6.4. model_levels.nml

This file configures the surface types, number of soil layers and maximum number of snow layers. It contains a single namelist called JULES_MODEL_LEVELS.

6.4.1. JULES_MODEL_LEVELS namelist members

JULES_MODEL_LEVELS::npft

Type:integer Permitted:>= 1 Default:5

The number of plant functional types to be modelled.

JULES_MODEL_LEVELS::nnvg

Type:integer Permitted:>= 1 Default:4

The number of non-plant surface types to be modelled.

The total number of surface types to be modelled is called ntype, and is given by ntype = npft + nnvg. In the standard setup, JULES models 5 vegetation types and 4 non-vegetation types (npft = 5, nnvg = 4). However, the model domain need not contain all 9 types, e.g. the domain could consist of a single point with 100% grass. The amount of each type in the domain is normally set in JULES_FRAC.

JULES_MODEL_LEVELS::urban

Type:integer Default:6

Index of the urban surface type.

A negative value indicates no urban surface type.

JULES_MODEL_LEVELS::lake

Type:integer Default:7

Index of the lake surface type.

A negative value indicates no lake surface type.

JULES_MODEL_LEVELS::soil

Type:integer Permitted:>= 1 Default:8

Index of the soil surface type.

Note

A soil surface type must be given.

JULES_MODEL_LEVELS::ice

Type:integer Default:9

Index of the ice surface type.

A negative value indicates no ice surface type.

JULES_MODEL_LEVELS::urban_canyon

Type:integer Default:-1

Index of the urban canyon surface type.

A negative value indicates no urban canyon surface type.

JULES_MODEL_LEVELS::urban_roof

Type:integer Default:-1

Index of the urban roof surface type.

A negative value indicates no urban roof surface type.

JULES_MODEL_LEVELS::sm_levels

Type:integer Permitted:>= 1 Default:4

Number of soil layers.

A value of 4 is often used, and the default soil layer depths have been tuned using this.

JULES_MODEL_LEVELS::nsmax

Type:integer Permitted:>= 0 Default:0

Maximum possible number of snow layers.

0

A composite soil/snow layer is used. This value gives the behaviour found in JULES2.0 and earlier.

> 0

The state of up to nsmax separate snow layers is modelled. Values of nsmax = 3 or more are recommended.

Note

The values of urban, urban_canyon and urban_roof are used to determine what urban scheme to use.

• At most one of urban and urban_canyon can be given.
• If urban_roof is present, then JULES will use one of the 2-tile urban schemes (and so either urban or urban_canyon must be present, and will represent the urban canyon surface type).
• If urban_roof is not present, urban_canyon cannot be given and, if present, urban is used as the single urban surface type.

When giving urban fraction data (see JULES_FRAC), total urban fraction should be given in the urban or urban_canyon tile, whichever is present. This is partitioned internally into roof and canyon.