Hi Stephan, I am using Rayleigh jeans. As I need to activate cloud box in some instances.
I understand that RJBT instead of Planck can cause a dip in the brightness temperatures. Is this the only factor that can cause a bias, or does pressure levels, lat/lon grid resolution also cause a bias? Thanks, Renish -------- Original message -------- From: Stefan Buehler <stefan.bueh...@uni-hamburg.de> Date: 4/20/21 6:11 AM (GMT-06:00) To: "Thomas,Renish" <renish.tho...@colostate.edu> Cc: "arts_users.mi@lists.uni-hamburg.de" <arts_users...@mailman.rrz.uni-hamburg.de> Subject: Re: [arts-users] Calculated brightness temperature bias causes. Dear Renish, do you use Planck or Rayleigh-Jeans brightness temperature? For Planck, you should indeed approach the ambient temperature if you go low enough. Cheers Stefan On 20 Apr 2021, at 12:46, Thomas,Renish wrote: > Hi Everyone, > > I had some questions about the calculated brightness temperature in > ARTS. > > When I calculate the brightness temperature for an atmospheric > scenario in "horizon looking mode" and in clearsky. I get a brightness > temperature at 183.31 GHz (Water vapor absorption line), which is > about 3 to 6 degrees lower than the ambient temperature. > > I would assume that at the water vapor absorption line and at low > altitudes (~2 km above sea level), I should measure very close to the > ambient temperature (Due to high absorption). > > So, my questions are: > > 1.) Is this brightness temperature bias expected?, or can something > else cause this? > > Thanks, > Renish > _______________________________________________ > arts_users.mi mailing list > arts_users.mi@lists.uni-hamburg.de > https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmailman.rrz.uni-hamburg.de%2Fmailman%2Flistinfo%2Farts_users.mi&data=04%7C01%7CRenish.Thomas%40colostate.edu%7C8bb1cd94b52a4724954408d903ed19cb%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C637545139171957024%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=7Qr43Du%2B54FAx%2FWFOIMnjdaHFegsWnBRslp2jGQYxb8%3D&reserved=0
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