that would 6.5 magnitudes brighter at around -5.3 which is considerably brighter than Venus at its brightest.

I would be surprised if it was this bright.....very surprised, but I suppose it's not outside the realms of possibility.

[Gray-Wolf]

I suppose it's possible.

An average lunar eclipse has an umbral magnitude of about 1.2 (about the same as a fairly bright star like Betelguese). Because each magnitude is 2.5 times brighter than the previous one, 1000 tiumes brighter than that would 6.5 magnitudes brighter at around -5.3 which is considerably brighter than Venus at its brightest.

I would be surprised if it was this bright.....very surprised, but I suppose it's not outside the realms of possibility.

I'm only as good as the spaceweather report but they seem to feel that the difference between a 'dark eclipse' and last weeks led to it appearing 'up to 1,000 times brighter'.

I remember and eclipse I viewed from York (passing through on my way to the 'iron & Steel rally' in Sc u nthorpe) in Oct 86 and that was really a 'blood moon' but then we must still have had a bit of St. Helens up there. Another notable one (though I'm a little sketchy on dates) was from the squat in Hulme in in the early 90's and I don't know whether it was the city smog (late aug early sept??) or Pinatubo's impact but it too was 'special' as you could plainly see the browny tinge of the earths atmosphere in front of the amber red shadow as the eclipse progressed.

Edited February 27, 2008 by Gray-Wolf