News and Events

A highly variable interference has long been considered the dominant feature of water vapor for practitioners who retrieve atmospheric total column amounts and profiles from infrared solar absorption spectra.

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.

NDACC established the designation of "Cooperating Network" to formalize the relationship with regional, hemispheric, or global networks of instruments that operate independently of NDACC, but where strong measurement and scientific collaboration is mutually beneficial.

The Measurements and Analyses Directory contains a complete listing of all NDACC Affiliated Measurements, both long-term and campaign, as well as a listing of the Cooperating Networks, and the Theory and Satellite Working Group Members.

The NDACC Steering Committee has developed a graphic to depict the measurement capabilities of the network. The chart provides a summary of the species and parameters whose measurements are archived in the DHF, the instrumental techniques employed for the measurements, and an indication of the approximate vertical resolution of the measurements.

NDACC recognizes the importance of new measurement capabilities and of existing capabilities whose heritage was developed external to NDACC, and has encouraged Network affiliation with such measurements.

Since the onset of formal operations, NDACC (formerly NDSC) has designated several specific instrument types as official measurement capabilities. These are: Dobson / Brewer Spectrometers, Fourier Transform IR Spectrometers (FTIRs), Lidars (temperature, ozone, and aerosol), Microwave Radiometers, and UV/Visible Spectrometers.

In the early days of NDACC (then NDSC), the Infrared Working Group (IRWG) targeted the retrieval of total columns of several gases considered of primary importance to the original goals of the Network. These goals focused on increasing our understanding of ozone chemistry and, in the post-Montreal Protocol period, observing the accumulation (and hopefully the eventual decline) of Cly and Fy in the stratosphere.

At the 2008 NDACC Steering Committee meeting, an ad hoc working group was established to review existing and assess future Network measurement strategies and emphases in light of the broadening of Network goals over those established at its inception.