Ozonesonde data are among the most popular observations in NDACC because the profiles are a mainstay of satellite calibration and are used to develop climatologies used in atmospheric chemical-climate models. Sonde data are used for analysis of lower stratospheric ozone trends, where satellites alone often do a poor job. However, the ozonesonde instrument that is used at ~100 stations worldwide shows biases at different stations and discontinuities in profile time-series due to a variety of measurement procedures.
As part of the SPARC (Stratosphere-troposphere Processes And their Role in Climate) water vapour assessment (WAVAS-II), satellite measurements taken from, or coincident with, seven sites from which ground-based microwave instruments measured water vapor in the middle atmosphere. Six of the ground-based instruments are part of the Network for the Detection of Atmospheric Composition Change (NDACC) and provide datasets which can be used for drift and trend assessment.
The annual meeting of the international Steering Committee (SC) for NDACC was held 6-10 November 2017 in Boulder, CO, USA at the National Center for Atmospheric Research (NCAR). James Hannigan of NCAR hosted the meeting. Dr. James Hurrell, a climate scientist and Director of NCAR, welcomed the attendees and gave a brief introduction to the Center’s facilities, mission, and associated programs in atmospheric and related sciences.
The proposal from the Australian Bureau of Meteorology for NDACC affiliation for four Dobson measurements was discussed and approved at the 2017 NDACC Steering Committee Meeting in Boulder, Colorado. The measurements were formally invited as NDACC Affiliated shortly thereafter. The four sites are Darwin (12°S), Brisbane (27°S), Melbourne (38°S) and Macquarie Island (55° S). Total ozone records at Brisbane, Melbourne and Macquarie Island began in 1957.