[GRASS-user] white/black sky albedo

GRASS GRASS user
1

Hi to everybody!

I´d like to calculate the ET(a) with the "senay" method.
Does anybody know the difference between white and black albedo and what effects they have in the calculation?
Thanks a lot!

Nadine

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2

On Wed, May 13, 2009 at 11:50 AM, Nadine Jeschke <blaubaere@gmx.de> wrote:

Hi to everybody!

I´d like to calculate the ET(a) with the "senay" method.
Does anybody know the difference between white and black albedo and what effects they have in the calculation?
Thanks a lot!

I am not sure what that is but I can point you to
http://grass.osgeo.org/grass70/manuals/html70_user/i.albedo.html
and in Addons
https://svn.osgeo.org/grass/grass-addons/gipe/i.evapo.senay/

Do you have a reference about white/black sky albedo?

Maybe that's of help,
Markus

3

hello!

Guess my last question was not clear enough...

I´d like to calculate i.evapo.senay and I´m not sure which MODIS albedo values I shall use. Do you use black or white-sky albedo for this calculation?
Or do I need both, calculated into blue sky albedo before?

hope someone can help! Thanks a lot!

Nadine
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Neu: GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate + Telefonanschluss für nur 17,95 Euro/mtl.!* http://dslspecial.gmx.de/freedsl-surfflat/?ac=OM.AD.PD003K11308T4569a