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NLC 2014-07-22/23

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: Royal Observatory Edinburgh, 55.9N 3.2W
          unattended compact camera with limited field of view
          A ~325-35, h ~0-40; images every 15 min
Date: 2014-07-22/23

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:15:01  0                                  haze to h 5
21:30:01  0                                  haze to h 5
21:45:06  0                                  haze to h 5
22:00:02  0                                  haze to h 5
22:15:19  I           2   12      <325  >35  through thin cirrus, contrail
22:30:32  I,III       2   12      <325  >35  contrail dark/bright
22:45:53  I,IV        3   12      <325   30  also fake NLC: cirrus above h 15
23:00:53  IV          3   10      <325       also fake NLC: cirrus above h 15
23:15:47  III,IV      4   10      <325       through cirrus
23:30:47  I           4    8      <325   30  through thin cirrus
23:45:48  I,II        3    7      <325   30  through thin cirrus
00:00:47  I           3    6      <325   30  through thin cirrus
00:15:47  I           3    5                 fog to h 2
00:30:47  X                                  fog
00:45:46  X                                  fog
01:00:47  X                                  fog
01:15:26  X                                  fog
01:30:25  X                                  fog
01:45:32  X                                  fog
02:00:32  X                                  fog
02:15:31  X                                  fog
02:30:09  X                                  fog
02:45:09  X                                  fog
03:00:08  X                                  fog
03:15:05  X                                  fog
03:30:04  X                                  fog

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 periods of positive sightings of NLC are reported to the NLC Observers' Home Page:

Name: Horst Meyerdierks
Country: Scotland
Location: Edinburgh
Date: 2014/07/22-23
Start: 22:15
End: 00:15
Forms: I,II,III,IV
Max elevation: 12
Max brightness: 4
Comments: Through cloud.
<a href="http://www.chiandh.me.uk/nlccam/20140722-23.shtml">Images</a>.

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: other than or multiple of I-IV
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

Images

Listed below are the images with positive sightings of 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)
-------- ------ ----- ----- ----- -----  ----- -------------------
22:15:19  4.000 330.7  -9.5  -1.6  55.4  0-255 q6356.jpg m6356.jpg
22:30:32  8.000 334.1 -10.5  -2.3  25.1  0-255 q6360.jpg
22:45:53 15.000 337.7 -11.4  -2.8  15.7  0-255 q6365.jpg
23:00:53 15.000 341.2 -12.2  -3.3  11.5  0-255 q6370.jpg
23:15:47 15.000 344.7 -12.8  -3.7   9.1  0-255 q6375.jpg
23:30:47 15.000 348.3 -13.3  -3.9   7.6  0-255 q6381.jpg
23:45:48 15.000 351.9 -13.6  -4.2   6.7  0-255 q6387.jpg
00:00:47 15.000 355.5 -13.8  -4.3   6.1  0-255 q6393.jpg
00:15:47 15.000 359.2 -13.9  -4.3   5.9  0-255 q6399.jpg

exp: Exposure time in seconds (200 ISO, f/2.8).
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).