HR: 0800h
AN: A21D-0739 [WITHDRAWN]    [Abstracts]
TI: Correlation Lengths and Measurement Uncertainties from Analysis of Historical Ozonesonde Data in North America and Europe
AU: * Liu, G
EM: Guiping.Liu@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada
AU: Tarasick, D W
EM: david.tarasick@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada
AU: Fioletov, V E
EM: Vitali.Fioletov@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada
AB: A spatial and temporal correlation analysis is performed on WOUDC (World Ozone Data Centre) ozonesonde data for 13 stations at mid-latitudes in North America and Europe. As much as 40 years of data is available for some stations. After removal of the seasonal cycle and periodic variations such as the QBO, as well as of long- term trends, spatial correlation (relative to other stations) coefficients and auto-correlation coefficients are calculated. Ozone partial pressure data at 1 km altitude resolution are used. The auto-correlation function appears to drop rapidly within few days, and the spatial correlation decreases with the distance between stations. The distance for the spatial correlation coefficient to decrease by 1/e is about 1000-2000 km in the stratosphere with a peak at around 22 km, and 500-1000 km in the troposphere. If the calculated values of the correlation coefficient with space (or time) are fitted to an exponential function, the extrapolation of this function to zero distance (or time) provides an estimate of the ozonesonde measurement uncertainty. The ozonesonde uncertainty is found to be less than 7% for altitudes in the 20-30 km range. In the troposphere the uncertainty is about 15% , with higher values in the boundary layer and near the tropopause. These results are broadly consistent with those from the recent JOSIE and BESOS field experiments (Smit et al., 2007; Deshler et al., 2007). If the profiles are normalized to total ozone measurements, the uncertainties decrease by few percent at altitudes higher than 20 km.
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
DE: 3315 Data assimilation
DE: 3394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting