From 0b7b34d5af4735805996018f91889cdb0375342a Mon Sep 17 00:00:00 2001 From: Leo van Kampenhout Date: Thu, 1 Feb 2018 17:01:20 +0100 Subject: [PATCH] fresh snow grain size is temperature dependent in CLM5 --- .../Surface_Albedos/CLM50_Tech_Note_Surface_Albedos.rst | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/doc/source/tech_note/Surface_Albedos/CLM50_Tech_Note_Surface_Albedos.rst b/doc/source/tech_note/Surface_Albedos/CLM50_Tech_Note_Surface_Albedos.rst index 386cf77bd2..3ecf53e0f2 100644 --- a/doc/source/tech_note/Surface_Albedos/CLM50_Tech_Note_Surface_Albedos.rst +++ b/doc/source/tech_note/Surface_Albedos/CLM50_Tech_Note_Surface_Albedos.rst @@ -956,8 +956,13 @@ each time step *t* as r_{e} \left(t\right)=\left[r_{e} \left(t-1\right)+dr_{e,\, dry} +dr_{e,\, wet} \right]f_{old} +r_{e,\, 0} f_{new} +r_{e,\, rfz} f_{rfrz} Here, the effective radius of freshly-fallen snow -(:math:`r_{e,0}`) is fixed globally at 54.5 :math:`\mu` m (corresponding to a specific surface area of 60 m\ :sup:`2` kg\ :sup:`-1`), and the effective -radius of refrozen liquid water (:math:`r_{e,rfz}`) is set to 1000\ :math:`\mu` m. +(:math:`r_{e,0}`) is based on a simple linear temperature-relationship. +Below -30 degrees Celcius, a minimum value is enforced of 54.5 :math:`\mu` m +(corresponding to a specific surface area of 60 m\ :sup:`2` kg\ :sup:`-1`). +Above 0 degrees Celcius, a maximum value is enforced of 204.5 :math:`\mu` m. +Between -30 and 0 a linear ramp is used. + +The effective radius of refrozen liquid water (:math:`r_{e,rfz}`) is set to 1000\ :math:`\mu` m. Dry snow aging is based on a microphysical model described by :ref:`Flanner and Zender (2006) `. This model simulates diffusive vapor flux