HR: 0830h
AN: A51A-06    [Abstracts]
TI: Ozonesonde measurements at Lauder, New Zealand, and the search for ozone recovery
AU: Bodeker, G E
EM: g.bodeker@niwa.co.nz
AF: National Institute of Water and Atmospheric Research (NIWA), Private Bag 50061, Omakau, CO 9182 New Zealand
AU: * Connor, B
EM: b.connor@niwa.co.nz
AF: National Institute of Water and Atmospheric Research (NIWA), Private Bag 50061, Omakau, CO 9182 New Zealand
AU: Chisholm, H
EM: h.chisholm@niwa.co.nz
AF: National Institute of Water and Atmospheric Research (NIWA), Private Bag 50061, Omakau, CO 9182 New Zealand
AU: Thomas, A
EM: a.thomas@niwa.co.nz
AF: National Institute of Water and Atmospheric Research (NIWA), Private Bag 50061, Omakau, CO 9182 New Zealand
AB: As part of the Network for Detection of Stratospheric Change (NDSC), ozonesonde flights at Lauder (45.04°S, 169.68°E) have been made approximately weekly from August 1986 to the present. In earlier years, flights were made twice weekly from September to December. These data have been subjected to a range of data quality control procedures including homogenization of the data set; ozonesondes before August 1996 were flown with a 1% KI cathode solution, while later flights were made with a 0.5% KI cathode solution¹. A brief discussion of the ozonesonde data quality control procedures developed at Lauder will be presented. Ozone number densities and ozone mixing ratios from these flights from August 1986 to December 2004 were interpolated onto 100 pressure levels from the surface (969.6 hPa, 370m) to 12.1 hPa (~30.1 km) and ~300 geopotential meters apart. These were then used as input to a linear least squares regression model to quantify the drivers of trends and variability in the vertical distribution of ozone over New Zealand. The regression model includes basis functions for a seasonally dependent long-term trend, a mean annual cycle, the Quasi-biennial Oscillation (QBO), the El Niño Southern Oscillation (ENSO), the solar cycle, the influence of tropopause height variability, and the influence of the Mt. Pinatubo volcanic eruption². The seasonal structure in the ozone trends derived using this statistical model provides constraints on the potential sources of the trends and is also a good test for models of southern hemisphere ozone change. A cumulative sum of residuals diagnostic³ was then applied to the residuals from the regression analysis to look for evidence of turnaround in ozone trends over New Zealand and/or the timing of minimum ozone levels over New Zealand. References
1) Boyd, I.S., G.E. Bodeker, B.J. Connor, D.P.J. Swart, and E.J. Brinksma, An assessment of ECC ozonesondes operated using 1% and 0.5% KI cathode solutions at Lauder, New Zealand, Geophysical Research Letters, 25 (13), 2409-2412, 1998.
2) Bodeker, G.E., I.S. Boyd, and W.A. Matthews, Trends and variability in vertical ozone and temperature profiles measured by ozonesondes at Lauder, New Zealand: 1986-1996, Journal of Geophysical Research, 103 (D22), 28661-28681, 1998.
3) Reinsel, G.C., Trend analysis of upper stratospheric Umkehr ozone data for evidence of turnaround, Geophysical Research Letters, 29 (10), 10.1029/2002GL014716, 2002.
DE: 0325 Evolution of the atmosphere
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0365 Troposphere--composition and chemistry
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly