[SQM] snow and the ground albedo

[Arne Danielsen]

Hello everyone,

I have similar readings from my observatory located about 40km outside Oslo (Norway's capital and largest city). 

Using a SQM-LE my readings dropped from ~20.4 down to ~19.0 after we got a snow. The temperatures have been around -15C to -20C during the last 2-3 weeks.

Best regards,
Arne
--
Arne Danielsen
Brages vei 2
1540 Vestby
Norway

Priv: +47 64 95 10 12
Mob: +47 90 19 77 99

E-mail: arne at astrophile.net
Web: http://astrophile.net/
Twitter: http://twitter.com/adanielsen
N59°36'18"  E10°45'40" A84m

  ----- Original Message ----- 
  From: Glenn and Gail Muller 
  To: sqm at unihedron.com 
  Sent: Sunday, January 10, 2010 3:13 PM
  Subject: [SQM] snow and the ground albedo


  January 11, 2010

  Hey Everybody (Jan & Fabio, in particular),

  Last night I managed to get the sought after SQM readings with snow cover.  My backyard observatory is in town, though away from the brightly lit center. On a clear night, like last night with good (but not great) transparency, I usually get readings around 19.7 - 19.8. Last night, with snow cover everywhere except the main streets, my best reading was 19.13 - a difference for my location of about 0.6 .  It was really cold, too, about -12C but the seeing was very steady - With my 12" reflector I easily picked out the E & F stars in Orion's Trapezium http://www.astropix.com/HTML/B_WINTER/TRAPEZ.HTM, and Rigels' companion was a piece of cake.

  Clear skies!

  Glenn Muller

  The GEM 'N I Dobservatory
  http://home.primus.ca/~gmuller/


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