Archiving of FTIR-Derived Volume Mixing Ratio Profiles in the NDACC Database


High spectral-resolution infrared solar transmission spectra contain information about the vertical distribution of the absorbing species in the terrestrial atmosphere due to the pressure broadening of the absorption lines. This feature is being exploited in the Infrared Working Group to retrieve vertical profile information of several atmospheric trace gases, such as O3, CO, N2O, CH4, HCl, HF, HNO3, C2H6 and HCN, in addition to the total column abundances. For more than 5 years, efforts have been made to define vertical profile retrievals that are consistent across the network and these retrieval standards are currently in a mature form. This implies that the IRWG will revise certain time series of column abundances in order to now deliver time series of vertical profile data to the NDACC DHF. The IRWG has adopted the HDF data format as it is well suited for storage of profile data and the associated averaging kernels and auxiliary data that characterize the retrieval results and has become the standard for distribution and archiving of remotely sensed data. In establishing its HDF formatting guideline the IRWG worked in close collaboration with AVDC (AURA Validation Data Center), EVDC (Envisat Validation Data Center) and the NDACC Data Host Facility. The archiving of profile data in HDF format began as of autumn 2009.