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with a constant ice conductivity. It is expressed as |
with a constant ice conductivity. It is expressed as |
228 |
$(K/h)(T_{w}-T_{0})$, where $K$ is the ice conductivity, $h$ the ice |
$(K/h)(T_{w}-T_{0})$, where $K$ is the ice conductivity, $h$ the ice |
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thickness, and $T_{w}-T_{0}$ the difference between water and ice |
thickness, and $T_{w}-T_{0}$ the difference between water and ice |
230 |
surface temperatures. TThis type of model is often refered to as a |
surface temperatures. This type of model is often refered to as a |
231 |
``zero-layer'' model. The surface heat flux is computed in a similar |
``zero-layer'' model. The surface heat flux is computed in a similar |
232 |
way to that of \citet{parkinson79} and \citet{manabe79}. |
way to that of \citet{parkinson79} and \citet{manabe79}. |
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|
|
234 |
The conductive heat flux depends strongly on the ice thickness $h$. |
The conductive heat flux depends strongly on the ice thickness $h$. |
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However, the ice thickness in the model represents a mean over a |
However, the ice thickness in the model represents a mean over a |
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\citet{menemenlis05}, this flux is not assumed to instantaneously melt |
\citet{menemenlis05}, this flux is not assumed to instantaneously melt |
253 |
or create ice, but a time scale of three days is used to relax $T_{w}$ |
or create ice, but a time scale of three days is used to relax $T_{w}$ |
254 |
to the freezing point.} |
to the freezing point.} |
255 |
|
% |
256 |
The parameterization of lateral and vertical growth of sea ice follows |
The parameterization of lateral and vertical growth of sea ice follows |
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that of \citet{hibler79, hibler80}. |
that of \citet{hibler79, hibler80}. |
258 |
|
|
259 |
On top of the ice there is a layer of snow that modifies the heat flux |
On top of the ice there is a layer of snow that modifies the heat flux |
260 |
and the albedo \citep{zhang98}. If enough snow accumulates so that its |
and the albedo \citep{zhang98}. Snow modifies the effective |
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weight submerges the ice and the snow is flooded, a simple mass |
conductivity according to |
262 |
conserving parameterization of snowice formation (a flood-freeze |
\[\frac{K}{h} \rightarrow \frac{1}{\frac{h_{s}}{K_{s}}+\frac{h}{K}},\] |
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algorithm following Archimedes' principle) turns snow into ice until |
where $K_s$ is the conductivity of snow and $h_s$ the snow thickness. |
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the ice surface is back at $z=0$ \citep{leppaeranta83}. |
If enough snow accumulates so that its weight submerges the ice and |
265 |
|
the snow is flooded, a simple mass conserving parameterization of |
266 |
|
snowice formation (a flood-freeze algorithm following Archimedes' |
267 |
|
principle) turns snow into ice until the ice surface is back at $z=0$ |
268 |
|
\citep{leppaeranta83}. |
269 |
|
|
270 |
Effective ice thickness (ice volume per unit area, |
Effective ice thickness (ice volume per unit area, |
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$c\cdot{h}$), concentration $c$ and effective snow thickness |
$c\cdot{h}$), concentration $c$ and effective snow thickness |