ECMWF SHEBA Data Set

 

 
Distribution of difference of ECMWF and rawinsonde temperature and relative humidity (sampled twice daily) for April 1998. Solid line gives the profile of monthly mean ECMWF bias vs. pressure, and dashed lines indicate one standard deviation of the difference from the monthly mean (Bretherton et al. 2000, Fig. 2).

 

Description of data set
 

For a detailed description, visit http://www.atmos.washington.edu/~breth/SHEBA/ECMWF.html.

The following table gives the netCDF variable names included in ECMWF.nc.

 

Summary of all variables in ECMWF.nc

netCDF VARIABLE NAME

DESCRIPTION

UNITS

nc{'yymmddhh'}

time

[UTC]

nc{'sigma'}

normalized pressure height, full levels (*1)

[UTC]

nc{'sigmah'}

normalized pressure height, half levels (for fluxes) (*1)

[UTC]

nc{'psurf'}

surface pressure

[Pa]

nc{'p'}

pressure

[Pa]

nc{'u'}

zonal wind component

[m/s]

nc{'v'}

meridional wind component

[m/s]

nc{'T'}

temperature

[K]

nc{'qv'}

specific humidity

[kg/kg]

nc{'ql'}

specific cloud liquid water content

[kg/kg]

nc{'qi'}

specific cloud ice content

[kg/kg]

nc{'cloud-frac'}

cloud fraction

[percent/100]

nc{'rel-hum'}

relative humidity

[percent/100]

nc{'omega'}

vertical velocity in pressure coordinates

[Pa/s]

nc{'dudt'}

total u tendency

[m/s^2]

nc{'dudt-nonadiabatic'}

diabatic u tendency

[m/s^2]

nc{'dvdt'}

total adiabatic v tendency

[m/s^2]

nc{'dvdt-nonadiabatic'}

diabatic v tendency

[m/s^2]

nc{'dTdt'}

total temperature tendency

[K/s]

nc{'dTdt-nonadiabatic'}

diabatic temperature tendency

[K/s]

nc{'dqdt'}

total moisture tendency

[s^-1]

nc{'dqdt-nonadiabatic'}

diabatic moisture tendency

[s^-1]

nc{'SW-net'}

net shortwave radiation

[W/m^2]

nc{'LW-net'}

net longwave radiation

[W/m^2]

nc{'turb-heat-flux'}

turbulent heat flux

[W/m^2]

nc{'turb-moist-flux'}

turbulent moisture flux

[kg/kg * kg/(m^2*s)]

nc{'turb-u-flux'}

turbulent flux of x-momentum

[kg m/s^2]

nc{'turb-v-flux'}

turbulent flux of y-momentum

[kg m/s^2]

nc{'rain-flux-convective'}

convective rainfall

[kg/(m^2*s)] = [mm/s]

nc{'snow-flux-convective'}

convective snowfall

[mm/s]

nc{'rain-flux-largescale'}

large-scale rainfall

[mm/s]

nc{'snow-flux-largescale'}

large-scale snowfall

[mm/s]

nc{'T2'}

2 m temperature

[K]

nc{'q2'}

2 m specific humidity

[kg/kg]

nc{'u10'}

10 m zonal wind component

[m/s]

nc{'v10'}

10 m meridional wind component

[m/s]

nc{'Tskin'}

surface skin temperature

[K]

nc{'surf-roughness-length'}

surface roughness length'

[m]

nc{'surface-roughness-length-heat'}

surface roughness length for heat

[m]

nc{'surf-albedo'}

surface albedo

[%/100]

nc{'SW-dn-surf'}

downwelling shortwave radiation

[W/m^2]

nc{'LW-dn-surf'}

downwelling longwave radiation

[W/m^2]

nc{'lon'}

ECMWF column latitude (N)

[degree]

nc{'lat'}

ECMWF column longitude (E, values negative for W)

[degree]

nc{'lonship'}

ship column latitude (N)

[degree]

nc{'latship'}

ship column longitude (E)

[degree]

(*1) sigma = pressure (z) / surface pressure.
 

 

The file ECMWF.nc can be downloaded by anonymous ftp: ftp eos.atmos.washington.edu, directory pub/breth/SHEBA (netCDF, 59.2 Mb)

The data can be read and plotted by the matlab routine readECMWF.m

 

Requested acknowledgements
 
'We thank Christian Jakob and his coworkers at ECMWF for producing the ECMWF column dataset for SHEBA.'

 

References
 
Bretherton, C. S., S. R. de Roode, C. Jakob, E. L Andreas, J. Intrieri, R. E. Moritz, and P. O. G. Persson, 2000: A comparison of the ECMWF forecast model with observations over the annual cycle at SHEBA. J. Geophys. Res., submitted 12/99, revised 5/00. Postscript version

Stephan de Roode (roode@phys.uu.nl)
Chris Bretherton (breth@atmos.washington.edu)

University of Washington
Dept of Atmospheric Sciences
Box 352640
Seattle, WA 98195-2640 USA