Index: palm/trunk/DOC/app/chapter_4.1.html
===================================================================
--- palm/trunk/DOC/app/chapter_4.1.html (revision 83)
+++ palm/trunk/DOC/app/chapter_4.1.html (revision 97)
@@ -208,5 +208,5 @@
bc_pt_t
| C * 20 |
-'initial gradient' |
+'initial_ gradient' |
Top boundary condition of the
potential temperature. Allowed are the
@@ -299,5 +299,12 @@
bc_s_t_val * dzu(nz+1) (up to k=nz the prognostic
equation for the scalar concentration is
-solved). |
bc_uv_b
+solved). |
bc_sa_t | C * 20 | 'neumann' | Top boundary condition of the salinity. This parameter only comes into effect for ocean runs (see parameter ocean). Allowed are the
+values 'dirichlet' (sa(k=nz+1)
+does not change during the run) and 'neumann'
+(sa(k=nz+1)=sa(k=nz)).
+When a constant salinity flux is used at the top boundary (top_salinityflux),
+bc_sa_t = 'neumann'
+must be used, because otherwise the resolved scale may contribute to
+the top flux so that a constant value cannot be guaranteed. |
bc_uv_b
| C * 20 |
'dirichlet' |
@@ -331,5 +338,8 @@
Neumann condition yields the free-slip condition with u(k=nz+1) =
u(k=nz) and v(k=nz+1) = v(k=nz) (up to k=nz the prognostic equations
-for the velocities are solved).
+for the velocities are solved).
bottom_salinityflux | R | 0.0 | Kinematic salinity flux near the surface (in psu m/s). This parameter only comes into effect for ocean runs (see parameter ocean).The
+respective salinity flux value is used
+as bottom (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann
+condition must be used for the salinity, which is currently the only available condition. |
building_height |
R | 50.0 | Height
@@ -1111,5 +1121,11 @@
be an integral multiple of
the number of processors in x-direction (due to data transposition
-restrictions). |
omega
+restrictions). |
ocean | L | .F. | Parameter to switch on ocean runs.
By default PALM is configured to simulate atmospheric flows. However, starting from version 3.3, ocean = .T. allows simulation of ocean turbulent flows. Setting this switch has several effects:
- An additional prognostic equation for salinity is solved.
- Potential temperature in buoyancy and stability-related terms is replaced by potential density.
- Potential
+density is calculated from the equation of state for seawater after
+each timestep, using the algorithm proposed by Jackett et al. (2006, J.
+Atmos. Oceanic Technol., 23, 1709-1728).
So far, only the initial hydrostatic pressure is entered into this equation. - z=0 (sea surface) is assumed at the model top (vertical grid index k=nzt on the w-grid), with negative values of z indicating the depth.
- Initial profiles are constructed (e.g. from pt_vertical_gradient / pt_vertical_gradient_level) starting from the sea surface, using surface values given by pt_surface, sa_surface, ug_surface, and vg_surface.
- Zero salinity flux is used as default boundary condition at the bottom of the sea.
- If switched on, random perturbations are by default imposed to the upper model domain from zu(nzt*2/3) to zu(nzt-3).
Relevant parameters to be exclusively used for steering ocean runs are bc_sa_t, bottom_salinityflux, sa_surface, sa_vertical_gradient, sa_vertical_gradient_level, and top_salinityflux.
Section 4.4.2 gives an example for appropriate settings of these and other parameters neccessary for ocean runs.
ocean = .T. does not allow settings of timestep_scheme = 'leapfrog' or 'leapfrog+euler' as well as scalar_advec = 'ups-scheme'.
Current limitations: Using
+a vertical grid stretching is not recommended since it would still
+stretch the grid towards the top boundary of the model (sea surface)
+instead of the bottom boundary. |
omega
| R |
7.29212E-5 |
@@ -1241,5 +1257,5 @@
temperature to be used in all buoyancy terms (in K).
By
default, the instantaneous horizontal average over the total model
-domain is used.
pt_surface
+domain is used.
Attention: In case of ocean runs (see ocean), always a reference temperature is used in the buoyancy terms with a default value of pt_reference = pt_surface. |
pt_surface
| R |
300.0 |
@@ -1247,10 +1263,13 @@
potential temperature (in K). This
parameter assigns the value of the potential temperature
-pt at the surface (k=0). Starting from this value,
+pt at the surface (k=0). Starting from this value,
the
initial vertical temperature profile is constructed with pt_vertical_gradient
and pt_vertical_gradient_level
.
-This profile is also used for the 1d-model as a stationary profile.
+This profile is also used for the 1d-model as a stationary profile.Attention:
In case of ocean runs (see ocean),
+this parameter gives the temperature value at the sea surface, which is
+at k=nzt. The profile is then constructed from the surface down to the
+bottom of the model.
pt_surface_initial
_change | R | 0.0 |
@@ -1291,5 +1310,8 @@
100 m and for z > 1000.0 m up to the top boundary it is
0.5 K / 100 m (it is assumed that the assigned height levels correspond
-with uv levels).
pt_vertical_gradient
+with uv levels). Attention: In case of ocean runs (see ocean),
+the profile is constructed like described above, but starting from the
+sea surface (k=nzt) down to the bottom boundary of the model. Height
+levels have then to be given as negative values, e.g. pt_vertical_gradient_level = -500.0, -1000.0. |
pt_vertical_gradient
_level | R (10) | 10 *
0.0
@@ -1297,10 +1319,9 @@
Height level from which on the temperature gradient defined by
pt_vertical_gradient
-is effective (in m). The height levels
-are to be assigned in ascending order. The
+is effective (in m). The height levels have to be assigned in ascending order. The
default values result in a neutral stratification regardless of the
values of pt_vertical_gradient
(unless the top boundary of the model is higher than 100000.0 m).
-For the piecewise construction of temperature profiles see pt_vertical_gradient.
+For the piecewise construction of temperature profiles see pt_vertical_gradient.Attention: In case of ocean runs (see ocean), the (negative) height levels have to be assigned in descending order.
|
q_surface
| R |
@@ -1453,5 +1474,36 @@
is switched
on (see prandtl_layer).
-
scalar_advec
+ |
sa_surface | R | 35.0 | Surface salinity (in psu). This parameter only comes into effect for ocean runs (see parameter ocean).This
+parameter assigns the value of the salinity sa at the sea surface (k=nzt). Starting from this value,
+the
+initial vertical salinity profile is constructed from the surface down to the bottom of the model (k=0) by using sa_vertical_gradient
+and sa_vertical_gradient_level
+. |
sa_vertical_gradient | R(10) | 10 * 0.0 | Salinity gradient(s) of the initial salinity profile (in psu
+/ 100 m). This parameter only comes into effect for ocean runs (see parameter ocean). This salinity gradient
+holds starting from the height
+level defined by sa_vertical_gradient_level
+(precisely: for all uv levels k where zu(k) <
+sa_vertical_gradient_level, sa_init(k) is set: sa_init(k) =
+sa_init(k+1) - dzu(k+1) * sa_vertical_gradient) down to the bottom boundary or down to the next height level defined
+by sa_vertical_gradient_level.
+A total of 10 different gradients for 11 height intervals (10 intervals
+if sa_vertical_gradient_level(1)
+= 0.0) can be assigned. The surface salinity at k=nzt is
+assigned via sa_surface.
+ Example: sa_vertical_gradient
+= 1.0, 0.5,
+sa_vertical_gradient_level = -500.0,
+-1000.0, That
+defines the salinity to be constant down to z = -500.0 m with a salinity given by sa_surface.
+For -500.0 m < z <= -1000.0 m the salinity gradient is
+1.0 psu /
+100 m and for z < -1000.0 m down to the bottom boundary it is
+0.5 psu / 100 m (it is assumed that the assigned height levels correspond
+with uv levels). |
sa_vertical_gradient_level | R(10) | 10 * 0.0 | Height level from which on the salinity gradient defined by sa_vertical_gradient
+is effective (in m). This parameter only comes into effect for ocean runs (see parameter ocean). The height levels have to be assigned in descending order. The
+default values result in a constant salinity profile regardless of the
+values of sa_vertical_gradient
+(unless the bottom boundary of the model is lower than -100000.0 m).
+For the piecewise construction of salinity profiles see sa_vertical_gradient. |
scalar_advec
| C * 10 |
'pw-scheme' |
@@ -1835,5 +1887,19 @@
Prandtl-layer is available at the top boundary so far.See
also surface_heatflux.
-
+ |
top_salinityflux | R | no prescribed
+salinityflux | Kinematic
+salinity flux at the top boundary, i.e. the sea surface (in psu m/s).
+This parameter only comes into effect for ocean runs (see parameter ocean). If a value is assigned to this parameter, the internal
+two-dimensional surface heat flux field saswst is
+initialized with the value of top_salinityflux as
+top (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann
+condition must be used for the salinity (see bc_sa_t),
+because otherwise the resolved scale may contribute to
+the top flux so that a constant value cannot be guaranteed.
+Note: The
+application of a salinity flux at the model top additionally requires the setting of
+initial parameter use_top_fluxes
+= .T.. See
+also bottom_salinityflux. |
ug_surface
| R |
@@ -1857,5 +1923,8 @@
value, it is recommended to use a Galilei-transformation of the
coordinate system, if possible (see galilei_transformation),
-in order to obtain larger time steps.
+in order to obtain larger time steps.
Attention:
In case of ocean runs (see ocean),
+this parameter gives the velocity value at the sea surface, which is
+at k=nzt. The profile is then constructed from the surface down to the
+bottom of the model.
ug_vertical_gradient
| R(10)
@@ -1872,5 +1941,8 @@
total of 10 different gradients for 11 height intervals (10
intervals if ug_vertical_gradient_level(1)
-= 0.0) can be assigned. The surface geostrophic wind is assigned by ug_surface. |
+= 0.0) can be assigned. The surface geostrophic wind is assigned by ug_surface.
Attention:
In case of ocean runs (see ocean),
+the profile is constructed like described above, but starting from the
+sea surface (k=nzt) down to the bottom boundary of the model. Height
+levels have then to be given as negative values, e.g. ug_vertical_gradient_level = -500.0, -1000.0.
ug_vertical_gradient_level
@@ -1880,8 +1952,7 @@
gradient defined by ug_vertical_gradient
is effective (in m).
-The height levels are to be assigned in ascending order. For the
+The height levels have to be assigned in ascending order. For the
piecewise construction of a profile of the u-component of the
-geostrophic wind component (ug) see ug_vertical_gradient.
- |
ups_limit_e
+geostrophic wind component (ug) see ug_vertical_gradient.
Attention: In case of ocean runs (see ocean), the (negative) height levels have to be assigned in descending order. |
ups_limit_e
| R |
0.0 |
@@ -2063,5 +2134,8 @@
if possible (see galilei_transformation),
in order to obtain larger
-time steps.
vg_vertical_gradient
+time steps.
Attention: In case of ocean runs (see ocean),
+this parameter gives the velocity value at the sea surface, which is
+at k=nzt. The profile is then constructed from the surface down to the
+bottom of the model. |
vg_vertical_gradient
| R(10)
| 10
@@ -2081,5 +2155,8 @@
=
0.0) can be assigned. The surface
-geostrophic wind is assigned by vg_surface. |
+geostrophic wind is assigned by vg_surface.
Attention:
In case of ocean runs (see ocean),
+the profile is constructed like described above, but starting from the
+sea surface (k=nzt) down to the bottom boundary of the model. Height
+levels have then to be given as negative values, e.g. vg_vertical_gradient_level = -500.0, -1000.0.
vg_vertical_gradient_level
@@ -2089,7 +2166,7 @@
gradient defined by vg_vertical_gradient
is effective (in m).
-The height levels are to be assigned in ascending order. For the
+The height levels have to be assigned in ascending order. For the
piecewise construction of a profile of the v-component of the
-geostrophic wind component (vg) see vg_vertical_gradient. |
+geostrophic wind component (vg) see vg_vertical_gradient.
Attention:
In case of ocean runs (see ocean), the (negative) height levels have to be assigned in descending order.
wall_adjustment
|