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. Due to the importance of water as a greenhouse gas and its possible long-term trend resulting from changes in the atmosphere and subsequent feedback effects there is renewed effort in extracting water vapor quantities from archived solar spectra, which for some sites stretch back to the 1970's.
NDACC News and Events
In the period from June–July 2009, a large scale intercomparison of UV-Visible spectrometers took place at the Cabauw meteorological observatory, a semi-rural site located in the Netherlands, 30 km South of Utrecht.
Despite its low abundance in the atmosphere, stratospheric bromine contributes up to 25% to the global ozone loss due to its high ozone depletion potential [e.g., World Meteorological Organization (WMO), 2007]. The main sources of bromine in the stratosphere are natural and anthropogenic long-lived and very short-lived brominated organic compounds [e.g., Pfeilsticker et al., 2000; Salawitch et al., 2005]. Long-term observations by in-situ ground-based networks have revealed a decline in total organic bromine from long-lived species by 3 to 5% during the 1998-2004 period [WMO, 2007].
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. This chart, available here, will also shortly be available in the instrument area of the NDACC web pages.
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.