Total column ozone and ozone partial columns measured in Dobson Units (1DU = 2.69×1016 ozone molecules/cm2). Dobson spectrophotometer instruments are located at Lauder (45.04oS, 169.68oE), New Zealand, and at Arrival Heights (77.82oS, 166.65oE), Antarctica. Archives of the measurements are maintained at NIWA, Lauder, and in various international data archives. A combined data set of satellite-based total column ozone measurements providing global coverage is maintained at NIWA using measurements from a variety of satellite-based instruments including TOMS, GOME, SBUV, and OMI.