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Output Files: Atmosphere data (_AT_)

Dimension Nr Variables Format
3D 36 Binary (EDX/EDT)

Atmosphere Data

Contains the general model state of the 3D atmospheric ENVI-met model from the first level above ground to the top of the 3D model.

The Atmosphere data files are produced each main output interval (default: 60 min) and represent the general state of the atmosphere at the given model time. These files contain a broad selection of different items from simple meteorological data such as wind speed and air temperature up to detailed information such as plant CO2 fluxes. Using the _AT_ files, most of the processes in the atmosphere can be analysed. However, there are further files concerning the atmosphere dealing with more specific topics such as radiation or pollutant dispersions. Note, that the surface data are not part of the atmosphere data, but of the surface and flux (_FX_) files.

Variable list

This list represents the variable structure used from Preview III on. In earlier versions, the same information is stored, but the names might differ and the order of the variables is different.

Nr Variable Unit Description
1 Objects - Single object IDs to visualize the model domain. Meaning of the different IDs is stored in LEONARDO Special Layer Definition Files
2 Flow u m/s Wind speed. Vector component along the West-East axis (+: East, -: West)
3 Flow v m/s Wind speed. Vector component along the North-South axis (+: South, -: North)
4 Flow w m/s Wind speed. Vector component along the vertical axis (+: up, -: down)
5 Wind Speed m/s Wind speed. Vector sum over all 3 axis
6 Wind Speed Change % Wind speed change in percent referring to the undisturbed inflow profile at the same height level.
7 Wind Direction deg Wind direction of horizontal component in geographic reference (0: N..90:E..180:S etc)
8 Pressure Perturbation Pa Dynamic pressure as a result of the wind field calculation. Pressure values will add up over time, use spatial difference values only if required
9 Air Temperature °C Potential air temperature at reference (and model default) pressure. For the 3D model, it can be treated like the absolute air temperature
10 Air Temperature difference to Inflow K Difference between the local air temperature and the reference air temperature at inflow at the same height level
11 Air Temperature Change K/h Changes of air temperature compared to the last _AT_ output file
12 Specific Humidity g/kg Specific air humidity
13 Relative Humidity % Relative air humidity (Caution: Depends both on Specific air humidity and air temperature)
14 TKE m²/m³ Local Turbulent Kinetic Energy
15 TKE Dissipation m³/m³ Local dissipation rate of Turbulent Kinetic Energy
16 Mean Radiant Temperature °C The composed radiative fluxes and air temperature for a standing person
17 CO2 Concentration mg/m3 CO2 concentration in the model domain (weight units)
18 CO2 Concentration ppm CO2 concentration in the model domain (parts units)
19 Vertical Exchange Coefficient Impulse m²/s Calculated vertical exchange coefficient for impulse
20 Horizontal Exchange Coefficient Impulse m²/s Calculated horizontal exchange coefficient for impulse (At the moment for microscale assumed to be equal to the vertical exchange coefficient)
21 Direct Shortwave Radiation W/m² Available direct solar radiation referring to a reference surface perpendicular to the incoming sun rays (maximum value before applying Lamberts' law)
22 Diffuse Shortwave Radiation W/m² Available diffuse solar radiation referring to a horizontal reference surface
23 Reflected Shortwave Radiation W/m² Availablereflected solar radiation from the environment referring to a horizontal reference surface
24 Air Temperature Change through LW Cooling K/h Effect of longwave radiation divergence on air temperature per time

Vegetation Data

25 Vegetation LAD m²/m³ One-sided Leaf Area Density (Surface of leaf area per m³ air)
26 Leaf Temperature °C Temperature of the leaf
27 Temperature Flux at Leaf K*m/s Temperature Flux in K from leaf to atmosphere
28 Stomata Resistance s/m Actual resistance of stomata to vapour transfer
29 Vapour Flux at Leaf g/kg*m/s
30 Water on Leaf g/ m²
31 CO2 Flux at Leaf mg/kg*m/s

Other Data

32 Local Mixing Length m
33 TKE normalised with 1D model -
34 Dissipation normalised with 1D model -
35 Km normalised with 1D model -
36 TKE Mechanical Turbulence Production ( )
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