Station/record codes

• First small letter: Record type

  a	Aircraft
  c	Total-column data
  d	Continuous (day-time selected)
  f	Flask
  h	Continuous (original hourly, half-hourly, etc.)
  n	Continuous (night-time selected)
  o	Ocean data

  
  
• Second small letter: Data selection

  v	Variability selection
  x	No further selection

  
  
• Capital letters (or numbers): STATION CODE
  
  
• First small letter after station code: Measuring institution
  

  a	CSIRO
  b	MPI-BGC
  c	NOAA ESRL (formerly CMDL)
  e	UBern
  g	AGAGE
  j	JMA
  k	SIO (CO2 program)
  l	LSCE
  m	EC (formerly MSC)
  n	NIES
  p	PU
  s	SIO (O2 program)
  r	RUG
  u	UBA
  x	NIPR, NIWA, SAWS, CAMM,

  
  
• Second small letter after station code (if any): Source data base
  

  (none)	Directly from data providers
  a	CarboEurope-Atmosphere
  w	WDCGG