# Afterburner¶

The "afterburner" is the standard post processor for ECHAM data which provides the following operations:

- Extract specified variables and levels # Compute derived variables # Transform spectral data to Gaussian grid representation # Vertical interpolation to pressure levels or height # Compute temporal means # Write data in GRIB, NetCDF, SERVICE or EXTRA format

## Variables computed by the afterburner¶

Code |
Name | Longname | Units | Level | Needed Codes/Computation | Comment |
---|---|---|---|---|---|---|

34 | low_cld | low cloud | single | 223 on modellevel | ||

35 | mid_cld | mid cloud | single | 223 on modellevel | ||

36 | hih_cld | high cloud | single | 223 on modellevel | ||

131 | u | u-velocity | atm (ml+pl) | 138, 155 | ||

132 | v | v-velocity | atm (ml+pl) | 138, 155 | ||

135 | omega | vertical velocity | Pa/s | atm (ml+pl) | 138, 152, 155 | |

148 | stream | streamfunction | atm (ml+pl) | 131, 132 | ||

149 | velopot | velocity potential | atm (ml+pl) | 131, 132 | ||

151 | slp | mean sea level pressure | surface | 129, 130, 152 | ||

156 | geopoth | geopotential height | atm (ml+pl) | 129, 130, 133, 152 | ||

157 | rhumidity | relative humidity | atm (ml+pl) | 130, 133, 152 | ||

189 | sclfs | surface solar cloud forcing | surface | 176-185 | ||

190 | tclfs | surface thermal cloud forcing | surface | 177-186 | ||

191 | sclf0 | top solar cloud forcing | surface | 178-187 | ||

192 | tclf0 | top thermal cloud forcing | surface | 179-188 | ||

259 | windspeed | windspeed | atm (ml+pl) | sqrt(u*u+v*v) | ||

260 | precip | total precipitation | surface | 142+143 | ||

261 | net_top | total top radiation | surface | 178+179 | Not available for ECHAM5 | |

262 | net_bot | total surface radiation | surface | 176+177 | Not available for ECHAM5 | |

263 | net_heat | net surface heat flux | surface | 146+147+176+177-220- C⋅218 |
Not available for ECHAM5 | |

264 | net_water | total surface water | surface | 142+143+182-160-221 | Not available for ECHAM5 |

*C = L _{f} ⋅ ρ _{H2O}*

*ρ*: Density of water

_{H2O}*L*: Latent heat of fusion

_{f}## Transform and interpolation (*TYPE*)¶

Transforming spectral data to Gaussian grid representation and vertical interpolation to pressure levels or height are performed in a chain of steps. The *TYPE* parameter may be used to stop the chain at a certain step.

TYPE |
Interpolation | Transformation | CDO equivalence | |
---|---|---|---|---|

0 (default) | Hybrid level | spectral coefficients | sp2gp | |

10 | Hybrid level | fourier coefficients | ||

11 | Hybrid level | zonal mean sections | ||

20 | Hybrid level | gauss grids | ml2pl | |

30 | Pressure or Height level | gauss grids | gp2sp | |

40 | Pressure or Height level | fourier coefficients | ||

41 | Pressure or Height level | zonal mean sections | ||

50 | Pressure or Height level | spectral coefficients | sp2gp | |

60 | Pressure or Height level | fourier coefficients | ||

61 | Pressure or Height level | zonal mean sections | ||

70 | Pressure or Height level | gauss grids |