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NLC 2010-06-20/21

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: 2010-06-20/21

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:45  X                                  widespread cloud patches
22:00  X                                  cloud to h 12
22:15  X                                  cloud to h 20 and above h 30
22:30  NLC?       1     2         0    5  only small clear areas
22:45  X                                  widespread cloud patches
23:00  NLC?       1     2         0    5  widespread cloud patches
23:15  X                                  cloud patches to h 20 and at h 30
23:30  I          1    17      <335 >360  cloud patches, lightbox top and right
23:45  I          2    17       325  >15  few cloud patches
00:00  I,III      2    18       318  >20  few cloud patches
00:15  I,III      3    18       312  >20  few cloud patches
00:30  I,III      3    19      <310  >20  almost clear
00:45  I,III,IV   3    19      ~310  >20  almost clear
01:00  I,III,IV   3    23      <310  >20  almost clear
01:15  I,III,IV   2    27      <310  >20  few cloud patches on horizon
01:30  I,III      2    35      <310  >20  few cloud patches on horizon
01:45  I,III      2   ~40      <310  >20  few cloud patches on horizon
02:00  I          2   whole field         cloud to h 5
02:15  II         1   whole field         cloud to h 5
02:30  0                                  cloud to h 7
02:45  0                                  cloud patches to h 10

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: Stichill
Date: 2010/06/20-21
Start: 23:30
End: 02:15
Forms: I,II,III
Max elevation: >40
Max brightness: 3
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2010-06-20/21">Images</a>.

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       O: 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)
----- ------ ----- ----- ----- -----  ----- ---------------------
22:30  0.800 336.6  -8.0  -0.4 145.7  0-255 q30038.jpg m30038.jpg
23:00  2.500 343.4  -9.5  -1.5  59.9  0-255 q30042.jpg m30042.jpg
23:30  3.200 350.4 -10.4  -2.2  26.9  0-255 q30048.jpg m30048.jpg
23:45  4.000 353.8 -10.7  -2.4  22.5  0-255 q30052.jpg
00:00  8.000 357.3 -10.9  -2.5  20.6  0-255 q30057.jpg
00:15 10.000   0.8 -10.9  -2.5  20.2  0-255 q30061.jpg
00:30  8.000   4.3 -10.8  -2.5  21.3  0-255 q30065.jpg
00:45  6.000   7.8 -10.6  -2.3  24.3  0-255 q30069.jpg
01:00  5.000  11.3 -10.2  -2.1  30.6  0-255 q30072.jpg
01:15  3.200  14.8  -9.8  -1.7  45.1  0-255 q30075.jpg
01:30  2.000  18.2  -9.2  -1.3  81.4  0-255 q30077.jpg
01:45  1.300  21.6  -8.4  -0.7 130.8  0-255 q30079.jpg
02:00  0.600  25.0  -7.6   0.0 154.4  0-255 q30081.jpg
02:15  0.167  28.3  -6.7   1.2 164.5  0-255 q30082.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).