% Data format description for the nonlocal gravity wave parameterization dataset
% Contact: https://github.com/amangupta2 or [email protected]
% Date: 29 August 2024
The nonlocal parameterization dataset contains inputs features for the background atmospheric field and output labels for the subgrid-scale fluxes for those fields computed using ECMWF's ERA5. The full dataset comprises atmospheric state and fluxes computed for the years 2010, 2012, 2014, and 2015. Out of the 48 months computed, 4 are provided here for testing.
Each netCDF file contains:
- dimensional variables: 64 latitudes (LAT) and 128 longitudes (LON)
- features: input features, i.e., the background state of the atmosphere, with dimension TIME x IDIM x LAT x LON
- output: output fluxes, i.e., the momentum fluxes carried by the gravity waves, computed using Helmholtz Decomposition, for the background state, with dimension TIME x ODIM x LAT x LON
IDIM = 369, ODIM = 244
The input (features) has a vertical dimension (IDIM) equal to 369 because it is created by concatenating the latitude, longitude, surface elevation zonal winds, meridional winds, and potential temperature along the vertical dimension. For example, the winds and potential temperature were computed on 122 pressure levels from ERA5. Thus, IDIM index 0 corresponds to latitude, 1 corresponds to longitude, 2 corresponds to surface elevation for the given latitude and longitude, 3 to 124 correspond to zonal wind, 125 to 246 correspond to meridional wind, 247 to 368 correspond to potential temperature.
Likewise, the output has a vertical dimension (ODIM) equal to 244 because it is created by concatenating the zonal flux of vertical momentum and the meridional flux of vertical momentum along the vertical dimension. ODIM 0 to 121 correspond to the zonal flux component and ODIM 122 to 243 correspond to the meridional flux component.
Therefore, the neural network would predict the zonal and meridional momentum fluxes on 122 pressure level each, using the latitude, longitude, and surface elevation, and the zonal wind, meridional wind, and potential temperature on 122 pressure levels.