Use of Short Time Series for Early Global Warming Trend Detection for OceanAcoustic Travel Times

摘要

In this report, we have attempted to establish the extent to which the use ofdata from a shorter period may allow better definition of the period needed to establish global warming trends. Truncated simulated data sets, generally 5 or 10 years, from the MASIG model of acoustic propagation time variability over decades have been used to establish the extent to which the statistical trend extraction techniques give stable results using these shorter series to define the noise background. It is found that the use of these shorter series provides an apparent reduction of time required to detect trends. This unfortunately indicates that meaningful estimates of warming trends cannot be made with use of a lengthy data set approaching the full 20 year interval. In another portion of this study, we find that the substantial short term variability seen in the first six months of the ATOC experiment is comparable with that seen by Spiesberger but that this variability plays almost no role for the long term trend detection problem, which is dominated by multiyear periods.