NLC (Noctilucent cloud) 2013

[stella]

There was an extensive display of NLC seen last night, May 30-31.
Observed from 22:00 to 23:20 U.T.

[David Frydman]

I did look a couple of nights ago when it was very clear but I saw no signs of NLC.

Regards David

[Brian]

Just noticed that Spaceweather.com are showing NLC images from the AIM satellites on their daily pages. See lower left margin.

Here's the polar image from May 29. There should be an update image from 31 May but I don't see it yet?

http://www.spaceweather.com/DAISY_PICS/ ... _daisy.png

ATB,

[David Frydman]

thanks Brian,

that is the first time I have seen noctilucent clouds from space. An interesting image.
The particular ones they show seemed to be a long way from Britain.

Regards David

[Alastair McBeath]

The May 30-31 NLC display started promisingly for me too here in NE England. It was already well underway when I first spotted it at 22:20 UT, around 25° elevation to the north, bright and complex, before fading and dipping lower towards midnight as might be expected. Unfortunately, it didn't really recover afterwards, as although it was still reasonably bright through till I last saw anything around 02h, it never grew higher than 10° elevation again for me, and being often lower, I was missing more than I could see at times thanks to near-horizon obstructions. Still, a good, early start to the season, and hopefully a lot more to come.

When I checked the Sun by projection this morning (May 31st), I was interested to see there was remarkably little sunspot activity, given it's been a generally much more active solar year than for some time in 2013 so far. There's long been a suspected antiphase correlation between NLC and solar activity (so when there's a lot of sunspots, NLC activity should be lower - in theory!). Maybe that helped the May 30-31 display along.

There's also been a long-suspected connection, with a circa two to four week delay, between NLC and meteor activity (the ice-crystals in the clouds are thought to nucleate around dust and ions of various kinds, most prominently meteoric ones, given the clouds occur below to just within the main meteor ablation zone of the upper atmosphere). The reasons for the delay aren't well-understood (and consequently, we can't be sure how real the connection may be), but it's intriguing too that the Eta Aquarids were much stronger than usual during the first to early second weeks of May this year, so that may be another positive factor with this display.

[David Frydman]

I too was surprised to find only one small sunspot with a partially braced filtered 10 x 25 binocular today after a long spell of a quite active solar disc.
However, I was not able to observe in H alpha because of cloud earlier so I don't know how active the sun is.

It was warmer than it has been of late.

Regards David

[David Frydman]

I think I saw and photographed noctilucent cloud.
2013 June 01
Woke up at about 02 25 UT

Bright bands from 29° to 39° elevation.
A-Z 290° to 345°.

Below 20° building to the left of 290° trees to the right of 345° trees.

Normal clouds in the North but didn't really interfere.

Bright moon in south-east about six days from new.

There were three main parallel narrow bands parallel to the horizon.

I don't know what the display was like earlier as I was asleep.

Regards David

[Brian]

Pete Lawrence has posted a short "movie" of NLC in motion, taken from Selsey June 3rd:

http://spaceweather.com/gallery/indiv_u ... d_id=82871

Well worth a look

[BillW]

Hi All,
Hopefully no will object to a little promotion of another forum.
If you're not aware of it there is an active and lively forum (over the summer anyway!) dedicated to NLC.
The URL is http://nlcnet.proboards.com/index.cgi
There is a related reporting page at http://www.nlcnet.co.uk/
and we now have a twitter feed #nlcnet
If your interested in NLC and would like to know more, have a look and join in.
Cheers,
Bill.

[stella]

Further considerable N.L.C. seen last night (June 7-8) extending along northern horizon.
Seen from 22.30 to 01.20 U.T

[BillW]

Hi,
Caught it myself also, although I had quite a bit of low level mist and cirrus higher up to contend with.
Some nice detail visible.
cheers,
Bill.

PS. Video at http://youtu.be/A_oi46WB_Ng

[David1952]

Just as a point of information. How far south are NLCs visible? I live just about on Lat 49N. Am I likely to see them from here.

David

[David Frydman]

. There is a video recently from Selsey. The display was bright and extensive.

I think it should be visible from 49° latitude but I'm not sure of the lower limit.

I always thought that the Sun had to be between 6° and 16° below the horizon.
But I think that maybe I follow them to about 4.5° below the horizon before sunrise.
Again I'm not sure of the exact limits.

One of the strangest NLCs that I saw amongst the very many from Helsinki was when the whole sky was covered in a layer of NLC for perhaps one or two minutes when the sun angle was exactly correct.

Binoculars often help in detecting the fainter or lower NLCs.

Regards David

[David1952]

David,

Many thanks. I will keep a look out for them.

Davod

[Brian]

NLC are regularly reported from the mid-United States (Kansas recently). That would be around latitude 40, same as southern Italy? I'm sure they will be spottable at latitude 49.