| 221 | }}} |
| 222 | |---------------- |
| 223 | {{{#!td style="vertical-align:top" |
| 224 | [=#bc_pt_b '''bc_pt_b'''] |
| 225 | }}} |
| 226 | {{{#!td style="vertical-align:top" |
| 227 | C*20 |
| 228 | }}} |
| 229 | {{{#!td style="vertical-align:top" |
| 230 | 'dirichlet' |
| 231 | }}} |
| 232 | {{{#!td |
| 233 | Bottom boundary condition of the potential temperature.\\\\ |
| 234 | Allowed values are '' 'dirichlet' '' (pt(k=0) = const. = [#pt_surface pt_surface] + [#pt_surface_initial_change pt_surface_initial_change]; the user may change this value during the run using [#user-defined] code) and '' 'neumann' '' (pt(k=0)=pt(k=1)). |
| 235 | When a constant surface sensible heat flux is used ([#surface_heatflux surface_heatflux]), '''bc_pt_b''' = '' 'neumann' '' must be used, because otherwise the resolved scale may contribute to the surface flux so that a constant value cannot be guaranteed.\\\\ |
| 236 | In the coupled atmosphere executable, '''bc_pt_b''' is internally set and does not need to be prescribed. |
| 237 | }}} |
| 238 | |---------------- |
| 239 | {{{#!td style="vertical-align:top" |
| 240 | [=#bc_pt_t '''bc_pt_t'''] |
| 241 | }}} |
| 242 | {{{#!td style="vertical-align:top" |
| 243 | C*20 |
| 244 | }}} |
| 245 | {{{#!td style="vertical-align:top" |
| 246 | 'initial_gradient' |
| 247 | }}} |
| 248 | {{{#!td |
| 249 | Top boundary condition of the potential temperature.\\\\ |
| 250 | Allowed are the values '' 'dirichlet' '' (pt(k=nz+1) does not change during the run), '' 'neumann' '' (pt(k=nz+1)=pt(k=nz)), and '' 'initial_gradient' ''. With the '' 'initial_gradient' ''-condition the value of the temperature gradient at the top is calculated from the initial temperature profile (see [#pt_surface pt_surface], [#pt_vertical_gradient pt_vertical_gradient]) by bc_pt_t_val = (pt_init(k=nz+1) - pt_init(k=nz)) / dzu(nz+1). |
| 251 | Using this value (assumed constant during the run) the temperature boundary values are calculated as |
| 252 | |
| 253 | pt(k=nz+1) = pt(k=nz) + bc_pt_t_val * dzu(nz+1) |
| 254 | |
| 255 | (up to k=nz the prognostic equation for the temperature is solved). |
| 256 | When a constant sensible heat flux is used at the top boundary ([#top_heatflux top_heatflux]), '''bc_pt_t''' = '' 'neumann' '' must be used, because otherwise the resolved scale may contribute to the top flux so that a constant value cannot be guaranteed. |
| 257 | }}} |
| 258 | |---------------- |
| 259 | {{{#!td style="vertical-align:top" |
| 260 | [=#<insert_parameter_name> '''<insert_parameter_name>'''] |
| 261 | }}} |
| 262 | {{{#!td style="vertical-align:top" |
| 263 | <insert type> |
| 264 | }}} |
| 265 | {{{#!td style="vertical-align:top" |
| 266 | <insert value> |
| 267 | }}} |
| 268 | {{{#!td |
| 269 | <insert explanation> |
| 270 | }}} |
| 271 | |---------------- |
| 272 | {{{#!td style="vertical-align:top" |
| 273 | [=#<insert_parameter_name> '''<insert_parameter_name>'''] |
| 274 | }}} |
| 275 | {{{#!td style="vertical-align:top" |
| 276 | <insert type> |
| 277 | }}} |
| 278 | {{{#!td style="vertical-align:top" |
| 279 | <insert value> |
| 280 | }}} |
| 281 | {{{#!td |
| 282 | <insert explanation> |
| 283 | }}} |
| 284 | |---------------- |
| 285 | {{{#!td style="vertical-align:top" |
| 286 | [=#<insert_parameter_name> '''<insert_parameter_name>'''] |
| 287 | }}} |
| 288 | {{{#!td style="vertical-align:top" |
| 289 | <insert type> |
| 290 | }}} |
| 291 | {{{#!td style="vertical-align:top" |
| 292 | <insert value> |
| 293 | }}} |
| 294 | {{{#!td |
| 295 | <insert explanation> |