The Mesosphere - as you've never seen it before!

[mesospheric]

Here's a plot that will be regularly updated on the BBC Facebook page over the summer.



Rather tantalisingly, you can see that the mesosphere is rapidly cooling to the general frost point where NLC will start to appear.

The data is from the AURA satellite, and obtained through the kind assistance of the University of Bath's Atmospheric Dynamics research group.

[markt]

Excellent! Thanks for that

I guess if we project the line forward, assuming the temp falls at a similar rate we could expect to see NLC in the 1st/2nd week of june???

[mesospheric]

Mark,

The rate of cooling isn't linear but, yes, the first horizon-hugging sighting here, which nevertheless had a considerable extent in azimuth, was, from memory, June 03 last year. I suspect that, if I'd been getting up for the early morning sector a bit sooner, I may have found them at the very end of May.

[prezes]

Hi,
As we can see in the diagram mesosphere was warmest in the winter (of course it's an annual cycle). I'm wondering about it.

[johnm]

Hello mesospheric - do you have access to last years data ? It would be useful to correlate this with sightings.

Does the temperature relate to a particular place in the UK ? I would think there would be a difference between the North of Scotland and the South of England though of course we are observing clouds at 30 to 100 miles North of our surface observing position.

[mesospheric]

I've got observations from this site, by kind agreement of Tom,
and the temp data 2009 appears in green on the graph posted previously.

[prezes]

Why mesosphere is warmer in winter?

[markt]

May 30, 2010 17:15:13 GMT prezes said:

Why mesosphere is warmer in winter?

As I understand it from Wikipedia...

An interesting feature is that the summer mesopause is cooler than the winter. This is sometimes referred to as the mesopause anomaly. It is due to a summer-to-winter circulation giving rise to upwelling at the summer pole and downwelling at the winter. Air rising will expand and cool resulting in a cold summer mesopause and conversely downwelling air results in compression and associated increase in temperature at the winter mesopause.

en.wikipedia.org/wiki/Mesopause

[hcp]

Further to requests for previous years data, I have put a plot with all of the available years at xweb.geos.ed.ac.uk/~hcp/meso_ts In answer to the question about coverage, I averaged over a box from 50N to 60N and 8W to 2E. The Bath guys picked a box 30 degrees wide in longitude and 4 degrees wide in latitude, centred 2 degrees to the North of Anglesey, so their plot looks different in detail.

The original data come as vertical profiles spaced 1.5 degrees apart along the Aura orbit track. Successive orbit tracks are 25 degrees apart and are at different longitudes on different days --- the pattern repeats every 16 days. The point being that if you average over too small a box then there will be no data in your box on some days.

[tmcewan]

Fantastic work - many thanks for making this available. Interesting to see the changing water content and temperature over each season.