SLUrb Driver PIDS_SLURB#
The SLUrb model driver is denoted by the suffix _slurb, e.g. jobname_slurb. The driver file, if found from the input data directory, will be automatically copied into job work directory by palmrun.
Global attributes#
Setting global attributes is optional, but it is highly recommended to set the attributes similarly to the static driver as they are important for data description and reusability. Note that for origin_*, values from static input driver will be used nevertheless.
| Attribute | Type | Description |
|---|---|---|
| acronym | NC_CHAR | Abbreviation of institution (max. 12 characters). |
| author | NC_CHAR | First name, last name, email address. |
| campaign | NC_CHAR | User-defined text, max. 12 characters. |
| comment | NC_CHAR | User-defined text. |
| contact_person | NC_CHAR | First name, last name, email address. |
| Conventions(*) | NC_CHAR | Must be set to "CF-1.7". |
| creation_time | NC_CHAR | File creation date (UTC), format: YYYY-MM-DD hh:mm:ss +00. |
| data_content | NC_CHAR | User-defined text, max. 16 characters. |
| dependencies | NC_CHAR | User-defined text. |
| history | NC_CHAR | Information of data processing, separation by comma, e.g., "2024-02-19 11:45: updated wall heat capacities". |
| keywords | NC_CHAR | User-defined list, separated by comma. |
| license | NC_CHAR | User-defined text. |
| location | NC_CHAR | User-defined text. |
| origin_lat | NC_FLOAT | Geographical latitude in degrees north. This attribute defines the south boundary of the model domain. |
| origin_lon | NC_FLOAT | Geographical longitude in degrees east. This attribute defines the left boundary of the model domain. |
| origin_time | NC_CHAR | Reference point in time (UTC) YYYY-MM-DD hh:mm:ss +00. |
| origin_x | NC_FLOAT | Reference x-location in m (UTM) of left model boundary. |
| origin_y | NC_FLOAT | Reference y-location in m (UTM) of lower model boundary. |
| origin_z | NC_FLOAT | Reference height in m above sea level. |
| palm_version | NC_FLOAT | E.g. "24.04" for compatibility checks. |
| references | NC_CHAR | User-defined text. |
| rotation_angle | NC_FLOAT | Clockwise angle of rotation in degrees between North positive y axis and the y axis in the data, e.g. 0.0. |
| site | NC_CHAR | User-defined text. |
| source | NC_CHAR | User-defined text. |
| title | NC_CHAR | Short description, e.g., "PALM-SLUrb input file for scenario 1b". |
| version | NC_INT | E.g. 1. |
Dimensions#
The dimensions of the SLUrb model driver file are defined as follows:
| Dimension name | Type | Attributes | Size | Description |
|---|---|---|---|---|
nroad_3d |
NC_INT | long_name="road layer identifier" |
n_layers_roads |
Sequence of integers from 1 to n_layers_roads identifying the road layer, with 1 being the layer closest to the surface. |
nroof_3d |
NC_INT | long_name="roof layer identifier" |
n_layers_roofs |
Sequence of integers from 1 to n_layers_roofs identifying the roof layer, with 1 being the layer closest to the surface. |
nwall_3d |
NC_INT | long_name="wall layer identifier" |
n_layers_walls |
Sequence of integers from 1 to n_layers_walls identifying the wall layer, with 1 being the layer closest to the surface. |
nwin_3d |
NC_INT | long_name="window layer identifier" |
n_layers_windows |
Sequence of integers from 1 to n_layers_windows identifying the window layer, with 1 being the layer closest to the surface. |
time |
NC_FLOAT | long_name="time", units="s" |
see below | Time dimension for the temporally dynamic inputs (e.g. sensible heat flux from traffic). Seconds from origin_date_time. |
x (*) |
NC_FLOAT | axis="X", long_name="distance to origin in x-direction", units="m" |
nx |
Distance to origin in x-direction. The size match the number of grid points in x-direction (nx) in the simulation domain. |
y (*) |
NC_FLOAT | axis="X", long_name="distance to origin in x-direction", units="m" |
ny |
Distance to origin in y-direction. The size match the number of grid points in y-direction (ny) in the simulation domain. |
(*) are mandatory dimensions
The time dimension, if present, has to cover the the entire simulation period, including initialization time (0.0 seconds) and end_time. Optionally, a dynamic input during the spinup period can be provided using negative time values (time(0) = -spinup_time, time(1) = -...). Otherwise, the first input value (at time(0)) will be used as a constant input during the spinup. The temporal interval of the inputs is not restricted, the inputs are interpolated linearly during runtime.
Variables#
In the case both a namelist and an input driver initialization are given (possible for certain variables such as building_type), input driver takes precedence. It is possible to give values only for certain grid cells, e.g. use custom wall heat capacities in certain grid cells and the default value of the building type elsewhere (value set to _FillValue). Any inputs for cells with urban fraction less than 1% (fr_urb(j,i) < 0.01) are ignored (e.g. _FillValue may be used for these cells.).
| Dimension name | Type | Attributes | Description |
|---|---|---|---|
albedo_road(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road surface shortwave albedo", res_orig, source, units="1" |
Shortwave albedo of road surfaces. |
albedo_roof(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof surface shortwave albedo", res_orig, source, units="1" |
Shortwave albedo of roof surfaces. |
albedo_wall(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="wall surface shortwave albedo", res_orig, source, units="1" |
Shortwave albedo of wall surfaces. |
albedo_window(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window surface shortwave albedo", res_orig, source, units="1" |
Shortwave albedo of window surfaces. |
building_frontal_area_fraction(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="building frontal area fraction", res_orig, source, units="1" |
Ratio of building frontal area to total plan area (incl. natural surfaces/pervious surfaces). |
building_height(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="mean building height", res_orig, source, units="m" |
Mean building height within the cell. Note that a single-layer model like SLUrb does not perform very well with deep urban canopies (>60 m). |
building_indoor_temperature(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="indoor air temperature", res_orig, source, units="K" |
Indoor air temperature in buildings. Used as a fixed inner boundary condition for the roof, wall and window models. |
building_plan_area_fraction(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="building plan area fraction", res_orig, source, units="1" |
Ratio of building plan area to total plan area (incl. natural surfaces/pervious surfaces). Cannot exceed urban_fraction. |
building_type(y,x) |
NC_BYTE | _FillValue=-127b(*), coordinates, grid_mapping, long_name="building type classification", res_orig, source, units="1" |
Building type (1-7) are used as presets for bulk definition of parameters for walls, windows and roofs. The default parameters may be overrided using parameter-specific (e.g. c_wall or fr_win) inputs. For reference on the available building types, please refer to the list of building types. |
c_road(nroad_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road layer volumetric heat capacity", res_orig, source, units="J/m3/K" |
Volumetric heat capacity of road layers. |
c_roof(nroof_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof layer volumetric heat capacity", res_orig, source, units="J/m3/K" |
Volumetric heat capacity of roof layers. |
c_wall(nwall_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="wall layer volumetric heat capacity", res_orig, source, units="J/m3/K" |
Volumetric heat capacity of wall layers. |
c_window(nwin_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window layer volumetric heat capacity", res_orig, source, units="J/m3/K" |
Volumetric heat capacity of window layers. |
deep_soil_temperature(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="deep soil temperature", res_orig, source, units="K" |
Deep soil temperature. Used as a fixed inner boundary condition for the road model. |
dz_road(nroad_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road layer thickness", res_orig, source, units="m" |
Thickness of road layers. |
dz_roof(nroof_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof layer thickness", res_orig, source, units="m" |
Thickness of roof layers. |
dz_wall(nwall_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="wall layer thickness", res_orig, source, units="m" |
Thickness of wall layers. |
dz_window(nwin_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window layer thickness", res_orig, source, units="m" |
Thickness of window layers. |
emiss_road(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road surface emissivity", res_orig, source, units="1" |
Emissivity of road surfaces. |
emiss_roof(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof surface emissivity", res_orig, source, units="1" |
Emissivity of roof surfaces. |
emiss_wall(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="wall surface emissivity", res_orig, source, units="1" |
Emissivity of wall surfaces. |
emiss_window(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window surface emissivity", res_orig, source, units="1" |
Emissivity of window surfaces. |
lambda_road(nroad_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road layer thermal conductivity", res_orig, source, units="W/m/K" |
Thermal conductivity of road layers. |
lambda_roof(nroof_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof layer thermal conductivity", res_orig, source, units="W/m/K" |
Thermal conductivity of roof layers. |
lambda_wall(nwall_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="wall layer thermal conductivity", res_orig, source, units="W/m/K" |
Thermal conductivity of wall layers. |
lambda_window(nwin_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window layer thermal conductivity", res_orig, source, units="W/m/K" |
Thermal conductivity of window layers. |
pavement_type(y,x) |
NC_BYTE | _FillValue=-127b(*), coordinates, grid_mapping, long_name="pavement type classification", res_orig, source, units="1" |
Pavement type (1-3) used to bulk definition of parameters for road surfaces (street canyon floor). The default parameters may be overrided using parameter-specific (e.g. c_road) inputs. For reference on the available pavement types, please refer to the list of pavement types. |
qsws_external(time,(y),(x)) |
NC_FLOAT | _FillValue=-9999.f(*), lod=1,2(*), coordinates, grid_mapping, long_name="latent heat flux from external sources", res_orig, source, units="W/m^2" |
Additional latent heat flux from sources external to the model (e.g. industry or HVAC exhaust) per unit area (W/m²). The flux is internally scaled to unit urban area and aggregated to atmospheric fluxes. With lod=1, a 1D input with only time dependency is assumed. With lod=2, data with both temporal and spatial dependency can be provided. |
shf_external(time,(y),(x)) |
NC_FLOAT | _FillValue=-9999.f(*), lod=1,2(*), coordinates, grid_mapping, long_name="sensible heat flux from external sources", res_orig, source, units="W/m^2" |
Additional sensible heat flux from sources external to the model (e.g. industry or HVAC exhaust) per unit area (W/m²). The flux is internally scaled to unit urban area and aggregated to atmospheric fluxes. With lod=1, a 1D input with only time dependency is assumed. With lod=2, data with both temporal and spatial dependency can be provided. |
shf_traffic(time,(y),(x)) |
NC_FLOAT | _FillValue=-9999.f(*), lod=1,2(*), coordinates, grid_mapping, long_name="sensible heat flux from traffic", res_orig, source, units="W/m^2" |
Additional sensible heat flux from traffic per unit area (W/m²). The flux is internally scaled to unit street area and entered into the prognostic equation for street canyon air temperature. With lod=1, a 1D input with only time dependency is assumed. With lod=2, data with both temporal and spatial dependency can be provided. |
street_canyon_aspect_ratio(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="street canyon aspect ratio", res_orig, source, units="1" |
Characteristic street canyon aspect ratio (height-to-width ratio). Typically estimated from urban morphometric data using relation \(\frac{H}{W}=\frac{1}{2}\frac{R_{wall,hor}}{1-f_{bld}}\), where \(R_{wall,hor}\) is the ratio of wall area to total plan area and \(f_{bld}\) is the ratio of building plan area to total plan area. |
street_canyon_orientation(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="street canyon orientation angle", res_orig, source, units="deg" |
Street canyon orientation angle in degrees (compass heading). If set to fill value, an isotropic street canyon will be assumed. Only effective when anisotropic_street_canyons = .T.. |
transmissivity_window(nwin_3d,y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window layer shortwave transmissivity, res_orig, source, units="1" |
Shortwave transmissivity of window layers. |
urban_fraction(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="urban plan area fraction", res_orig, source, units="1" |
Urban fraction, more precisely the plan area fraction of buildings and streets comibined. The remaining surface area will be modelled as vegetation, water or open pavement surface by PALM-LSM depending on the user's setup. Any pervious or water surfaces should be included in the non-urban fraction, irregardless if they are part of urban fabric or not. As SLUrb's physical formulation is based on a street canyon, large paved areas without buildings (e.g. large parking lots) are better to be omitted from this fraction as well and modelled with PALM-LSM instead (surface_type = 'pavement'). |
window_fraction(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window fraction, res_orig, source, units="1" |
Area fraction of windows of the total facade area. |
z0_road(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road surface aerodynamic roughness length for momentum", res_orig, source, units="m" |
Aerodynamic roughness length for momentum of road surfaces. |
z0_roof(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof surface aerodynamic roughness length for momentum", res_orig, source, units="m" |
Aerodynamic roughness length for momentum of roof surfaces. |
z0_urb(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="urban roughness length for momentum", res_orig, source, units="m" |
Roughness length for momentum representative of the whole urban surface. |
z0_wall(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="wall surface aerodynamic roughness length for momentum", res_orig, source, units="m" |
Aerodynamic roughness length for momentum of wall. surfaces. Only used with facade_resistance_parametrization = 'krayenhoff&voogt' or 'rowley'. |
z0_window(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="window surface aerodynamic roughness length for momentum", res_orig, source, units="m" |
Aerodynamic roughness length for momentum of window surfaces. Only used with facade_resistance_parametrization = 'krayenhoff&voogt' or 'rowley'. |
z0h_road(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="road surface aerodynamic roughness length heat", res_orig, source, units="m" |
Aerodynamic roughness length for heat of road surfaces. Used only if aero_roughness_heat = 'fixed'). |
z0h_roof(y,x) |
NC_FLOAT | _FillValue=-9999.f(*), coordinates, grid_mapping, long_name="roof surface aerodynamic roughness length heat", res_orig, source, units="m" |
Aerodynamic roughness length for heat of roof surfaces. Used only if aero_roughness_heat = 'fixed'). |
(*) are mandatory attributes
Building types#
The building types (1-6) are used as presets for bulk definition of surface and subsurface parameters for roofs, walls and windows. The following types are predefined in the model, based on German building stock classification:
| Building type | Description | Reference |
|---|---|---|
| 1 | Residential, < 1950 | Helbig et al. (2018), DIN 4108-4 (2017), Levison et al. (2001), and Masson et al. (2002) |
| 2 | Residential, 1950 - 2000 | Helbig et al. (2018), DIN 4108-4 (2017), Levison et al. (2001), and Masson et al. (2002) |
| 3 | Residential, > 2000 | Helbig et al. (2028), DIN 4108-4 (2017), Levison et al. (2001), and Masson et al. (2002) |
| 4 | Office, < 1950 | Helbig et al. (2018), DIN 4108-4 (2017), Levison et al. (2001), and Masson et al. (2002) |
| 5 | Office, 1950 - 2000 | Helbig et al. (2018), DIN 4108-4 (2017), Levison et al. (2001), and Masson et al. (2002) |
| 6 | Office, 1950 - 2000 | Helbig et al. (2018) DIN 4108-4 (2017), Levison et al. (2001), and Masson et al. (2002) |
The default building type in SLUrb is 2.
Please note that the building material properties may differ strongly from these default values depending on the exact material used locally. This applies especially to the surface albedo, for which the model is relatively sensitive to. Therefore, it is up to the user to validate if the default parameter values are applicable in the study area and to provide case-specific values if needed (by providing e.g. albedo_roof).
Surface parameters#
| Surface | Parameter | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|---|
| Roofs | \(z_0\) (m) | 0.15 | 0.15 | 0.15 | 0.15 | 0.15 | 0.15 |
| \(z_{0,h}\)¹ (m) | 1.5E-3 | 1.5E-3 | 1.5E-3 | 1.5E-3 | 1.5E-3 | 1.5E-3 | |
| Albedo | 0.17 | 0.10 | 0.17 | 0.17 | 0.10 | 0.17 | |
| Emissivity | 0.90 | 0.95 | 0.92 | 0.90 | 0.95 | 0.92 | |
| Walls | \(z_0\) (m) | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 |
| \(z_{0,h}\)¹ (m) | 5.0E-4 | 1.0E-4 | 1.0E-4 | 1.0E-4 | 1.0E-4 | 1.0E-4 | |
| Albedo | 0.30 | 0.30 | 0.37 | 0.30 | 0.30 | 0.37 | |
| Emissivity | 0.93 | 0.93 | 0.93 | 0.93 | 0.93 | 0.93 | |
| Windows | Window fraction | 0.18 | 0.25 | 0.29 | 0.18 | 0.25 | 0.29 |
| \(z_0\) (m) | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | |
| \(z_{0,h}\)¹ (m) | 1.0E-4 | 1.0E-4 | 5.0E-4 | 1.0E-4 | 1.0E-4 | 1.0E-4 | |
| Albedo | 0.12 | 0.15 | 0.18 | 0.12 | 0.15 | 0.18 | |
| Emissivity | 0.91 | 0.87 | 0.80 | 0.91 | 0.87 | 0.80 | |
| Transmissivity | 0.70 | 0.65 | 0.57 | 0.70 | 0.65 | 0.57 |
\(^1\): Used only if \(z_{0,h}\) is fixed to constant value (aero_roughness_heat = 'fixed'). The roughness lengths for the vertical surfaces are only used only with the Krayenhoff&Voogt (2007) resistance parameterization, with the DOE-2 parameterization using different roughness representation and Rowley (1930) being independent of surface roughness.
Subsurface parameters#
The preset subsurface parameters are only used with the default four-layer configuration.
| Surface | Parameter | Layer | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|---|---|
| Roofs | Material | 1 | roof tiles | bitumen | gravel | roof tiles | bitumen | gravel |
| 2 | wooden formwork | thermal insulation | wooden formwork | wooden formwork | thermal insulation | wooden formwork | ||
| 3 | planks | concrete | thermal insulation | planks | concrete | thermal insulation | ||
| 4 | gypsum plaster | gypsum plaster | gypsum plaster | gypsum plaster | gypsum plaster | gypsum plaster | ||
| Thickness (m) | 1 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | |
| 2 | 0.04 | 0.15 | 0.04 | 0.04 | 0.15 | 0.04 | ||
| 3 | 0.02 | 0.20 | 0.30 | 0.02 | 0.20 | 0.30 | ||
| 4 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | ||
| Specific heat capacity (MJ/m3/K) | 1 | 1.51200 | 1.70000 | 3.75360 | 1.51200 | 1.70000 | 3.75360 | |
| 2 | 0.70965 | 0.07920 | 0.70965 | 0.70965 | 0.07920 | 0.70965 | ||
| 3 | 0.70965 | 2.11200 | 0.07920 | 0.70965 | 2.11200 | 0.07920 | ||
| 4 | 1.52600 | 1.52600 | 1.52600 | 1.52600 | 1.52600 | 1.52600 | ||
| Thermal conductivity (W/m/K) | 1 | 0.520 | 0.160 | 0.520 | 0.520 | 0.160 | 0.520 | |
| 2 | 0.120 | 0.046 | 0.120 | 0.120 | 0.0460 | 0.120 | ||
| 3 | 0.120 | 2.100 | 0.035 | 0.120 | 2.100 | 0.035 | ||
| 4 | 0.700 | 0.700 | 0.700 | 0.700 | 0.700 | 0.700 | ||
| Walls | Material | 1 | mortar plaster | mortar plaster | mortar plaster | mortar plaster | mortar plaster | mortar plaster |
| 2 | solid brick | thermal insulation | thermal insulation | solid brick | thermal insulation | thermal insulation | ||
| 3 | solid brick | concrete | brick | solid brick | concrete | brick | ||
| 4 | gypsum plaster | gypsum plaster | gypsum plaster | gypsum plaster | gypsum plaster | gypsum plaster | ||
| Thickness (m) | 1 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | |
| 2 | 0.18 | 0.06 | 0.20 | 0.18 | 0.06 | 0.20 | ||
| 3 | 0.18 | 0.24 | 0.36 | 0.18 | 0.24 | 0.36 | ||
| 4 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | ||
| Specific heat capacity (MJ/m3/K) | 1 | 1.5200 | 1.5200 | 1.5200 | 1.5200 | 1.5200 | 1.5200 | |
| 2 | 1.5120 | 0.0792 | 0.0792 | 1.5120 | 0.0792 | 0.0792 | ||
| 3 | 1.5120 | 2.1120 | 1.3400 | 1.5120 | 2.1120 | 1.3440 | ||
| 4 | 1.5260 | 1.5260 | 1.5260 | 1.5260 | 1.5260 | 1.5260 | ||
| Thermal conductivity (W/m/K) | 1 | 0.930 | 0.930 | 0.930 | 0.930 | 0.930 | 0.930 | |
| 2 | 0.810 | 0.046 | 0.035 | 0.810 | 0.046 | 0.035 | ||
| 3 | 0.810 | 2.100 | 0.680 | 0.810 | 2.100 | 0.680 | ||
| 4 | 0.700 | 0.700 | 0.700 | 0.700 | 0.700 | 0.700 | ||
| Windows | Window type | box-type | double-layer glazing | triple-layer glazing | box-type | double-layer glazing | triple-layer glazing | |
| Thickness (m) | 1-4 | 0.02 | 0.02 | 0.03 | 0.02 | 0.02 | 0.03 | |
| Specific heat capacity (MJ/m3/K) | 1-4 | 1.736 | 1.736 | 1.736 | 1.736 | 1.736 | 1.736 | |
| Thermal conductivity (W/m/K) | 1-4 | 0.45 | 0.18 | 0.11 | 0.45 | 0.18 | 0.11 | |
| Transmissivity | 1-4 | 0.70 | 0.65 | 0.57 | 0.70 | 0.65 | 0.57 |
Pavement types#
The pavement types (1-5) are used for bulk definition of surface and subsurface parameters for road surface, which covers the street canyon floor in the model. The following types are predefined in the model:
| Pavement_type | Description | Reference |
|---|---|---|
| 1 | Asphalt concrete mix (I-II), stone aggregate(III), gravel and soil(IV). | PALM-LSM default |
| 2 | Asphalt concrete (I-II), stone aggregate (III), gravel and soil (IV). | Masson et al. (2002) |
| 3 | Concrete (Portland concrete, I-II), stone aggregate (III), gravel and soil (IV). | Masson et al. (2002) and Yaghoobian et al. (2002) |
| 4 | Sett (I-II), stone aggregate (III), gravel and soil (IV). | Masson et al. (2002), Oke and Cleugh (1987) and Mandanici et al. (2016) |
| 5 | Pavement stones (I-II), stone aggregate (III), gravel and soil (IV). | Masson et al. (2002), Oke and Cleugh (1987) and Göttsche & Hulley (2012) |
The default pavement type in SLUrb is 2.
Please note that the pavement material properties may differ strongly from these default values depending on the exact material used locally. This applies especially to the surface albedo, for which the model is relatively sensitive to. For example the albedo of sett/paving stones depends strongly on the particular type of rock used as a starting material for the stones. The albedo of asphalt concrete on the other hand has a dependency on the age of the particular pavement, with new asphalt being considerably darker than old one (0.05 to 0.15). Therefore, it is up to the user to validate if the default parameter values are applicable in the study area and to provide case-specific values if needed (by providing e.g. albedo_road).
Surface parameters#
| Pavement type | \(z_0\) (m) | \(z_{0,h}\)¹ (m) | Albedo | Emissivity |
|---|---|---|---|---|
| 1 | 5.0E-2 | 5.0E-4 | 0.17 | 0.93 |
| 2 | 5.0E-2 | 5.0E-4 | 0.10 | 0.95 |
| 3 | 5.0E-2 | 5.0E-4 | 0.30 | 0.90 |
| 4 | 5.0E-2 | 5.0E-4 | 0.17 | 0.95 |
| 5 | 5.0E-2 | 5.0E-4 | 0.17 | 0.93 |
\(^1\): Used only if \(z_{0,h}\) is fixed to constant value (aero_roughness_heat = 'fixed' in slurb_parameters).
Subsurface parameters#
All pavement types share the same default four-layer configuration with following layer thicknesses and depths:
| Layer | Thickness (m) | Depth (m) |
|---|---|---|
| 1 | 0.01 | 0.00-0.01 |
| 2 | 0.04 | 0.01-0.05 |
| 3 | 0.20 | 0.05-0.25 |
| 4 | 1.00 | 0.25-1.25 |
The default layer specific heat capacities (MJ/m3/K) are defined as follows:
| Pavement type | Layer I | Layer II | Layer II | Layer IV |
|---|---|---|---|---|
| 1 | 2.00 | 2.00 | 2.00 | 1.40 |
| 2 | 1.74 | 1.74 | 2.00 | 1.40 |
| 3 | 2.11 | 2.11 | 2.00 | 1.40 |
| 4 | 2.25 | 2.25 | 2.00 | 1.40 |
| 5 | 2.25 | 2.25 | 2.00 | 1.40 |
The default layer thermal conductivities (W/m/K) are defined as follows:
| Pavement type | Layer I | Layer II | Layer II | Layer IV |
|---|---|---|---|---|
| 1 | 1.00 | 1.00 | 2.10 | 0.40 |
| 2 | 0.82 | 0.82 | 2.10 | 0.40 |
| 3 | 1.51 | 1.51 | 2.10 | 0.40 |
| 4 | 2.19 | 2.19 | 2.10 | 0.40 |
| 5 | 2.19 | 2.19 | 2.10 | 0.40 |
References#
A. Helbig, J. Baumüller, and M.J. Kerschgen (2018): Stadtklima und Luftreinhaltung, Springer-Verlag 2013. Institut für Wohnen und Umwelt IWU: Deutsche Gebäudetypologie
DIN 4108-4:2017-02 (2017): Thermal insulation and energy economy in buildings - Part 4: Hygrothermal design values, Beuth-Verlag, Berlin
Göttsche, F-M., G. C. Hulley (2012): Validation of six satellite-retrieved land surface emissivity products over two land cover types in a hyper-arid region, Remote Sens. Environ., 124, 149-158
Levinson, R., and H. Akbari (2001): "Effects of Composition and Exposure on the Solar Reflectance of Portland Cement Concrete," Lawrence Berkeley National Laboratory Report LBNL-48334, Berkeley, CA
Mandanici, E., P. Conte, and V. A. Girelli (2016): Integration of Aerial Thermal Imagery, LiDAR Data and Ground Surveys for Surface Temperature Mapping in Urban Environments, Remote Sens., 8(10), 880
Masson, V., C. S. B. Grimmond, and T. R. Oke (2002): Evaluation of the Town Energy Balance (TEB) Scheme with Direct Measurements from Dry Districts in Two Cities, J. Appl. Meteor. Climatol., 41, 1011–1026
Oke, T. R., and H. A. Cleugh (1987): Urban heat storage derived as energy balance residuals, Boundary-Layer Meteorol., 39, 333-245
Yaghoobian, N., and J. Kleissl (2012): Effect of reflective pavements on building energy use, Urban Climate, 2, 25-42