Variable Types in ERA5Reanalysis.jl

In order to download data from the Climate Data Store, we need to specify at least a variable to download. This variable can be one found directly from CDS, or it can be a custom user-defined variable (in which case it has to be calculated by the user). Information regarding this variable will be loaded into an ERA5Variable.

ERA5Reanalysis.ERA5Variable — Type
ERA5Variable

Abstract supertype for ERA5 variables.

All ERA5Variable Types contain the following fields:

  • varID : The variable ID, that is also the identifier in the NetCDF files
  • lname : The variable long-name, which is used to specify retrievals from CDS
  • vname : The full-name of the variable
  • units : The units of the variable

SingleLevel and PressureLevel variables

There are two main ERA5Variable types in ERA5 reanalysis:

  • SingleLevel variables, such as surface temperature, or total cloud cover, that are provided in the (lon,lat) space
  • PressureLevel variables, such as atmospheric temperature, or specific humidity, that are provided in the (lon,lat,pressure) space
ERA5Reanalysis.SingleLevel — Type
SingleLevel <: ERA5Variable

Abstract supertype for Single-Level variables. Contains the following fields:

  • varID : The variable ID, that is also the identifier in the NetCDF files
  • lname : The variable long-name, which is used to specify retrievals from CDS
  • vname : The full-name of the variable
  • units : The units of the variable
  • dname : The name of the ERA5 dataset containing the variable
ERA5Reanalysis.PressureLevel — Type
PressureLevel <: ERA5Variable

Abstract supertype for Pressure-Level variables. Contains the following fields:

  • varID : The variable ID, that is also the identifier in the NetCDF files
  • lname : The variable long-name, which is used to specify retrievals from CDS
  • vname : The full-name of the variable
  • units : The units of the variable
  • hPa : The pressure-level height of the variable in concern
  • dname : The name of the ERA5 dataset containing the variable

Custom ERA5Variables

Each of these supertypes are further broken down into XXVariable and XXCustom subtypes, where XXVariable represents a variable that is available directly from CDS, and XXCustom variables are user-defined variables. XXCustom variables therefore cannot be downloaded - trying to do so will result in a method error - and can only be calculated from existing variable data.

ERA5Reanalysis.SingleVariable — Type
SingleVariable <: SingleLevel

Subtype for Single-Level variables that can be directly retrieved from the CDS