NLC 2010-05-23/24
The first tentative NLC reports have appeared on the NLC Observers' Home Page. My observations show some kind of thin cloud or ash low on the horizon. At times the play of light and dark strands looks a bit like NLC, but my reports are of "no NLC". I include here some images though.
BAA report
The report to the BAA Aurora Section gives an overview of the night, which times were cloudy, free of NLC, or with sightings of NLC.
Name of observer: Horst Meyerdierks
Location: Stichill Eastfield, 55.7N 2.4W
unattended dSLR with limited field of view A ~310-20, h ~0-40
images every 15 min
Date: 2010-05-23/24
UT forms bright height azimuth comments
ness top bot left rght e.g. weather
----- ----- ------ --- --- ---- ---- --------------------------------
21:00 0 cloud to h 5
21:15 0 cumulus to h 4, cirrus to h 7
21:30 0 cumulus to h 4, cirrus to h 8
21:45 0 cumulus to h 4, cirrus to h 8
22:00 0 cumulus to h 4, cirrus to h 8
22:15 0 cumulus to h 4, cirrus to h 8
22:30 0 cumulus to h 5, cirrus to h 7
22:45 0 cirrus to h 8
23:00 0 cirrus to h 7
23:15 X cirrus to h 7, fake NLC
23:30 X cirrus to h 7
23:45 X cirrus to h 8
00:00 X cirrus to h 8
00:15 X cirrus to h 7, fake NLC
00:30 X cirrus to h 7
00:45 X cirrus to h 5
01:00 X cirrus to h 7
01:15 0 cirrus to h 7
01:30 0 cirrus to h 7
01:45 0 cirrus to h 7, fake NLC
02:00 0 cirrus to h 10
02:15 0 cirrus to h 5
02:30 0 clear
02:45 0 cloud to h 5
03:00 0 cloud to h 8, birds, one near top
forms: I: veil
II: bands
III: waves
IV: whirls
NLC: other than or multiple of I-IV
0: no NLC
X: no decision possible (mist, cloud etc.)
brightness: 1: very weak
2: clearly detected
3: clearly visible
4: very bright
5: extremely bright
NLCnet report
The main periods of absence of NLC are reported to the NLC Observers' Home Page:
Name: Horst Meyerdierks Country: Scotland Location: Stichill Date: 2010/05/23-24 Start: 21:00 End: 03:00 Comments: A "no NLC" result cannot be confirmed between 23:15 and 01:00, as low cirrus obstructs the altitudes where NLC might occur.
Images
Listed below are the images with sightings of fake NLC. These have been processed merely to adjust the brightness for underexposure. For some there may also be an unsharp-masked version of the image.
UT exp A hSun h15 h85 stretch image (masked) ----- ------ ----- ----- ----- ----- ----- --------------------- 17:30 0.000 274.7 22.0 0.0 0.0 0-255 q28303.jpg 23:15 30.000 347.7 -12.9 -3.7 8.7 0-150 q28333.jpg 00:15 30.000 2.0 -13.6 -4.2 6.6 0-80 q28357.jpg 01:45 8.000 23.4 -10.8 -2.5 21.3 0-100 q28390.jpg exp: Exposure time in seconds (400 ISO, f/3.5). A: Azimuth of the Sun (degrees). hSun: Altitude of the Sun (degrees, negative below horizon). h15: Max. altitude of sunlight at 15 km height (degrees). h85: Max. altitude of sunlight at 85 km height (degrees). stretch: Contrast stretch (0-255 means no stretch).
