Hi everyone,
As we know, CICE-master calculates sea ice albedo using delta-Eddington method.
''With the Delta-Eddington parameterization, the albedo depends on the cosine of the zenith angle(coszen)and
is one if the sun is below the horizon (:math:`\cos\varphi`, ``coszen``). Thus, the albedos will be one in the dark,
polar winter hemisphere. However, the time-averaged albedo fields will be high if a diurnal solar cycle is used,
because values of one would be included in the average for half of each 24-hour period. To rectify this, a separate
counter should be used for the averaging that is incremented only when :math:`\cos\varphi > 0`. However, this is still
a work in progress.''
The passage above can be found in the file 'ug_troubleshooting.rst' under the directory /CICE-master/icepack/doc/source/user_guide.
It means that when calculating the time average of albedo, the CICE model doesn't get rid of the hours whose solar zenith angle
is less than 0, in other words, when the sun is below horizon.
Hence, what I wonder is whether the problem mentioned above has been solved in the current version of CICE model. I have to find
it out because if the answer is no, maybe the problem of the large albedo value in the current CICE model can be explained.
That's all about my question. Look forward to your reply.
Best wishes!
Sincerely,
Shutao Cao
As we know, CICE-master calculates sea ice albedo using delta-Eddington method.
''With the Delta-Eddington parameterization, the albedo depends on the cosine of the zenith angle(coszen)and
is one if the sun is below the horizon (:math:`\cos\varphi`, ``coszen``). Thus, the albedos will be one in the dark,
polar winter hemisphere. However, the time-averaged albedo fields will be high if a diurnal solar cycle is used,
because values of one would be included in the average for half of each 24-hour period. To rectify this, a separate
counter should be used for the averaging that is incremented only when :math:`\cos\varphi > 0`. However, this is still
a work in progress.''
The passage above can be found in the file 'ug_troubleshooting.rst' under the directory /CICE-master/icepack/doc/source/user_guide.
It means that when calculating the time average of albedo, the CICE model doesn't get rid of the hours whose solar zenith angle
is less than 0, in other words, when the sun is below horizon.
Hence, what I wonder is whether the problem mentioned above has been solved in the current version of CICE model. I have to find
it out because if the answer is no, maybe the problem of the large albedo value in the current CICE model can be explained.
That's all about my question. Look forward to your reply.
Best wishes!
Sincerely,
Shutao Cao